Dark Flow, Gravity and Love

By Rob Bryanton

The above video is tied to a previous blog entry from last January of the same name, Dark Flow.

Last time, in Placebos and Biocentrism, we returned to the idea that so much of what we talk about with this project is tied to visualizing our reality from “outside” of spacetime, a perspective that many of the great minds of the last hundred years have also tried to get us to embrace. Here’s a quote I just came across from Max Planck that I think is particularly powerful:

As a man who has devoted his whole life to the most clear headed science, to the study of matter, I can tell you as a result of my research about atoms this much: There is no matter as such. All matter originates and exists only by virtue of a force which brings the particle of an atom to vibration and holds this most minute solar system of the atom together. We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter.

Image-Golden ratio line

Image via Wikipedia

It’s so easy to look at some of the phrases from this quote and imagine them on some new age site, where mainstream scientists would then smugly dismiss these ideas as hogwash from crackpots. Like me, folks like Dan Winter and Nassim Haramein also sometimes get painted with the crackpot brush, but they are both serious about the ideas they are exploring, and they are not far away from the ideas that Max Planck promoted above, or that I have been pursuing with my project.

On July 1st of this year, I published a well-received blog entry called Love and Gravity. It looked at some new age ideas about wellness and spirituality, and related them to some mainstream science ideas about extra dimensions, timelessness, and the fact that physicists tell us that gravity is the only force which exerts itself across the extra dimensions.

Last week Dan Winter forwarded me a link to a new web page of his which yet again seems to tie into the same viewpoint that I’m promoting: Dan is calling this new page “Gravity is Love“. As usual, this page is a sprawling collection of graphics, animations, and articles, most of which are found on a number of Dan’s other pages, but there’s important new information here as well. Here’s a few paragraphs excerpted from the page which will give you the flavor of what Dan is saying about this concept:

Love really IS the nature of gravity!
First we discovered Golden Ratio identifies the change in pressure over time- of the TOUCH that says I LOVE YOU: goldenmean.info/touch
Then we discovered (with Korotkov’s help) … that the moment of peak perception- bliss – enlightenment- was defined by Golden Ratio in brainwaves :goldenmean.info/clinicalintro
Then medicine discovered: the healthy heart is a fractal heart. ( References/ pictures:goldenmean.info/holarchy, and also: goldenmean.info/heartmathmistake
Then – I pioneered the proof that Golden Ratio perfects fractality because being perfect wave interference it is therefore perfect compression. It is my view that all centripetal forces- like gravity, life, consciousness, and black holes, are CAUSED by Golden Ratio in waves of charge.
Nassim Haramein says that although he sees Golden Ratio emerge from his black hole equations repeatedly – he sees it as an effect of black holes/ gravity – not the cause… Clearly – from the logic of waves – I say the black hole / gravity is the effect of golden ratio and not the other way around!
– although some might say that this is a chicken and egg difference – may be just semantics… at least we agree on the profound importance of Golden RATIO…/ fractality…
AND love :

perfect embedding IS perfect fusion IS perfect compression… ah the romance.

Dan Winter is a fascinating fellow, I hope you can spend some time following the links in the above quote. Next time we’re going to look at another somewhat related approach to imagining the extra-dimensional patterns that link us all together, in an entry called Biosemiotics: Monkeys, Metallica, and Music.

Enjoy the journey!

Rob Bryanton

Carnival of Space #168

Welcome to the Carnival of  Space #168 and WeirdSciences. If you are visiting the carnival of space for the first time and you have no idea what a carnival of space is, you can try to go to Universe Today page.  Now it’s time to start the carnival of space:-

  • Discovery images of Neptune Trojan 2008 LC18Congratulations to Scott Sheppard and Chad Trujillo for identifying the first known L5 Trojan asteroid of Neptune! This story is not just interesting because it is a first-of-its-kind discovery, but because of the tricky way that the astronomers went about searching for it, and because of the collateral benefits that their search will have for the New Horizons mission.

Emily Lakdawalla at Planetary Blog has explained about the discovery of  Trojan Asteroid[and yeah, Trojan Asteroid itself too] with animation showing how this excelling discovery was made.

What? You can’t believe..? Dr. Ian O’Neill of Discovery Space has a stunning article delving much into the topic with high resolution images of moon obtained from LRO.

  • Interesting fact of the day: examining the fossil record suggests that mass extinctions on Earth occur approximately once every 26 million years (Myr). One possible explanation for this is a companion dwarf  star to the Sun on a 26 Myr orbit.

Emma at We Are All in The Gutter Blog, is seeking out the connections between mass exinction and so called Nemesis, a dwarf star based on a newly published research paper.

  • Steve Nerlich at Cheap Astronomy investigates the likelihood of Robonaut 2  refusing to open the pod bay door after it’s deployed on the ISS.
  • This is the light speed limit, which makes us too shy whenever we plan for a interstellar human mission. We can’t ignore the laws of special relativity, but we can still change the speed of  light.

Chris Dann of WeirdWarp Blog is elucidating whether it is plausible?

  • Wayne Hall at Kentucky Space is telling that the second Kentucky Space-built plug-and-play micro-G research rack will be turned up on ISS  Monday.
  • Jupiter’s moon IO is quite fascinating if you are talking about the possibility of exotic life. Jason Perry of Gish Bar Times, is exposing IO’s true colors based on datas obtained from Galileo. A well researched article!
  • Our universe is very mysterious. Astronomers are constantly looking into the past. No matter where you look out into space you are seeing things as they were minutes, hours or millions of years ago. Even at 186,000 miles per second, it takes eight minutes for light to reach us from the Sun. It takes four and a half years for light to reach us from the next nearest star, and millions or billions of years to reach us from other galaxies. So astronomers spend a great deal of time looking into the past.

Mike Somonsen of  Simostronomy Blog is focusing over future surveys to solve the mystery of universe. Really, an excellent article..!!

Alen VerseFeld of The Urban Astronomer blog has a entry featuring stunning discoveries made by LRO missions.

A ceiling full of sky, a beautiful historical  ceiling with an astronomical theme by Ian Musgrave and Peta O’Donohue of Astroblogger blog.

Daniel Sims of  Space Tweep Society Blog has a article providing more information about that contest. If you are interested in contest, please participate in it.

  • Bruce Irving of FlyingSinger blog is talking about Apollo 13 mission.
  • If, at first glance, the preceding account appears fanciful, it is because our thinking has not caught up with the engineering advances of the last few years. . .All the engines are either being developed or are programmed to be developed in the next few years. No new or exotic fuels are required. Indeed, our calculations reflect the sober degree of conservatism that should characterize a preliminary study. We believe that the feasibility has been shown. There remains now the intriguing task of doing the job.

David S.F. Portree of  BeyondApollo has a excellent article about Rosen and Schwenk’s moon mission.

Below are the two articles from Stuart Atkinson

Pradeep Mohandas of Parallel Spirals blog has a article  First anniversary of the Chandrayaan-I – LRO Bistatic Experiment today ,explaining more about that.

See the article by Paul Sutherland of SKYMANIA blog.

Enjoy!!

‘Survivor’ Black Holes May Be Mid-Sized:NASA News

New evidence from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton strengthens the case that two mid-sized black holes exist close to the center of a nearby starburst galaxy. These “survivor” black holes avoided falling into the center of the galaxy and could be examples of the seeds required for the growth of supermassive black holes in galaxies, including the one in the Milky Way.

For several decades, scientists have had strong evidence for two distinct classes of black hole: the stellar-mass variety with masses about ten times that of the Sun, and the supermassive ones, located at the center of galaxies, that range from hundreds of thousands to billions of solar masses.

But a mystery has remained: what about black holes that are in between? Evidence for these objects has remained controversial, and until now there were no strong claims of more than one such black hole in a single galaxy. Recently, a team of researchers has found signatures in X-ray data of two mid-sized black holes in the starburst galaxy M82 located 12 million light years from Earth.

“This is the first time that good evidence for two mid-sized black holes has been found in one galaxy,” said Hua Feng of the Tsinghua University in China, who led two papers describing the results. “Their location near the center of the galaxy might provide clues about the origin of the Universe’s largest black holes — supermassive black holes found in the centers of most galaxies.” 

Composite image of the nearby starburst galaxy M82

Composite image of the nearby starburst galaxy M82. Image credit: X-ray: NASA/ CXC/Tsinghua Univ./H. Feng et al.

One possible mechanism for the formation of supermassive black holes involves a chain reaction of collisions of stars in compact star clusters that results in the buildup of extremely massive stars, which then collapse to form intermediate-mass black holes. The star clusters then sink to the center of the galaxy, where the intermediate-mass black holes merge to form a supermassive black hole.

In this picture, clusters that were not massive enough or close enough to the center of the galaxy to fall in would survive, as would any black holes they contain.

“We can’t say whether this process actually occurred in M82, but we do know that both of these possible mid-sized black holes are located in or near star clusters,” said Phil Kaaret from the University of Iowa, who co-authored both papers. “Also, M82 is the nearest place to us where the conditions are similar to those in the early Universe, with lots of stars forming.”

The evidence for these two “survivor” black holes comes from how their X-ray emission varies over time and analysis of their X-ray brightness and spectra, i.e., the distribution of X-rays with energy.

Chandra and XMM-Newton data show that the X-ray emission for one of these objects changes in a distinctive manner similar to stellar-mass black holes found in the Milky Way. Using this information and theoretical models, the team estimated this black hole’s mass is between 12,000 and 43,000 times the mass of the Sun. This mass is large enough for the black hole to generate copious X-rays by pulling gas directly from its surroundings, rather than from a binary companion, like with stellar-mass black holes.

The black hole is located at a projected distance of 290 light years from the center of M82. The authors estimate that, at this close distance, if the black hole was born at the same time as the galaxy and its mass was more than about 30,000 solar masses it would have been pulled into the center of the galaxy. That is, it may have just escaped falling into the supermassive black hole that is presumably located in the center of M82.

The second object, located 600 light years in projection away from the center of M82, was observed by both Chandra and XMM-Newton. During X-ray outbursts, periodic and random variations normally present in the X-ray emission disappear, a strong indication that a disk of hot gas dominates the X-ray emission. A detailed fit of the X-ray data indicates that the disk extends all the way to the innermost stable orbit around the black hole. Similar behavior has been seen from stellar-mass black holes in our Galaxy, but this is the first likely detection in a candidate intermediate-mass black hole.

The radius of the innermost stable orbit depends only on the mass and spin of the black hole. The best model for the X-ray emission implies a rapidly spinning black hole with mass in the range 200 to 800 times the mass of the Sun. The mass agrees with theoretical estimates for a black hole created in a star cluster by runaway collisions of stars.

“This result is one of the strongest pieces of evidence to date for the existence of an intermediate-mass black hole,” said Feng. “This looks just like well-studied examples of stellar-mass black holes, except for being more than 20 times as massive.”

Kerr Black Holes

The Schwarzschild reference frame is static outside the Black Hole, so even though space is curved, and time is slowed down close to the Black Hole, it is much like the absolute space of Newton. But we will need a generalized reference frame in the case of rotating Black Holes. Roy Kerr generalized the Schwarzschild geometry to include rotating stars, and especially rotating Black Holes. Most stars are rotating, so it is natural to expect newly formed Black Holes to process significant rotation too.

Features of a Kerr Black Hole

Image

The Kerr black hole consists of a rotating mass at the center, surrounded by two event horizons. The outer event horizon marks the boundary within which an observer cannot resist being dragged around the black hole with space-time. The inner event horizon marks the boundary from within which an observer cannot escape. The volume between the event horizons is known as the ergosphere.

What is a Kerr black hole?

The usual idealised “static” black hole is stationary, unaccelerated, at an arbitarily-large distance from the observer, is perfectly spherical, and has a point-singularity at its centre.

When one of these idealised black holes rotates, it gets an extra property. It’s no longer spherically symmetrical , the receding and approaching edges have different pulling strengths and spectral shifts, and the central singularity is no longer supposed to be a dimensionless point.

Image

The equatorial bulge in the event horizon can be deduced in several ways

  • … as a sort of centrifugal forces effect. Since it’s possible to model the (distantly-observed) hole as having all its mass existing as an infinitely-thin film at the event horizon itself (i.e. where the mass is “seen” to be), you’d expect this virtual film to have a conventional-looking equatorial bulge, through centrifugal forces.
  • … as a sort of mass-dilation effect. Viewed from the background frame, the “moving film” of matter ought to appear mass-dilated, and therefore ought to have a greater gravitational effect, producing an increase in the extent of the event horizon. Since the background universe sees the bh equator to be moving faster than the region near the bh poles, the equator should appear more mass-dilated, and should have a horizon that extends further.
  • … as a shift effect. This tidy ellipsoidal shape isn’t necessarily what people actually see – it’s an idealised shape that’s designed to illustrate an aspect of the hole’s deduced geometry independent of the observer’s viewing angle. In fact, the receding and approaching sides of the hole (viewed from the equator) might appear to have different radii, because it’s easier for light to reach the observer from the approaching (blueshifted) side than the receding (redshifted) side (these shifts are superimposed on top of the normal Schwarzchild redshift).
    If we calculate these motion shifts using either the SR shift assumptions f’/f = (flat spacetime propagation shift) × root[1 – v²/c²] or the plain fixed-emitter shift law f’/f = (c-v)/c, and then treat them as “gravitational”, then by multiplying the two opposing shifts together and rooting the result, we can get the same averaged dilation factor of f’/f=root(1 – v²/c²) in each case, and by applying the averaged value, we recreate the same sort of equatorially-dilated shape that we got in the other two arguments.

Of course, none of these “film” arguments work for a rotating point, which immediately tells us that the distribution of matter within a rotating black hole is important, and that the usual method of treating the actual extent of a body within the horizon as irrelevant (allowing the use of a point-singularity) no longer works when the hole is rotating (a rotating hole can’t be said to contain a point-singularity).
In the case of a rotating hole, the simplest state that we can claim is equivalent to the rotating film of matter for a distant observer is a ring-singularity.

Notes

  • The idea of being able to treat a non-rotating black hole as either a point-singularity or a hollow infinitely-thin film is a consequence of the result that the actual mass-distribution is a “null” property for a black hole, as long as it is spherically symmetrical. If the mass fits into a Schwarzchild sphere, the usual static model of a black hole allows the hole’s mass to be point-sized, golfball-sized, or of any size up to the size of the event horizon.
    It’s usual to treat all the matter as being compacted to a dimensionless point, but sometimes it’s useful to go to the other extreme and treat the matter as being at its “observed” position – as an infinitely-thin film at the event horizon (see Thorne’s membrane paradigm).
  • The idea of being able to treat all shifts as being propagation effects is something that probably ought to be part of GR – in the context of black holes, the time-dilation effect comes out as a curved-space propagation effect due the enhanced gravitation due to kinetic energy. However, there’s a slight “political” problem here, in that GR is supposed to reduce to SR, and SR is usually interpreted as having Lorentz shifts which are supposed to be non-gravitational (because allowing the possibility of gravitational effects upsets the usual SR derivations). A GR-centred physicist might not have a problem with this approach of treating all shift effects as being equivalent, a SR-centred one probably would.
  • The “bulginess” of a Kerr black hole is illustrated on p.293 of the Thorne book (fig 7.9). Thorne says that the effect of the spin on the horizon shape was discovered Larry Smarr in 1973.

Overview of Kerr Spacetime

Kerr spacetime is the unique explicitly defined model of the gravitational field of a rotating star. The spacetime is fully revealed only when the star collapses, leaving a black hole — otherwise the bulk of the star blocks exploration. The qualitative character of Kerr spacetime depends on its mass and its rate of rotation, the most interesting case being when the rotation is slow. (If the rotation stops completely, Kerr spacetime reduces to Schwarzschild spacetime.)

The existence of black holes in our universe is generally accepted — by now it would be hard for astronomers to run the universe without them. Everyone knows that no light can escape from a black hole, but convincing evidence for their existence is provided their effect on their visible neighbors, as when an observable star behaves like one of a binary pair but no companion is visible.

Suppose that, travelling our spacecraft, we approach an isolated, slowly rotating black hole. It can then be observed as a black disk against the stars of the background sky. Explorers familiar with the Schwarzschild black holes will refuse to cross its boundary horizon. First of all, return trips through a horizon are never possible, and in the Schwarzschild case, there is a more immediate objection: after the passage, any material object will, in a fraction of a second, be devoured by a singularity in spacetime.

If we dare to penetrate the horizon of this Kerr black hole we will find … another horizon. Behind this, the singularity in spacetime now appears, not as a central focus, but as a ring — a circle of infinite gravitational forces. Fortunately, this ring singularity is not quite as dangerous as the Schwarzschild one — it is possible to avoid it and enter a new region of spacetime, by passing through either of two “throats” bounded by the ring (see The Big Picture).

Image

In the new region, escape from the ring singularity is easy because the gravitational effect of the black hole is reversed — it now repels rather than attracts. As distance increases, this negative gravity weakens, just as on the positive side, until its effect becomes negligible.

A quick departure may be prudent, but will prevent discovery of something strange: the ring singularity is the outer equator of a spatial solid torus that is, quite simply, a time machine. Travelling within it, one can reach arbitrarily far back into the past of any entity inside the double horizons. In principle you can arrange a bridge game, with all four players being you yourself, at different ages. But there is no way to meet Julius Caesar or your (predeparture) childhood self since these lie on the other side of two impassable horizons.

This rough description is reasonably accurate within its limits, but its apparent completeness is deceptive. Kerr spacetime is vaster — and more symmetrical. Outside the horizons, it turns out that the model described above lacks a distant past, and, on the negative gravity side, a distant future. Harder to imagine are the deficiencies of the spacetime region between the two horizons. This region definitely does not resemble the Newtonian 3-spacebetween two bounding spheres, furnished with a clock to tell time. In it, space and time are turbulently mixed. Pebbles dropped experimentally there can simply vanish in finite time — and new objects can magically appear.


Kerr-Newman Black Hole

A rotating charged black hole. An exact, unique, and complete solution to the Einstein field equations in the exterior of such a black hole was found by Newman et al. (1965), although its connection to black holes was not realized until later (Shapiro and Teukolsky 1983, p. 338).

Rotating (Kerr) Black Holes, Charged and Uncharged
Most stars spin on an axis. In 1963, Roy Kerr reasoned that when rotating stars shrink, they would continue to rotate. Kip Thorne calculated that most black holes would rotate at a speed 99.8% of their mass. Unlike the static black holes, rotating black holes are oblate and spheroidal. The lines of constant distance here are ellipses, and lines of constant angle are hyperbolas.

Image

Unlike static black holes, rotating black holes have two photon spheres. In a sense, this results in a more stable orbit of photons. The collapsing star “drags” the space around it into rotating with it, kind of like a whirlpool drags the water around it into rotating. As in the diagram above, there would be two different distances for photons. The outer sphere would be composed of photons orbiting in the opposite direction as the black hole. Photons in this sphere travel slower than the photons in the inner sphere. In a sense, since they are orbiting in the opposite direction, they have to deal with more resistance, hence they are “slowed down”. Similarly, photons in the inner ring travel faster since they are not going against the flow. It is because the photon sphere in agreement with the rotation can travel “faster” that it is on the inside. The closer one gets to the event horizon, the faster one has to travel to avoid falling into the singularity – hence the “slower” moving photons travel on the outer sphere to lessen the gravitational hold the black hole has.

The rotating black hole has an axis of rotation. This, however, is not spherically symmetric. The structure depends on the angle at which one approaches the black hole. If one approaches from the equator, then one would see the cross-section as in the diagram above, with two photon spheres. However, if one approached at angles to the equator, then one would only see a single photon sphere.

The position of the photon spheres also depend on the speed at which the black hole rotates. The faster the black hole rotates, the further apart the two photon spheres would be. For that matter, a black hole with a speed equal to its mass would have the greatest possible distance between the two photon spheres. This is because of greater difference in the speed between the photon spheres. As the speed of rotation increases, the outer sphere of photons would slow down as it meets greater resistance, even as the inner sphere would travel “faster” as it is pushed along by the centripetal forces.

Next, we move on to look at the ergosphere. The ergosphere is unique to the rotating black hole. Unlike the event horizon, the ergosphere is a region, and not a mathematical distance. It is a solid ellipsoid (or a 3-dimensional ellipse). The ergosphere billows out from the black hole above the outer event horizon of a charged black hole (a.k.a. Kerr-Newman), and above the event horizon of an uncharged black hole (a.k.a. Kerr). This distance is known as the static limit of a rotating black hole. At this distance, it is no longer possible to stay still even if one travels at the speed of light. One would inevitably be drawn towards the singularity. The faster the rotation, the further out it billows. When the ergosphere’s radius is half the Schwarzschild radius along the axis of rotation, it experiences the greatest distance it can billow out. At this point, even light rays are dragged along in the direction of rotation. Strangely enough, it is postulated that one can enter and leave as one likes since technically, you have not hit the event horizon yet.

For a rotating black hole, the outer event horizon switches time and space as we know it. The inner event horizon, in turn, returns it to the way we know it. Singularity then becomes a place rather than a time, and can technically be avoided. When angular velocity increases, both the outer and the inner event horizon move closer together.

In the diagram, you would have noticed that the singularity here is drawn as a ring, and not a point, as it was for the static black hole. In the case of a rotating black hole, the gravity around the ringed singularity is repulsive. In other words, it actually pushes one away, allowing you to actually leave the black hole. The only way to approach the ring singularity would be to come in from the equatorial plane. Other trajectories would be repelled with greater strength, proportional to the closer the angle is to the axis of rotation.

In addition, there would be a third photon sphere about the ring singularity. If light is parallel to the axis of rotation, the gravity and the anti-gravity of the singularity are balanced out. Light then traces out the path of constant distance (which, in the case is an ellipsoid). Technically, this might lead the light into another universe through the singularity, and then back out again. At this point within the black hole, we may see three types of light: the light reflected from our universe behind us; the light from other universes; and the light from the singularity.

Again On The Plausibility Of Time Machine

High in the sky on a clear fall evening is the star group called Cygnus, the Swan. It is not hard to find. Look for a large pattern of stars in the shape of a cross, or a swan in flight.

A map of the constellation Cygnus is shown below. On the map, the end of the swan’s tail is marked by a bright star called Deneb. Slightly ahead of Deneb are three stars in a line. They represent the swan’s body and the tips of its wings. Finally some distance away is a fifth, fairly bright star, Albireo. It marks the position of the great bird’s head.

Now look halfway along the neck of the swan. There is a point on the map labeled Cygnus X-1. The next time you are outside on a clear, dark fall evening, locate Cygnus and gaze at the spot where Cygnus X-1 lies. Though you will not actually see anything, you will be looking at the exact point in space where scientists believe there may be a black hole.

The location of Cygnus X-1, thought to be a black hole, in Cygnus the Swan

Crushed Out of Sight

Black holes are popular subjects in films, as well as in many science fiction stories. But there is a good chance that black holes really exist in space. They are places where the pull of gravity is so strong that nothing, not even light, can escape from them. Once inside a black hole, you could never come back out the same way. However, it is possible that you could escape by a different route and arrive at a totally different part of the Universe. What is more, a journey into a black hole might transport you through time, either into the far future or the remote past.

The Crab Nebula is the remains of a massive star that blew apart at the end of its life. Though the Crab Nebula does not contain a black hole, these strange objects may be found in the supernova wreckage of some other giant stars.


How can black holes be made? One way is by the explosion of very heavy stars. A star that weighs 20 or 30 times as much as the Sun can shine brightly for only a few million years. Then it blows itself apart. During this huge explosion, known as a supernova, all the top layers of the old star are blasted away into space at high speed. However, the core, or central part, of the star may remain whole.

In a normal, middle-aged star, such as the Sun, the core is the place where light and heat are made. Here the temperature is incredibly high – many millions of degrees. The outward pressure of this light and heat prevents the inward force of gravity from squeezing the core any smaller. For most of a star’s life, these two great forces struggle against one another in an evenly matched game of tug-of-war. But in a dead star, there is no longer any light pressure to oppose gravity. As a result, the core is squeezed tighter and tighter and gets smaller and smaller.

When average-sized stars, such as the Sun, reach the end of their lives, their cores shrink down to hot balls of squashed matter. These are called white dwarfs. Then another force, caused by particles of matter becoming too crowded together, stops gravity from crushing a white dwarf to an even smaller size.

In bigger, heavier stars, the force of gravity acting on the dead star’s core is much stronger. Even after the supernova explosion has blown away much of the star’s contents, the core that remains may be heavier than the Sun. If the core is more than three times as heavy as the Sun, nothing can prevent gravity from crushing the core smaller and smaller. From an original size of more than 20,000 miles across, the core is squashed in less than a tenth of a second to a ball only 25 miles across. At this stage, a tablespoonful of its matter would weigh the same as four billion full-grown elephants. But gravity squeezes it still smaller. In a fraction of a second, more than three sun’s worth of star material becomes crammed into an incredibly tiny space. Now it may be no larger than the period at the end of this sentence.

Within a few miles of the totally crushed star, gravity is so strong that it will pull in anything that comes too close. And it will allow nothing to escape, not even a ray of light traveling at more than 186,000 miles per second. The region around the crushed star is completely black and invisible. That is why scientists call it a black hole.

The Mystery of Cygnus X-1

An artist imagines how the black hole in Cygnus X-1 might look. It lies at the center of the spinning whirlpool of matter that has been pulled off the large yellow star


If black holes are black and invisible, then how can we ever know they are there? In fact, we cannot, unless there is something nearby that can be seen and upon which the black hole has a noticeable effect. This is the case with Cygnus X-1.

From observations made by instruments in space, scientists have discovered that huge amounts of X-rays – rays that carry a great deal of energy – are coming from the direction of Cygnus X-1. They have also found that a binary star lies in the same position as the source of the X-rays. A binary star consists of two stars that are circling around each other. One of these stars is much bigger and brighter than the Sun, but it can only be seen through a large telescope because it is so far away. Astronomers know it is there because of the “wobbles” it causes in the movement of its giant neighbor.

From the extent of the wobbles, astronomers think the dark star in Cygnus X-1 must weigh from five to eight times as much as the Sun. This fact alone suggests that it is likely to be a black hole. But the X-rays offer still stronger evidence. Careful studies of the X-rays have revealed that they are almost certainly coming from a whirlpool of extremely hot gas. This gas, scientists believe, has been stripped away from the bright giant star by the gravitational pull of a nearby black hole. Just before it disappears down the black hole, the gas is heated to more than 18 million °F. At that superhigh temperature, it gives off an intense X-ray glow.

Into the Black Hole

To travel from a point in space and time A to another point in space and timeB, spaceship 1 takes an ordinary route around the Universe. Spaceship 2, though, takes a shortcut using a wormhole. If B lies farther back in time thanA, then the journey could only be made through the wormhole.


Even before scientists found signs of real black holes in the Universe, they had studied the mathematics of what black holes might be like inside. According to their theories, black holes may be like the entrances of tunnels that join different regions of space and time. These strange tunnels are called wormholes. At the end of a wormhole is an exit known as a white hole. By going into a black hole, traveling along its wormhole, and then coming out the white hole at the other end, a spacecraft might be able to leap across huge distances of space and millions of years in time.

But two British scientists, Stephen Hawking and Roger Penrose, pointed out some problems with this wonderful way to travel. For one thing, there seems to be an energy barrier inside a black hole. No normal object, such as a spacecraft, could pass through this barrier without being torn to bits. The two scientists identified a second major problem. It appears that the wormhole tunnel would instantly squeeze shut if a piece of matter tried to move along it.

However, in 1988, new results were published by researchers Michael Morris, Kip Thorne, and Ulvi Yurtsever at the California Institute of Technology. These showed that a wormhole might be kept open with the help of two round plates that carried a charge of electricity. The plates would be located on either side of the “throat” leading into the wormhole. Results from even more recent research have shown that objects entering a spinning black hole might also be able to travel through time.

Yet, just because something is possible in theory does not mean it will quickly, or ever, become fact. We are still not certain that black holes exist. The evidence for them, though, is strong. If they do exist, then the nearest one is likely to be many trillions of miles away. Cygnus X-1 is about 10,000 light-years from Earth. One light-year is the distance that light travels in a year, or about 6 trillion miles. Cygnus X-1, then, lies about 60 thousand trillion miles away!

It is possible that there are closer black holes to Earth that we have not yet found. If they are not members of binary systems, then they would be extremely hard to detect. Still, it would be surprising if there were a black hole similar to Cygnus X-1 that was closer than a few hundred light-years to the Sun. At such a distance, it would be very difficult to reach such an object. And it would be even harder to use it as a time machine.

Black Holes, Large and Small

Much larger black holes, weighing millions or even billions of times as much as the Sun, are thought to lie in the center of galaxies. Galaxies are huge collections of stars arranged in spiral, round, oval, or irregular shapes. We live in a galaxy called the Milky Way. To explain the unusual amount of energy coming from the middle of large galaxies, scientists have proposed the idea of “supermassive” black holes. But these would lie even farther from Earth than black holes that formed from neighboring stars.

There may also be mini back holes. These may be smaller than a pea but with the mass, or amount of matter, of a mountain. It is also possible that scientists will someday be able to create their own tiny black holes in the laboratory. They might do this by directing extremely intense, pure beams of light into a tiny pellet of matter. If enough energy could be focused onto the pellet at one time, it would collapse to form a black hole so small that it could only be seen under a microscope.

But there is a problem with this plan. Small black holes would tend to rip apart any object that was sent into them. This would happen because the pull of gravity on anything approaching a mini black hole would be much greater at the front of the object than at the back.

In the case of a very large, massive black hole, the difference in gravitational pull across an approaching object would be much less. The supermassive black holes that may occupy the center of some galaxies also appear to be the only kind that human beings might be able to enter and survive.

Beyond the Light Barrier


According to Einstein’s Special Theory of Relativity, no object can accelerate up to the speed of light. As an object goes faster, its mass increases. That makes it harder and harder to boost its speed further. To reach the speed of light, even a particle that started out with a tiny mass would require more energy than there is in the whole Universe.

Einstein’s theory, though, does not say that faster-than-light particles cannot exist. It only says that if there are such particles, known as tachyons, then they can never travel at or less than light speed.

If tachyons did turn out to be real, they would behave in a very strange way. They would travel backward in time! This is another prediction of Einstein’s theory. Any object that travels faster than light would seem to us to be moving into the past. As a result, a tachyon could be detected by an instrument before it was actually formed. On the practical side, tachyons might make possible an unusual kind of telephone. On this phone, calls could be sent into the past! So far, despite searches carried out by various groups of researchers, no real tachyon has yet been found.

The Prospect for Time Travel

Could you then build a time machine? With devices such as cameras and video recorders, it is already possible to review events from the past. Researchers are also making progress in learning how humans age and how the aging process might be slowed. Perhaps within 20 or 30 years, there will be methods to allow people to live longer. If so, they will see much more of the future.

Other forms of time travel will probably take longer to develop. It is unlikely that there will be any crew carrying spaceships that can fly close to the speed of light by the end of the twenty-first century. But such craft will be built. Then human beings who travel to the stars will go on journeys through time. They will leap hundreds, thousands, or even millions of years into the future during their own lifetimes.

Scientists today do not know if black holes will ever be used as a means to jump instantly into the remote past or future. The technical problems to be overcome, even if such journeys are possible, are among the most difficult imaginable. Yet the people who lived a century ago might have thought of human missions to the Moon in the same way.

Someday, in some form, the human race is likely to build a machine that can swiftly travel through time. Where that will lead us to, no one yet knows.

Space Time:Continuums And Curvature

Relativity views space-time as a continuum; that is, time becomes another dimension of space, making space four-dimensional. This is really common sense-we know that it takes time to move through the physical dimensions of space. (length, width, and heigth) Time is a property of space that is distinct from yet closely related to the other three. (Althought we know we can move through space in any direction, we can only move forward in time, at least until wormholes are discovered.)

Curvature of space-time can be more difficult to understand. Although the rubber sheet model gives a picture of how it happens, one cannot easily picture the so-called nothingness of space being curved or a non-physical property like time being warped. But relativity (a theory which has yet to be disproved) predicts this curvature and uses gravity as proof of it. In fact, relativity predicts singularities, points in space-time where the curvature reaches infinity. Singularities are the centers of black holes, points of gravity so strong that nothing, not even light, can escape.

According to relativity, the curvature of space-time is gravity, and this raises an intersting paradox: the amount of curvature is governed by the distribution of matter and energy in the univers, but this distribution is determined by the curvature of space-time. Thinking back to the rubber sheet model, this becomes an obvious truth. A large object, such as a shot put, would cause a large indentation that would cause a marble to roll in. Or, if an area of rubber sheet space contained only small objects, several marbles might roll together to form an area of ‘strong gravity’, which would in turn attract more objects.

Besides creating the all-important force of gravity, space-time curvature also makes a major dent (no pun intended) in one of our most common beliefs from geometry and family vacations: in curved space-time, a straight line is NOT always the shortest distance between two points. But that’s a different topic.

In order to move through the physical dimensions of space, one must also move through time. In this graph, time surrounds the axes, and although the lines could be extended so that we could move in any physical direction, we do not extend them because we do not know how to move backwards in time.

                                               

Black holea re probably the most researched and best known of the topics dealing with relativity. Their existence has been speculated for over 200 years, but has yet to be proven.

A black hole is a region of space where gravity is so strong that nothing, not even light, can escape. (According to relativity, nothing can travel faster than light, so this makes sense.)

But what would cause this strong of a gravitational force? According astronomer John Michell in 1783, it would have to be the collapse of a massive star. And today we know that these massive stars exist-neutron stars.

A neutron star is the final phase of a star more than two times as large as the sun. The sun would collapse into a white dwarf-a dense, earth-sized ball of gas that can collapse no further due to the outward pressure of electrons spinning at near the speed of light.

But in a large star, the gravitational force is so strong that the electrons are pulled into the atomic nucleus where they combine with protons to form neutrons. A neutron star is small and unchanged-only a few miles in diameter. Then one of two things can happen.

That ‘strong force’-the force that holds the atomic nucleus together can abruptly stop the implosion and cause the start to burst into a supernova. But if they star is more than two times the sun’s size, nothing can stop its collapse into a small, dense object that traps even light- a black hole.

How does aone picture this in the rubber sheet model? Imagine placing an object so massive on the sheet that it cause its indentation to pinch off. This would cause the rest of the sheet to angle down towards the hole, and smaller objects would roll in towards this huge ‘gravitational pull’.

Anatomy of a Black Hole…

Although black holes would seem the upitome of chaos, they have a definite structure, and it is even thought that the more matter and energy they pull in, the more ordered they become. (This distintly goes against Newton’s Laws of Physics, but who’s going to tell the black hole that?)

The outermost edge of a black hole is the event horizon, or Schwarzschild radius. It’s the point at which the star collapsed into a black hole, and its size is therefore proportional to the star’s mass.

That’s the only definite part of a black hole. It used to be also generally agreed that there is a singularity at the center of a black holes where the laws of physics break down, but recently, Stephen Hawking, the leading expert on black holes, has begun to suspect that this may not be true.

Although black holes have the same structure, they are not all alike. Size varies greatly among black holes, with smaller ones causing more distortion of space-time; space-time would have to wrap itself more tightly around a smaller one to close it off. (Think of tine, extremely dense object being dropped on the rubber sheet.)

The physical difference with the most impact, though, is whether it is a rotating or non-rotating black hole. A still black hole is just as was discribed: event horizon, that singularity. But a rotating black hole has two even horizons, and makes some major differences.

Inside the first event horizon, it is just like a non-rotating black hole (the rotation, by the way, is from the rotation of the star before it collapses): gravity pulling you in faster and faster. But when you hit the second event horizon, it’s like the eye of a storm: There is no singularity, and space-time seems to return to normal.

There is a problem, of course-there may be anti-gravity after the second event horizon, so you would be spit right back out. To where? Perhaps an alternate universe.

 

…And some other important schtuff

As was mentioned earlies, black holes are not known for sure to exist. But there may be one at the center of our galaxy, or in the binary system Cygnus X-1, 6000 light years from Earth.

Besides looking for the obvious area of ‘nothingness’ in space, there are other clues to the presence of one. In a binary system, one looks for accretion disks, a disk of gas that swirls into the suspected black hole from a neighboring star.

There is also the gravitational red shift. Longer light waves (red colors) have less energy. Photons of light will lose more and more energy as they try to escape the steadily stronger gravity of a black hole. The wavelengths lengthens until we must use radio and infrared telescopes to detect it, and then it either becomes to long to detect or it disappears.

The newest proof of black holes may be quasars-stars that radiate enough energy like an entire galaxy. These could be ‘white holes’, the opposite end of a black hole.

Black holes may have another way of being detected – Hawking Radiatin. Although nothing escapes from a black hole, Steven Hawking theorized that something must, because black holes have entropy. Anything with entropy must have a temperature, and anything with a temperature must emit radiation. The empty space around a black hole, he says, contains miniscule virtual particles that have positive and negative charges. Normally they combine to annhiliate each other. Sometimes the negative one will fall into the black hole, and the positively charged one will escape.

We have, been, plenty of proof that black holes exist. We just have yet to prove that they do exist. If the do, the all important question would be;

What happens when you fall into a black hole???

Good question. And there is two ways to look at it.

From the point of view of the person falling in, not much would change. You would feel fine, time would run normally, and life would be good. That is, until you began to be stretched apart by the difference in gravity between your head and feet. All parts of you body would be pulled towards the center of gravity, so you would be taffy before you reached the event horizon.

To the person watching you, this would not be the case. Say that you were sending singals back to the observer every second. To you, the singals would be sent out every second, but the closer you got the the event horizon, the longer they would take to reach the observer. The one sent out when you are at the event horizon can (ingnoring the fact that you would be dead) would never reach them. In fact, they would never see you reach the event horizon. Time at the event horizon is so slowed down according to the observers relative time, that you would seem to hang at the brink forever.

Black holes are still an unproven enigma, but their presence could lead to the discovery of an even more elusive theory-wormholes.

Parallel universes would seem to be the most unlikely prediction of relativity, but their proposal is just as fact-based as those dealing with black holes.

The idea of parallel universes was taken seriously after experiments with properties of light. Night exhibits wave-particle duality-it acts like both a particle and a wave. But even this odd characteristic did not account for the surprising results scientists noted in ‘double slit tests’. A beam of light would be shined at a screen through another screen with two slits in it. When both slits were open, it seemed as if an electron would pass through both at the same time; and with one open, some areas of the screen would get more light then when both were open. While some of this could be attributed to particle-wave duality, in some cases it seemed almost as though the possibilities of what the light could do was affecting the outcome.

The only way for this to happen is for all the possiblities to exist at once. This idea is the backbone of the parallel universe theory-that all the possibilities for every action exist as an alternate universe. At the moment when an outcome is needed, they can overlap, or one of the separate universes will bend its solution.

Because there are an infinite number of possibilities, there is an infinite number of parallel universes, and therefore, an infinite number of you. A parallel universe for you oversleeping this morning, losing your homework, wearing different clothes… it goes on. For every interaction, there is a myriad of possibilites.

This all seems very far-fetched from Einstein’s theory, but Einstein actually speculated and believed in parallel universes. He helped to discover the Einstein-Rosen  Bridge-the area at the singularity of a rotating black hole where one can cross into a parallel universe.

Which is really the heart of the problem-reaching the singularity of a rotating black hole. But you’ll have to read about black holes to find out why.

Myth of Strange Matter And Black Hole at LHC

The LHC, like other particle accelerators, recreates the natural phenomena of cosmic rays under controlled laboratory conditions, enabling them to be studied in more detail. Cosmic rays are particles produced in outer space, some of which are accelerated to energies far exceeding those of the LHC. The energy and the rate at which they reach the Earth’s atmosphere have been measured in experiments for some 70 years. Over the past billions of years, Nature has already generated on Earth as many collisions as about a million LHC experiments – and the planet still exists. Astronomers observe an enormous number of larger astronomical bodies throughout the Universe, all of which are also struck by cosmic rays. The Universe as a whole conducts more than 10 million million LHC-like experiments per second. The possibility of any dangerous consequences contradicts what astronomers see – stars and galaxies still exist.

Microscopic black holes

Microscopic black holes which are said to be formed at LHC and related dooms day myth is one of the most popularized myth. I can remember when news channels were highlighting those myths. Well, how this implication came to existence?

Nature forms black holes when certain stars, much larger than our Sun, collapse on themselves at the end of their lives. They concentrate a very large amount of matter in a very small space. Speculations about microscopic black holes at the LHC refer to particles produced in the collisions of pairs of protons, each of which has an energy comparable to that of a mosquito in flight. Astronomical black holes are much heavier than anything that could be produced at the LHC.

According to the well-established properties of gravity, described by Einstein’s relativity, it is impossible for microscopic black holes to be produced at the LHC. There are, however, some speculative theories that predict the production of such particles at the LHC. All these theories predict that these particles would disintegrate immediately. Black holes, therefore, would have no time to start accreting matter and to cause macroscopic effects.

Although theory predicts that microscopic black holes decay rapidly, even hypothetical stable black holes can be shown to be harmless by studying  the consequences of their production by cosmic rays.  Whilst collisions at the LHC differ from cosmic-ray collisions with astronomical bodies like the Earth in that new particles produced in LHC collisions tend to move more slowly than those produced by cosmic rays, one can still demonstrate their safety.  The specific reasons for this depend whether the black holes are electrically charged, or neutral. Many stable black holes would be expected to be electrically charged, since they are created by charged particles.  In this case they would interact with ordinary matter and be stopped while traversing the Earth or Sun, whether produced by cosmic rays or the LHC. The fact that the Earth and Sun are still here rules out the possibility that cosmic rays or the LHC could produce dangerous charged microscopic black holes. If stable microscopic black holes had no electric charge, their interactions with the Earth would be very weak. Those produced by cosmic rays would pass harmlessly through the Earth into space, whereas those produced by the LHC could remain on Earth. However, there are much larger and denser astronomical bodies than the Earth in the Universe. Black holes produced in cosmic-ray collisions with bodies such as neutron stars and white dwarf stars would be brought to rest. The continued existence of such dense bodies, as well as the Earth, rules out the possibility of the LHC producing any dangerous black holes.

Strangelets

Strangelet is the term given to a hypothetical microscopic lump of ‘strange matter’ containing almost equal numbers of particles called up, down and strange quarks. According to most theoretical work, strangelets should change to ordinary matter within a thousand-millionth of a second. But could strangelets coalesce with ordinary matter and change it to strange matter? This question was first raised before the start up of the Relativistic Heavy Ion Collider, RHIC, in 2000 in the United States. A study at the time showed that there was no cause for concern, and RHIC has now run for eight years, searching for strangelets without detecting any. At times, the LHC will run with beams of heavy nuclei, just as RHIC does. The LHC’s beams will have more energy than RHIC, but this makes it even less likely that strangelets could form. It is difficult for strange matter to stick together in the high temperatures produced by such colliders, rather as ice does not form in hot water. In addition, quarks will be more dilute at the LHC than at RHIC, making it more difficult to assemble strange matter. Strangelet production at the LHC is therefore less likely than at RHIC, and experience there has already validated the arguments that strangelets cannot be produced. 

Vacuum bubbles

There have been speculations that the Universe is not in its most stable configuration, and that perturbations caused by the LHC could tip it into a more stable state, called a vacuum bubble, in which we could not exist. If the LHC could do this, then so could cosmic-ray collisions. Since such vacuum bubbles have not been produced anywhere in the visible Universe, they will not be made by the LHC.

Magnetic monopoles

Magnetic monopoles are hypothetical particles with a single magnetic charge, either a north pole or a south pole. Some speculative theories suggest that, if they do exist, magnetic monopoles could cause protons to decay. These theories also say that such monopoles would be too heavy to be produced at the LHC. Nevertheless, if the magnetic monopoles were light enough to appear at the LHC, cosmic rays striking the Earth’s atmosphere would already be making them, and the Earth would very effectively stop and trap them. The continued existence of the Earth and other astronomical bodies therefore rules out dangerous proton-eating magnetic monopoles light enough to be produced at the LHC.

Other aspects of LHC safety:

Concern has recently been expressed that a ‘runaway fusion reaction’ might be created in the LHC carbon beam dump. The safety of the LHC beam dump had previously been reviewed by the relevant regulatory authorities of the CERN host states, France and Switzerland. The specific concerns expressed more recently have been addressed in a technical memorandum by Assmann et al. As they point out, fusion reactions can be maintained only in material compressed by some external pressure, such as that provided by gravity inside a star, a fission explosion in a thermonuclear device, a magnetic field in a Tokamak, or by continuing isotropic laser or particle beams in the case of inertial fusion. In the case of the LHC beam dump, it is struck once by the beam coming from a single direction. There is no countervailing pressure, so the dump material is not compressed, and no fusion is possible.

Concern has been expressed that a ‘runaway fusion reaction’ might be created in a nitrogen tank inside the LHC tunnel. There are no such nitrogen tanks. Moreover, the arguments in the previous paragraph prove that no fusion would be possible even if there were.

Finally, concern has also been expressed that the LHC beam might somehow trigger a ‘Bose-Nova’ in the liquid helium used to cool the LHC magnets. A study by Fairbairn and McElrath has clearly shown there is no possibility of the LHC beam triggering a fusion reaction in helium.

We recall that ‘Bose-Novae’ are known to be related to chemical reactions that release an infinitesimal amount of energy by nuclear standards. We also recall that helium is one of the most stable elements known, and that liquid helium has been used in many previous particle accelerators without mishap. The facts that helium is chemically inert and has no nuclear spin imply that no ‘Bose-Nova’ can be triggered in the superfluid helium used in the LHC.

Comments on the papers by Giddings and Mangano, and by LSAG

The papers by Giddings and Mangano and LSAG demonstrating the safety of the LHC have been studied, reviewed and endorsed by leading experts from the CERN Member States, Japan, Russia and the United States, working in astrophysics, cosmology, general relativity, mathematics, particle physics and risk analysis, including several Nobel Laureates in Physics. They all agree that the LHC is safe.

The paper by Giddings and Mangano has been peer-reviewed by anonymous experts in astrophysics and particle physics and published in the professional scientific journal Physical Review D. The American Physical Society chose to highlight this as one of the most significant papers it has published recently, commissioning a commentary by Prof. Peskin from the Stanford Linear Accelerator Laboratory in which he endorses its conclusions. The Executive Committee of the Division of Particles and Fields of the American Physical Society has issued a statement endorsing the LSAG report.

The LSAG report has been published by the UK Institute of Physics in its publication Journal of Physics G. The conclusions of the LSAG report were endorsed in a press release that announced this publication.

The conclusions of LSAG have also been endorsed by the Particle and Nuclear Physics Section (KET) of the German Physical Society. A translation into German of the complete LSAG report may be found on the KET website, as well as here. (A translation into French of the complete LSAG report is also available.)

Thus, the conclusion that LHC collisions are completely safe has been endorsed by the three respected professional societies of physicists that have reviewed it, which rank among the most highly respected professional societies in the world.

The overwhelming majority of physicists agree that microscopic black holes would be unstable, as predicted by basic principles of quantum mechanics. As discussed in the LSAG report, if microscopic black holes can be produced by the collisions of quarks and/or gluons inside protons, they must also be able to decay back into quarks and/or gluons. Moreover, quantum mechanics predicts specifically that they should decay via Hawking radiation.

Nevertheless, a few papers have suggested that microscopic black holes might be stable. The paper by Giddings and Mangano and the LSAG report analyzed very conservatively the hypothetical case of stable microscopic black holes and concluded that even in this case there would be no conceivable danger. Another analysis with similar conclusions has been documented by Dr. Koch, Prof. Bleicher and Prof. Stoecker of Frankfurt University and GSI, Darmstadt, who conclude:

“We discussed the logically possible black hole evolution paths. Then we discussed every single outcome of those paths and showed that none of the physically sensible paths can lead to a black hole disaster at the LHC.”

Professor Roessler (who has a medical degree and was formerly a chaos theorist in Tuebingen) also raised doubts on the existence of Hawking radiation. His ideas have been refuted by Profs. Nicolai (Director at the Max Planck Institute for Gravitational Physics – Albert-Einstein-Institut – in Potsdam) and Giulini, whose report (see here for the English translation, and here for further statements) point to his failure to understand general relativity and the Schwarzschild metric, and his reliance on an alternative theory of gravity that was disproven in 1915. Their verdict:

“[Roessler’s] argument is not valid; the argument is not self-consistent.”

The paper of Prof. Roessler has also been criticized by Prof. Bruhn of the Darmstadt University of Technology, who concludes that:

“Roessler’s misinterpretation of the Schwarzschild metric [renders] his further considerations … null and void. These are not papers that could be taken into account when problems of black holes are discussed.”

A hypothetical scenario for possibly dangerous metastable black holes has recently been proposed by Dr. Plaga. The conclusions of this work have been shown to be inconsistent in a second paper by Giddings and Mangano, where it is also stated that the safety of this class of metastable black hole scenarios is already established by their original work. Finally I can decern that such existing myths are nonexistent.

KOCH, B., BLEICHER, M., & STOCKER, H. (2009). Exclusion of black hole disaster scenarios at the LHC Physics Letters B, 672 (1), 71-76 DOI: 10.1016/j.physletb.2009.01.003

 
PANAGIOTOU, A., & KATSAS, P. (2007). Searching for Strange Quark Matter with the CMS/CASTOR Detector at the LHC Nuclear Physics A, 782 (1-4), 383-391 DOI: 10.1016/j.nuclphysa.2006.10.020

Behind The Star Trek Physics

Inertial Dampers

You are at the helm of the starship Defiant (NCC-1 764), currently in orbit around the planet Iconia, near the Neutral Zone. Your mission: to rendezvous with a nearby supply vessel at the other end of this solar system in order to pick up components to repair faulty transporter primary energizing coils. There is no need to achieve warp speeds; you direct the impulse drive to be set at full power for leisurely half-light-speed travel, which should bring you to your destination in a few hours, giving you time to bring the captain’s log up to date. However, as you begin to pull out of orbit, you feel an intense pressure in your chest. Your hands are leaden, and you are glued to your seat. Your mouth is fixed in an evil-looking grimace, your eyes feel like they are about to burst out of their sockets, and the blood flowing through your body refuses to rise to your head. Slowly, you lose consciousness … and within minutes you die.

What happened? It is not the first signs of spatial “interphase” drift, which will later overwhelm the ship, or an attack from a previously cloaked Romulan vessel. Rather, you have fallen prey to something far more powerful. The ingenious writers of Star Trek, on whom you depend, have not yet invented inertial dampers, which they will introduce sometime later in the series. You have been defeated by nothing more exotic than Isaac Newton’s laws of motion – the very first things one can forget about high school physics.

OK, I know some trekkers out there are saying to themselves, “How lame! Don’t give me Newton. Tell me things I really want to know, like ‘How does warp drive work?’ or ‘What is the flash before going to warp speed – Is it like a sonic boom?’ or’What is a dilithium crystal anyway?”‘ All I can say is that we will get there eventually. Travel in the Star Trek universe involves some of the most exotic concepts in physics. But many different aspects come together before we can really address everyone’s most fundamental question about Star Trek: “Is any of this really possible, and if so, how?”

To go where no one has gone before – indeed, before we even get out of Starfleet Headquarters – we first have to confront the same peculiarities that Galileo and Newton did over three hundred years ago. The ultimate motivation will be the truly cosmic question which was at the heart of Gene Roddenberry’s vision of Star Trek and which, to me, makes this whole subject worth thinking about: “What does modern science allow us to imagine about our possible future as a civilization?”

Anyone who has ever been in an airplane or a fast car knows the feeling of being pushed back into the seat as the vehicle accelerates from a standstill. This phenomenon works with a vengeance aboard a starship. The fusion reactions in the impulse drive produce huge pressures, which push gases and radiation backward away from the ship at high velocity. It is the backreaction force on the engines – from the escaping gas and radiation – that causes the engines to “recoil” forward. The ship, being anchored to the engines, also recoils forward. At the helm, you are pushed forward too, by the force of the captain’s seat on your body. In turn, your body pushes back on the seat.

If you are in the captain’s seat and you issue a command for the ship to accelerate, you must take into account the force with which the seat will push you forward. If you request an acceleration twice as great, the force on you from the seat will be twice as great. The greater the acceleration, the greater the push. The only problem is that nothing can withstand the kind of force needed to accelerate to impulse speed quickly – certainly not your body.

By the way, this same problem crops up in different contexts throughout Star Trek – even on Earth. At the beginning of Star Trek V: The Final Frontier, James Kirk is free-climbing while on vacation in Yosemite when he slips and fails. Spock, who has on his rocket boots, speeds to the rescue, aborting the captain’s fall within a foot or two of the ground. Unfortunately, this is a case where the solution can be as bad as the problem. It is the process of stopping over a distance of a few inches which can kill you, whether or not it is the ground that does the stopping or Spock’s Vulcan grip.

Well before the reaction forces that will physically tear or break your body occur, other severe physiological problems set in. First and foremost, it becomes impossible for your heart to pump strongly enough to force the blood up to your head. This is why fighter pilots sometimes black out when they perform maneuvers involving rapid acceleration. Special suits have been created to force the blood up from pilots’ legs to keep them conscious during acceleration. This physiological reaction remains one of the limiting factors in determining how fast the acceleration of present-day spacecraft can be, and it is why NASA, unlike Jules Verne in his classic From the Earth to the Moon, has never launched three men into orbit from a giant cannon.

To accelerate gently from rest to half the speed of light, with an acceleration of 3g, it will take 2.5 months to reach this speed! This would not make for an exciting episode of Star Trek. To resolve this dilemma, sometime after the production of the first Constitution Class starship – the Enterprise (NCC-1701) – the Star Trek writers had to develop a response to the criticism that the accelerations aboard a starship would instantly turn the crew into “chunky salsa.” They came up with “inertial dampers,” a kind of cosmic shock absorber and an ingenious plot device designed to get around this sticky little problem.

The inertial dampers are most notable in their absence. Indeed, almost every time the Enterprise is destroyed (usually in some renegade timeline), the destruction is preceded by loss of the inertial dampers.

Tractor Beam

Another technological marvel that has to face Newton’s laws is the Enterprise’s tractor beam. It seems simple enough: more like an invisible rope or rod. The only problem is that when we pull something with a rope our feet are firmly anchored on the ground. Without any firm grounding, you are a helpless victim of your own inertia. If the Enterprise tries to use the tractor beam to push away any object, the resulting force would push the Enterprise back as well!

This phenomenon has already dramatically affected the way we work in space at present. Say, for example, that you are an astronaut assigned to tighten a bolt on the Hubble Space Telescope. If you take an electric screwdriver with you to do the job, you are in for a rude awakening after you drift over to the offending bolt. When you switch on the screwdriver as it is pressed against the bolt, you are as likely to start spinning around as the bolt is to turn. This is because the Hubble Telescope is a lot heavier than you are. When the screwdriver applies a force to the bolt, the reaction force you feel may more easily turn you than the bolt, especially if the bolt is still fairly tightly secured to the frame.

Likewise, you can see what will happen if the Enterprise tries to pull another spacecraft toward it. Unless the Enterprise is very much heavier, it will move toward the other object when the tractor beam turns on, rather than vice versa. In the depths of space, this distinction is a meaningless semantic one. With no reference system nearby, who is to say who is pulling whom? However, if you are on a hapless planet like Moab IV in the path of a renegade star on a collision course, it makes a great deal of difference whether the Enterprise pushes the star aside or the star pushes the Enterprise aside!

Time Loops

While every one of us is a time traveler, the cosmic pathos that elevates human history to the level of tragedy arises precisely because we seem doomed to travel in only one direction – into the future. What wouldn’t any of us give to travel into the past, relive glories, correct wrongs, meet our heroes, perhaps even avert disasters, or simply revisit youth with the wisdom of age? The possibilities of space travel beckon us every time we gaze up at the stars, yet we seem to be permanent captives in the present. The question that motivates not only dramatic license but a surprising amount of modern theoretical physics research can be simply put: Are we or are we not prisoners on a cosmic temporal freight train that cannot jump the tracks?

Perhaps the most fascinating aspect of time travel as far as Star Trek is concerned is that there is no stronger potential for violation of the Prime Directive. The crews of Starfleet are admonished not to interfere with the present normal historical development of any alien society they visit. Yet by traveling back in time it is possible to remove the present altogether. Indeed, it is possible to remove history altogether!

A famous paradox is to be found in both science fiction and physics: What happens if you go back in time and kill your mother before you were born? You must then cease to exist. But if you cease to exist, you could not have gone back and killed your mother. But if you didn’t kill your mother, then you have not ceased to exist. Put another way: if you exist, then you cannot exist, while if you don’t exist, you must exist. (Reread the article that was posted on the relativity page: click .)

Actually, if the above plot line is confusing, it is nothing compared to the Mother of all time paradoxes, which arises in the final episode of Star Trek: The Next Generation, when Picard sets off a chain of events that will travel back in time and destroy not just his own ancestry but all life on Earth. Specifically, a “subspace temporal distortion” involving “antitime” threatens to grow backward in time, eventually engulfing the amino acid protoplasm on the nascent Earth before the first proteins, which will be the building blocks of life, can form. This is the ultimate case of an effect producing a cause. The temporal distortion is apparently created in the future. If, in the distant past, the subspace temporal distortion was able to destroy the first life on Earth, then life on Earth could never have evolved to establish a civilization capable of creating the distortion in the future!

The standard resolution of these paradoxes, at least among many physicists, is to argue a priori that such possibilities must not be allowed in a sensible universe, such as the one we presumably live in. However, the problem is that Einstein’s equations of general relativity not only do not directly forbid such possibilities, they encourage them.

Within thirty years of the development of the equations of general relativity, an explicit solution in which time travel could occur was developed by the famous mathematician Kurt Godel, who worked at the Institute for Advanced Study in Princeton along with Einstein. In Star Trek language, this solution allowed the creation of a “temporal causality loop,” such as the one the Enterprise got caught in after being hit by the starship Bozeman. The dryer terminology of modern physics labels this a “closed timelike curve.” In either case, what it implies is that you can travel on a round-trip and return to your starting point in both space and time! Godel’s solution involved a universe that, unlike the one we happen to live in, is not expanding but instead is spinning uniformly. In such a universe, it turns out that one could in principle go back in time merely by traveling in a large circle in space. While such a hypothetical universe is dramatically different than the one in which we live, the mere fact that this solution exists at all indicates clearly that time travel is possible within the context of general relativity.

As was discussed in class, as one approaches light speed, it is speed that becomes an absolute quantity, and therefore space and time must become relative! Einstein’s Special Relativity Theory (STR), also produced the remarkable consequences of time dilation, length contraction and suprises in simultaneity. The later refers to the inability to synchronize clocks for observers that are moving with respect to each other. This fact is critical in Star Trek. It is absolutely essential that (a) light speed be avoided, in order not to put the Federation out of synchronization, and (b) faster-than-light speed be realized, in order to move practically about the galaxy.

The kicker is that, in the context of special relativity alone, the latter possibility cannot be realized. Physics becomes full of impossibilities if super light speed is allowed. Not least among the problems is that because objects get more massive as they approach the speed of light, it takes progressively more and more energy to accelerate them by a smaller and smaller amount. As in the myth of the Greek hero Sisyphus, who was condemned to push a boulder uphill for all eternity only to be continually thwarted near the very top, all the energy in the universe would not be sufficient to allow us to push even a speck of dust, much less a starship, past this ultimate speed limit.

By the same token, not just light but all massless radiation must travel at the speed of light. This means that the many types of beings of “pure energy” encountered by the Enterprise, and later by the Voyager, would have difficulty existing as shown. In the first place, they wouldn’t be able to sit still. Light cannot be slowed down, let alone stopped in empty space. In the second place, any form of intelligent-energy being (such as the “photonic” energy beings in the Voyager series; the energy beings in the Beta Renna cloud, in The Next Generation; the Zetarians, in the original series; and the Dal’Rok, in Deep Space Nine), which is constrained to travel at the speed of light, would have clocks that are infinitely slowed compared to our own. The entire history of the universe would pass by in a single instant. If energy beings could experience anything, they would experience everything at once! Needless to say, before they could actually interact with corporeal beings the corporeal beings would be long dead.

Warp Drive

Warp Drive is the main power system of the Enterprise, which propels it to faster-than-light travel. Warp power relies on the annihilation of matter with antimatter, and the resulting energy pushes the Enterprise. For speeds lower than the speed of light, the Enterprise uses impulse power engines.

However, while the warp drive aboard the Enterprise uses matter-antimatter fuel, the impulse drive does not. It is powered instead by nuclear fusion – the same nuclear reaction that powers the Sun by turning hydrogen into helium. In fusion reactions, about 1 percent of the available mass is converted into energy. With this much available energy, the helium atoms that are produced can come streaming out the back of the rocket at about an eighth of the speed of light. Using this exhaust velocity for the propellant, we then can calculate the amount of fuel the Enterprise needs in order to accelerate to, say, half the speed of light. The calculation is not difficult, but I will just give the answer here. It may surprise you. Each time the Enterprise accelerates to half the speed of light, it must burn 81 TIMES ITS ENTIRE MASS in hydrogen fuel. Given that a Galaxy Class starship such as Picard’s Enterprise-D would weigh in excess of 4 million metric tons, this means that over 300 million metric tons of fuel would need to be used each time the impulse drive is used to accelerate the ship to half light speed! And then, of course, energy is needed to slow down the Enterprise as well!

The Curvature of Spacetime

The central premise of Einstein’s general relativity is simple to state in words: the curvature of spacetime is directly determined by the distribution of matter and energy contained within it. Einstein’s equations, in fact, provide simply the strict mathematical relation between curvature on the one hand and matter and energy on the other:

Left-hand side  =   Right-hand side
  {CURVATURE}      {MATTER AND ENERGY}

What makes the theory so devilishly difficult to work with is this simple feedback loop: The curvature of spacetime is determined by the distribution of matter and energy in the universe, but this distribution is in turn governed by the curvature of space. It is like the chicken and the egg. Which was there first? Matter acts as the source of curvature, which in turn determines how matter evolves, which in turn alters the curvature, and so on.

Indeed, this may be perhaps the most important single aspect of general relativity as far as Star Trek is concerned. The complexity of the theory means that we still have not yet fully understood all its consequences; therefore we cannot rule out various exotic possibilities. It is these exotic possibilities that are the grist of Star Trek’s mill. In fact, we shall see that all these possibilities rely on one great unknown that permeates everything, from wormholes and black holes to time machines.

If space is curved, in fact, then a straight line need not be the shortest distance between two points. Consider the two figures below

The shortest distance between two points located on opposite sides of the circle above, is a diameter of the circle. Travelling around the circle from A to B increases this distance by 1.5. However, if the circle was drawn on a rubber sheet which was then stretched, we see clearly that going through the central region is no longer the shortest path! This time, going around the perimeter of the circle is shorter. In other words, if, in curved space, the shortest distance between two points need not be a straight line, then it might be possible to traverse what appearsalong the line of sight to be a huge distance, by finding instead a shorter route through curved spacetime.

Wormholes

 

Let’s look at a consequence of the short-path argument from above. Assume I have a large rubber sheet which looks something like this:

If I were to poke a pencil down A until I touched B, and then sewed the two parts together, I would create a “short-cut” from A to B. As you have no doubt surmised, the tunnel connecting A and B in this figure is a two-dimensional analogue of a three-dimensional wormhole, which could, in principle, connect distant regions of space-time. As exciting as this possibility is, there are several deceptive aspects of the picture which I want to bring to your attention. In the first place, even though the rubber sheet is shown embedded in a three-dimensional space in order for us to “see” the curvature of the sheet, the curved sheet can exist without the three-dimensional space around it needing to exist. Thus, while a wormhole could exist joining A and B, there is no sense in which A and B are “close” without the wormhole being present. It is not as if one is free to leave the rubber sheet and move from A to B through the three-dimensional space in which the sheet is embedded. If the three-dimensional space is not there, the rubber sheet is all there is to the universe.

Finally, although mathematically wormholes can exist, their construction is unpredictable, they are unstable, and they need huge amounts exotic (negative energy) to exist. If one was to open a wormhole, one could never guess where it would open to, nor how long would it stay open. Travelling through such a construct undoubtedly would be hazardous to one’s health! Nevertheless, without such exotic possibilities we will probably never voyage through space.

Black Holes

 

We have alreary discussed these in the lectures on Relativity and Astrophysics. Black holes are “singularities” (essentially a point, with infinite mass and density) in space. Gravity is so large near a black hole that it is governed by the laws of quantum mechanics. Yet no one has yet been able to write down a theory that consistently accommodates both general relativity (that is, gravity) and quantum mechanics. Star Trek writers correctly recognized this tension between quantum mechanics and gravity, as they usually refer to all spacetime singularities as “quantum singularities.” One thing is certain, however: by the time the gravitational field at the center of a black hole reaches a strength large enough for our present picture of physics to break down, any ordinary physical object will be torn apart beyond recognition. Nothing could survive intact.

You may notice that I referred to a black hole as “hiding” a singularity at its center. The reason is that at the outskirts of a black hole is a mathematically defined surface we call the “event horizon,” which shields our view of what happens to objects that fall into the hole. Inside the event horizon, everything must eventually hit the ominous singularity. Outside the event horizon, objects can escape. While an observer unlucky enough to fall into a black hole will notice nothing special at all as he or she (soon to be “it”) crosses the event horizon, an observer watching the process from far away sees something very different. Time slows down for the observer freely falling in the vicinity of the event horizon, relative to an observer located far away. As a result, the falling observer appears from the outside to slow down as he or she nears the event horizon. The closer the falling observer gets to the event horizon, the slower is his or her clock relative to the outside observer’s. While it may take the falling observer a few moments (local time) to cross the event horizon – where, I repeat, nothing special happens and nothing special sits – it will take an eternity as observed by someone on the outside. The infalling object appears to become frozen in time.

Moreover, the light emitted by any infalling object gets harder and harder to see from the outside. As an object approaches the event horizon, the object gets dimmer and dimmer (because the observable radiation from it gets shifted to frequencies below the visible). Finally, even if you could see, from the outside, the object’s transit of the event horizon (which you cannot, in any finite amount of time), the object would disappear completely once it passed the horizon, because any light it emitted would be trapped inside, along with the object. Whatever falls inside the event horizon is lost forever to the outside world. It appears that this lack of communication is a one-way street: an observer on the outside can send signals into the black hole, but no signal can ever be returned.

This brings us to Steven Hawking’s remarkable result about black holes. Under normal circumstances, when a quantum fluctuation creates a virtual particle pair, the pair will annihilate and disappear back into the vacuum in a time short enough so that the violation of conservation of energy (incurred by the pair’s creation from nothing) is not observable (this is Heisenberg’s uncertainty principle, discussed in class). However, when a virtual particle pair pops out in the curved space near a black hole, one of the particles may fall into the hole, and then the other can escape and be observed. This is because the particle that falls into the black hole can in principle lose more energy in the process than the amount required to create it from nothing. It thus contributes “negative energy” to the black hole, and the black hole’s own energy is therefore decreased. This satisfies the energy-conservation law’s balance-sheet, making up for the energy that the escaping particle is observed to have. This is how the black hole emits radiation. Moreover, as the black hole’s own energy decreases bit by bit in this process, there is a concomitant decrease in its mass. Eventually, it may completely evaporate, leaving behind only the radiation it produced in its lifetime.

Wormhole Time Machines

 

If wormholes exist, they can and will be time machines! This startling realization has grown over the last decade, as various theorists, for lack of anything more interesting to do, began to investigate the physics of wormholes a little more seriously. Wormhole time machines are easy to design: perhaps the simplest example (due again to the physicist Kip Thorne) is to imagine a wormhole with one end fixed and the other end moving at a fast but sublight speed through a remote region of the galaxy. In principle, this is possible even if the length of the wormhole remains unchanged. In the earlier two-dimensional wormhole drawing, just drag the bottom half of the sheet to the left, letting space “slide” past the bottom mouth of the wormhole while this mouth stays fixed relative to the wormhole’s other mouth:

 

Because the bottom mouth of the wormhole will be moving with respect to the space in which it is situated, while the top mouth will not, special relativity tells us that clocks will tick at different rates at each mouth. On the other hand, if the length of the wormhole remains fixed, then as long as one is inside the wormhole the two ends appear to be at rest relative to each other. In this frame, clocks at either end should be ticking at the same rate. Now slide the bottom sheet back to where it used to be, so that the bottom mouth of the wormhole ends up back where it started relative to the background space. Let’s say that this process takes a day, as observed by someone near the bottom mouth. But for an observer near the top mouth, this same process could appear to take ten days. If this second observer were to peer through the top mouth to look at the observer located near the bottom mouth, he would see on the wall calendar next to the observer a date nine days earlier! If he now decides to go though the wormhole for a visit, he will travel back in time.

 

 

 

 

 

 

 

 

 

 

 

 

Warp Speed, Deflector Shields and Cloaking

 

 

 

 

 

 

 

 

 

 

 

 

Is warp speed, i.e. speed faster than that of light, possible? The answer is a resounding “Maybe”!

The curvature in spacetime produces a loophole in special relativistic arguments – a loophole large enough to drive a Federation starship through. If spacetime itself can be manipulated, objects can travel locally at very slow velocities, yet an accompanying expansion or contraction of space could allow huge distances to be traversed in short time intervals. We have already seen how an extreme manipulation – namely, cutting and pasting distant parts of the universe together with a wormhole – might create shortcuts through spacetime. What is argued here is that even if we do not resort to this surgery, faster-than-light travel might globally be possible, even if it is not locally possible.

A proof in principle of this idea was recently developed by a physicist in Wales, Miguel Alcubierre, who for fun decided to explore whether a consistent solution in general relativity could be derived which would correspond to “warp travel.” He was able to demonstrate that it was possible to tailor a spacetime configuration wherein a spacecraft could travel between two points in an arbitrarily short time. Moreover, throughout the journey the spacecraft could be moving with respect to its local surroundings at speeds much less than the speed of light, so that clocks aboard the spacecraft would remain synchronized with those at its place of origin and at its destination. General relativity appears to allow us to have our cake and eat it too. The idea is straightforward. If spacetime can locally be warped so that it expands behind a starship and contracts in front of it, then the craft will be propelled along with the space it is in, like a surfboard on a wave. The craft will never travel locally faster than the speed of light, because the light, too, will be carried along with the expanding wave of space.

One way to picture what is happening is to imagine yourself on the starship. If space suddenly expands behind you by a huge amount, you will find that the starbase you just left a few minutes ago is now many light-years away. Similarly, if space contracts in front of you, you will find that the starbase you are heading for, which formerly was a few light-years away, is now close to you, within reach by normal rocket propulsion in a matter of minutes.

It is also possible to arrange the geometry of spacetlme in this solution so that the huge gravitational fields necessary to expand and contract space in this way are never large near the ship or any of the starbases. In the vicinity of the ship and the bases, space can be almost flat, and therefore clocks on the ship and the starbases remain synchronized. Somewhere in between the ship and the bases, the tidal forces due to gravity will be immense, but that’s OK as long as we aren’t located there.

This scenario must be what the Star Trek writers intended when they invented warp drive, even if it bears little resemblance to the technical descriptions they have provided. It fulfills all the requirements we listed earlier for successful controlled intergalactic space travel: (1) faster-than-light travel, (2) no time dilation, and (3) no resort to rocket propulsion. Of course, we have begged a pretty big question thus far. By making spacetime itself dynamical, general relativity allows the creation of “designer spacetimes,” in which almost any type of motion in space and time is possible. However, the cost is that the theory relates these spacetimes to some underlying distribution of matter and energy. Thus, for the desired spacetime to be “physical,” the underlying distribution of matter and energy must be attainable.

First, however, the wonder of such “designer spacetimes” is that they allow us to return to Newton’s original challenge and to create inertial dampers and tractor beams. The idea is identical to warp drive. If spacetime around the ship can be warped, then objects can move apart or together without experiencing any sense of local acceleration, which you will recall was Newton’s bane. To avoid the incredible accelerations required to get to impulse sublight speeds, one must resort to the same spacetime shenanigans as one does to travel at warp speeds. The distinction between impulse drive and warp drive is thus diminished. Similarly, to use a tractor beam to pull a heavy object like a planet, one merely has to expand space on the other side of the planet and contract it on the near side. Simple!

Warping space has other advantages as well. Clearly, if spacetime becomes strongly curved in front of the Enterprise, then any light ray – or phaser beam, for that matter – will be deflected away from the ship. This is doubtless the principle behind deflector shields. Indeed, we are told that the deflector shields operate by “coherent graviton emission.” Since gravitons are by definition particles that transmit the force of gravity, then “coherent graviton emission” is nothing other than the creation of a coherent gravitational field. A coherent gravitational field is, in modern parlance, precisely what curves space! So once again the Star Trek writers have at least settled upon the right language.

I would imagine that the Romulans’ cloaking device might operate in a similar manner. In fact, an Enterprise that has its deflector shield deployed should be very close to a cloaked Enterprise. After all, the reason we see something that doesn’t shine of its own accord is that it reflects light, which travels back to us. Cloaking must somehow warp space so that incident light rays bend around a Warbird instead of being reflected from it. The distinction between this and deflecting light rays away from the Enterprise is thus pretty subtle.

 

 

 

 

 

 

 

 

 

 

 

 

“Beam me up Scotty!”

 

 

 

 

 

 

 

 

 

 

 

 

To avoid the costly special effects of landing the Enterprise on various new worlds each week, the “transporter” was invented by the writers of Star Trek. This is one of the best recognized features of Star Trek. The phrase “Beam me up Scotty!” has been ingrained into our culture, in the sense that it is even known by persons who have never watched a single episode of Star Trek.

Transporting an inanimate object, like a book for example, is one thing. The book’s information can be digitized into bits and sent to the recipient, who can “read” the book on his/her computer. Thus, it is not necessary to physically send the book.

But what about people? If you are going to move people around, do you have to move their atoms or just their information? At first you might think that moving the information is a lot easier; for one thing, information can travel at the speed of light. However, in the case of people, you have two problems you don’t have with books: first, you have to extract the information, which is not so easy, and then you have to recombine it with matter. After all, people, unlike books, require the atoms.

The Star Trek writers seem never to have got it exactly clear what they want the transporter to do. Does the transporter send the atoms and the bits, or just the bits? You might wonder why I make this point, since the Next Generation Technical Manual describes the process in detail: First the transporter locks on target. Then it scans the image to be transported, “dematerializes” it, holds it in a “pattern buffer” for a while, and then transmits the “matter stream,” in an “annular confinement beam,” to its destination. The transporter thus apparently sends out the matter along with the information.

WHEN A BODY HAS NO BODY: Perhaps the most fascinating question about beaming – one that is usually not even addressed – is, What comprises a human being? Are we merely the sum of all our atoms? More precisely, if I were to re-create each atom in your body, in precisely the same chemical state of excitation as your atoms are in at this moment, would I produce a functionally identical person who has exactly all your memories, hopes, dreams, spirit? There is every reason to expect that this would be the case, but it is worth noting that it flies in the face of a great deal of spiritual belief about the existence of a “soul” that is somehow distinct from one’s body. What happens when you die, after all? Don’t many religions hold that the “soul” can exist after death? What then happens to the soul during the transport process? In this sense, the transporter would be a wonderful experiment in spirituality. If a person were beamed aboard the Enterprise and remained intact and observably unchanged, it would provide dramatic evidence that a human being is no more than the sum of his or her parts, and the demonstration would directly confront a wealth of spiritual beliefs.

OK, KEEP THE ATOMS: The preceding arguments suggest that on both practical and ethical grounds it might be better to imagine a transporter that carries a matter stream along with the signal, just as we are told the Star Trek transporters do. The problem then becomes, How do you move the atoms? Again, the challenge turns out to be energetics, although in a somewhat more subtle way.

What would be required to “dematerialize” something in the transporter? To answer this, we have to consider a little more carefully a simpler question: What is matter? All normal matter is made up of atoms, which are in turn made up of very dense central nuclei surrounded by a cloud of electrons. As you may recall from high school chemistry or physics, most of the volume of an atom is empty space. The region occupied by the outer electrons is about ten thousand times larger than the region occupied by the nucleus.

Why, if atoms are mostly empty space, doesn’t matter pass through other matter? The answer to this is that what makes a wall solid is not the existence of the particles but of the electric fields between the particles. My hand is stopped from going through my desk when I slam it down primarily because of the electric repulsion felt by the electrons in the atoms in my hand due to the presence of the electrons in the atoms of the desk and not because of the lack of available space for the electrons to move through. As we discussed in class, humans are “electrical creatures.”

And what computing power would I need to process all the information of the 10^28 (ten to the power twenty eight) atoms that a human is composed of? Even though computers are now remarkably fast, they are still not fast enough. Maybe the next generation of computers, namely biocomputers, will be able to solve this dilemma. Or maybe, we will eventually be able to construct an android like Lt. Commander Data, in all his intellectual and physical might!

 

Let’s make a simple estimate of how much information is encoded in a human body. Start with our standard estimate of 10^28 atoms. For each atom, we first must encode its location, which requires three coordinates (the x, y, and z positions). Next, we would have to record the internal state of each atom, which would include things like which energy levels are occupied by its electrons, whether it is bound to a nearby atom to make up a molecule, whether the molecule is vibrating or rotating, and so forth. Let’s be conservative and assume that we can encode all the relevant information in a kilobyte of data. (This is roughly the amount of information on a double-spaced typewritten page.) That means we would need roughly 10^28 kilobytes to store a human pattern in the pattern buffer. I remind you that this is a 1 followed by 28 zeros.

Compare this with, say, the total information stored in all the books ever written. The largest libraries contain several million volumes, so let’s be very generous and say that there are a billion different books in existence (one written for every five people now alive on the planet). Say each book contains the equivalent of a thousand typewritten pages of information (again on the generous side) – or about a megabyte. Then all the information in all the books ever written would require about 10^12, or about a million million, kilobytes of storage. This is about sixteen orders of magnitude – or about one tenmillionth of a billionth – smaller than the storage capacity needed to record a single human pattern! When numbers get this large, it is difficult to comprehend the enormity of the task. Perhaps a comparison is in order. The storage requirements for a human pattern are ten thousand times as large, compared to the information in all the books ever written, as the information in all the books ever written is compared to the information on this page.

Storing this much information is, in an understatement physicists love to use, nontrivial. At present, the largest commercially available single hard disks store about 10 gigabytes, or 10,000 thousand megabytes, of information. If each disk is about 10 cm thick, then if we stacked all the disks currently needed to store a human pattern on top of one another, they would reach a third of the way to the center of the galaxy-about 10,000 light-years, or about 5 years’ travel in the Enterprise at warp 9!

Retrieving this information in real time is no less of a challenge. The fastest digital information transfer mechanisms at present can move somewhat less than about 100 megabytes per second. At this rate, it would take about 2000 times the present age of the universe (assuming an approximate age of 10 billion years) to write the data describing a human pattern to tape! Imagine then the dramatic tension: Kirk and McCoy have escaped to the surface of the penal colony at Rura Penthe. You don’t have even the age of the universe to beam them back, but rather just seconds to transfer a million billion billion megabytes of information in the time it takes the jailor to aim his weapon before firing.

There are mainy other problems with transporters as well. In other words, transporters are a tough cookie!

 

 

 

 

 

 

 

 

 

 

 

 

Antimatter

 

 

 

 

 

 

 

 

 

 

 

 

We discussed this in class as well. Every particle has an antiparticle, which has opposite charge. In the case of neutral particles, they are their own antiparticle.

Antiparticles are produced by cosmic rays at the top of the atmosphere, but also by particle accelerators. In the later, magnetic fields are employed to contain the antiparticles, usually, in circles of prescribed sizes. In this way, for example, they can travel around inside a doughnut-shaped container without ever touching the walls. This principle is also used in so-called Tokomak devices (see p. 624-627 in our text) to contain the high-temperature plasmas in studies of controlled nuclear fusion.

Besides containment, another problem faces us immediately if we want to use a matter-antimatter drive: where to get the antimatter. As far as we can tell, the universe is made mostly of matter, not antimatter. We can confirm that this is the case by examining the content of high-energy cosmic rays, many of which originate well outside our own galaxy. Some antiparticles should be created during the collisions of high-energy cosmic rays with matter, and if one explores the cosmic-ray signatures over wide energy ranges, the antimatter signal is completely consistent with this phenomenon alone; there is no evidence of a primordial antimatter component.

 

 

 

 

 

 

 

 

 

 

 

 

Dilithium Crystals

 

 

 

 

 

 

 

 

 

 

 

 

The famous dilithium crystals are a crucial component of the matter-antimatter drive of the Enterprise. It would be unthinkable not to mention them, since they are a centerpiece of the warp drive and as such figure prominently in the economics of the Federation and in various plot developments. (For example, without the economic importance of dilithlum, the Enterprise would never have been sent to the Halkan system to secure its mining rights, and we would never have been treated to the “mirror universe,” in which the Federation is an evil empire!)

What do these remarkable figments of the Star Trek writers’ imaginations do? These crystals (known also by their longer formula- 2(5)6 dilithlum 2(:)l diallosilicate 1:9:1 heptoferranide) can regulate the matter-antimatter annihilation rate, because they are claimed to be the only form of matter known which is “porous” to antimatter. This can be liberally interpreted this as follows: Crystals are atoms regularly arrayed in a lattice; I assume therefore that the antihydrogen atoms are threaded through the lattices of the dilithium crystals and therefore remain a fixed distance both from atoms of normal matter and one another. In this way, dilithlum could regulate the antimatter density, and thus the matter-antimatter reaction rate.

 

 

 

 

 

 

 

 

 

 

 

 

Holodecks and Holograms

 

 

 

 

 

 

 

 

 

 

 

 

Given the rather cerebral pastimes the crew generally engage in on the holodeck, one may imagine that the hormonal instincts driving twentieth-century humanity have evolved somewhat by the twenty-third century (although if this is the case, Will Riker is not representative of his peers). Based on what is known of the world of today, we would have expected that sex would almost completely drive the holodeck. (Indeed, the holodeck would give safe sex a whole new meaning.) The holodeck represents what is so enticing about fantasy, particularly sexual fantasy: actions without consequences, pleasure without pain, and situations that can be repeated and refined at will.

However, holograms aren’t all there is to the holodeck. As we know, they have no corporeal integrity. You can walk through one-or shoot through one. This incorporeality simply will not do for the objects one would like to interact with – that is, touch on the holodeck. Here techniques that are more esoteric are required, and the Star Trek writers have turned to the transporter, or at least to the replicators, which are less sophisticated versions of the transporter. Presumably, using transporter technology, matter is replicated and moved around on the holodeck to resemble exactly the beings in question, in careful coordination with computer programs that control the voices and movements of the re-created beings. Similarly, the replicators reproduce the inanimate objects in the scene – tables, chairs, and so forth. This “holodeck matter” owes its form to the pattern held in the replicator buffer. When the transporter is turned off or the object is removed from the holodeck, the matter can then disassemble as easily as it would if the pattern buffer were turned off during the beaming process. Thus, creatures created from holodeck matter can be trapped on the holodeck.

So here is how I envisage the holodeck: holograms would be effective around the walls, to give one the impression of being in a three-dimensional environment that extended to the horizon, and the transporter-based replicators would then create the moving “solid” objects within the scene. Since holography is realistic, while transporters are not, one would have to find some other way of molding and moving matter around in order to make a workable holodeck. Still, one out of two technologies in hand isn’t bad.

 

 

 

 

 

 

 

 

 

 

 

 

Other Intelligent Life in the Universe?

 

 

 

 

 

 

 

 

 

 

 

 

 
 "It's difficult to work in a group when
 you are omnipotent."
    -Q, upon joining the crew of the
              Enterprise, in "Deja Q"

Restless aggression, territorial conquest, and genocidal “annihilation … whenever possible…. The colony is integrated as though it were in fact one organism ruled by a genome that constrains behavior as it also enables it…. The physical superorganism acts to adjust the demographic mix so as to optimize its energy economy… The austere rules allow of no play, no art, no empathy.”

The Borg are among the most frightening, and intriguing, species of alien creature ever portrayed on the television screen. What makes them so fascinating, from my point of view, is that some organism like them seems plausible on the basis of natural selection. Indeed, although the paragraph quoted above provides an apt description of the Borg, it is not taken from a Star Trek episode. Rather it appears in a review of Bert Holldobler and Edward O. Wilson’s Journey to the Ants, and it is a description not of the Borg but of our own terrestrial insect friends. Ants have been remarkably successful on an evolutionary scale, and it is not hard to see why. Is it impossible to imagine a cognizant society developing into a similar communal superorganism? Would intellectual refinements such as empathy be necessary to such a society? Or would they be a hindrance?

Indeed, the “continuing mission” of the starship Enterprise is not to further explore the laws of physics but “to explore strange new worlds, to seek out new life and new civilizations.” What makes Star Trek so fascinating – and so long-lived, I suspect – is that this allows the human drama to be extended far beyond the human realm. We get to imagine how alien species might develop to deal with the same problems and issues that confront humanity. We are exposed to new imaginary cultures, new threats. It provides some of the same fascination as visiting a foreign country for the first time does, or as one sometimes gets from reading history and discovering both what is completely different and what is exactly the same about the behavior of people living centuries apart.

So, does other life, intelligent or not, exist out there? The important fact to recognize is that life did form in the galaxy at least once. I cannot overemphasize how important this is. Based on all our experience in science, nature rarely produces a phenomenon just once. We are a test case. The fact that we exist proves that the formation of life is possible. Once we know that life can originate here in the galaxy, the likelihood of it occurring elsewhere is vastly increased. (Of course, as some evolutionary biologists have argued, it need not develop an intelligence.)

Such a question can be computed numerically, by assigning probabilities to various requirements: the universe is certainly very large and old enough for the task at hand, with billion billion billion stars in it. If we try to estimate how many of these are like our sun, then how many have planets around them that are not too close, not too far, not too cold, not too hot, and with an atmosphere, the number we are left with is still very large! So the chances of life elsewhere, are pretty good.

What are some of the more important details? Well, an atmosphere containing oxygen certainly helps. Only when there is sufficient oxygen in the atmosphere can ozone form. Ozone, as we are becoming more and more aware, is essential to life on Earth because it screens out ultraviolet radiation, which is harmful to most life-forms. It is therefore not surprising that the rapid explosion of life on Earth began only after oxygen was abundant.

Recent measurements indicate that oxygen began building up in the atmosphere about 2 billion years ago, and reached current levels within 600 million years after that. While oxygen had been produced earlier, by photosynthesis in the blue-green algae of the primordial oceans, it could not at first build up in the atmosphere. Oxygen reacts with so many substances, such as iron, that whatever was photosynthetically produced combined with other elements before it could reach the atmosphere. Eventually, enough materials in the ocean were oxidized so that free oxygen could accumulate in the atmosphere. (This process never took place on Venus because the temperature was too high there for oceans to form, and thus the life-forming and life-saving blue-green algae never arose there.)

So, after conditions were really ripe for complex life-forms, it took about a billion years for them to evolve. Of course, it is not clear at all that this is a characteristic timescale. Accidents such as evolutionary wrong turns, climate changes, and cataclysmic events that caused extinctions affected both the biological timescale and the end results.

Nevertheless, these results indicate that intelligent life can evolve in a rather short interval on the cosmic timescale – a billion years or so. The extent of this timeframe has to do with purely physical factors, such as heat production and chemical reaction rates. Our terrestrial experience suggests that even if we limit our expectations of intelligent life to the organic and aerobic – surely a very conservative assumption, and one that the Star Trek writers were willing to abandon (the silicon-based Horta is one of my favorites) – planets surrounding several-billion-year-old stars of about 1 solar mass are good candidates. And, as we saw in class, the Hubble Space Telescope has identified Proplyds (Proto-Planetary Discs) in the Orion Nebula, that show how planets are created from discs fulll of interstellar debris, surrounding a star. All the basic ingredients are out there!

There are many popular SciFi TV drama series, many of which involve extraterrestrials. TV’s X-Files is perhaps the best known series, and huge numbers flocked to the movie theaters to seeIndependence Day and Starship Troopers. Both these shows presented extraterrestrials, the usual “greys” in X-files (large black eyes, large cranium), while the ones in ID-4 looked similar, but were encased in a powerful biomechanical suit. These aliens, are conveniently hidden by the US Government in a secret location in Nevada, called Area 51. Is this scenario plausible? (Well,…)

 

In the first place, we have clearly seen how daunting interstellar space travel would be. Energy expenditures beyond our current wildest dreams would be needed – warp drive or no warp drive. Recall that to power a rocket by propulsion using matter-antimatter engines at something like 3/4 the speed of light for a 10-year round-trip voyage to just the nearest star would require an energy release that could fulfill the entire current power needs in the United States for more than 100,000 years! This is dwarfed by the power that would be required to actually warp space. Moreover, to have a fair chance of finding life, one would probably want to be able to sample at least several thousand stars. I’m afraid that even at the speed of light this couldn’t be done anytime in the next millennium.

That’s the bad news. The good news, I suppose, is that by the same token we probably don’t have to worry too much about being abducted by aliens. They, too, have probably figured out the energy budget and will have discovered that it is easier to learn about us from afar.

 

 

 

 

 

 

 

 

 

 

 

 

Star Trek Physics?

 

 

 

 

 

 

 

 

 

 

 

 

 
 "That is the exploration that awaits you!  Not mapping
 stars and studying nebula, but charting the unknown
 possibilities of existence."
              -Q to Picard, in "All Good Things  ......

In the course of more than 13 TV-years of the various Star Trek I series, the writers have had the opportunity to tap into some of the most exciting ideas from all fields of physics. Sometimes they get it right; sometimes they blow it. Sometimes they just use the words that physicists use, and sometimes they incorporate the ideas associated with them. The topics they have dealt with read like a review of modern physics: special relativity, general relativity, cosmology, particle physics, time travel, space warping, and quantum fluctuations, to name just a few.

Let’s have a look at a few more interesting ideas from modern physics which the Star Trek writers have borrowed.

 

 

 

 

 

 

 

 

 

 

 

 

Neutron Stars

 

 

 

 

 

 

 

 

 

 

 

 

These are leftovers from the collapsed core of a star that has undergone a supernova. They have as much mass as our sun, but are compressed to the size of Manhattan!

 

The Enterprise has several times encountered material expelled from a neutron star – a material that the writers have dubbed “neutronium.” Since neutron stars are composed almost entirely of neutrons held so tightly together that the star is basically one huge atomic nucleus, the name is a good one. The Doomsday machine in the episode of the same name was apparently made of pure neutronium, which is why it was impervious to Federation weapons. However, in order for this material to be stable it has to be under the incredibly high pressure created by the gravitational attraction of a stellar mass of material only 15 kilometers in radius. In the real world, such material exists only as part of a neutron star.

There are no doubt millions of neutron stars in the galaxy. Most of these are born with incredibly large magnetic fields inside them. If they are spinning rapidly, they make wonderful radio beacons. Radiation is emitted from each of their poles, and if the magnetic field is tilted with respect to the spin axis, a rotating beacon is created. On Earth, we detect these periodic bursts of radio waves, and call their sources pulsars. Rotating out in space, they make the best clocks in the universe. The pulsar signals can keep time to better than one microsecond per year. Moreover, some pulsars produce more than 1000 pulses per second. This means that an object that is essentially a huge atomic nucleus with the mass of the Sun and 10 to 20 kilometers across is rotating over 1000 times each second. Think about that. The rotation speed at the neutron star surface is therefore almost half the speed of light. Pulsars are one illustration of the fact that nature produces objects more remarkable than any Star Trek writer is likely to invent.

 

 

 

From another dimension

 

 

 

Physicists, science fiction writers and even psychiatric patients (no jokes for listing all these groups together) have all discussed additional dimensions to the four-dimensional spacetime that we reside in. In the calculation of the theoretical physicists Kaluza and Klein, the only waves that can be sent into the fifth dimension have much more energy than we can produce even in high-energy accelerators, then we cannot experience this extra dimension. The fifth dimension is thus “curled up” in a tight circle, due to gravity effects.

In spite of its intrinsic interest, the Kaluza-Klein theory cannot be a complete theory. First, it does not explain why the fifth dimension would be curled up into a tiny circle. Second, we now know of the existence of two other fundamental forces in nature beyond electro-magnetism and gravity – the strong nuclear force and the weak nuclear force. Why stop at a fifth dimension? Why not include enough extra dimensions to accommodate all the fundamental forces?

In fact, modern particle physics has raised just such a possibility. The modern effort, centered around what is called superstring theory, focused initially on extending the general theory of relativity so that a consistent theory of quantum gravity could be constructed. In the end, however, the goal of a unified theory of all interactions has resurfaced.

The challenges faced in developing a theory wherein general relativity is made consistent with quantum mechanics are enormous. The key difficulty in this effort is trying to understand how quantum fluctuations in spacetime can be handled. In elementary particle theory, quantum excitations in fields – the electric field, for example – are manifested as elementary particles, or quanta. If one tries to understand quantum excitations in the gravitational field – which, in general relativity, correspond to quantum excitations of spacetime – the mathematics leads to nonsensical predictions.

The advance of string theory was to suppose that at microscopic levels, typical of the very small scales (that is, 10^-33 cm) where quantum gravitational effects might be important, what we think of as pointlike elementary particles actually could be resolved as vibrating strings. The mass of each particle would correspond in some sense to the energy of vibration of these strings.

The reason for making this otherwise rather outlandish proposal is that it was discovered as early as the 1970s that such a theory requires the existence of particles having the properties that quantum excitations in spacetime – known as gravitons – should have. General relativity is thus in some sense imbedded in the theory in a way that may be consistent with quantum mechanics.

However, a quantum theory of strings cannot be made mathematically consistent in 4 dimensions, or 5, or even 6. It turns out that such theories can exist consistently only in 10 dimensions, or perhaps only 26! Indeed, Lieutenant Reginald Barclay, while he momentarily possessed an IQ of 1200 after having been zapped by a Cytherian probe, had quite a debate with Albert Einstein on the holodeck about which of these two possibilities was more palatable in order to incorporate quantum mechanics in general relativity.

This plethora of dimensions may seem an embarrassment, but it was quickly recognized that like many embarrassments it also presented an opportunity. Perhaps all the fundamental forces in nature could be incorporated in a theory of 10 or more dimensions, in which all the dimensions but the four we know curl up with diameters on the order of the Planck scale (10-33 cm) – as Lieutenant Barclay surmised they must – and are thus unmeasurable today.

Alas, this great hope has remained no more than that. We have, at the present time, absolutely no idea whether the tentative proposals of string theory can produce a unified Theory of Everything. Also, just as with the Kaluza-Klein theory, no one has any clear notion of why the other dimensions, if they exist, would curl up, leaving four-dimensional spacetime on large scales.

 

 

 

Schrodinger’s Cat

 

 

 

A characteristic property of subatomic particles is their “spin”, which is a quantum number. This spin can either be “up” or “down”. Once you make a measurement of the spin, the quantum mechanical wavefunction of the particle (which describes it’s condition completely) it will from then on include only the component you measured the particle to have; if you measured spin up, you will go on measuring this same value for this particle.

This picture presents problems. How, you may ask, can the particle have had both spin up and spin down before the measurement? The correct answer is that it had neither. The configuration of its spin was indeterminate before the measurement. (Isn’t Quantum Mechanics wonderful?)

The fact that the quantum mechanical wavefunction that describes objects does not correspond to unique values for observables is especially disturbing when one begins to think of living objects. There is a famous paradox called “Schrodinger’s cat.” (Erwin Schrodinger was one of the young Turks in their twenties who, early in this century, helped uncover the laws of quantum mechanics. The equation describing the time evolution of the quantum mechanical wavefunction is known as Schrodinger’s equation.) Imagine a box, inside of which is a cat. Inside the box, aimed at the cat, is a gun, which is hooked up to a radioactive source. The radioactive source has a certain quantum mechanical probability of decaying at any given time. When the source decays, the gun will fire and kill the cat. Is the wavefunction describing the cat, before I open the box, a linear superposition of a live cat and a dead cat? This seems absurd.

Similarly, our consciousness is always unique, never indeterminate. Is the act of consciousness a measurement? If so, then it could be said that at any instant there is a nonzero quantum mechanical probability for a number of different outcomes to occur, and our act of consciousness determines which outcome we experience. Reality then has an infinite number of branches. At every instant our consciousness determines which branch we inhabit, but an infinite number of other possibilities exist a priori.

However, we cannot jump from one possibility to another, as some Star Trek episodes have suggested with parallel worlds. Once we make a measurement (i.e. experience a particular world) we fix reality. Quantum mechanics demands this. So, fortunately or unfortunately, you will never get to meet that evil twin of yours, who resides in a parallel universe.

 

 

 

Star Trek Blunders

 

 

 

Star Trek physics must be taken with a grain of salt. While finding obscure technical flaws with each episode is a universal trekker pastime, it is not the subtle errors that physicists and physics students seem to relish catching. It is the really big ones that are most talked about over lunch and at coffee breaks during professional meetings. (Nerdy, huh?)

To be fair, sometimes a sweet piece of physics in the series – even a minor moment – can trigger a morning-after discussion at coffee time. Indeed, I remember vividly the day when a former graduate student of mine at Yale – Martin White, who is now at the University of Chicago – came into my office fresh from seeing Star Trek VI: The Undiscovered Country. I had thought we were going to talk about gravitational waves from the very early universe. But instead Martin started raving about one particular scene from the movie-a scene that lasted all of about 15 seconds. Two helmeted assassins board Chancellor Gorkon’s vessel – which has been disabled by photon torpedoes fired from the Enterprise and is thus in zero gravity conditions – and shoot everyone in sight, including Gorkon. What impressed Martin and, to my surprise, a number of other physics students and faculty I discussed the movie with, was that the drops of blood flying about the ship were spherical. On Earth, all drops of liquid are tear-shaped, because of the relentless pull of gravity. In a region devoid of gravity, like Gorkon’s ship, even tears would be spherical. Physicists know this but seldom have the opportunity to see it. So by getting this simple fact perfectly right, the Star Trek special effects people made a lot of physics types happy. It doesn’t take that much….

But let’s have a look at a few prominent physics blunders by the Star Trek writers. This is not meant as an excersise to make fun of the writers; however, this is a physics course, and it’s good practice to think in correct physics terms. Afterall, completely correct physics often makes for poor Hollywood drama.

 

 

 

“In Space, No One Can Hear You Scream”

 

 

 

The promo for the movie Alien got it right, but Star Trek usually doesn’t. Sound waves DO NOT travel in empty space! [A flunking grade will be given to anyone who forgets this in the final exam!] Indeed, in many Star Trek episodes, sure enough, kaboom! Example from the most recent Star Trek movie, Generations. There, even a bottle of champagne makes noise when it explodes in space.

In fact, a physics colleague, Mark Srednicki of U.C. Santa Barbara, brought to my attention a much greater gaffe in one episode, in which sound waves are used as a weapon against an orbiting ship. As if that weren’t bad enough, the sound waves are said to reach “18 to the 12th power decibels.” What makes this particularly grate on the ear of a physicist is that the decibel scale Is a logarithmic scale, like the Richter scale for seismic events. This means that the number of decibels already represents a power of 10, and they are normalized so that 20 decibels is 10 times louder than 10 decibels, and 30 decibels is 10 times louder again. Thus, 18 to the 12th power decibels would be (10^18)^12, or 1 followed by 11,568,313,814,300 zeroes times louder than a jet plane!

 

 

 

Faster than a Speeding Phaser

 

 

 

While faster-than-light warp travel is something we must live with in Star Trek, such a possibility relies on all the subtleties of general relativity and exotic new forms of matter, as I have described. But for normal objects doing everyday kinds of things, light speed is and always will be the ultimate barrier. Sometimes this simple fact is forgotten. In a wild episode called “Wink of an Eye,” Kirk is tricked by the Scalosians into drinking a potion that speeds up his actions by a huge factor to the Scalosian level, so that he can become a mate for their queen, Deela. The Scalosians live a hyperaccelerated existence and cannot be sensed by the Enterprise’s crew. Before bedding the queen, Kirk first tries to shoot her with his phaser. However, since she can move in the wink of an eye by normal human standards, she moves out of the way before the beam can hit her. Now what is wrong with this picture? The answer is, Everything! For this to be true within the framework of special relativity, she has to be moving so fast, that her clock will be slowed down by a factor of 300 million, and thus for her it takes 10 years for what takes a fraction of a second in Enterprise time!

OK, let’s forgive the Star Trek writers this lapse. Nevertheless, there is a much bigger problem, which is impossible to solve and which several physicists I know have leapt upon. Phasers are, we are told, directed energy weapons, so that the phaser beam travels at the speed of light. Sorry, but there is no way out of this. If phasers are pure energy and not particle beams, as the Star Trek technical manual states, the beams must move at the speed of light. No matter how fast one moves, even 1 if one is sped up by a factor of 300 million, one can never move out of the way of an oncoming phaser beam. Why? Because in order to know it is coming, you have to first see the gun being fired. But the light that allows you to see this travels at the same speed as the beam. Put simply, it is impossible to know it is going to hit you until it hits you! As long as phaser beams are energy beams, there is no escape.

 

 

 

Crack in a Black Hole?

 

 

 

In an episode of Voyager, the ship becomes trapped in a black hole, and escapes through a crack in its event horizon. This saves the day for the Voyager but sounds particularly ludicrous to physicists. A “crack” in an event horizon is like removing one end of a circle, or like being a little bit pregnant. It doesn’t mean anything. The event horizon around a black hole is not a physical entity, but rather a location inside of which all trajectories remain inside the hole. It is a property of curved space that the trajectory of anything, including light, will bend back toward the hole once you are inside a certain radius. Either the event horizon exists, in which case a black hole exists, or it doesn’t. There is no middle ground big enough to slip a needle through, much less theVoyager.

 

 

 

How Solid a Guy is the Doctor?

 

 

 

I must admit that the technological twist I like the most in the Voyager series is the holographic doctor. There is a wonderful scene in which a patient asks the doctor how he can be solid if he is only a hologram. This is a good question. The doctor answers by turning off a “magnetic confinement beam” to show that without it he is as noncorporeal as a mirage. He then orders the beam turned back on, so that he can slap the poor patient around. It’s a great moment, but unfortunately it’s also an impossible one. As we know from class magnetic confinement works wonders for charged particles, which experience a force in a constant magnetic field that causes them to move in circular orbits. However, light is not charged. It experiences no force in a magnetic field. Since a hologram is no more than a light image, neither is the doctor.

 

 

 

Sweeping out the Baby with the Bathwater

 

 

 

In the Next Generation episode “Starship Mine,” the Enterprise docks at the Remmler Array to have a “baryon sweep.” It seems that these particles build up on starship superstructures as a result of long-term travel at warp speed, and must be removed. During the sweep, the crew must evacuate, because the removal beam is lethal to living tissue. Well, it certainly would be! The only stable baryons are (1) protons and (2) neutrons in atomic nuclei. Since these particles make up everything we see, ridding the Enterprise of them wouldn’t leave much of it for future episodes.

 

 

 

How Cold is Cold?

 

 

 

Another favorite Star Trek gaffe involves an object’s being frozen to a temperature of -295 Celsius. This is a very exciting discovery, because on the Celsius scale, absolute zero is -273. Absolute zero, as its name implies, is the lowest temperature anything can potentially attain, because it is defined as the temperature at which all molecular and atomic motions, vibrations, and rotations cease. Though it is impossible to achieve this theoretical zero temperature, atomic systems have been cooled to within a millionth of a degree above it (and as of this writing have just been cooled to 2 billionths of a degree above absolute zero). Since temperature is associated with molecular and atomic motion, you can never get less than no motion at all; hence, even 400 years from now, absolute zero will still be absolute.

 

 

 

Closing Remarks by Lawrence M. Krauss

 

 

 

So I will instead close this book where I began – not with the mistakes but with the possibilities. Our culture has been as surely shaped by the miracles of modern physics – and here I include Galileo and Newton among the moderns – as it has by any other human intellectual endeavor. And while it is an unfortunate modern misconception that science is somehow divorced from culture, it is, in fact, a vital part of what makes up our civilization. Our explorations of the universe represent some of the most remarkable discoveries of the human intellect, and it is a pity that they are not shared among as broad an audience as enjoys the inspirations of great literature, or painting, or music.

By emphasizing the potential role of science in the development of the human species, Star Trek whimsically displays the powerful connection between science and culture. While I have argued at times that the science of the twenty-third century may bear very little resemblance to anything the imaginations of the Star Trek writers have come up with, nevertheless I expect that this science may be even more remarkable. In any case I am convinced that the physics of today and tomorrow will as surely determine the character of our future as the physics of Newton and Galileo colors our present existence. I suppose I am a scientist in part because of my faith in the potential of our species to continue to uncover hidden wonders in the universe. And this is after all the spirit animating the Star Trek series. Perhaps Gene Roddenberry should have the last word. As he said on the twenty-fifth anniversary of the Star Trek series, one year before his death: “The human race is a remarkable creature, one with great potential, and I hope that Star Trek has helped to show us what we can be if we believe in ourselves and our abilities.”

Time Travel Possibilities: Review

This time travel that I refered to is the same time travel that I touched upon in my discussions on relativity.  Basically, time is relative to the person or object that measures it.  This measurement almost completely relies on the speed of the person or object.  Therefore, according to relativity, as a person approaches the speed of light the more time appears to freeze to onlookers watching the person.  For the person, however, time is at a normal pace and the person views the onlookers at going extremely fast.  Although it is technically impossible for an object to hit the speed of light, if it were possible then time would appear to absolutly freeze to the onlookers.  To illustrate, if a spaceship was able to attain the speed of light and be visible from earth, people on earth would see this spaceship is if it was at rest.

So time travel is possible, but its more of a handicap then good to astronauts.  To understand why you would have to understand the dimentions of our galaxy.  Pretend we could shrink the Earth so small that it’s size would be diminished to the size of a marble.  Place this marble on the ground and count off four inches.  This is where the moon resides in relation to the marble sized Earth.  Now keep in mind how long the trip was for us to send men on the moon.  Neglecting the time taken to build the rocketship (and keep in mind the speeds in which they traveled).  Now walk 3 miles away from this location.  What’s wrong?  Can you not see Earth anymore?  if you can’t you are doing the correct thing because three miles is a long way.  But this is the distance that Pluto sits at.  This is the last known planet in our solar system if you even count it as a planet because it is just the largest rock in a belt of asteroids.  There is nothing presently here, so there would be no reason to reside here unless it was used as a space dock where spaceships used the elements as a fuel (Low gravity is a plus as well). Now lets see, we got a marble at zero, moon at four inches and Pluto at 3 miles… so the question is how far away is the closest solar system Alpha Centuri (4.3 light years in reality or 25,000,000,000,000 miles)?  Put on your tennis shoes for this one.  The closest solar system in our tiny model would be the equivalent as a complete trip around the planet.  Feel insignificant? You should, After all when we look into the sky at this star all we see is a four year old photograph .

So at these great distances it would be extremely unrealistic to travel at speeds that are measured at anything but at lightspeed.  This is not the problem because we have designed plans for a spaceship that could travel exactly at those speeds, but these super spaceshuttles ran basically on Nuclear weapons (which is now illegal [worldwide treaty] to shoot off into space because of the fact that 10% of unmanned rockets fail which would produce a nuclear blast in the atmosphere [not good!]).  The true problem in travel to other solar systems is relativity.  By the time the Astronauts returned from alpha centuri relatively un-aged, the world could have passed thousands of years here on Earth.  Think of it, the fact that we even sent astronauts could be forgotten.  Then there is the problem that the astronauts would not know anyone.  Maybe the computers are so outdated that the data is untransferable.  The idea I’m getting at here is so much could happen in thousands of years.  On top of all this I’m ignoring the problems of space dementia, bone loss due to the lack of gravity, spare parts for the ship, food, waste, mechanical problems, computer problems and cost (and since we’re talking about time travel we’ll leave it to that)

So how have scientists decided to solve this problem?  Here comes a huge headache for the faint hearted.  Time travel back in time by exceeding the speed of light.  What?  Past the speed of light! I know what you are thinking… I just spent half an hour learning that the speed of light was the universal speed limit enforced by spacetime.  It still is, but there might be a trick of hitching a ride on something that doesn’t quite follow spacetime rules.  The answer to this is what scientists call a wormhole.

Think of this concept as the following example.  Imagine you need to traverse the super wavy Lombard street in San Francisco.  One way is to follow the law and walk down the road following all the turns.  The other way is against the law, but still doable.  Construct a wire grapple 5 feet off the ground, grapple onto it and slide down.  Both get to the bottom, but the wire way is fastest.  On a galactic view you can beat your own light that is following the curvature of spacetime with your shortcut.  So how do we construct this wormhole.  The answer is all theoretical.  Take two blackholes singularities and connect them together.  When this happens they are supposed to hypothetically annihilate each other giving a moment when a wormhole exists, but only for a moment because they will quickly pinch off and reform their singularities.  Although this theory is allowed by the theory of relativity, it would take a massively  negatively  reversible field to do it-which scientists have no idea how to do it.

There is one more theory as well, but this one is even more confusing.  You enter the very center of a large gas planet like Jupiter without bursting into flames (no gravity in the center because all points of the planet attract you which cancels them out).  Then you collapse the planet to near black hole limit around you in a perfectly round shell.  Then because of the warping and fall of light into the black hole you will have a time machine.  The problem is that a planet the mass of Jupiter would not give any more space in the center, while still working, then ten feet. Implausible? Yes. Possible?

Yes.

Wormhole Function As Time Machine

WORMHOLE

White holes perform exactly opposite of black holes. A white hole emits everything, and has no gravity. Although white holes are not believed to exist they are mathematically possible. The possibility of white holes has been proven using Einstein’s Theory of Relativity (Bunn). In short, the Theory of Relativity is a mathematical formula dealing with time, energy, speed, and mass. The possibility of white hole uses the time portion of relativity. If white holes do exist they might be in another universe, in a separate space and time from our own (Hawking, Black Holes 116). White holes are the output of black holes. Where a white hole spits things out is unknown (“Black”).

See video

The existence of black holes is real. White holes are mathematically possible and now the wormhole enters the picture. Wormholes are a special link between a black and a white hole. The special link is made when both the black and white hole are rotating or spinning in the same direction. If the black hole is spinning, matter will miss the singularity in the black hole. Second, both the black hole and the white hole must have the same electrical charge. Identical electrical charges are important such that matter is not changed passing through the wormhole. As a result of the special conditions, matter enters a black hole, misses the singularity, and pops out the white hole. The entrance of the black hole is in one place and time; the exit of the white hole is in an another space and time. All wormholes function as time machines (“Tech”).

The illustration left shows a basic wormhole. On the topside of the plane is a black hole. On the bottom side of the plane is white hole. The entire assembly is called a wormhole. The plane represents space-time, notice how space-time is warped. The light emitted from a star is warped as it travels to us. The gravity of large objects causes the curvature of space-time. For example, to get from Earth to Alpha Centauri, a distance of 20 million million miles would have to be traveled around the curve. By taking a short cut such as a wormhole, only a few million miles would have to be traversed (Hawking, Illustrated 201). The wormhole is direct, whereas the curved route is much longer. The only other way to cut down on time is to travel faster than the speed of light. The Theory of Relativity forbids this outlaw speed. The speed of light limit has not been violated, because a short cut is taken. Relativity has no problem with the short cut. Travelling through a wormhole is not travelling faster, just covering a shorter distance. Like a rubber band, space and time are stretched inside the wormhole. Traveling one mile in a wormhole would be equivalent to millions of miles outside the wormhole. One could start a trip into one wormhole, and return via another wormhole. If these wormholes are set up correctly, the return time could be before one even departed (Hawking, Illustrated 202).

Wormholes could be the best method of travel to far distant galaxies. It would take a hundred thousand years traveling to the center of our galaxy and back at the speed of light. Taking a wormhole could get us back in time for dinner. As it stands now, wormholes are not within our reach. If a wormhole does exist, it most likely is not stable. If anything were to disturb a wormhole, such as a person, it would collapse. Wormholes are half black holes hence; the collapse of wormhole would result in entering a black hole. If a wormhole could be stabilized, theoretically we could use one for time travel. Our understanding of the universe disables us from the skills needed to stabilize wormholes. Most scientists do not believe wormholes exist because no proof has been found. At one time scientists did not believe humans could fly to the moon, but that was accomplished in the late 1960’s. Our rate of scientific advancement is such, that in some distant future we may find a wormhole.

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