CHAPTER TEN
Impossibilities:
The
Undiscoverable Country
Geordi: “Suddenly it's like the laws of physics went right out the window.” Q: “And why shouldn't they? They're so inconvenient!” In “True Q” “Bones, I want the impossible checked out too.” Kirk to McCoy, in “The Naked Time” “What you're describing is ... nonexistence!” Kirk to Spock, in “The Alternative factor”
Any sensible trekker-physicist recognizes that Star Trek must be taken with a rather large grain of salt. Nevertheless, there are times when for one reason or another the Star Trek writers cross the boundaries from the merely vague or implausible to the utterly impossible. While finding even 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.
To be fair, sometimes a sweet piece of physics in the serieseven a minor momentcan 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 moviea scene that lasted all of about 15 seconds. Two helmeted assassins board Chancellor Gorkon's vesselwhich has been disabled by photon torpedoes fired from the Enterprise and is thus in zero gravity conditionsand 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 the mistakes also keep us going. In fact, what may be the most memorable Star Trek mistake mentioned by a physicist doesn't involve physics at all. It was reported to me by the particle physicist (and science writer) Steven Weinberg, who won the Nobel Prize for helping develop what is now called the Standard Model of elementary particle interactions. As I knew that he keeps the TV on while doing intricate calculations, I wrote to him and asked for his Star Trek memories. Weinberg replied that “the main mistake made on Star Trek is to split an infinitive every damn time: To boldly go ... !”
More often than not, though, it is the physics errors that get the attention of physicists. I think this is because these mistakes validate the perception of many physicists that physics is far removed from popular culturenot to mention the superior feeling it gives us to joke about the English majors who write the show. It is impossible to imagine that a major motion picture would somehow have Napoleon speaking German instead of French, or date the signing of the Declaration of Independence in the nineteenth century. And so when a physics mistake of comparable magnitude manages to creep into what is after all supposed to be a scientifically oriented series, physicists like to pounce. I was surprised to find out how many of my distinguished colleaguesfrom Kip Thorne to Weinberg to Sheldon Glashow, not to mention Stephen Hawking, perhaps the most famous physicist trekker of allhave watched the Star Trek series. Here is a list of my favorite blunders, gleaned from discussions with these and other physicists and e-mail from techni-trekkers. I have made an effort here to focus mostly (but not
exclusively) on blunders of “down-to-Earth physics.” Thus, for example, I don't address such popular complaints as “Why does the starlight spread out whenever warp speed is engaged?” and the like. Similarly, I ignore here the technobabblethe indiscriminant use of scientific and pseudoscientific terminology used during each episode to give the flavor of futuristic technology. Finally, I have tried for the most part to choose examples I haven't discussed before.
“IN SPACE, NO ONE CAN HEAR YOU SCREAM”: The promo for Alien got it right, but Star Trek usually doesn't. Sound waves DO NOT travel in empty space! Yet when a space station orbiting the planet Tanuga IV blows up, from our vantage point aboard the Enterprise we hear it as well as see it. What's worse, we hear it at the same time as we see it. Even if sound waves could travel in space, which they can't, the speed of a pressure wave such as sound is generally orders of magnitude smaller than the speed of light. You don't have to go farther than a local football game to discover that you see things before you hear them.
A famous experiment in high school physics involves putting an electric buzzer in a bell jar, a glass container from which the air can be removed by a pump. When the air is removed, the sound of the buzzer disappears. As early as the seventeenth century, it was recognized that sound needed some medium to travel in. In a vacuum, such as exists inside the bell jar, there is nothing to carry the sound waves, so you don't hear the buzzer inside. To be more specific, sound is a pressure wave, or disturbance, which moves as regions where the pressure is higher or lower than the average pressure propagate through a medium. Take away the medium, and there is no pressure to have a disturbance in. Incidentally, the bell jar example was at the origin of a mystery I discussed earlier, which was very important in the history of physics. For while you cannot hear the buzzer, you can still see it! Hence, if light is supposed to be some sort of wave, what medium does it travel in which isn't removed when you remove the air? This was one of the prime justifications for the postulation of the aether.
I had never taken much notice of the sound or lack of it in space in the series. However, after Steven Weinberg and several others mentioned that they remembered sound associated with Star Trek explosions, I checked the episode I had just watched“A Matter of Perspective,” the one in which the Tanuga IV space station explodes.
Sure enough, kaboom! The same thing happened in the next episode I watched (when a shuttle which was carrying stolen trilithium crystals away from the Enterprise blew up with a loud bang near the planet Arkaria). I next went to 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. 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!
What has been noticed by some trekkers is that the accelerated existence required for Deela to move significantly in the time it would take a phaser beam to move at the speed of light across the room would make the rest of the episode impossible. Light speed is 300 million meters per second. Deela is about a meter or so away from Kirk when he fires, implying a light travel time of about 1/300 millionth of a second. For this time to appear to take a second or so for her, the Scalosian clock must be faster by a factor of 300 million. However, if this is so, 300 million Scalosian seconds take 1 second in normal Enterprise time. Unfortunately, 300 million seconds is about 10
years.
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 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. A similar problem involving the attempt to beat a phaser beam is found in the Voyager episode “The Phage.”
Sometimes, however, it is the Star Trek critics who make the mistakes. I was told that I should take note of an error in Generations in which a star shining down on a planet is made to disappear and at the same instant the planet darkens. This of course is impossible, because it takes light a finite time to travel from the star to the planet. Thus, when I turn off the light from a star, the planet will not know it for some time. However, in Generations, the whole process is seen from the surface of the planet. When viewed from the planet, the minute the star is seen to implode, the planet's surface should indeed get dark. This is because both the information that the star has imploded and the lack of light will arrive at the planet at the same time. Both will be delayed, but they will be coincident!
Though the writers got this right, they blew it by collapsing the delay to an unreasonably short time. We are told that the probe that will destroy the star will take only 11 seconds to reach it after launch from the planet's surface. The probe is traveling at sublight speeds as we can ascertain because it takes much less than twice that time after the probe is launched for those on the planet to see the star begin to implode, which indicates that the light must have taken fewer than 11 seconds to make the return journey. The Earth, by comparison, is 8 light-minutes from our Sun, as I have noted. If the Sun exploded now, it would take 8 minutes for us to know about it. I find it hard to believe that the Class M planet in Generations could exist at a distance of 10 light-seconds from a hydrogen-burning star like our Sun. This distance is about 5 times the size of the Sunfar too close for comfort.
IF THE PLOT ISN'T CRACKED, MAYBE THE EVENT HORIZON IS: While I said I wouldn't dwell on technobabble, I can't help mentioning that the Voyager series wins in that department hands down. Every piece of jargon known to modern physics is thrown in as the Voyager tries to head home, traveling in time with the regularity of a commuter train. However, physics terms usually mean something, so that when you use them as a plot device you are bound to screw up every now and then. I mentioned in chapter 3 that the “crack” in the event horizon that saves the day for the Voyager (in the feckless “Phage” episode) 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 the Voyager.
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 I described in chapter 6, 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.
WHICH IS MORE SENSITIVE, YOUR HANDS OR YOUR BUTT? OR, TO INTERPHASE, OR NOT TO INTERPHASE: Star Trek has on occasion committed what I call the infamous Ghost error. I refer to a recent movie by this name in which the main character, a ghost, walks through walls and cannot lift objects because his hand passes through them. However, miraculously, whenever he sits on a chair or a couch, his butt manages to stay put. Similarly, the ground seems pretty firm beneath his feet. In the last chapter, I described how Geordi
LaForge and Ro Laren were rendered “out of phase” with normal matter by a Romulan “interphase generator.” They discovered to their surprise that they were invisible and could walk through people and walls leading Ro, at least, to believe that she was dead (perhaps she saw a replay of Ghost at some old movie house in her youth). Yet Geordi and Ro could stand on the floor and sit on chairs with impunity. Matter is matter, and chairs and floors are no different from walls, and as far as I know feet and butts are no more or less solid than hands.
Incidentally, there is another fatal flaw associated with this particular episode which also destroys the consistency of a number of other Star Trek dramas. In physics, two things that both interact with something else will always be able to interact with each other. This leads us full circle back to Newton's First Law. If I exert a force on you, you exert an equal and opposite force on me. Thus, if Geordi and Ro could observe the Enterprise from their new “phase,” they could interact with light, an electromagnetic wave. By Newton's Law if nothing else, they in turn should have been visible. Glass is invisible precisely because it does not absorb visible light. In order to seethat is, to sense lightyou have to absorb it. By absorbing light, you must disturb it. If you disturb light, you must be visible to someone else. The same goes for the invisible interphase insects that invaded the Enterprise by clinging to the bodies of the crew, in the Next Generation episode “Phantasms.” The force that allows them to rest on normal matter without going through it is nothing other than electro-magnetismthe electrostatic repulsion between the charged particles making up the atoms in one body with the atoms in another body. Once you interact electromagnetically, you are part of our world. There is no such thing as a free lunch.
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?: The favorite Star Trek gaffe of my colleague and fellow Star Trek aficionado Chuck Rosenblatt 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.
1 HAVE SEEN THE LIGHT!: I am embarrassed to say that this obvious error, which I should have caught myself, was in fact pointed out to me by a first-year physics student, Ryan Smith, when I was lecturing to his class and mentioned that I was writing this book. Whenever the Enterprise shoots a phaser beam, we see it. But of course this is impossible unless the phaser itself emits light in all directions. Light is not visible unless it reflects off something. If you have ever been to a lecture given with the help of a laser pointergenerally, these are helium- neon red lasersyou may recall that you see only the spot where the beam hits the screen, and not anything in between. The only way to make the whole beam visible is to make the room dusty, by clapping chalkboard erasers together, or something like that. (You should try this sometime; the light show is really quite spectacular.) Laser light shows are created by bouncing the laser light off either smoke or water. Thus, unless empty space is particularly dusty, we shouldn't see the phaser beam except where it hits.
ASTRONOMERS GET PICKY: Perhaps it is not surprising to find that the physics errors various people find in the series are often closely related to their own areas of interest. As I polled people for examples, I invariably got responses that bore a correlation to the specific occupations of those who volunteered the information. I received several responses by e-mail from astronomer-trekkers who reacted to several subtle Star Trek errors. One astronomy student turned a valiant effort by the Star Trek writers to use a piece of real astronomy into an error. The energy-eating life-form in “Galaxy's Child” is an infant space creature, who mistakes the Enterprise for its mother and begins draining its energy. Just in the nick of time LaForge comes up with a way to get the baby to let go. The baby is attracted to the radiation the Enterprise is emitting, at a 21cm wavelength. By changing the frequency of the emission, the crew “spoils the milk,” and the baby lets go. What makes this episode interesting, and at the same time incorrect, is that the writers picked up on a fact I mentioned in chapter 8 namely, the 21- cm radiation is a universal frequency emitted by hydrogen, which astronomers use to map out interstellar gas.
However, the writers interpreted this to mean that everything radiates at 21 cm, including the Enterprise. In fact, the atomic transition in hydrogen responsible for this radiation is extremely rare, so that a particular atom in interstellar space might produce such radiation on average only once every 400 years. However, because the universe is filled with hydrogen, the 21-cm signal is strong enough to detect on Earth. So, in this case, I would give the writers A for effort and reduce this grade to B+ for the misinterpretationbut I am known as an easy grader.
A NASA scientist pointed out an error I had missed and which you might expect someone working for NASA to recognize. It is generally standard starship procedure to move into geosynchronous orbit around planetsthat is, the orbital period of the ship is the same as that of the planet. Thus the ship should remain above the same place on the planet's surface, just as geosynchronous weather satellites do on Earth. Nevertheless, when the Enterprise is shown orbiting a planet it is usually moving against the background of the planet's surface. And indeed, if it is not in a geosynchronous orbit, then you run into considerable beaming-up problems.
THOSE DARNED NEUTRINOS: I suppose I can't help but bring up neutrinos again. And since I have skipped lightly over Deep Space Nine in this book perhaps it is fair to finish with a blooper from this seriesone I was told about by David Brahm, another physicist trekker. It seems that Quark has gotten hold of a machine that alters the laws of probability in its vicinity. One can imagine how useful this would be at his gambling tables, providing the kind of unfair advantage that a Ferengi couldn't resist. This ruse is discovered, however, by Dax, who happens to analyze the neutrino flux through the space station. To her surprise, she finds that all the neutrinos are coming through left-handedthat is, all spinning in one direction relative to their motion. Something must be wrong! The neutrinos that spin in the opposite direction seem to be missing!
Unfortunately, of all the phenomena the Star Trek writers could have chosen to uncover Quark's shenanigans, they managed to pick one that is actually true. As far as we know, neutrinos are only left-handed! They are the only known particles in nature that apparently can exist in only one spin state. If Dax's analysis had yielded this information, she would have every reason to believe that all was as it should be.
What makes this example so poignant, as far as I am concerned, is exactly what makes the physics of Star Trek so interesting: sometimes truth is indeed stranger than fiction.