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"Light Barrier" bothers me

As tachyons have not been shown to exist, I see no reason not to use that name until such time as tachyons are actually found.

What problems do you have with those gamma numbers I have listed above? I obtained those by plugging in the numbers into the same equation used to determine the gamma factor for slower than light objects. Seems Heretic Keklas Rekoblah seems concerned about whether tachyons can actually be found in the real universe. He mentioned that modern theory doesn't call for them, well so what? Its darn useful to have them in a science fiction campaign, whether contemprary real life physicists believe they exist or not. I've heard that according to the theory that faster tachyons are supposed to be less energetic than slower ones just above the speed of light. The numbers I have plotted above seem to bear this out, and besides the tachyons that move at infinite speed have zero energy, seems fairly convenient that at such a speed they do not exist. It would appear that these tachyons do not present time travel problem unless someone would acquire a negative energy source to generate them, but I imagine the process would involve first converting slower than light particles into energy and then converting that energy into tachyons. Never mind that no current experiments have done this, the assumption being that scientists in the future have found away. Probably alot of energy gets wasted in the process, but some of the energy goes to form tachyons. The high amount of energy involved would produce a tachyon just above the speed of light. These slow tachyons would have to be accelerated in an acceleration ring, lets assume they have some sort of charge and can be manipulated by magnetic fields. The tachyons would be accelerated up to the point where they can barely be detected.If you accelerated the tachyons to 1,387,584,00 times the speed of light, you could send a tachyon message to Alpha Centauri with a 0.2 second time delay, crossing 4.4 light years every 0.1 seconds, I think that would be acceptable for real time communications.

Let me try to rewrite the formula so that it produces the same results for slower than light but doesn't deal with imaginary numbers.

The original formula is:
gamma = 1 / square_root( 1 - (V^2/c^2) )

The modified formula is this:
gamma = 1 / square_root( Absolute_Value(1 - (V^2/c^2) ) )

Now both formulas produce the same results for slower than light particles, and since tachyons have not been detected, we don't know which one of the two formulas would hold for faster than light particles. Since we don't know what an imaginary gamma factor is, I'me inclined to go with the second formula even though there is no way to prove which one of the two formulas is the correct one, they both work equally well in the slower than light regime. It could simply be that since no tachyons were ever discovered, the first formula worked well enough and there was no need to modify it to account for faster than light particles.

For tachyons that have negative energy simply place a minus sign in front of the gamma factor thus computed.

I think most tachyon acceleratetors would have trouble accelerating an tachyon to infinite speed and beyond, as the relative mass of the particles approaches zero, so would the devices ability to detect it and contain it. A massless particle would be deflected toward the center of the ring since even the slightest force would propell it in the direction of that force, while the particles inertia would be zero with a zero mass. A tachyon accelerated to a high enough velocity would escape the confinement ring and it would be lost.

I think a tachyon communicator would involve an energy to tachyon machine, and then a particle accelerator, and once the required velocity is reached, a beam of tachyons would be released towards the target system where a receiver would pick up the signal and a similar machine would generate a tachyon stream back for a reply allowing two-way communications. According to some, high velocity sublight frames of reference, some tachyon streams would appear to go back in time, but most of the stars in the galaxy travel at the same speed, and there would not be any going at 99.9999 percent of the speed of light that could perceive this. Works well for a science fiction campaign. Any more problems with this?
 
Originally posted by Paul Snow:


It doesn't seem helpful to instead try to achieve believability by choosing to use words and ideas that are not congruent with current scientific understanding and usage. (i.e. photons must have mass.. NO. No No ...)

Paul Snow (real physicist)
Was Einstein wrong about E=mc^2 then?
A photon swallowed by a black hole increases the black hole's mass, doesn't it? If it does, the the photon must have had some mass in order to have added some to the black hole.

What photons don't seem to possess is inertia.

Photons always move at the speed of light. The phenomina of glass slowing them down has something to do with the atoms interfereing with the path of the light, and differeing wavelengths of light get slow down to different degrees. A photon in a vacuum cannot be accelerated of slowed down though, it has a wavelength that can be lengthened or shortened, but you cannot apply a force on it that would change its velocity in a vaccum.
 
"Here is my gamma values again. Notice the i at the end of the gamma values to FTL velocities, this indicates that they are imaginary numbers."
*AHEM* "Here ARE my gamma values again..." Keep the verb in context with the plural nature of the subject.

What makes them imaginary? I still see only real-number scalars. Merely pasting the letter "i" in front of a number does not make it imaginary. There has to be a mathematical basis for it.

Now if by "imaginary" you mean "fantasy," then you are on target, as those velocities can not be achieved by any means known to science.

Also, merely stating a wish for trans-luminary velocities does not make them possible. Show some real mathematics; something that I can show my colleagues without causing them to break into laughter.

"Was Einstein wrong about E=mc^2 then?"
{Fallacy of Appeal To Authority}

No, but your applications of it are inappropriate, if not entirely far-fetched.

"A photon swallowed by a black hole increases the black hole's mass, doesn't it?"
{Fallacy of Equivocation}

No. Photons have no rest mass; matter does. Matter increases a black hole's mass. When a photon falls into a black hole, it increases the energy level of that black hole. This is translated as an increase in angular momentum, not mass. However, an increase in mass does decrease the Schwarzschild Radius, which in turn increases the angular momentum, accomplishing much the same thing. So I can see where your confusion originates.

(Dr. Snow; please correct me if I'm wrong.)

- Keklas Rekobah (A Real Electrical Engineer, with a minor in Physics)
 
Originally posted by Heretic Keklas Rekobah:
What makes them imaginary? I still see only real-number scalars. Merely pasting the letter "i" in front of a number does not make it imaginary.
Right, you normally put the 'i' after a number. In math, 'i' is a constant equal to the square root of -1; by definition, any real number multiplied by i becomes imaginary (and the sum of a real number and an imaginary number is a complex number).

Now, if a tachyon has an imaginary rest mass, it will have a real energy when moving at FTL velocities. The math on that is solid enough, if not terribly useful -- if you propose the existence of a particle with imaginary rest mass, it will naturally only travel FTL, but there is no reason to presume that such a particle exists or can exist.
 
Can you think of a better FTL Communication system? Tachyons don't invoke a higher dimension or a special kind of "Space" such as jump space or hyperspace.

One can write definite rules for an FTL communications system based on the properties of tachyons. The faster the tachyon, the lower the energy and the harder it is to detect. If you want to communicate across interstellar distances in real time, the tachyons need to move at billions of times the speed of light. The gamma factor of a particle moving this fast is very small, so the energy associated with it is very small as well, it would still take enourmous energy to accelerate a tachyon from just above the speed of light to billions of times the speed of light, not as much as you might think due to its diminishing relative mass, but still quite a bit. Most of the energy in accelerating the tachyon would go towards accelerating the particle to 1.5 times the speed of light, after that it becomes much easier to reach 1,000,000,000c. As the mass of the particle diminishes it becomes easier to accelerate, but on the other side of the ledger much harder to detect. The device that detects these ultra fast tachyons would have to be ultra sensitive to seperate them out from the cosmic background radiation.
 
Another problem is that the tachyons wouldn't move at a fixed velocity, for instance the one that comes next might move faster than the one that came prior, the message might get jumbled if the tachyons arrive out of order, this may tend to limit the baud rate as tachyons may have to be sererated out so that later ones don't catch up with previous ones.

You see, I'm developing a logical tachyon communication system. Higher bit rates of transmission require more precise fine tuning of the tachyon's exit velocity.

I presume that tachyons like matter and antimatter are created at high energy levels, thus at speed close to that of light but on the other side of the light barrier.

In fact tachyons might even have been created in today's particle accelerators, but their velocities might be too close to that of light to be distinguished.

Smash two particles together and out of that particle shower might come a tachyon, but the tachyon might be traveling so close to the speed of light that its hard to tell whether its traveling over or under that speed. I don't know of any process that would create stationary antimatter atoms, they are always created at hgh velocity levels. likewise with tachyons, they would be created at velocities near the speed of light and would need to be accelerated more to be made useful for interstellar communication. Also tachyons might come in two types tachyons and antitachyons, those two have to be seperated and kept a part otherwise they'd annhilate and form gamma rays that travel merely at the speed of light.
 
A photon in a vacuum cannot be accelerated of slowed down though, it has a wavelength that can be lengthened or shortened, but you cannot apply a force on it that would change its velocity in a vaccum.
In vacuum, when the velocity of the wave is constant at c; the wavelength and frequency are linked and constant. They can't be changed.


Originally posted by Space Cadet:
Was Einstein wrong about E=mc^2 then?
A photon swallowed by a black hole increases the black hole's mass, doesn't it? If it does, the the photon must have had some mass in order to have added some to the black hole.


You really don't get the idea of the mass-energy equivalence theorem. If the mass were conserved in the process it would be on both sides of the equation. An equivalence isn't the same as conservation. Mass is not conserved in process; it is not in the photon to start with.

Answer me this. If you eat a donut and gain weight. Does this mean that the donut contained some of you before you ate it?
 
Originally posted by Space Cadet:
Can you think of a better FTL Communication system? Tachyons don't invoke a higher dimension or a special kind of "Space" such as jump space or hyperspace.
Any sort of FTL communication involves some sort of handwave that isn't supported by Physics As We Know It. You have some choice as to what the handwave is.
 
Originally posted by Anthony:
</font><blockquote>quote:</font><hr />Originally posted by Space Cadet:
Can you think of a better FTL Communication system? Tachyons don't invoke a higher dimension or a special kind of "Space" such as jump space or hyperspace.
Any sort of FTL communication involves some sort of handwave that isn't supported by Physics As We Know It. You have some choice as to what the handwave is. </font>[/QUOTE]Psionics involves Human awareness, whic falls into the realm of metaphysics and not physics. If psionics exist (a big if) then there is no reason to assume that thought is subject to the speed of light. The handwave is still there, it is just not in the realm of physics.
 
A "better" FTL communications system would be one that actually works.

Tachyons do not exist. Therefore, Tachyon-based FTL comms do not exist.

Your entire concept simply will not work!

Face it, Space-C, you're up against real degreed professionals who know more about this subject than you do. Any "handwave" fantasy you might try will be seen through and debunked almost immediately.

Suggestion: Admit that you have minimal knowledge of physics, and move on. Either that, or apply some of that imagination to writing fiction; including Traveller adventures.

With a fantasy life like yours, you could really succeed as an SF author, as long as you do not take yourself so seriously.

By Atpollard: "If psionics exist (a big if) then there is no reason to assume that thought is subject to the speed of light.
Thought is an artifact of electro-chemical interactions, and as such, it is limited to less than the speed of light. Prove to me otherwise, and I know where you can pick up an easy million dollars for just a few minutes' work.

However, in all of human history, there has been no definative proof of psionic activity, psychic ability, or other such concepts that could only violate one of the Laws Of Science.

Either everything in the universe operates under the same laws all of the time without exception, or causality, relativity, and the very fabric of time and space comes unravelled in less than a blink of an eye.

Sure, I'd love to be able to read a woman's mind (what do they really mean when they say "I love you"?). For that matter, being able to anticipate the flip of a card or the roll of the dice -- or even influence the outcome -- would be an awsome ability. I could retire and just make the rounds of the casinos when I needed extra cash.

But no, we're all locked inside our own minds, doomed to make contact with others and manipulate matter only through material means.

... and that's why we play RPG's like Traveller.
 
Originally posted by atpollard:
Psionics involves Human awareness, whic falls into the realm of metaphysics and not physics.
At such point as psionics proposes physical effects (such as, for example, communication) it falls into the realm of physics.
 
Originally posted by Paul Snow:
A photon in a vacuum cannot be accelerated of slowed down though, it has a wavelength that can be lengthened or shortened, but you cannot apply a force on it that would change its velocity in a vaccum.
In vacuum, when the velocity of the wave is constant at c; the wavelength and frequency are linked and constant. They can't be changed.


Originally posted by Space Cadet:
Was Einstein wrong about E=mc^2 then?
A photon swallowed by a black hole increases the black hole's mass, doesn't it? If it does, the the photon must have had some mass in order to have added some to the black hole.


You really don't get the idea of the mass-energy equivalence theorem. If the mass were conserved in the process it would be on both sides of the equation. An equivalence isn't the same as conservation. Mass is not conserved in process; it is not in the photon to start with.

Answer me this. If you eat a donut and gain weight. Does this mean that the donut contained some of you before you ate it?
If I'm the black hole and the donut is the photon, then yes, I gain weight after eating the donut, thats because the donut had mass and I added its mass to my own and thus I gained weight. What a donut has that a photon does not is rest mass. A photon's mass is inversely proportional to its wavelength. Photons have gravity.
 
Originally posted by Paul Snow:
Originally posted by Space Cadet:
I don't know of any process that would create stationary antimatter atoms, they are always created at high velocity levels.
Positrons (that's an anti-electron) are ejected at relatively low velocities from nuclear decay processes.

For details on slow-positron work :
http://staff.bath.ac.uk/pyspgc/main_in_framehtm.htm
I didn't say a positron or an antiproton couldn't be slowed down after they have been created, but initially they are at high velocities due to the nature of how they were created, namely by collisions of relativistic ion beams, some of the kinetic energy released by the collisions gets converted into a particle/antiparticle pair such as an electron/positron, or a proton/antiproton, these particle pairs initially are at high velocity, and to store the antiparticles, they have to be slowed down and stored in an electromagnetic trap to prevent contact with the walls of the accelerator. Just as its possible to slowdown antimatter, it should also be possible to speed up tachyons and fire them out of a gun. The lowest energy state for a tachyon is theoretically at infinite velocity, of course at infinite velocity, its energy state is zero, so it doesn't exit. An finite velocities such as 1 billion times the speed of light, the energy level of a tachyon is low. But a tachyon can't be created in that state. Since the creation process for creating matter involves high energy states, the tachyon would presumably start out just above the speed of light relative to the ion collider.
 
Originally posted by Anthony:
</font><blockquote>quote:</font><hr />Originally posted by Space Cadet:
Can you think of a better FTL Communication system? Tachyons don't invoke a higher dimension or a special kind of "Space" such as jump space or hyperspace.
Any sort of FTL communication involves some sort of handwave that isn't supported by Physics As We Know It. You have some choice as to what the handwave is. </font>[/QUOTE]True, my hand wave is that some process for creating tachyons is discovered and that tachyons exist. The most likely way to create tachyons I think would be with the collision of heavy ion beams, resulting in a shower of particles, some of those particles may be tachyons.

After much experimentation a way is cound to guide tachyons through the accelerator ring and accelerate them further. After this discover, some investment occurs and heavy ion colliders are built in space and "tachyon factories" are created as well as tachyon detectors, both devices are incredibly massive and expensive, it becomes possible to have real time communication with colonists on Mars for instance with FTL tachyon communication satellites around both planets. After a while these things are made more efficient and less massive, the Solar System is dotted with these satellites, and some experiments are made with a tachyon propulsion system, these are incredibly efficient, but the thrust is rather weak, fusion rockets are utilized instead. Generation ships are launched to the stars, but the colonists remain in real time communication with Earth as they travel outwards. No ships as of yet can go FTL as the light barrier remains impassable. After 3 or 4 centuries of interstellar travel the Alpha Centauri system is approached, and telephone calls can be made between the various star systems. One popular method for exploring Alpha Centauri is through telepresence, with tachon relays in orbit around the planet at Alpha Centauri. More telepresence probes are sent to a number of different stars, travel is slow, but communication is near instantaneous, then some nanotechnology is developed and people are able to fax themselves to the stars through these Tachyon relays. The duplication of the person is on the cellular level, it doesn't quite work out the same way as star trek transporters, but it does work.
 
Originally posted by Space Cadet:
True, my hand wave is that some process for creating tachyons is discovered and that tachyons exist. The most likely way to create tachyons I think would be with the collision of heavy ion beams, resulting in a shower of particles, some of those particles may be tachyons.
We've got a lot of experience with whacking together heavy ion beams. No evidence of tachyons.
 
True but this is science fiction. My purpose isn't to prove the existance of tachyons, only to make their discovery in a science fiction setting sound plausible as if it actually could happen. To obtain a little wiggle room, one could always say, that the heavy ion colliders didn't operate at high enough energy levels to obtain tachyons, or perhaps tachyons were created but the detectors weren't sensitive enough to detect them.

You see its a big mistake to accept the burden of trying to prove that tachyons exist, just like it would be for me to prove that maneuver drives are possible, because someone could always say, "Ok smarty pants, lets see you build one!" If I took up that challenge and actually succeeded, I would be fairly rich, but such things don't normally happen, and not with out a huge research institution with alot of money to spend. With science fiction, one must go beyond the current state of science, but not too far beyond otherwise you lose plausibility. We know what happens when particles approach the speed of light from the slower side of it, I'm just projecting what would happen on the faster side.
 
Originally posted by Heretic Keklas Rekobah:
A "better" FTL communications system would be one that actually works.

Tachyons do not exist. Therefore, Tachyon-based FTL comms do not exist.

Your entire concept simply will not work!

Face it, Space-C, you're up against real degreed professionals who know more about this subject than you do. Any "handwave" fantasy you might try will be seen through and debunked almost immediately.

Suggestion: Admit that you have minimal knowledge of physics, and move on. Either that, or apply some of that imagination to writing fiction; including Traveller adventures.

With a fantasy life like yours, you could really succeed as an SF author, as long as you do not take yourself so seriously.
The statement "Tachyons do not exist" is incredibly unscientific. If you follow the reasoning "tachyons have not been found, therefore they do not exsist" then before they discovered x-rays they did not exsist. An important thing to remember is that not to long ago, people would never have thought up the idea of computers, because they had nothing like them. In the future, there will be things no one could have thought of today.
 
Originally posted by Kaale Dasar:
The statement "Tachyons do not exist" is incredibly unscientific. If you follow the reasoning "tachyons have not been found, therefore they do not exsist" then before they discovered x-rays they did not exsist. An important thing to remember is that not to long ago, people would never have thought up the idea of computers, because they had nothing like them. In the future, there will be things no one could have thought of today.
Conversely, what you are saying is that things that do not exist today simply have not yet been discovered. This is derived from the pseudo-scientific idea that anything that can be conceived of will eventually be proven.

Here's a hypothetical example: I say that turtles that engage in natural flight under their own power do not exist (free-falling turtles do not count). By your reasoning, you might say that they do, despite an utter lack of evidence. "Flying turtles exist," you might say. "They just don't show up on radar."

X-rays are a natural part of the electromagnetic spectrum. Their existance does not violate any physical laws -- Tachyons do (causality and the light barrier). X-rays were discovered after their effects were observed, and a probable cause was determined. Then experiments with X-ray emitting substances and devices were performed and measurements were made. Then a model was written up to explain them. Under the already-established electromagnetic theory, they made perfect sense. Thus the existance of X-rays was proven and accepted.

Computers were in use more than two thousand years ago. True, they were crude mechanical devices (astrolab, for example), and were used primarily to predict the seasons, the tides, and a sailing ship's lattitude, but they existed. They do not violate any physical laws, and can be constructed from common materials by anyone capable of handling tools and observing the heavens. Computers are mere extrapolations of theses devices and others, like the Chinese abacus and the Mayan quipa. This becomes obvious when you examine the numerical nature of each one. Computers, calculators, and all other calculating devices really do nothing more than manipulate numerical data.

Originally posted by Anthony:
We've got a lot of experience with whacking together heavy ion beams. No evidence of tachyons.
Good call, Anthony! There are no known effects that can even be hypothesized to be caused by Tachyons aside from a few obscure quantum events; and even those are easier to explain by instrumental and interpretive error. Look up Occam's Razor. The simplest explanation is usually the most valid.

Tachyons are unique fantasy particles that have no slower-than-light "anti-particle" component. Nor are they the product of any breakdown or combination of any other particle or particles. There is no proven explanation for their generation or existance. They can not be derived from previously discovered particles, and have not been precisely detected at all, despite our most sensitive instruments and methods.

Belief in things that can not be proven to exist is called faith, which is a necessary part of religion and its evil twin, superstition.

Are you trying to convert others and me to some pseudo-scientific religion, which is based on little more than wishful thinking and a few mathematical constructs that were developed to make things more convenient for theoreticians?

Convince me, and I'll become the Pope of your new religion. But it will take a lot of convincing. Tell me all you know about Tachyons, and I'll ignore it. Provide a reputable scientific paper on the existance of Tachyons, and I'll consider it. Show me the effects of Tachyons interacting with the observable world in a consistant and predictable way (one that can not be easier to explain by previously known science), and I'll believe.

Until then, I'll stick with known and provable scientific facts and principles, such as causality, relativity, the light barrier, and the non-existance of tachyons.
 
Conversely, what you are saying is that things that do not exist today simply have not yet been discovered. This is derived from the pseudo-scientific idea that anything that can be conceived of will eventually be proven.
Actually, that's not what he said. He said things that have not been found either:
1) Do not exist

or

2) Have not been discovered yet

The problem you have is that you assume the current state of science and scientific understanding is the be all and end all of all that is possible. Every Era has someone who claims ultimate knowledge over what is possible. I do not believe we live in a special time where science has finally come within the grasp of a complete understanding of the Universe. I don't know what evidence you have that the current understanding of the Universe is correct. Part of science fiction is keeping an open mind about things.

Here's a hypothetical example: I say that turtles that engage in natural flight under their own power do not exist (free-falling turtles do not count). By your reasoning, you might say that they do, despite an utter lack of evidence. "Flying turtles exist," you might say. "They just don't show up on radar."
Flying turtles is fair game for science fiction. If a turtle is small enough and had wings, then it could fly, just as a beetle does. I can't rule out the existance of flying turtles because I haven't seen every planet with life on it, and it occurs to me that such a life form may be possible under the right condition, that is what thinking like a science fiction writer is all about.

X-rays are a natural part of the electromagnetic spectrum. Their existance does not violate any physical laws -- Tachyons do (causality and the light barrier).
How do you know that causality and the light barrier are natural laws?

The birth of the Universe requires a violation of the light barrier. Some nitpicky Physics lawyer might say that the light barrier doesn't apply to spacial expansion, but it still proves that the light barrier isn't universal. the Universe would look alot different if it universally adhered to the light barrier without exception. Some common sense notions than no object can be in two places at once appear to be violated with quantum physics. Physicists are always finding out new things about the Universe, and are often proven wrong, so I wouldn't be too sure about what you know.

How do you know tachyons cause casuality violations? How do you know what is meant by a "negative duration"? Are you sure that means a rewinding of time? And if time is rewound, how do you know it has to play the same again? Seems to me that if something is going back in time, we wouldn't be able to detect it. One cannot perceive a change in history after all as all our memories would change with the change in history and we would perceive no difference, Those who went back in time might perceive a change in history though. One cannot exist in one's own history. If you went back in time, it would play differently due to your presence where you memory wouldn't contain a visit from you of the future.

Tachyons are unique fantasy particles that have no slower-than-light "anti-particle" component. Nor are they the product of any breakdown or combination of any other particle or particles. There is no proven explanation for their generation or existance. They can not be derived from previously discovered particles, and have not been precisely detected at all, despite our most sensitive instruments and methods.
Again since no one has discovered tachyons, how can one know how they are made? Einstein establishes the equivalence of energy and matter. Matter is just another form of energy that is stationary. Matter moves at sublight velocities and is a form of energy, another form of energy is photons, which move at the speed of light. Photons can be turned into matter and matter can be turned into photons. If light can become a slower than light electron, whos to say that it cannot also become a faster than light tachyon. Just because none have been discovered doesn't mean that it doesn't happen.


Belief in things that can not be proven to exist is called faith, which is a necessary part of religion and its evil twin, superstition.
You have faith that our current understanding of the Universe is the correct one. Many people in the past thought they understood the Universe and were wrong, what makes us so special that we should get everything right and should be the final arbitrator of what is and isn't possible? Science Fiction is all about exploring Terra Incognita. We don't know what particles we haven't found yet, it is the science fiction writers job to imagine what hasn't been discovered yet. Most of the time, when youuguess about something, your wrong, but there is always something, and it is realistic to assume that we'll know about stuff in the future that we know nothing about today.

Convince me, and I'll become the Pope of your new religion. But it will take a lot of convincing. Tell me all you know about Tachyons, and I'll ignore it. Provide a reputable scientific paper on the existance of Tachyons, and I'll consider it. Show me the effects of Tachyons interacting with the observable world in a consistant and predictable way (one that can not be easier to explain by previously known science), and I'll believe.
If science fiction writers could invent and discover things, then they wouldn't need to write books to earn a living. I don't know why you thing science fiction must be all about today and what we are capable of now.
 
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