Tachyons

[timespace]

Tachyons are particles that can surpass the speed of light, in fact their slowest speed is that of light. As it gains energy, it slows, and as it loses energy, it speeds up...have any of you heard of these particles?
http://scienceworld.wolfram.com/physics/Tachyon.html

[jinydu]

Sure I've read about them from that website before. But if you read the article more closely, you'll see that nowhere do they claim that tachyons exist, and other articles on that site there say that there is no accepted proof that they do.

[timespace]

meh. i still think travel beyond light is possible...no matter how much you may disagree. :wink:

[wendy]

The speed of light is something like sqrt(EH/DB), where these are electromagnetic field strengths. This varies from place to place, and it can be somewhat slower than that of free space.

The entry of a fast-moving particle at a speed greater than sqrt(EH/DB) is then makes it a tachon. Such have been experimentally observed.

The only trouble is, that the laws of gravity ensure that regions where the sqrt(EH/DB) is lower than 983574900 ft/s is not extensive, because extensive regions of even low density make for a black hole.

[houserichichi]

Tachyon doesn't mean particle that travels faster than light, that's just a result of the maths. To be a tachyon, a particle has to have either negative squared mass (a la classical methods) or negative real mass (a la modern approaches).

[Flawless]

think of dimensions as getting bigger as they progress like a piece of pie. in order for this to be possible time would have to be slower on higher dimensional levels meaning that the speed of light is easier to attain. now think of regressing dimensional levels instead of progressing.. faster than light my friend.....

[jinydu]

think of dimensions as getting bigger as they progress like a piece of pie.

You haven't provided any justification for why this should be so.

in order for this to be possible time would have to be slower on higher dimensional levels

Looks like a total non-sequitr from the previous point.

meaning that the speed of light is easier to attain. now think of regressing dimensional levels instead of progressing.. faster than light my friend.....

Not only is this yet another non-sequitr, but it violates the constancy of the speed of light, a fundamental postulate of relativity.

[bsaucer]

I've read that there's experimental evidence that neutrinos are tachyons. But I have a theoretical question:

Can two or more tachyons (and /or anti-tachyons) be combined to form a composite "tachyonium" which is a massive particle (positive "net" mass)travelling slower than light? What kind of virtual particals would these tachyons need to exchange to hold them together?


I always wondered if quarks are tachyons permanently bound in a composite hadron state...

[Eric B]

Since tachyons would have imaginary mass (not simply "negative", houserichichi, but rather the square root of a negative), adding them together will not produce a real mass particle, but simply a greater imaginary quantity.
(also, the math dictates that these would necessarily move faster than light, with the speed of light as the asymptotically slowest limit).
Then, there's the causality problem from the Lorenz Time cintractions. If you fire one out at thousands of times the speed of light, it will still take years and maybe even centuries and more to reach other parts of the universe, but the problem arises if it is intercepted by a traveler moving away from us at relativistic speeds (approaching the speed of light where the Lorentz contractions become quite significant), and then they try to fire it back to us at the same speed we sent it (but in their inertial frame of reference, now). The math predicts that it would return earlier than it was sent. (though I wonder if there might be some sort of "cosmic censorship" principle that would prevent that).
So it is believed that if tachyons exist, they do not interact with matter, but inhabit basically a ghost realm with the space and time coordinates reversed.

What evidence is offered that neutrinoes are tachyons?

[houserichichi]

!!!! I made a grave error...tachyons have real mass energy. How I didn't catch that blunder myself is beyond me...

A tachyon's rest mass would be imaginary but, because they never stop moving, the mass energy is real.

As for the three neutrinos being tachyonic...didn't the experiments at SNO prove that they have real mass? Or did they just find upper / lower bounds?

[Eric B]

OK, you're right, but still, bsaucer asked about two of them combining and then moving slower than light. In which case, they would be imaginary. (even if these faster than light particles exist, still, nothing can cross the "barrier")

[bsaucer]

But if the tachyons were to "revolve" about each other faster than light, couldn't the composite object appear to be stationary to an outside observer?

[Eric B]

Know nothing about revolution at the speed of light, let alone faster than light. I always wondered what time and langth dilation would be like for staying in the same place, but going arooud in a tight circle. But centrifugal forces usually tear such orbits apart, though in the world of tachyons, who knows.

[Frankseesall]

i know this isnt 2 relative 2 the subject but do tell me simple as possiable please - how would a 3rd demensional charachter see a 4th dimentional object?

[Eric B]

This would have been better in one of the "Geometry" section discussions.
Anyway, you theoretically would see a three dimensional "cross section" of the object. But this cross section from its original 4D perspective, is really infinitessimally "hyperthin" (i.e. you would be seeing right between its subatomic particles).
If we were to look at 4D objects by being taken into 4 space ourselves, then we would be infinitessimally hyperthin. In 4space, all volumes are h×w×d×t(4th dimension). But t would then be 0, which would cancel out the rest of the dimensions of the volume (h×w×d×0=0)

So I do not think matter could interrelate interdimensionally.

[thigle]

what do you mean by 'interelate interdimensionally'. why matter can not ?

[Eric B]

In other words, we couldn't see or touch them, nor even exist in the higher or lower dimension, because the lower dimensional creature has zero volume in the higher space (one or more of his dimensions is zero, which means he has no volume in that dimension), and higher dimensional creatures can only have a zero volume "slice" of himself in the lower space at one time.

[papernuke]

yes i have heard of these, but they cant surpass the speed of light, they can go about 0.999999% the speed of light, they can do that because their mass^2 is still under zero

[Keiji]

What?

And don't double post. There's an edit button for a reason.

[Nick]

What?

And don't double post. There's an edit button for a reason.

What double post? Look again... it was Eric B, then icon.

[Alex S]

How would tachyons be created? Could the collision of matter and antimatter create tachyons in addition to energy?

[papernuke]

How would tachyons be created? Could the collision of matter and antimatter create tachyons in addition to energy?

Well, in a low-energy collision, then the matter and antimatter would annihilate to create light, although that wouldn't be a tachyon would it?

Take a positron and electron collision. If the energy and momentum are conserved, and eventually, the created photon must decay back into the positron and elcron, where would you get the energy to create a tachyon?