Highest velocity possible

Originally posted by FabianFnas
Got me there. Perhaps I should write |velocity| or speed or something. I think everyone understand what I mean. Is speed the right word for what I mean?

I still say that there is not any highest speed for massive objects in normal space. Any objections?

Uhm... well,
As far as I can tell, light speed isn't actually a limit, it's just a discontinuity. Like ATY posted, the c^2-v^2 denominator means that there's a point which is at infinity where c=v, but it's symmetric, so at v>c, the function continues on... so the speed of light wouldn't be a speed limit, but moreso a point speed you can't rest at. If you can somehow get over that infinity problem, you could probably continue on to as many times the speed of light as you want, getting back to normal speed would be another problem.... Well, that's my reading of the situation.
It's like the cops saying that you can go any speed except 41.2mph. Effectively you can't go faster, but an imaginative enough guy could probably find a way.
I think this is the general idea behind tachyons...
http://en.wikipedia.org/wiki/Tachyon

Originally posted by Phlabibit
It would be interesting if anyone heard this and could find the write up.

I believe light or particles were passed through xenon gas, and registered on the other side .0000000000000000000000003 seconds earlier than when the light was emitted.

My understanding is the light pulse traveled faster than the speed of light through the gas and actually reac ...[text shortened]... nyone hear anything similar to this? Not sure where I read it some time last year or so.

P-

I saw something similar once on the science channel. What they did was create a conduit between a sender and receiver and then sent some kind of high freqency signal with data and measured the time it took from sender to receiver.

Then they installed a barrier so the data frequency couldn't get through. In amazement the recorded message was received before it was sent!!!

If you are interested in this you should use google to look for it. Sorry that I can't give you more infor on the experiment.

Arrakis

Originally posted by agryson
Uhm... well,
As far as I can tell, light speed isn't actually a limit, it's just a discontinuity. Like ATY posted, the c^2-v^2 denominator means that there's a point which is at infinity where c=v, but it's symmetric, so at v>c, the function continues on... so the speed of light wouldn't be a speed limit, but moreso a point speed you can't rest at. If you think this is the general idea behind tachyons...
http://en.wikipedia.org/wiki/Tachyon

Well, you're right there, but what happens with mass when you go faster than light? It get imaginary. So now you have two numeric components in your mass: a+ib kg, where a and b are real and i= sqrt(-1) Weird isn't it? So even if nothing forbids faster than light speeds I don't see this as an answer.

My postulate is: "There is no highest speed for things with ordinary mass."
What do I mean by this? Is the postulate of mine faulty or correct?

Originally posted by FabianFnas
My postulate is: "There is no highest speed for things with ordinary mass."
What do I mean by this? Is the postulate of mine faulty or correct?

Do you just mean that mass can travel at a speed of c-x (c = speed of light) and x can be as small as you like?

Originally posted by Schumi
Do you just mean that mass can travel at a speed of c-x (c = speed of light) and x can be as small as you like?

Good remark. Perhaps you know what explanation I want.
Is there a highest speed? I say no, what do you say?

Originally posted by FabianFnas
Good remark. Perhaps you know what explanation I want.
Is there a highest speed? I say no, what do you say?

You might want to read about tachyons -> theoretical particles that might be going faster then the speed of light.

Relativity only forbids massive particles to accelerate up to the speed of light. To that, there seems to be no way around it. No one told if you start already with a speed bigger than light.

Good science fiction, at least 🙂

Originally posted by Schumi
Do you just mean that mass can travel at a speed of c-x (c = speed of light) and x can be as small as you like?

Yes, but it takes more and more fuel to get to lower values of x. At some point there isn't enough energy in the universe to go faster I would imagine.

So if an object (with mass) is traveling at the speed of light and collides with another object then is:
1. an infinite amount of energy released.
or
2. since the energy available is infinite, it deflects the other object without any effect on itself.

Originally posted by twhitehead
So if an object (with mass) is traveling at the speed of light and collides with another object then is:
1. an infinite amount of energy released.
or
2. since the energy available is infinite, it deflects the other object without any effect on itself.

I'll start by saying that an object with mass can't travel at light speed but answers can be given anyway.

1. The energy released in a shock doesn't has to be necessarily all the kinetic energy that the impacting body has.

2. We can study this case by limiting. At greater and greater energies the impacting body deflects less and less so it seems that with infinite energy the impacting body wouldn't deflect at all.

Now the thing is that we ar applying everyday knowledge and reasoning to stuff that isn't what we deal everyday. One mistake that we often make is to think at light moving particles as of being normal particles. But we can't do that. Light moving particles have their own dynamics.

http://arxiv.org/PS_cache/physics/pdf/0303/0303004v1.pdf This article is a very nice one explaining the previous problem.

Edit: This one is more complete but it's a little bit harder. http://arxiv.org/PS_cache/hep-ph/pdf/9911/9911441v2.pdf

Originally posted by twhitehead
So if an object (with mass) is traveling at the speed of light and collides with another object then is:
1. an infinite amount of energy released.
or
2. since the energy available is infinite, it deflects the other object without any effect on itself.

You started your example with an impossibility, so there's no reasonable answer.

How about Jesus and Mohammed appear upon the collision and then do an Irish jig together?

Originally posted by tomtom232
I am not sure, though I read somewhere that the speed of light is unattainable by anything other than light, but any speed above or below it is theoretically attainable...I don't remember the reasoning for this...I will have to look it up.

Technically, nothing in the universe that isn't completely abstract and unexplainable has achieved greater than lightspeed. The Starship Enterprise doesn't count: it's fiction. Anything going faster than light would warp the spacetime continuum, thus altering the "personal time" experienced by the object.

Originally posted by adam warlock
1. The energy released in a shock doesn't has to be necessarily all the kinetic energy that the impacting body has.

But my point was that if the body slows down in any way to anything less than light speed then it must emit an infinite amount of energy.

Originally posted by AThousandYoung
You started your example with an impossibility, so there's no reasonable answer.

How about Jesus and Mohammed appear upon the collision and then do an Irish jig together?

Why is it an impossibility? (I don't disagree that it is, but think it is interesting to discuss the reasons).
Maybe:
1. All matter started off at sunlight speed and thus could not be accelerated to light speed? Do we know this?
2. If such a particle existed in the universe it would be causing problems. Again - do we know this?

Originally posted by twhitehead
But my point was that if the body slows down in any way to anything less than light speed then it must emit an infinite amount of energy.

Why so then? I don't see any reason for that to happen.

isn't the heart of all this confusion that mass actually doesn't change at all when an object accelerates?

M = sqrt( m/(1-v­²/c² ) ) does grow, but m doesn't. which means an apple approaching light speed won't become a black hole, it'll just have a huge energy. and that energy would be equal to the energy of a corresponding object with a rest mass equal to M, but it doesn't mean the mass actually grows to M.

the amount of energy changes, the mass doesn't.