Can something move faster than light?

[Jay-qu]

I have another question.

If an object is falling towards a black hole is it possible that the objects could reach speeds beyond that of light? because even if its mass is increased because of acceleration doesnt gravity work the same for all masses...

[Qfwfq]

If an object is falling towards a black hole is it possible that the objects could reach speeds beyond that of light?

No.

[Jay-qu]

I have no objection to your answer but can you please explain why?

[Qfwfq]

I have no objection to your answer but can you please explain why?

It would be a manifest inconsistency within GR if something, as decribed by GR, permitted a violation of something on which GR is based. If you want detail, I couldn't really give much on these boards, you'd be better going through a good text book. Weinberg's "Gravitation and Cosmology" has good introductory chapters and also illustrates the Schwarzschild solution.

[Guest liliangrn]

Can anything go faster than light? Possibly or possibly not.

 

We have no evidence either way.

 

Another question may be:

 

Does anything go faster than light?

 

To say theoretically something could but, then again, probably wouldn't. You are actually offering two opposing theories, not one.

 

I answered this poll to the negative. If I could I'd withdraw that and say: I don't know.

 

Josephine

[wazzuuup]

Tachyons are hypothetical particles that are said to go faster than light. As in, they really travel the same distance as light and go faster. They could never go slower than the speed of light and if one were to appraoch you from a distant star, it would look like it is actually traveling away from you since the light that reaches you first is that showing it hit Earth.

[ldsoftwaresteve]

I guess it would be nice to know why light has the speed it has.

[EWright]

I guess it would be nice to know why light has the speed it has.

 

 

No one here can tell you that; only I can. But I need to finish developing my complete theory before I can reveal this.

 

To those asking whether something can travel faster than the speed of light when approaching a black hole, keep in mind that modern physics break down inside of a black hole and can not accurately describe what happens there when approaching the point of a singularity, so physics (including GR) can not presume to say that nothing travels faster than light beyond the S. Radius.

 

Tachyons would not appear to be traveling backwards *if* you could even view them. You would simply not see them until *after* they had passed you because the light travels slower than the particle.

 

Particles do not increase in mass when excelerated near the speed of light. Despite the 'evidence' suggested from particle accelerators, I will explain the actual phenomenon in time.

[goku]

i voted yes.

IF light does travel or move, all you have to do is go faster.

there's no magic to it or quantum crap, you just go faster.

i do believe magnetic or (warp) fields is the key to faster than light travel.

have you ever seen EVENT HORIZON?

[EWright]

i voted yes.

IF light does travel or move, all you have to do is go faster.

there's no magic to it or quantum crap, you just go faster.

i do believe magnetic or (warp) fields is the key to faster than light travel.

have you ever seen EVENT HORIZON?

 

Physicists have a problem with this because SR formulas *require* that nothing can go faster than light. This is because Einstein chose to 'zero out' his formulas at light speed because it travels at a constant measurable speed and because we know of nothing that can travel faster. This makes it impossible to formulate an equation in which anything travels faster than this speed, because the concepts forces time to warp in a way in which there is considered to be no passage of time at light speed (there is) and in which particles increase in mass (they do not) to the extent that it would take an infinite amount of energy to accelerate to accelerate a particle to light speed, thus rendering this an impossibility.

[Qfwfq]

because SR formulas *require* that nothing can go faster than light.

Not quite.

 

SR has the consequence that if ftl causality is possible, so is time-reversed causality. This is quite simply because if two events have a spacelike separation then, in different coordinate frames, they can be simultaneous or either of the two before the other. Even without actually being able to travel ftl but only to send information that you can freely choose, if you can find a way to do it you can also send it back in time. Next Monday send me the right six numbers so that I can play them Friday evening and we split more than 13 million between us.

 

and in which particles increase in mass (they do not) to the extent that it would take an infinite amount of energy to accelerate to accelerate a particle to light speed, thus rendering this an impossibility.

The kinetic energy does have infinite limit for v --> c, if rest energy (mass) isn't zero.

 

I disagree with calling the kinetic energy extra mass because this has always only caused confusion. Try designing a particle accelerator that can give a kinetic energy up to at least a few times the particle's rest energy and plot the graph, check it against:

 

E = m/(1 - v^2)^(1/2)

 

Where E is total energy, mass plus kinetic. They've been doing it for decades.

[colin590]

so why cant some thing go faster than light?

[CraigD]

so why cant some thing go faster than light?

There are at least 3 answers to this questions: a theoretical one, and a practical one, and a “it’s a trick question” one.

 

Theoretically (and note that this theory, Relativity, is extraordinarily well supported by observed and experimental evidence), the reason that an object with mass can only approach, but not actually reach, the speed of light c (as observed by someone not traveling with the object) is that, as it approaches c, it’s mass approaches infinity (M=Mrest/(1-(V/c)^2)^.5), so there’s not enough energy in the universe to give it the final, infinite push to reach c. This is a good thing, as having an object with infinite mass around would be a universe-devouring catastrophy! :shrug:

 

Practically accelerating an object to even nearly c, even if you have galaxies worth of energy at your disposal, raises some severe engineering worries, as each individual atom of interstellar hydrogen begins to pack the punch of many atomic bombs, not to mention actual multi-billion atom specks of dust or a 10^30 + atom chunk of visible debris – a perilous spaceflight regime, “deflector shields” or no.

 

It’s a trick question, because, according to Relativity, not being able to reach or exceed c isn’t a barrier to getting wherever you want to go in as little time as you wish. The maximum “effective velocity” due to length contraction (D=Drest*(1-(V/c)^2)^.5) of, say, a spacecraft, is limited only by the amount of available energy, and the engineering problem mentioned above. The “universal speed limit”, c, applies only to the objects “actual velocity”, as observed by someone not traveling with the spacecraft. To quote goku (something I don’t do very often :umno:)

there's no magic to it or quantum crap, you just go faster.

There are lot of discussions and demonstrations of this in old threads at this site, if you’re looking for mathematical details.

[EWright]

Quote:

Originally Posted by EWright

because SR formulas *require* that nothing can go faster than light.

 

Not quite.

 

SR has the consequence that if ftl causality is possible, so is time-reversed causality.

[/Quote]

Not even remotely true. If ftl is possible it does not mean that the information can be sent back in time. Any formulas indicating this can happen are the direct cause of errors within SR. If a particle were to travel faster than light and it gave off light as it traveled, the signal would not move back in time, but would rather take longer to reach an observer than the speed at which the particle is actually moving. Thus the observer could not accurately measure the speed of the particle using light speed as a tool of measurement. If the particle was approaching you, you'd see it after it passed... just as you hear a supersonic jet after it has passed. Nothing moves back in time, but you perceive it at a later time than it occurred due to the relatively slow speed of the light signal.

 

This is quite simply because if two events have a spacelike separation then, in different coordinate frames, they can be simultaneous or either of the two before the other. Even without actually being able to travel ftl but only to send information that you can freely choose, if you can find a way to do it you can also send it back in time. Next Monday send me the right six numbers so that I can play them Friday evening and we split more than 13 million between us.

[/Quote]

Untrue for reasons stated above.

Quote:

Originally Posted by EWright

and in which particles increase in mass (they do not) to the extent that it would take an infinite amount of energy to accelerate to accelerate a particle to light speed, thus rendering this an impossibility.

 

The kinetic energy does have infinite limit for v --> c, if rest energy (mass) isn't zero.

 

I disagree with calling the kinetic energy extra mass because this has always only caused confusion. Try designing a particle accelerator that can give a kinetic energy up to at least a few times the particle's rest energy and plot the graph, check it against:

 

E = m/(1 - v^2)^(1/2)

 

Where E is total energy, mass plus kinetic. They've been doing it for decades.

[/Quote]

 

Another falsity of relativity theory is that particles gain mass under these conditions of being accelerated. Yes, it does appear so, but it is another 'illusion' as the one I explained above. The particles do not in fact gain mass; there is another reason for the resistance to increased acceleration beyond what we are able to achieve; one which I can not yet expand upon here.

[colin590]

thank you CraigD.

[Edge]

Well, after understanding theories, I do agree that it's more possible that nothing can travel faster than light.

 

However, in some way it can be a paradigm.

 

and goku, just because you don't understand it, does not make Quantum Theory merely crap.

 

I don't understand it either... :evil:

[goku]

and goku, just because you don't understand it, does not make Quantum Theory merely crap.

theory is the key word here, an idea.

does quantum theory contribute anything other than deep thoughts to mankind?