Einstein and idea that nothing can travel faster than the speed of light

[cyberfish99]

I was reading about Eisteins theories and had a question. If light can not escape the gravitational pull of a black hole, then assuming that the black hole accelerates (at a constant acceleration) all matter and energy into its event horizon, then if the gravitational pull overcomes the speed of light, anything that enters the event horizon is accelerated to a speed faster than the speed of light. I would just like to know if I am onto something or if this idea has already been posed. I understand that tachyons go faster than the speed of light. Please let me know if anything in this post is completely off basis.

 

[DaveC426913]

I was reading about Eisteins theories and had a question. If light can not escape the gravitational pull of a black hole, then assuming that the black hole accelerates (at a constant acceleration) all matter and energy into its event horizon,

This assumption is incorrect. As any object approaches relativistic speeds, its velocity is calculated using a non-linear formula - the Lorentz transformation.

\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}

 

[cyberfish99]

Could you just explain the Lorentz Transformation a little better, I am not sure what it is.

 

[Dale]

I understand that tachyons go faster than the speed of light.

Tachyons are completely hypothetical, they have never been observed.

 

[Phyisab****]

Yep you are going to revolutionize physics with this half baked idea. Maybe you should learn some math before you start believing that you are "onto something".

 

[cyberfish99]

Tachyons are completely hypothetical, they have never been observed.

Yes while this is true, tachyons are theorized to release Vavilov–Cherenkov radiation which we know about. Like black holes, while we can't actually see them, we can postualize where they are by their interactions with observable phenomina

 

[Dale]

Please cite a peer-reviewed source for the claim that anyone has purported to have detected tachyons by their Vavilov-Cherenkov radiation.

 

[cyberfish99]

Please look at this google book result. http://books.google.com/books?id=5Uq3J_jrfxoC&pg=PA278&lpg=PA278&dq=detecting+tachyons&source=bl&ots=AAq2QoeINF&sig=bJ8iL3JufeLgY8PQmuWv-LSyyWE&hl=en&ei=2O8XS-2uN8LilAeYq-3oAg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CCgQ6AEwCQ#v=onepage&q=detecting%20tachyons&f=false"

 

[Danger]

Between my fatigue level and watching Family Feud, I managed to read only the first couple of pages of that. I cannot, therefore, comment upon the scientific accuracy. It definitely is not a peer-reviewed publication, though.

 

[Dale]

Please look at this google book result.

I asked for a peer-reviewed source. If you cannot provide such then you are in violation of the PF guidelines which you agreed to when you signed up for your account. Please re-read the "Rules" link at the top of each page.

Also, from the pages I could see there was not even any non-peer-reviewed evidence provided supporting the experimental confirmation of tachyons, merely a description of what they could be like theoretically and how they might possibly be detected experimentally. There is a large difference between saying how something could be detected and saying that it has been detected.

 

[DaveC426913]

Yep you are going to revolutionize physics with this half baked idea. Maybe you should learn some math before you start believing that you are "onto something".

The poster has done some reading and has asked some questions, even going as far as asking where his thinking is off.

There is no call for sarcasm or for put-downs.

(Please note that this exchange occurred in posts 1-4, prior to any speculative discussion about Vavilov-Cherenkov radiation.)

 

[cyberfish99]

Well no need to snippy. I am new to this physics forum and just wanted to know if something that I had postulated had any leg to stand on. As for the peer-reviewed article, I am sorry I came prepared to a fight with only a derringer when I obviously needed a nuclear warhead. You can easily turn people off to the idea of physics just by doing things like that. Instead of biting their head off, how about giving them irrefutable evidence that their idea is wrong. I just posed a question, I didn't want this to turn into some giant debate.

 

[sophiecentaur]

Now now boys.
Stop squabbling.

If we got cross at every ill thought out idea where would we be?
Let him that is without sin cast the first stone. (Ducks)

 

[Neo_Anderson]

Could you just explain the Lorentz Transformation a little better, I am not sure what it is.

The Lorentz Transformations ("LT's") are among the most important system of equations in all of physics. They describe frames of reference (a frame of reference is really nothing more than an observer) that are moving relative to each other.

The LT's show that time slows down when you're moving relative to someone who [thinks] he's stationary relative to you.
The LT's also show that there is a very real, physical 'contraction', or compression of matter; this contraction of matter can only be seen if you are moving relative to a 'stationary' object. What does that mean? That means that if you have a camera that can capture pic's of objects that can move very, very fast (almost speed-of-light fast), and if you take a pic of such a fast-moving object, you will see that object appear 'scrunched up,' as if it is being compressed in the direction of travel.

This is part of the LT:

\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}

If you replace gamma (that "Y"-looking symbol to the left of the equation) with t, and make the right side of the equation equal to t', then you have the equation that describes how slowly a clock ticks as you are moving relative to it. Please note that your watch = t, and the clock's ticks = t'.

 

[Neo_Anderson]

Also cyberfish, please understand that the tachyon is nothing but crackpot physics. It's cocklemamy junk. It's nonsense that tried to account for violations of Bell's inequalities long before better ideas came into being.
Like superstrings, no Physicist takes tachyons very seriously...

 

[DaveC426913]

Also cyberfish, please understand that the tachyon is nothing but crackpot physics. It's cocklemamy junk. It's nonsense that tried to account for violations of Bell's inequalities long before better ideas came into being.
Like superstrings, no Physicist takes tachyons very seriously...

Tachyons are not crackpot physics. It is true that they are only hypothetical particles, with no evidence to support their existence. That's not quite the same thing as crackpottery. Trying to make use of tachyons for some thing may be crackpottery but that does not make the hypothetical particle crackpottery.

And relativity does not rule them out.

 

[planethunter]

The google books post poses an interesting inference. It states that nothing can travel faster than light in a vacuum. However, something can travel faster than light if the speed of light were to decrease. Thoughts on this?

 

[DaveC426913]

http://en.wikipedia.org/wiki/Cherenkov_radiation" had some thoughts on this, yes.

 

[Neo_Anderson]

Tachyons are not crackpot physics. It is true that they are only hypothetical particles, with no evidence to support their existence. That's not quite the same thing as crackpottery. Trying to make use of tachyons for some thing may be crackpottery but that does not make the hypothetical particle crackpottery.

And relativity does not rule them out.

Tachyons are crackpottery of the highest order.
Suppose no one had ever created the concept of the tachyon. Suppose further that someone comes on this forum and declares that there may be a subatomic particle that can move much faster than the velocity of light, and that this particle is infinitely massive at the speed of light. That's right. He's get his IP banned for bringing crackpot theories to the forum.

 

[JesseM]

Tachyons are crackpottery of the highest order.
Suppose no one had ever created the concept of the tachyon. Suppose further that someone comes on this forum and declares that there may be a subatomic particle that can move much faster than the velocity of light, and that this particle is infinitely massive at the speed of light. That's right. He's get his IP banned for bringing crackpot theories to the forum.

If this person supported their arguments with math (specifically the fact that if you set the tachyon's rest mass to be an imaginary number, all its measurable attributes turn out to be real-valued) I don't think the discussion would be banned. And "this particle is infinitely massive at the speed of light" doesn't really make sense, it would be just as impossible for a tachyon to reach the speed of light as it is for a sublight particle to reach the speed of light.

Obviously the causality issues and the complete lack of experimental evidence make tachyons extremely far-fetched, but I don't think they're a crackpot notion.

 

[DaveC426913]

Tachyons are crackpottery of the highest order.
Suppose no one had ever created the concept of the tachyon. Suppose further that someone comes on this forum and declares that there may be a subatomic particle that can move much faster than the velocity of light, and that this particle is infinitely massive at the speed of light. That's right. He's get his IP banned for bringing crackpot theories to the forum.

Suppose no one had ever created the concept of relativity. Then someone comes along and declares that relativistic velocites have weird effects on things...



I don't see your argument leading anywhere. They did think of it, and I'm pretty sure I can find somew peer-reviewed articles that discuss it. Thus, no crackpottery.

 

[Dale]

To everyone, my objection and request for peer-reviewed evidence above was in the context of tachyons, not as a hypothetical idea, but as an actual particle with indirect evidence for their existence. In my personal opinion, discussing tachyons as hypothetical particles is pushing the edge of the forum rules, but discussing tachyons as actual verified particles is clearly breaking the forum rules.

 

[DaveC426913]

In my personal opinion, discussing tachyons as hypothetical particles is pushing the edge of the forum rules...

Right, except all the OP did was ask if tachyons go faster than the speed of light. Which they do by definition. (If they existed.)

 

[Dale]

all the OP did was ask if tachyons go faster than the speed of light

In post 6 he objected to my description of tachyons as hypothetical and insisted that they could be indirectly observed by Cherenkov radiation. That is not just asking.

 

[DaveC426913]

In post 6 he objected to my description of tachyons as hypothetical and insisted that they could be indirectly observed by Cherenkov radiation. That is not just asking.

Well OK, but it's still not like he was assuming their existence, then proposing applications. That would be crackpottery.

 

[Neo_Anderson]

People, people, people. Show me one hypothesis outlined by either the Standard Model or QM that predicts the existence of tachyons. QM is brilliant at predicting things, up to and including quantum hall-effect anomolies in graphene (predicted long ago and verified recently!), yet nowhere is the tachyon predicted in any QM or Satndard Model hypotheses.

Thus, the tachyon is a purely speculative particle, and a far, far-fetched one at that. Because of this, the tachyon is crackpottery, and those that stand by the tachyon are crackpots.

 

[Neo_Anderson]

I firmly believe that dilithium crystals would be a useful and powerful source of propultion that have the ability to power an Atlas rocket up to and including Warp 9.8. Does anyone object to my brilliant idea on technical or theoretical grounds?

 

[JesseM]

People, people, people. Show me one hypothesis outlined by either the Standard Model or QM that predicts the existence of tachyons. QM is brilliant at predicting things, up to and including quantum hall-effect anomolies in graphene (predicted long ago and verified recently!), yet nowhere is the tachyon predicted in any QM or Satndard Model hypotheses.

QM alone does not predict any specific particles, it's just a general framework for dealing with particles. The standard model doesn't predict tachyons, but no one really believes the standard model includes all the types of particles that will appear in a complete theory of quantum gravity or TOE.

Thus, the tachyon is a purely speculative particle, and a far, far-fetched one at that. Because of this, the tachyon is crackpottery, and those that stand by the tachyon are crackpots.

Speculative things are fine as long as they don't explicitly conflict with what we already know. Speculative does not equal crackpot, if it did all attempts at new theories (like string theory) would be crackpot.

 

[DrGreg]

In this forum, concepts published in peer-reviewed academic journals are not deemed to be crackpot. The Wikipedia article on tachyons (references section) lists a number of such articles.

Nevertheless, there's no experimental evidence for the existence of tachyons, and as far as I can tell (from that article), there are good theoretical reasons for suspecting they don't exist. But we can't dismiss the whole topic as crackpot.

 

[Neo_Anderson]

In this forum, concepts published in peer-reviewed academic journals are not deemed to be crackpot. The Wikipedia article on tachyons (references section) lists a number of such articles.

Nevertheless, there's no experimental evidence for the existence of tachyons, and as far as I can tell (from that article), there are good theoretical reasons for suspecting they don't exist. But we can't dismiss the whole topic as crackpot.

Please, Dr. Greg, I'm hoping you don't reference Wikipedia articles. If there be a peer-reviewed article on the topic of discussion, I'm hoping you'll reference the peer-reviewed article. Thank you in advance.

We have every reason to "suspect" that tachyons do not exist; the only very flimsy reason for their alleged existence would be explinations of violations of Bell's inequalities (the 'carriers' of action-at-a-distance, perhaps?). Even then, we have a long way to go in that area of interest, as QM formalism has yet to mop up unfair sampling and hidden variables. Even if and when the formalism disproves hidden variables, there will be a far better idea behind the properties of entanglement and non-locality than the crude, rudimentary and downright incompatible tachyon.

I am requesting we abandon this discussion on tachyons and its crackpot tenets. We continue to violate forum rules by not doing so. If this impulse cannot be controlled, then might I suggest a move to the appropriate forum: either Skepticism and Debunking, or the Independant Research Forums.