Are Faster-Than-Light Effects Predicted by Special Relativity?

[tade]

I was watching a video of Michio Kaku. He said that when you go faster than light, time goes backwards and objects have negative mass.

Does SR really predict such FTL effects?

 

[HomogenousCow]

I wouldn't take any of that seriously.

 

[Dick]

Kaku has become a media shill for bizarre intrepretations of physics. He'll say whatever they want him to say if it fits their programming. So he can be on TV.

 

[tade]

Kaku has become a media shill for bizarre intrepretations of physics. He'll say whatever they want him to say if it fits their programming. So he can be on TV.

He's not a shill in the sense of misleading customers to buy things, but I agree that he is a "media man".

And also a bit of a sensationalist attention-seeker.

He's not the only one though. Even some supposedly respectable physicists have taken the same route.

 

[HomogenousCow]

Back on topic, there is no answer to your question OP.
Massive particles simply do not travel at or beyond the speed of light, it is similar to asking a question like "What if the magnetic field had non zero divergence", it would just be a different physical model.

 

[Dick]

He's not a shill in the sense of misleading customers to buy things, but I agree that he is a "media man".

And also a bit of a sensationalist attention-seeker.

He's not the only one though. Even some supposedly respectable physicists have taken the same route.

Sure. I've got his quantum field theory book. Which is really not bad. It's just odd to see him on the Discovery Channel spouting garbage. I suppose if somebody offered me the right price, I might do it.

 

[tade]

Back on topic, there is no answer to your question OP.
Massive particles simply do not travel at or beyond the speed of light, it is similar to asking a question like "What if the magnetic field had non zero divergence", it would just be a different physical model.

I see.

 

[tade]

Sure. I've got his quantum field theory book. Which is really not bad. It's just odd to see him on the Discovery Channel spouting garbage. I suppose if somebody offered me the right price, I might do it.

I think it's perfectly within character. Nah, have some dignity.

 

[Dick]

I think it's perfectly within character. Nah, have some dignity.

I'll shed it. What's it worth? In $$?

 

[tade]

I'll shed it. What's it worth? In $$?

First of all, you must get a cool haircut and write a couple of those nonsense pop science books for laymen. Then they may consider you.

 

[HomogenousCow]

Anyone can write a pop science book for layman, simply follow these great steps.

1.Find a picture of a black hole, hydrogen atom or some equations (preferably with some greek indices, the EFE work well) and make it the front cover

2.Use these words frequently and in any context:
Quantum, Energy, Negative, Space-time (Or its more awesome cousin, "space time continuum" ), Einstein, Feynman, Black holes, dark matter, entanglement

3.Publish and make millions
(Or not, in which case add a few chapters on time travel and teleportation)

4.Lose all respect in the science communityCongratulations! Now you too can become a popularizer of science.

 

[WannabeNewton]

The notion of "time going backwards" in the case of FTL travel is a standard SR problem in textbooks; it involves a simple exercise in spacetime diagrams (but a very fun one). The point of the problem is to show that if you do assume FTL travel then causality is violated thus yielding a contradiction. Let's be careful before making overly sarcastic remarks.

 

[tade]

Anyone can write a pop science book for layman, simply follow these great steps.

1.Find a picture of a black hole, hydrogen atom or some equations (preferably with some greek indices, the EFE work well) and make it the front cover

2.Use these words frequently and in any context:
Quantum, Energy, Negative, Space-time (Or its more awesome cousin, "space time continuum" ), Einstein, Feynman, Black holes, dark matter, entanglement

3.Publish and make millions
(Or not, in which case add a few chapters on time travel and teleportation)

4.Lose all respect in the science community


Congratulations! Now you too can become a popularizer of science.

haha. it's not easy because there are so many others who want to share the limelight.

 

[tade]

The notion of "time going backwards" in the case of FTL travel is a standard SR problem in textbooks; it involves a simple exercise in spacetime diagrams (but a very fun one). The point of the problem is to show that if you do assume FTL travel then causality is violated thus yielding a contradiction. Let's be careful before making overly sarcastic remarks.

is it the antitelephone?

 

[WannabeNewton]

is it the antitelephone?

Yes: http://en.wikipedia.org/wiki/Tachyonic_antitelephone

 

[tade]

Yes: http://en.wikipedia.org/wiki/Tachyonic_antitelephone

I don't think Kaku meant that. But as he always says, "It's the future!"

 

[Brute Force]

The speed faster than light speed were observed in many experiments. (Speed of light in the media of coarse)
The particle moving faster than light starts to emitt "Cherenkov radiation".
No time reversing were observed so far.

 

[Nugatory]

The speed faster than light speed were observed in many experiments. (Speed of light in the media of coarse)
The particle moving faster than light starts to emitt "Cherenkov radiation".
No time reversing were observed so far.

It's the speed of light in vacuum that matters here.

It's worth adding that light traveling through a medium is a completely different phenomenon than light traveling through a vacuum; when we say "speed" we're not even talking about the same thing in the two cases. Light passing through a medium is continuously interacting with the atoms of the medium, propagating at c through the vacuum between the atoms and then being absorbed and re-emitted, scattered in various directions, and generally not doing anything that looks like the smooth propagation of electromagnetic waves through vacuum that Maxwell's equations and special relativity deal with.

 

[tade]

It's the speed of light in vacuum that matters here.

It's worth adding that light traveling through a medium is a completely different phenomenon than light traveling through a vacuum; when we say "speed" we're not even talking about the same thing in the two cases. Light passing through a medium is continuously interacting with the atoms of the medium, propagating at c through the vacuum between the atoms and then being absorbed and re-emitted, scattered in various directions, and generally not doing anything that looks like the smooth propagation of electromagnetic waves through vacuum that Maxwell's equations and special relativity deal with.

kaku's statements are still crap right?

 

[Harry Wilson]

kaku's statements are still crap right?

Well, you haven't said exactly what his statement was.
If you go faster than c, you do go back in time, so no; I think he's right. It's just actually achieving that speed is, in all current theory, impossible.

 

[tade]

Well, you haven't said exactly what his statement was.
If you go faster than c, you do go back in time, so no; I think he's right. It's just actually achieving that speed is, in all current theory, impossible.

You create an antitelephone, but I don't think that's what Kaku meant.

 

[Nugatory]

If you go faster than c, you do go back in time,.

You do not. All that happens is that it becomes possible that there is some observer somewhere (but not you!) who could conclude that according to his definition of simultaneity you arrived at your destination before you left your origin.

To actually "go back in time", you have to construct a closed timeline curve (CTC), and that's a bit more work than just going faster than light.