Special Relativity: Theoretical Questions

[d.smith292]

I am still trying to understand a few things about special relativity.

Lets say I am traveling at the speed of light on a space ship.

1. Would this speed allow time to stand still for me?
2. Will this cause me to never age?
3. If I travel faster, would I be able to travel to the past?
4. If time slows at faster speeds, does this stall the aging process or do i continue to age normally?
5. If I age normal and time slowed would I gain a couple years in just a few hours?

These are a few things I have been pondering as of late.

What are your thoughts on the subject?

 

[KayEl9]

Hello.

If I remember it right, when coming near to the speed of light (theoretically), timespace starts to curve for the object and time slows down. So (again, theoretically), at absolute speed of light, time could possibly stop, so that could object wouldn't age.

I'm not sure if object could go to the past when it exceeds the speed of light - because, according to the Theory of Relativity, the speed of light plays the role of an absolute speed in the universe, which means nothing could exceed this speed.
But then, traveling at the speed of light that you mention is probably impossible too...

 

[JesseM]

I don't really understand what "almost someday" means, are you asking if we will someday be able to travel at almost the speed of light but slightly slower, or are you just asking if we "almost" believe it will be possible to travel at exactly the speed of light someday?

Anyway, according to relativity it would take an infinite amount of energy to accelerate a massive object to exactly the speed of light, and the object would have to experience infinite proper acceleration (infinite G-force), so I'd say it will never be possible to travel at exactly light speed, though traveling very close to light speed might someday be possible.

 

[PAllen]

If we complete the ultimate diet we must travel at the speed of light.

 

[d.smith292]

Sorry about the confusion in the poll, I'm asking if you think we will ever be able to travel at the speed of light.

I know it would take an infinite amount of energy to propell something at the speed of light, but this is a theoretical question. If we did travel that fast, would we be able to go back in time?

 

[PAllen]

Sorry about the confusion in the poll, I'm asking if you think we will ever be able to travel at the speed of light.

I know it would take an infinite amount of energy to propell something at the speed of light, but this is a theoretical question. If we did travel that fast, would we be able to go back in time?

No. Going faster than the speed of light is equivalent to going back in time, in SR.

 

[d.smith292]

Right, because that would put us in the impossible zone, outside of the light cone and into the past light cone.
Is this right?

 

[Nabeshin]

I know it would take an infinite amount of energy to propell something at the speed of light, but this is a theoretical question. If we did travel that fast, would we be able to go back in time?

You're right it is a theoretical question, since practically we cannot even get anywhere close to the speed of light. And the theoretical answer is unambiguously: no. You seem to acknowledge this by stating that you know it requires an infinite amount of energy, so clearly it is impossible!

To then go on an say "If we did travel that fast" is completely meaningless. You are asking what a theory would predict if that theory were wrong, which is complete rubbish.

 

[d.smith292]

I started this post with the intention of having some fun discussing physics with what we know as science fiction. I know time travel is imposible, but it's still fun to talk about. Keep your knickers on and calm down pal. Take yourself back to the first time you saw Doc Brown take marty Mcfly back to the future and enjoy the thoughts of time travel. It's fun to dream about traveling at the speed of light or traveling through time.

 

[jtbell]

We do science here, not science fiction.