What do you see at the speed of light?

[KingMerv00]

Ok, I strap on a rocket and slowly accelerate towards the speed of light.

Of course, assume I don't accelerate so fast that my skin is torn off and thrown around like confetti.

If you're wondering how I'll eat and breathe and other science facts, repeat to yourself "It's just a question, I should really just re-lax". (If you don't get the reference...I feel bad for you. You are missing out.)

1) I look in the direction I am traveling. What do I see?

2) I look to my left or right. What do I see?

3) I look behind me. What do I see?


Just to test myself I will try and answer them. I'm sure I'm missing something.


1) As I accelerate, the electromagnetic waves (say from stars) will be blue shifted. In other words, I should eventually be able to see radio waves as if it were visible light.

2) A little trouble here. Length contraction would make the stars on either side appear smashed together more and more with respect the the direction I am traveling. No red or blue shift.

3) Same as number 1 only red shifting. I could see UV and gamma radiaion as if it were visible light.

Um...right?

[Ziggurat]

Originally posted by KingMerv00
Ok, I strap on a rocket and slowly accelerate towards the speed of light.
...
1) I look in the direction I am traveling. What do I see?

2) I look to my left or right. What do I see?

3) I look behind me. What do I see?
...
1) As I accelerate, the electromagnetic waves (say from stars) will be blue shifted. In other words, I should eventually be able to see radio waves as if it were visible light.

Yes, the light from stars in the direction you accelerated will be blueshifted. But that's not all: what you will also notice is the apparent "smooshing" of the field of view in front of you. I'm finding it hard to explain concisely, but basically, if you imagine that at rest, the stars around you are uniformly distributed, then after you've accelerated to relativistic speeds, the apparent density of stars will be greater in front of you than behind you. This is an optical effect, and is different than what you "observe" in a relativistic sense (star density shouldn't change).

In case you're unfamiliar with this distinction, it's analogous to hearing sound from a jet passing overhead coming from behind the jet, but (knowing the speed of sound) being able to calculate, and thus observe, that the sound comes from the jet.

2) A little trouble here. Length contraction would make the stars on either side appear smashed together more and more with respect the the direction I am traveling. No red or blue shift.[QUOTE][B]

Not quite. Here it becomes important to distinguish between stars that are observed to be to your side, and stars which look like they are to your side. Stars which are OBSERVED to be at right angles to your direction of travel do not LOOK that way, they look like they're at some angle forward of that. These stars will not have any doppler shift associated with them, but they do have a (smaller) red shift associated with relativistic time dilation.

[QUOTE][B]3) Same as number 1 only red shifting. I could see UV and gamma radiaion as if it were visible light.

Yes.

[espritch]

The red and blue shifting is correct.

I'm thinking that you would see stars parallel to you stretched rather than compressed. You are the one that is actually experiencing lenght contraction due to your relavistic velocity. The outside observer would see you as compressed but I would think you would see the outside observer as stretched since you would not be aware of your own compression.

[Crossbow]

Just a quick point.

If one were really travelling just a tad below the the speed of light,
Then the blue shifting would be so severe that one would be vaporized by all of the extremely short wavelength radation that one would be encountering.

Happy trails!

:p

[KingMerv00]

Originally posted by espritch
I'm thinking that you would see stars parallel to you stretched rather than compressed. You are the one that is actually experiencing lenght contraction due to your relavistic velocity. The outside observer would see you as compressed but I would think you would see the outside observer as stretched since you would not be aware of your own compression.

So Star Trek got it kinda right?

[69dodge]

Originally posted by espritch
I'm thinking that you would see stars parallel to you stretched rather than compressed. You are the one that is actually experiencing lenght contraction due to your relavistic velocity. The outside observer would see you as compressed but I would think you would see the outside observer as stretched since you would not be aware of your own compression.The theory of relativity says that velocity is relative. So, neither one is "the one that is actually experiencing length contraction"; rather, each observes the other as experiencing it.

(Yes, relativity really is that weird.)

[Earthborn]

Here (http://www.anu.edu.au/Physics/Searle/index.html) is what you would see if you were accelerating towards lightspeed.

[espritch]

The theory of relativity says that velocity is relative. So, neither one is "the one that is actually experiencing length contraction"; rather, each observes the other as experiencing it.


You are correct. I got to thinking about this after I posted it and it occured to me that I wasn't taking into account that from the point of the one going near light speed, he is essentially sitting still and everything else is moving very fast in the other direction. It's in those four little words "relative to the observer". D'oah!

It's a good thing I'm not a physicist. :p

[CFLarsen]

Originally posted by KingMerv00
1) I look in the direction I am traveling. What do I see?

Sylvia Browne, running from the JREF Challenge...

[tracer]

None of this addresses the issue in the Topic: line of this thread, namely, what do you see at the speed of light?

The answer is, of course, you wouldn't be able to "see" at all, because at the speed of light time-dilation will be infinite. Your clock will run infinitely slowly (that is, not at all), so the nerve impulses won't be able to propagate from your retina to the vision centers of your brain. (Of course, your brain wouldn't be able to process the information anyway, because the impulses from one brain neuron to the next also won't be able to propagate, so you won't be aware that you're not seeing anything.)

[Soapy Sam]

What do you see at the speed of light?


Everything.

[kalen]

Smokey in your rear-view mirror.

[Soapy Sam]

-who may be closer than it appears.