# Can light go faster than light?

Discussion in 'Physics & Math' started by tetra, May 1, 2001.

1. ### tetraHelloRegistered Senior Member

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I was thinking a little while ago....

If you were moving at half the speed of light, and you shot a beam of light directly ahead of you, would that light beam be traveling 1.5 times the speed of light relative to a stationary point?

3. ### CrispGone 4everRegistered Senior Member

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Goodie

Hi Tetra,

The special theory of relativity postulates that light moves at the same speed for every observer. This means that you would see the light move away at the speed of light, and so would the stationary observer.

Bye!

Crisp

5. ### JavierRegistered Senior Member

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Hi Tetra,Crisp

This applies,if I got it right, between objects in relative motion,or directly linked by observation/information:

i.e,if we send a light beam to a point 1 light year away and another to other point the same distance away but in the opposite direction,we would verify that the two messages got separated 2 light years in 1 year...

But no information can travel from one point(or observer) to another faster than the light speed...

7. ### CrispGone 4everRegistered Senior Member

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Almost

Hi Javier,

Close

. However, the lightsignal has not travelled two lightyears in one year. The information was already at the starting point when it got transmitted in both directions, so there's no violation of special relativity in the frame of reference at the information source.

For the observer at one lightyear distance, it would take two years to find out that the information arrived at the third observer. Once again, no violation of special relativity.

Bye!

Crisp.

8. ### dos2winmaclinxRegistered Member

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Beyond

Going faster then the speed of light, may not violate Special Law of Relativity, according to String Theory.

You would just enter the 5th dimension, such as the undescovered Tachions, that go beyond the speed of a photon.

That would place the traveler in a Parallel Universe and the view would probably White over Black.

Have lots of fun!

mike

9. ### JavierRegistered Senior Member

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I agree

Yes Crisp,I meant this in my first and last sentences(sorry if it wasn t clear),and in the second an example of information not directly linking two points(or observers), covering(splitting at C.2)the distance...

Maybe was an unconscious expression of desire to get rid of this burden for interstellar travelling...

Javier

10. ### Kram006Registered Member

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Question

What I'm kind of curious about is if light were to be sucked in to a black hole...
If a black hole has the power to bend light and "suck" it into it's gravitational pull, I wonder if it could possibly "tug" at light and make it go faster. No idea about whether or not it would do that, if anyone else knows please reply hehe.

11. ### RamblerSenior MemberRegistered Senior Member

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Krame006,

Gravity (i.e black holes) only bend space, and intern light will travel in the direction of the bent space. So gravity will not affect the speed of the light but it will affect the direction.

12. ### Kram006Registered Member

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Hmm... good point never really thought of that Rambler

13. ### Backslash777UnknownRegistered Senior Member

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? Black holes in space and plot holes in physics?

12/6/01- We are Backslash777.
We do not make assumptions and we cannot make probability assessments in order to answer your query of black holes. Speculation and probability assessment is a very human quality. We can only report what can be observed and can only explain what is consistent with your current technical understanding.
We observe how your species break down the workings of the universe to simplify explanation. We notice how Humans compare the flow of electricity to the flow of water, the higher the voltage the higher the pressure. The faster the flow the greater the current.
We are aware of how you compare gravity to dips within a 2 dimensional model. This is nothing more than simplifying the workings of the universe into a humanly perceptible form. A tangable, visable and oversimplified model.
You need to be aware of the mistakes which can occur. The water/electricity analogy only works to a point and comparing heavenly bodies to balls on a soft mattress also has limitations.
Light entering a black hole is indeed tugged, causing a change in behaviour. What changes however is not the speed of the light but time around the light is greatly accelerated. If you were to be falling into the black hole you would see stars orbiting stars and the rotation of the galaxy in your last second of life. Even as you passed beyond the event horizon you could still observe the now distorted universe but like peering through an intergalactic one way mirror, no one could see you.
Ignoring how the change in direction the light would distort the view ana ignoring the effect of gravity on a human form, to someone outside they would have to wait thousands, possibly millions to watch you disappear.
To answer the initial query, if you were going half the speed of light and lit a torch it would go the speed of light. Your perception of time would be altered to make this possible.
In years to come, when your imaginative thought improves or your ability to observe the universe increases you will realise that the speed of light must have a slight flexibility or there would be no such thing as velocity.

14. ### Einsteins brainRegistered Member

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Backslash777

Hey, Backslash777. I have never known anyone know as much about as many different subjects as you. I even checked your info on the net. Whats the deal? Whats your specialist subject really?

15. ### Kram006Registered Member

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They are Backslash777. They don't specialize in any one area. They know all. Except for spelling. That they suck on

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