<p>This would be more appropiate at Physics.s.c but here is the answer nonetheless.</p>

<p>Your object may be perfectly rigid or not.</p>

<p>If the object is perfectly rigid, you would not be able to accelerate it to the point at which the extreme points of the spires reach the speed of light, because when they are approaching it, their mass will increment towards infinity and the energy you will need to continue accelerating will increment to infinity as well.</p>

<p>So you will simply not be able to accelerate the whole thing to a rotation speed where the extreme points will reach the speed of light.</p>

<p>If the object is not rigid, well, it will simply bend, plus the previous explanation.</p>

CC BY-SA 3.0
2014-02-03T11:46:48.050Z
This weirds me out, if there is no friction in space, I can't imagine more needed energy. Thank you for the answer.
Nkciy84
CC BY-SA 3.0
2014-02-03T11:49:42.030Z
Yes, the speed of light is hard to reach not because friction, but for the increment of mass. Photons have mass 0 so they reach easily the speed of light (in fact, they can not travel slower! - at least in vacuum)
Envite
CC BY-SA 3.0
2014-02-03T11:54:23.410Z
So faster movement means increase of weight means increase in energy needed to turn the sphere. What if we replaced the spires with, say, lasers? I guess you would create a situation where gravity starts to pull on the light emitted.
Nkciy84
CC BY-SA 3.0
2014-02-03T12:06:07.507Z
Lasers are light, not matter. You can have speeds larger than 'c' due to the geometrical effect, but these will not be the speed of any material object. Gravity not affectin there.
Envite
CC BY-SA 3.0
2014-02-03T11:42:48.860Z
2014-02-03T11:42:48.860Z
Envite
<p>According to the theory of relativity (If I understand correctly), nothing is supposed to be able to travel faster then the speed of light. I believe, to my limited knowledge and grasp of the concept, that quantum theorie speaks against, i.e. extend, the theory of relativity, hence my question:</p>

<p>Suppose we find (or imagine) a place in the universe where there is no obstruction for this thought experiment to take place. We take a spherical object and attach a spire at both sides so you get an object shaped like this: -O-</p>

<p>We start turning the object so the ends of the spire travel in an orbital mather according to the spherical object. What if the sphere starts to orbit near the spead of light, wouldn't the ends of the spires travel faster than the speed of light?</p>

<p>Sorry if this is the wrong place for this question.</p>

CC BY-SA 3.0
2014-02-03T16:34:01.310Z
Related Physics.SE question: http://physics.stackexchange.com/questions/2774/rotate-a-long-bar-in-space-and-get-close-to-or-even-beyond-the-speed-of-light
called2voyage
CC BY-SA 3.0
2014-02-03T16:35:36.113Z
This question appears to be off-topic because it is about the theory of relativity without any concrete reference to astronomy. which is more appropriate at Physics Stack Exchange (where an answer to this question already exists).
called2voyage
<light><space-time><pulsar>
traveling past the speed of light
Nkciy84
# traveling past the speed of light

(Asked by: username_0 on 2014-02-03)

According to the theory of relativity (If I understand correctly), nothing is supposed to be able to travel faster then the speed of light. I believe, to my limited knowledge and grasp of the concept, that quantum theorie speaks against, i.e. extend, the theory of relativity, hence my question:

Suppose we find (or imagine) a place in the universe where there is no obstruction for this thought experiment to take place. We take a spherical object and attach a spire at both sides so you get an object shaped like this: -O-

We start turning the object so the ends of the spire travel in an orbital mather according to the spherical object. What if the sphere starts to orbit near the spead of light, wouldn't the ends of the spires travel faster than the speed of light?

Sorry if this is the wrong place for this question.

**Tags:** light, space-time, pulsar
> **Comments:**
> **username_1**: Related Physics.SE question: http://physics.stackexchange.com/questions/2774/rotate-a-long-bar-in-space-and-get-close-to-or-even-beyond-the-speed-of-light  
> **username_1**: This question appears to be off-topic because it is about the theory of relativity without any concrete reference to astronomy. which is more appropriate at Physics Stack Exchange (where an answer to this question already exists).  

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## 1 answers

### Answer by username_2 on 2014-02-03. Score: 3 | Accepted answer

This would be more appropiate at Physics.s.c but here is the answer nonetheless.

Your object may be perfectly rigid or not.

If the object is perfectly rigid, you would not be able to accelerate it to the point at which the extreme points of the spires reach the speed of light, because when they are approaching it, their mass will increment towards infinity and the energy you will need to continue accelerating will increment to infinity as well.

So you will simply not be able to accelerate the whole thing to a rotation speed where the extreme points will reach the speed of light.

If the object is not rigid, well, it will simply bend, plus the previous explanation.

> **Comments:**
> **username_0**: This weirds me out, if there is no friction in space, I can't imagine more needed energy. Thank you for the answer.  
> **username_2**: Yes, the speed of light is hard to reach not because friction, but for the increment of mass. Photons have mass 0 so they reach easily the speed of light (in fact, they can not travel slower! - at least in vacuum)  
> **username_0**: So faster movement means increase of weight means increase in energy needed to turn the sphere. What if we replaced the spires with, say, lasers? I guess you would create a situation where gravity starts to pull on the light emitted.  
> **username_2**: Lasers are light, not matter. You can have speeds larger than 'c' due to the geometrical effect, but these will not be the speed of any material object. Gravity not affectin there.  

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