Assume that I have a giant stick in space...

 

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Now, lets assume I start spinning that stick clockwise around its axis in the middle.

 

 

What happens when the outside edges of the stick start moving faster than light, but closer to the middle of the stick its still subliminal?

 

Whats the effect on the geometry?

 

[i tried to make beautiful stick diagrams out of text, but it didn't work ]

As v -> c, m -> :inf:, so it would collapse into a singularity rather than move superluminally.

But this leads to the question... what if your stick was a cosmic string, which would already have a density of a singularity?

Since a singularity can effect space/time around it, it is hard to measure what speed it really is travelling. I imagine it would create interesting waves in our existance we might not be able to detect.

Just aman

is it true that if you had a pole that was a light-year long and you pushed one end of the pole toward the other end, the other end would not move until a year later?

 

basically saying that movment in the pole would propigate at the speed of sound?

 

I heard this on another forum but it seems that the Mach-limitation is a bit strong? (eg. the movement would propigate throught the pole at some speed faster than sound but slower than light) I assume faster than sound because of the higher density hence smaller interval in atom-atom action.

crap...never mind, the argument was that the change would propigate through the pole at the speed of sound *through the pole*

 

and the answer to my question is that the other end of the pole would recieve the motion effect instantaniously only if the material was incompressible (which is just as unlikely as mass moving faster than light)

how the freak did you make a stick spin the speed of light in the first place? it's a stick!!

He's referring to the speed of the center of the stick being close to the speed of light, which under incorrect thought would require the edges of the stick to be moving faster than c. This is of course neglecting that motion in a rigid body does not propagate instantaneously.

so basically, this guy using my avatar is a communist and blike is Posting Under the Influence again

bigjnorman said in post #6 :

crap...never mind, the argument was that the change would propigate through the pole at the speed of sound *through the pole*

 

and the answer to my question is that the other end of the pole would recieve the motion effect instantaniously only if the material was incompressible (which is just as unlikely as mass moving faster than light)

 

Speed of light not speed of sound.

 

And it wouldn't move instantaneously, because the carrier particle for the force involved IS light, so it's not exactly going to go faster than itself.

Originally posted by Dudde

so basically, this guy using my avatar

 

yes, because you own the trademark to spaceghost?

 

Originally posted by MrL_JaKiri

Speed of light not speed of sound.

 

oops, he he

what is singularity? The word implies something simple but i don't know what you guys mean. I've seen it before too, it must be important to science, but i've never learned what it means, so educate me. Please.

Google it.

alt_f13 said in post #13 :

Google it.

 

http://www.dictionary.com it might be better.

Good man.