# If I were to build a tower 1 million miles high, would I break the speed of light.

## Main Question or Discussion Point

I dont know the formula that I would need to use in order to calculate the exact length needed to reach, or even break the speed of light, but in theory isnt this possible? Wouldnt the outer-most point of the tower be rotating with such a high velocity that it could break the speed of light, assuming it was far out enough? :surprise:

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Staff Emeritus
Gold Member
Dearly Missed
No, because even without the practical difficulties with real matter, relativity woould modify the tower all along its length to keep the tip from exceeding the speed of light. I think the tower would be seen from the ground as curled into a spiral.

Relativity can't be fooled.

Cool that's really a neat idea and a neat solution. I wonder how would the earth appear to someone on top of the tower though.

HallsofIvy
Homework Helper
You are assuming that your tower would be of rigid material- even theoretically, in relativity there is no rigid material.

But in space you wouldnt need to deal with friction or anything of the sort, why would the material need to be rigid, what kind of g forces would it need to deal with?

Gza
But in space you wouldnt need to deal with friction or anything of the sort, why would the material need to be rigid, what kind of g forces would it need to deal with?

Thinking back to Newton's second law, a force causes an acceleration. An acceleration is anything that changes the velocity of an object. The particles making up the tower are undergoing changes in velocity since they are rotating with the same angular velocity of the earth. The forces causing these accelerations are provided by the tower, so yes the tower would need to be rigid, or it would bend.

Maybe I'm wrong, but I don't agree. I think it would not be possible because of conservation of angular momentum and relativistic mass increase.

note also that all the atoms that make up the structure of the tower are held together as a result of electromagnetic interactions between the atoms. This means the maximum speed of interaction between adjacent atoms is c, so the top end of the tower would just get ripped off.