Can We Reach the Speed of Light?

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Discussion Overview

The discussion centers on the theoretical possibility of reaching or exceeding the speed of light using a rotating tower. Participants explore the implications of relativity, material properties, and forces involved in such a scenario, touching on concepts from physics such as angular momentum and electromagnetic interactions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions whether a sufficiently long rotating tower could theoretically break the speed of light at its outermost point.
  • Another participant argues that relativity would prevent the tip of the tower from exceeding the speed of light, suggesting it would appear as a spiral from the ground.
  • A participant expresses curiosity about how the Earth would appear from the top of the tower.
  • Concerns are raised about the assumption of a rigid material for the tower, with a participant noting that relativity implies no rigid materials exist.
  • One participant counters that in space, friction is not an issue, questioning the need for rigidity and the associated g-forces.
  • A participant references Newton's second law, stating that the forces causing accelerations in the tower's particles would require it to be rigid to avoid bending.
  • Another participant expresses skepticism about the feasibility of the idea, citing conservation of angular momentum and relativistic mass increase as limiting factors.
  • One participant notes that the electromagnetic interactions holding the tower's atoms together would limit the speed of interaction to the speed of light, suggesting that the top of the tower would be torn apart.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of a rotating tower reaching the speed of light, with no consensus reached on the theoretical implications or material requirements.

Contextual Notes

Limitations include assumptions about material properties, the nature of forces in a relativistic context, and the effects of angular momentum and relativistic mass increase, which remain unresolved.

mlip
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I don't 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 isn't 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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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.
 
You are assuming that your tower would be of rigid material- even theoretically, in relativity there is no rigid material.
 
But in space you wouldn't 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?
 
But in space you wouldn't 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.
 

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