Special Relativity: Ultimate Speed Limit

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SUMMARY

The discussion centers on the implications of special relativity, particularly regarding the speed of light and the perception of events from different frames of reference. It highlights a scenario where Alice and Bob are on a spaceship traveling at nearly the speed of light (0.9999999999999999999999999c) and the paradox that arises when Bob fires a laser at Alice. While observers on Earth and the spaceship may disagree on the timing of events, they ultimately agree on the occurrence of those events, underscoring the consistency of physical laws across different frames of reference.

PREREQUISITES
  • Understanding of Einstein's Theory of Special Relativity
  • Familiarity with the concept of light speed (c)
  • Knowledge of reference frames in physics
  • Basic grasp of relativistic effects on time and space
NEXT STEPS
  • Study the implications of Lorentz transformations in special relativity
  • Explore the concept of simultaneity in different reference frames
  • Learn about the twin paradox and its resolution
  • Investigate the role of light cones in spacetime diagrams
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in the foundational concepts of special relativity and its paradoxes.

kidsmoker
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Hi,
i'm just revising for my special relativity module and this bothers me:

http://img259.imageshack.us/img259/1482/17053293.jpg

If the spaceship was going at slightly less than c then you would still see a completely different thing on Earth to what you would see on the ship. On earth, it would appear as if the light was moving a little ahead of the ship, whereas on the ship, the light would travel away with speed c. What is more special about the contradiction they derive?

Thanks!
 
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Suppose that Alice and Bob are on the ship, and that Alice is closer to the front than Bob. Now Bob fires a very powerful laser in her direction. If the ship travels at c, she dies in one frame and survives in the other. That's a contradiction.

If the ship travels at 0.9999999999999999999999999c, Charlie on Earth may disagree with Bob about at what time Alice died, but they both agree that she dies. So there's no disagreement about what actually happens at that event, or any other. They only disagree about what numbers (coordinates) to assign to the event.
 

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