How can simultaneity and the constant speed of light stay coexist.

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SUMMARY

The discussion centers on the relativity of simultaneity as illustrated by a thought experiment involving a train observer and a platform observer witnessing lightning strikes. The platform observer sees both strikes simultaneously, while the train observer perceives them at different times due to their relative motion. This discrepancy arises because the train observer concludes that the strikes occurred at different times in their frame, despite the constant speed of light. The key takeaway is that the perception of simultaneity is relative and depends on the observer's frame of reference.

PREREQUISITES
  • Understanding of Einstein's theory of relativity
  • Familiarity with the concept of simultaneity in physics
  • Basic knowledge of light speed as a constant
  • Ability to analyze thought experiments in physics
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  • Explore Einstein's theory of special relativity in detail
  • Study the implications of simultaneity in different frames of reference
  • Investigate the concept of light cones and causality
  • Review practical examples of relativity in modern physics
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Students of physics, educators teaching relativity, and anyone interested in the foundational concepts of modern physics and how observers perceive events differently based on their relative motion.

fa7alerr0r
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Watch this video and tell me shouldn't the passenger in the train see both lightning strikes at the same time considering that light speed is perceived as the same speed no matter how fast you travel or where it comes from? Watch both these vids.
http://www.youtube.com/watch?v=8JKdqKtNPsU&feature=related
 
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Because of the way the experiment is set up, the observer on the platform sees the strikes at the same time, and sees the flashes reach the train observer at different times. And both observers have to agree as whether the flashes reach either observer at the same time or not.

If the train observer saw both flashes at the same time then they would see the flashes arrive at the platform observer at different times and then you would have a contradiction as the platform observer sees just the opposite.
 
fa7alerr0r said:
Watch this video and tell me shouldn't the passenger in the train see both lightning strikes at the same time considering that light speed is perceived as the same speed no matter how fast you travel or where it comes from? Watch both these vids.
http://www.youtube.com/watch?v=8JKdqKtNPsU&feature=related

The point is that since the train-observer does think the light from each strike traveled towards him at the same speed, the only way he can square this with the fact that the light from each strike reached him at different times is to conclude the strikes actually occurred at different times in his frame. If there are two trees on either side of me and both are exactly 50 feet away from me, and at 3:00 I see lightning strike one tree and at 4:00 I see lightning strike the other tree, there's no reason this should conflict with the idea that the light from each strike took the same time to reach me, since I can just conclude one strike happened an hour later than the other one.
 
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