Relative motion and proper time

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Discussion Overview

The discussion revolves around the concept of relative motion and proper time, specifically examining how two observers, one on a spaceship traveling at 0.7c and the other on Earth, perceive the timing of events (in this case, cooking popcorn) due to their relative velocities. The scope includes theoretical implications of simultaneity in special relativity.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether both observers will see their own popcorn ready first, suggesting that they have different definitions of simultaneity.
  • Another participant confirms that both observers will find their popcorn done three minutes after starting it, implying that they will perceive the other's popcorn as not yet done at that moment.
  • A later post introduces a scenario where popcorn is exchanged between the spaceship and Earth, calculating the time it takes for the popcorn to be received on each side, indicating that different observers will experience different elapsed times due to their relative motion.

Areas of Agreement / Disagreement

Participants generally agree that each observer perceives their own popcorn as ready first, but the implications of simultaneity and the effects of relative motion remain a topic of exploration and discussion.

Contextual Notes

The discussion includes assumptions about the constancy of the speed of light and the effects of time dilation, but these are not fully resolved or elaborated upon in the posts.

Who May Find This Useful

This discussion may be useful for individuals interested in the principles of special relativity, particularly in understanding how relative motion affects the perception of time and simultaneity.

Joao
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Hi everyone! Sorry for the bad english!

Quick question Just to see if I understood:

If a person on a spaceship moving at 0.7c in relation to a person in the earth, and both of then agreed they started making microwave popcorn at the same time (like when the spaceship is just above the head of the Earth one). And it takes 3 minutes for the popcorn to be ready. Each one Will ser that their own popcorn was ready first?

Thanks!
 
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Joao said:
Each one Will ser that their own popcorn was ready first?
Yes. In essence, this is because they have different definitions of what it means for two events to be simultaneous.
 
Joao said:
Each on will see that their own popcorn was ready first?
Yes. Both of them will find that their popcorn is done three minutes after they started it, just as you would expect. Both will find that at the same time that their popcorn is done, the other' popcorn is not yet done.
 
Thanks a lot! I wish I was smarter, in order to study physics (and yonger) hehehehe! Reality is far more amazing than any work of fiction! Thanks all! Please fell free to close the post!
 
Popcorn exchange just for fun.

Say the rocket sends just cooked popcorn to Earth by missile which move -0.7c in the Earth IFR, the Earth receives 3-minutes- after-cooked popcorn. Earth time then is 6/√0.51=8.40 minutes so 5.4 minutes after own cooking. Hotter one comes. Earth people can enjoy different temperature tastes.

Say the Earth sends just cooked popcorn to Rocket by missile which move 0.7c in the Rocket IFR, Rocket receives 3-minutes- after-cooked popcorn. Rocket time then is 6/√0.51=8.40 minutes so 5.4 minutes after own cooking. Hotter one comes. Rocket people can enjoy different temperature tastes.
 

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