Seeking clarification of time dilation

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Discussion Overview

The discussion revolves around the concept of time dilation in the context of special relativity, particularly focusing on the perception of time for observers in different frames of reference. Participants explore the implications of relative motion on the measurement of time and aging, as well as the interpretation of a specific passage regarding clocks and aging.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant notes that while they have understood that moving clocks run slower, a passage suggests that being at rest makes one's clock appear slower, leading to confusion.
  • Another participant emphasizes that all motion is relative, stating that a clock moving close to the speed of light appears slower to an observer, but the observer of that clock will see their own clock as running slower.
  • A hypothetical scenario is presented where a person traveling in a spaceship for 70 years returns to Earth, suggesting that they will have aged less than those who remained on Earth, as measured by Earth clocks.
  • There is a question raised about why, if one observes other clocks running slower, those clocks are considered to age faster, leading to further confusion about the relationship between time dilation and aging.
  • A participant expresses confusion about associating the slowing of time with less aging, realizing that the opposite is implied in the context of time dilation.

Areas of Agreement / Disagreement

Participants express differing interpretations of time dilation and its implications for aging, indicating that there is no consensus on the understanding of the concepts discussed. The discussion remains unresolved with multiple competing views on the nature of time and aging in different frames of reference.

Contextual Notes

Participants have not fully resolved the implications of relative motion on time perception and aging, and there are assumptions about the definitions of "slowing" and "aging" that remain unexamined.

acesuv
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"Since we are always at rest with respect to ourselves, ignoring the effects of acceleration, our lifetime, as measured by us, will always appear shorter than it appears to others. To others our clocks will seem to run slow. But we will die, alas, on the cue of the internal timer that travels with us. In special relativity the grass is greener on the other person's lawn." - Euclid's Window, PG 188

I've been under the impression that when you are moving, your clock will slow down; however, the above passage seems to imply that being at rest is what slows your clock down.

What's going on here?
 
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To start with, all motion is relative. There is no absolute at rest.

When you observe a clock moving close to the speed of light it appears to be going slower. However someone traveling with that clock looking at your clock will observe it is going slower.

http://en.wikipedia.org/wiki/Special_relativity

See above for a detailed description.
 
hi acesuv! :smile:
acesuv said:
… our lifetime, as measured by us, will always appear shorter than it appears to others.

suppose you live 70 years, on a spaceship, and you return to Earth to die

you will return more than 70 years later according to an Earth clock, so an observer who stays on Earth will say that you lived for more than 70 years :wink:
 
mathman said:
To start with, all motion is relative. There is no absolute at rest.

When you observe a clock moving close to the speed of light it appears to be going slower. However someone traveling with that clock looking at your clock will observe it is going slower.

http://en.wikipedia.org/wiki/Special_relativity

See above for a detailed description.

If you observe other clocks as going slower when they move relative to you, then why are they the ones that age faster? The passage implies that I should be the one whose clock is slowing down from my frame of reference, I think.
 
tiny-tim said:
hi acesuv! :smile:


suppose you live 70 years, on a spaceship, and you return to Earth to die

you will return more than 70 years later according to an Earth clock, so an observer who stays on Earth will say that you lived for more than 70 years :wink:

acesuv said:
If you observe other clocks as going slower when they move relative to you, then why are they the ones that age faster? The passage implies that I should be the one whose clock is slowing down from my frame of reference, I think.

Sorry guys; I got myself confused! I was associating a slowing of time with less aging; however, the opposite is actually true. "Slowing", meaning "less speed", I got myself confused...

Thanks for the help
 

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