Seeking clarification of time dilation

acesuv
Messages
63
Reaction score
0
"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?
 
Physics news on Phys.org
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
 
Thread 'Can this experiment break Lorentz symmetry?'
1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. The Relativator was sold by (as printed) Atomic Laboratories, Inc. 3086 Claremont Ave, Berkeley 5, California , which seems to be a division of Cenco Instruments (Central Scientific Company)... Source: https://www.physicsforums.com/insights/relativator-circular-slide-rule-simulated-with-desmos/ by @robphy
Does the speed of light change in a gravitational field depending on whether the direction of travel is parallel to the field, or perpendicular to the field? And is it the same in both directions at each orientation? This question could be answered experimentally to some degree of accuracy. Experiment design: Place two identical clocks A and B on the circumference of a wheel at opposite ends of the diameter of length L. The wheel is positioned upright, i.e., perpendicular to the ground...
Back
Top