Time slowing down

[matt_london]

<PRE>I have read in many books about time running slower on a clock that is moving relative to a clock that is stationary but one thing puzzles me. Surely each clock could consider itself to be moving relative to the other one. If this happened in the vastness of space with no reference points how is it decided which one is moving and has the clock with a slower time on it when they are placed side by side afterwards and compared? </PRE>

[scotstone]

As with all problems involving relative motion you have to assume one point of reference is at rest.

[mibn2cweus]

This may take some time and some mental dilation (concentration). Bon voyage. Happy clicking!

slow moving clock

[mibn2cweus]

Remember that Einstein thought long and hard about this before he awoke from a dream with the solution in mind.

[boobesque]

good stuff mibn2cweus but what if the apparant traveller returns at high speed instead of just passing by. i have read in a brief history of time that one person travelling at high speed and later erturning will have aged less. but surely then the concept of relative perspective doesnt fit this analogy.

[Mac attack]

Hasn't this experiment been done here on Earth with two atomic clocks. One which stays on the ground and one which is carried on a plane for long enough so that when the two are compared, the one that was on the plane showed less time had passed. Now, considering Matt's question, would it not be reasonable to think that the clock that stayed on Earth had been moving relative to the one on the plane, and that this Earth clock showed a slower time than the plane clock?
Oh - I think I get it... its all about the observer. If the observer had stayed on Earth too then he see's the plane clock as slower. If the observer had been with the plane clock all along he would see the earth clock as slower? Is that right???!!

[mibn2cweus]

Time dilation is more than a perception, it actually happens. This is not intuitive, be patient and enjoy the experience. I'm going to check out EDDIE51's link now.

[mibn2cweus]

One thing I've observed is that my clock seems to run faster when I'm investigating time relativity. Would anyone care to explain this phenomenon? <�?

see ya later c�>

[mibn2cweus]

Oh yeah, the question was "how is it decided which one is moving and has the clock with a slower time on it when they are placed side by side afterwards and compared?" The one that changes velocity (accellerates) will have experienced less elapsed time.

equation and graph here

[matt_london]

<PRE>Is it only during the velocity change period that the clock slows down or from that point on? Also, does deceleratting or changing back to the original direction reverse the time dilation? If not, why not???</PRE>

[nancie]

The mind boggles

[mibn2cweus]

matt_london, You are testing (if not exceeding) the limits of my knowledge, but not my patience. I hope you�re finding these explorations into time as fascinating as I am.

The rate at which time passes is independent of and does not respond to the direction of motion. There is no �forward/reverse� direction for time in space. The change in velocity (from the initially equivalent velocities) is the corner that when turned defines the dimensions of time (and space) for that reference frame.

The rate at which time passes would be restored when the velocity is restored to the initial velocity, (no relative motion between observers). Acceleration back to the point of origin is no different than acceleration in that direction from the point of origin as far as time dilation is concerned.

Remember; both observers would see their own clocks �ticking� at a constant rate (and the velocity of light equal to c) throughout this journey.

Right now, I�m imagining a group of scientists gathered around a computer monitor somewhere out there in cyberspace ltao while reading my �explanation� of time dilation.

Review:
Starting at rest (no relative motion) from point of origin-
Acceleration brings about time dilation-
The greater your velocity (with respect to point of origin) the greater the time dilation-
The longer this velocity is maintained the greater will be the loss of time your clock will accumulate and show when compared with the clock at the point of origin.

[nancie]

the mind is now very boggled