Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Isaac Lee on 12/02/2011 11:30:02

Title: Is time a constant?
Post by: Isaac Lee on 12/02/2011 11:30:02

Isaac Lee asked the Naked Scientists:
   
Hey Scientists!

Is time a constant? If not, is it possible to perceive a difference in the flow of time?

Thanks!

Isaac Lee
Grade 9

What do you think?

Title: Is time a constant?
Post by: yor_on on 12/02/2011 21:38:18

You and me seem to lean to the same side there Isaac :)
It is a constant, if we ignore all comparisons made between 'frames of reference'. You can invite anyone you like home to you, like phieew, Darth Wader, or Princess Leia (How dorky can one become?) from outer space, or the whole star trek crew, and then compare clocks to see if they agree. And they will. But as fast as they are back fighting in their death stars etc their clocks will show you the 'wrong time' if you make the same experiment, even after adapting to the distance between you.

But it doesn't stop their clocks from synchronizing their 'durations/seconds' etc with yours as soon as you teleport them back. so in a very weird way one could assume that there is one indifferent duration for us each, and also one that all other will share with us 'instantly' as soon as they come to visit. That 'times duration' will be the same for us all, meaning that we never will find time go faster or slower when tested against for example our heartbeats.

Title: Is time a constant?
Post by: Lamprey5 on 12/02/2011 21:59:48

Time appears longer in duration for a moving observer. This has been confirmed experimentally by measuring time on a very fast airplane using an atomic clock, and comparing the elapsed time with that measured in the same period on the ground.
So there is no "absolute time" per se. That is, not all observers will not agree on how much time has passed. The nature of time is described by special and general relativity. Time is intertwined with space to form spacetime, where space influences time through gravity and the curvature in spacetime it produces.

Title: Is time a constant?
Post by: yor_on on 13/02/2011 00:23:43

Well, that's the other side of it.

Doesn't mean that it is wrong to see it as a 'constant' though.
You can't really test a 'time dilation', except conceptually and theoretically. But you can test your heartbeats against a clock anywhere and it will give you the exact same durations, more or less :)

So there are two truths to it, although I suspect you and me are the only two developing this special interpretation of the theory of relativity, for the moment :) You're actually the first one I've seen asking that, and it's a really good question.

Title: Is time a constant?
Post by: syhprum on 13/02/2011 06:05:07

Time is a constant in as much as the second is one of the building blocks of the SI system of units corresponding to the the duration of 9,192,631,770 periods of the radiation of the cesium 133 atom.

Title: Is time a constant?
Post by: simplified on 13/02/2011 06:47:03

Travel in gravitation field slows down time of traveler.

Title: Is time a constant?
Post by: yor_on on 14/02/2011 07:01:02

You know, when I think of time as a constant I almost always end up with thinking of lights speed in a vacuum. Then how you split that into 'durations' will be of less importance to me. If you assume that light is a 'constant' you already made 'times arrow' one too, it seems to me? Eh, inside your own frame, that is :)