rate of movement through time

According to special relativity, essentially as you move faster through space you move slower through time. When we talk about rates, such as velocity, we're talking about something happening per unit time. So what's the rate when that "something" is time? If we think about time as a fourth spacial dimension, can we consider the rate as time per unit space? But, relativity also indicates that space changes with velocity - a meter is shorter at faster speeds (relative to the length in the slower reference frame).

So, really the question now becomes: what are the absolutes? Is there an absolute time? An absolute space? I would imagine that the absolute fastest rate though time occurs when velocity is zero. But, we then need absolute velocity! Is it possible that there are no absolutes? Everything must be considered relative to something else??

I was just curious if anyone had seen any theories on this, or if you had any theories of your own?

Relativly speaking you move faster through time as you age. When you are 2, 1 year is half your life, 20, the same amont of time is 1/20th your experience.

If the Earth were slowing/spinning at a noticible rate, minutes+/- a day range how would a normal human notice the change assuming there was a conspiracy to keep the changing the clocks.

I like to assume we are going the speed light through time.

Relativity is about different observers. You can not describe movement without a reference point. For you, wether you're in a spaceship moving away from the earth at 0.9c or you're on earth, your velocity four vector u (t/τ, x/τ, y/τ, z/τ ) is always (1, 0, 0, 0). τ is the so-called proper time, which is defined by dτ = dt/γ (source).

The difference in the rate of time is only noticed by inertial observers that see you moving. It depends on who watches how fast the time in your ship is seen moving.

[Edited on 2-5-2004 by amantine]

Maybe, if there were an observer outside of our universe, and that observer was at absolute rest, what they observed when they observed our universe could be construed to be an "absolute" time and space.

But I wouldn't bet on it.

Maybe that's a good definition of god, though.

lol dnt u jus luv temporal physics? i thought time waz jus releativ 2 the obsever, as an object nears the speed of light, its relativistic mass increases until, at the speed of light, it becomes infinite. Accelerating an infinite mass any faster than that is impossible, or at least it seems to be right now... ....but dnt u wish it cud b

The whole infinite mass thing is very interesting. It brings up the issue of multiple infinities, which is an area of mathematics first developed by George Cantor that I don't know much about. It also brings up the issue of what happens to the surrounding universe if something with mass, say a spaceship, is accelerated to 99.999...% the speed of light.

What happens to the gravity well the spaceship creates? Does it get deeper and deeper, attracting more and more matter, making the spaceship more and more massive? Does the spaceship fall in on itself and become a black hole? Is it less dense, more like a neutron star, perhaps? If it creates larger and larger distortions in the spacetime fabric, does it have an affect on the way time is experienced by other nearby things with mass?

I have good math, but I'm not a physicist. Are there any physicists out there who can answer my questions? Or point me to some answers?

amantine - right, we use relativity to compare observers in different reference frames. It's kinda of interesting that if I see a car drive by me, without the reference of the earth I wouldn't be able to tell if it was me or the car that was moving. In fact, either or both could be right (maybe we're moving towards each other!).

You did answer one of my questions - the rate through time could be considered time per proper time - it's dimensionless, which I guess makes sense.

The absolutes I'm talking about would be when you compare any reference frame to one that is fixed in space. If the universe is finite, then such a reference could be determined. If the universe is infinite, however, then there really wouldn't be a truly stationary pont, at least, not that we could determine.

So this brings up an interesting question - when we talk about the age of the universe, what reference frame are we in?

wait, so if you were in a space where there were no glaxies and stuff and you were watching all these galaxies zoom around(lets say theres no speed limit to light to view them) they are travelling at about 50% speed of light some of them, wuldn't they gain all this extra mass? - so that nothing we measure is the true mass, or does the frame of reference also effect the increase in mass due to speed?.

Originally posted by quiksilver
wait, so if you were in a space where there were no glaxies and stuff and you were watching all these galaxies zoom around(lets say theres no speed limit to light to view them) they are travelling at about 50% speed of light some of them, wuldn't they gain all this extra mass? - so that nothing we measure is the true mass, or does the frame of reference also effect the increase in mass due to speed?.

You percieve them as having extra mass, if you had some way to measure this. This is not as easy as you might think. You don't notice anything in the gravity, because the components of the stress-energy tensor use the rest mass. This also solves one of the questions most people have: if you accelerate a particle enough, does it become a black hole? It doesn't, become the gravity depends on the Einstein tensor Gab = 8*pi*Tab, and Tab is the stress-energy tensor, which only uses the rest mass, not the relativistic mass.

An observer also never sees himself change. Time also goes the same in his spaceship and everything in the spaceship has the same mass. You percieve your environment as changing.

Originally posted by amantine
This also solves one of the questions most people have: if you accelerate a particle enough, does it become a black hole? It doesn't, become the gravity depends on the Einstein tensor Gab = 8*pi*Tab, and Tab is the stress-energy tensor, which only uses the rest mass, not the relativistic mass.

Thanks, amantine. I always wondered about that.

"In part the misunderstanding arises because of the use of the concept of relativistic mass in the equation E = mc2. Relativistic mass, which increases with the velocity and kinetic energy of an object, cannot be blindly substituted into formulae such as the one that gives the radius for a black hole in terms of its mass. One way to avoid this is to not speak about relativistic mass and think only in terms of invariant rest mass." (source)