Thread: Relativity of the speed of time

I have recently been reading some books and listening to some of Hawking's tapes on theoretical physcs, and I when they came to the question of "What is time and what is its speed?" I though of something:

The space-time continuum is bent by mass and the time is what is being bent. Would it be true to say that the relativity of the speed of time of the Earth and another planet would just be e/x, where e is the Earth's mass and x would be the mass of another planet? The answer would then be taken into a percentage.

I know that this is just a very simple equation....REALLY SIMPLE, but I feel that I am missing something. Like could the mass of a planet not bend the continuum enough to significally change the speed of time or maybe it would on change the speed of time between two areas only like 1% or so.

HELP ME!!!!!!!

Time doesn't exist =)

It's not quite so simple. Basically I think the equation is:

Code:

Te / Ta = sqrt(   ( 1 - (2GMe) / (Re c^2)
                  -----------------------
                  ( 1 - (2GMa) / (Ra c^2)
)

Where:

Te is time rate on earth
Ta is time rate on alien world
G is universal gravitational constant
Me is mass of Earth
Ma is mass of alien world
Re is radius of Earth
Ra is radius of alien world.
c is speed of light in a vacuum

See wiki.

Well it depends on your definition of time.

My definition of time, is the continued interaction between factors (atoms). During this interaction, variability and probability is always affecting them. As time passes, outcomes (Interaction) occurs, atoms collide with each other. One atom colliding with another would be one outcome, this continued interaction between factors which produces outcomes is what I think the continuum of time is. So, if one was to argue this, time is relative. If no matter exists, no interaction exists, there aren't two points of reference, ergo, no time exists.

We can only measure time by comparing something to something else (The amount of time the sky is dark by the amount of time it is light). Time on Earth measured on a 24 hour interval isn't exactly measured by the lightness or darkness of the sky, but rather it is an invariable system which accurately allows one to predict when the sky will darken and lighten due to its referencing the darkening and lightening of the sky. The system is one point of reference, the darkening and lightening of the sky is the other.

So, I think time is completely relative, the equation changes when a new factor is added to be compared. Such is the variability of relativity.

In metric, they're very precise about what they mean by time:

"The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom."

If I understand it right, they mean that the radiation (light) a cesium 133 atom releases has a certain well defined wavelength ("color"), and so a second is defined as the time it takes for that radiation "beam"'s wave to go through a full period (down then back up) 9 billion times.

How does this fit in with your hypothesis? This definition doesn't require any interactions, or even matter. All you need is the radiation a cesium atom releases. You don't even need the cesium.

More to the point, how does that in any way have anything to do with the OP's question regarding the relative time rate for aliens on a different world from us? You didn't even address gravitational time dilation, which is at the heard of the OP's question.

you're saying (well hawking really) that space is bent by mass, so if that is the case do you think in scale where we are viewing the universe in a super macroscopic view (the outside of space) things that exist of that size would go through time slower? (for example if space is the inside of something the object we are in because of it's size, time would go slower(I know crappy example but can't think of a good way to ask))

The idea that mass bends time and space predates Hawking by quite a bit. I believe it's a pretty straightforward consequence of general relativity. Though maybe it even predates that? It's also pretty well empirically verified by experiments (the clocks of orbiting satellites in Geosynch run slightly faster than ground based clocks, for instance).

I'm really not following the rest of your post, but I believe this should answer your question: If you're on the surface of a planet, time goes slower for you than an observer in deep space. If you're weightless in orbit around that planet, you still experience that time dilation compared to an observer in deep space (although slightly less since you're further from the planet).