Does Acceleration Affect Time Dilation?

[jbriggs444]

I know that if I'm deep in a gravity well, and you are not, then my clock will appear to you to run slower. Will your clock then appear to run faster to me? If so, the universe must look very strange with planets and galaxies spinning around > c.

Yes, a clock higher in a gravitational field will appear to run fast. Gravitational time dilation is not symmetric.

In special relativity, the speed of light is a global limit. Spacetime is flat and velocities here can compared with velocities there unambiguously. The speed of light is what it is (as long as we are all using inertial frames).

In general relativity, the speed of light is a local limit. Spacetime is not flat and comparing velocities here to velocities there is ambiguous. There is no such thing as an global inertial frame and the velocity that you get when you measure something far away depends on the coordinate system you use.

As we speak, you are sitting in a gravitational potential well. Does the universe look strange to you?

 

[timmdeeg]

No he doesn't die, because his atoms also slow down their heartbeat,

So if atoms slow down consequently molecules will slow down too. If water molecules slow down due to cooling the water freezes. So in case of our twin, the water in his glass will freeze, right? Not because of cooling in this case but because of the slowing down of the water molecules due to less aging.

 

[jbriggs444]

So if atoms slow down consequently molecules will slow down too. If water molecules slow down due to cooling the water freezes. So in case of our twin, the water in his glass will freeze, right? Not because of cooling in this case but because of the slowing down of the water molecules due to less aging.

The fact that you are, right now, moving very rapidly in the rest frame of a particle in an accelerator at CERN does not cause your body to freeze instantly.

 

[Raymond Potvin]

So if atoms slow down consequently molecules will slow down too. If water molecules slow down due to cooling the water freezes. So in case of our twin, the water in his glass will freeze, right? Not because of cooling in this case but because of the slowing down of the water molecules due to less aging.

If our own time dilation is unobservable, then any phenomenon that is happening inside us because of that is also unobservable. Length contraction is unobservable for instance, but without it, our data would be unexplainable. If our atoms' frequencies slow down with regard to an observer, then our molecules must slow down, our metabolism must slow down, everything we do must slow down. To me, that's the only way to explain relativistic aging anyway, otherwise we might as well invoke magic to explain the data.

 

[Raymond Potvin]

The fact that you are, right now, moving very rapidly in the rest frame of a particle in an accelerator at CERN does not cause your body to freeze instantly.

Hi Jbriggs,

The fact that we know the particle is actually accelerating with regard to us means that we know it is actually getting speed with regard to us, and we know it is not us that is getting speed because we know we are not accelerating, so we also know that it is the particle that is suffering more and more time dilation.

 

[A.T.]

The fact that we know the particle is actually accelerating with regard to us means that we know it is actually getting speed with regard to us,

Not if it goes in circles. Centripetal acceleration doesn't increase speed.

 

[timmdeeg]

The fact that you are, right now, moving very rapidly in the rest frame of a particle in an accelerator at CERN does not cause your body to freeze instantly.

I know, I was interested in the answer. I wasn't sure about the meaning of "slowing down" as Raymond Potvin understands it.

 

[phinds]

I know, I was interested in the answer. I wasn't sure about the meaning of "slowing down" as Raymond Potvin understands it.

Yes, but he DOESN'T understand it. He has not yet grasped differential aging due to different world-lines.

 

[timmdeeg]

If our own time dilation is unobservable, then any phenomenon that is happening inside us because of that is also unobservable.

It is unobservable for us, because in our frame nothing slows down which is at rest with us.

 

[phinds]

It is unobservable for us, because in our frame nothing slows down which is at rest with us.

Actually, it's not that this "slowing down" that he thinks is happening is "unobservable", it's that it IS NOT HAPPENING. In our rest frame there is no "slowing down", no "time dilation", no nuttin'. @Raymond Potvin you really need to come to grips with differential aging and world lines and stop with this nonsense about "slowing down".

 

[Bartolomeo]

Actually, it's not that this "slowing down" that he thinks is happening is "unobservable", it's that it IS NOT HAPPENING. In our rest frame there is no "slowing down", no "time dilation", no nuttin'. @Raymond Potvin you really need to come to grips with differential aging and world lines and stop with this nonsense about "slowing down".

Note: rotating absorber in centrifuge dilates himself. That's why observer on the rim of rotating disc sees, that that clock in the center ticks faster. Two rotating observers on the opposite sides of rotating disc will not see any dilation (though they are in relative motion) since they dilate themselves on the same magnitude. It is experimentally proven fact. Two inertial observers, that momentarily coincide with those rotating observers on the rim, will not see any dilation of each other clock.
An observer, who moves in reference frame of another twin, will see that other twin's clock is ticking faster since his own clock dilates - R. Feynman, Feynman Lectures, Relativistic Effects in radiation.

 

[PeterDonis]

Two inertial observers, that momentarily coincide with those rotating observers on the rim, will not see any dilation of each other clock.

Yes, they will, because they are moving relative to each other.

It is experimentally proven fact.

What experiment are you thinking of? Please give a reference.

An observer, who moves in reference frame of another twin, will see that other twin's clock is ticking faster since his own clock dilates

You are misinterpreting this and misapplying it as well.

 

[PeterDonis]

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