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Once you accept that time measurements disagree between observers, then point (2) tells you that the laws of physics for each observer within their reference frame seem to work according to their personal clock. This includes biological processes, such as aging. According to their own points of view, Tony and Paula would appear to age normally and time would appear to flow normally for them. But if they compared their clocks, they'd find disagreement.
Since the light originated from 1 train length in front of her and appears to her to be moving at the speed of light, it only takes 1 tick of her clock for the light to reach her. Since Tony is further ahead of her, she deduces that the light passed Tony in under 1 tick.
There must be something wrong here, but I can’t see it.
What does an outside observer, who perceives himself as being stationary relative Paula, observe? Assuming the light is a single, very brief flash he does not observe the source as moving, but he does see Tony moving towards the source. He sees light travelling at “c” and Tony travelling at half that speed. Therefore, he sees the light as reaching Tony in 1 tick, but Tony’s clock took 2 ticks, so in the F of R of the outside observer, Tony’s clock is running faster, but he perceives Tony as moving relative to him.
How does light decide how quickly or slowly clocks, either mechanical or biological, run?
Jartza - I have trouble linking the the spinning spring with time dilation. I presume that spin and expansion are all at non-relativistic speeds and there is something in the combination of motions that triggers a similarity in your thoughts - I cannot see that similarity, perhaps you could explain.
why does the spreading of a beam of light get _slower_ when a spotlight pushed?
Quote from: Jartzawhy does the spreading of a beam of light get _slower_ when a spotlight pushed? I'm not sure that I have grasped this. The speed of light does not change, so in what sense does the "spreading" slow down; and in which F of R does this happen?
Now we push the spot light, direction of the push is the direction of the light beam. When the spotlight is moving the distance between two randomly chosen photons grows slower, on the average, because the beam is a narrower beam now, in the F of R of the table.
4. “But when a spinning cannon shoots a cannon ball, the cannon ball's spinning does not change.” Why would it not change in the F of R of the observer?
Because of it's velocity with respect to the observer.
BUT the cannon ball shot from a spinning cannon spins at the SAME rate that it did spin when sitting in the barrel, in F of R of the observer.
When the canon ball was in the barrel, it, the canon and the observer were in the same inertial frame. Once fired, it is no longer in that inertial frame, so although its rotational rate, in its own F of R remains the same, it appears slower when viewed from the F of R of either the observer or the canon. Right?
Now what if we accelerate ourselves into the flying gyroscope's F of R ?Well, we observe that spinning of the gyroscope accelerates when we accelerate.
Quote from: JartzaNow what if we accelerate ourselves into the flying gyroscope's F of R ?Well, we observe that spinning of the gyroscope accelerates when we accelerate.I'm not clear what you are saying here. Are you saying (1)that the spinning of the gyroscope accelerates relative to us as we accelerate in the course of moving ourselves into the F of R of the gyroscope; or (2)that it would accelerate if the whole system accelerated, after we had arrived in the gyroscope's F of R?If (1), I see no problem.If (2), why?
Jartza, I've just returned to this thread and read your last post, several times. there are a couple of things I don't understand.1. Why should the spinning/not spinning of the exhaust make a difference to our perception of the spinning of the rocket?
2. Why should these factors impose any speed limit (other than c) on the rocket?
They don't teach the law of conservation of mass at school. So maybe I should start a thread about conservation of mass.
So the explanation of time dilation is that there is no time dilation, but there are some cases when something slows down when something else speeds up.
One way to accelerate a flywheel is to put it in a rocket. In the rocket a clock slows down because of time dilation, and the flywheel slows down because of Coriolis force. If we eliminate the Coriolis force, a person with his brain slowing down observing a flywheel that is not slowing down, will say that "this flywheel is speeding up".
No he won't. if "his brain is slowing down" - you mean he is in the rocket too, yes? But the flywheels being exposed to the same time dilation as the astronaut so his observation of it would be as normal.If the flywheel were back on Earth and slowing (although I'm not certain how this would be down to the Coriolis effect), he might observe no change in its speed if the acceleration of his ship was just acceleration of his right.
Here's a method to accelerate a spinning disk:You place the disk horizontally. Under the disk there should be an "under disk"The under disk must always spin like the upper disk, sensors and motors take care of that. Then there is a mechanism that gives every part of the upper disk regular kicks, this "kick unit" is attached to the under disk. Now we have managed to produce such kicks that don't affect the spinning of the upper disk....And this way time dilation effect is eliminated from the spinning of the disk.
This may be too far beyond my intellect, but I've really no idea what this device is or what relevance it has to time or its modulation.I may regret suggesting this, but how about a diagram?
And this way time dilation effect is eliminated from the spinning of the disk
Let's say SH is exerting radiation torque on an object that is free to spin.
In which F of R is the time dilation effect eliminated?
One of these?http://en.wikipedia.org/wiki/Crookes_radiometerAll these 'devices' are lovely, but they seem to have little to do with time or effects on it. Please stick to the thread (if you must at all).
Quote from: peppercorn on 22/11/2010 16:22:06One of these?Quit fretting 'Device' 2 is the same device as 'device' 1.By device 2 if was clarifying device 1 for you.So here's device 2:Spinning hotplate emits photons, that carry angular momentum to a black object, that experiences torque.
One of these?Quit fretting 'Device' 2 is the same device as 'device' 1.By device 2 if was clarifying device 1 for you.So here's device 2:Spinning hotplate emits photons, that carry angular momentum to a black object, that experiences torque.
Again, perhaps diagrams have a chance to 'illuminate' me and any others not so able to make the, erm, intuitive jumps.