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Types Of Clocks Which Have Actually Measured Time Dilation


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Anything that measures the passage of time is a clock. GPS satellites have to take time dilation into account to be accurate.

 

We know that time dilation and length contraction occur because the speed of light is always the same for every inertial object. If you think about how two objects that are in motion relative to each other could measure light moving past themselves at the same velocity, the only way is if they measure time and/or space differently. Either time dilates or length contracts. It's actually both because time and space are equivalent.

Edited by A-wal
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because the speed of light is always the same for every inertial object.

Gravity/the speed of "light"/causality (C for "constant") actually changes beneath the Planck length & for objects larger than the particle horizon.

 

This is why we get wave functions (quantum matter breaking apart beneath our relative Planck length) & why galaxies propagate at superluminal velocities.

 

This is all apart of exponentially special relativity.

Edited by Super Polymath
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Just a quick question: Is time dilation always measured by decay of radio isotopes? What sort of actual physical clocks have been used to measure dilation? What other evidence of time dilation is there that is as simple as that?

Light clock is a simple way of showing a basic feature of Special relativity. A clock is designed to work by bouncing a flash of light off a distant mirror and using its return to trigger another flash of light, meanwhile counting how many flashes have occurred along the way. It is easy to show that people on Earth watching a spaceship fly overhead with such a clock would see it ticking relatively slowly. 

https://simple.wikipedia.org/wiki/Light_clock

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Gravity/the speed of "light"/causality (C for "constant") actually changes beneath the Planck length & for objects larger than the particle horizon.

 

This is why we get wave functions (quantum matter breaking apart beneath our relative Planck length) & why galaxies propagate at superluminal velocities.

 

This is all apart of exponentially special relativity.

I don't think red-shift is a reliable enough indication that galaxies a reseeding, and definitely not at a rate faster than the speed of light.

 

I know that on the quantum level there's entanglement but that's not really a signal that's traveling. Quantum entanglement is truly fascinating.

Edited by A-wal
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Light clock is a simple way of showing a basic feature of Special relativity. A clock is designed to work by bouncing a flash of light off a distant mirror and using its return to trigger another flash of light, meanwhile counting how many flashes have occurred along the way. It is easy to show that people on Earth watching a spaceship fly overhead with such a clock would see it ticking relatively slowly. 

https://simple.wikipedia.org/wiki/Light_clock

I should clarify that I'm talking about material clocks that are reunited, but you get me thinking about an interesting question about the light clock. Unless the beam hits something, no one off-axis should be able to see the beam of light. Not only that, but the beam moves in a curve realtive to the perspective of the viewer. So if your closest point between viewer and clock is the mid point beween the mirrors; that actually makes both mirrors further from the viewer than the mid point.

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Think about a vertical light clock on a ship that's passing your ship. Each tick is a second and on board the ship they see the light going up and down so it's just makes a vertical I journey but you see the horizontal motion of the ship as well so the light clock on the other ship makes a WWWWWW pattern from your perspective, but light has a constant speed.

 

The light's horizontal velocity from your perspective reduces it's vertical velocity, and so reduces its tick rate. If the other ship were traveling at half the speed of light relative to you, you might expect the tick rate to be halved but that doesn't take length contraction into account. The ship, and therefor the light clock, are contracted in the spacial dimension of the relative motion, so the WWWWWWWW path gets squished horizontally and the amount of time dilation needed is reduced.

 

From their perspective, your light clock is making a WWWWWWWW path and you're the one who's time dilated and length contracted. These are measurement of length in time and space so anything that measures them will show it.

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I know that part. What I am saying is that relative to the focal points, the extents of the "clock" are thus farther from the viewer relatively. There must be a doppler effect and I'm not sure how that affects the results.

 

 

I'm not sure there is a mechanical clock accurate enough to show time dilation... 

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