B Thought experiment to compare the present with the future flow of time

[witold]

Let's assume that we can build a kind of a perfect Faraday cage 1x1x1 meters, which contains today's cosmic background radiation with its peak wavelength and density. Radiation in the cage cannot escape from it, and the external radiation cannot penetrate it. Now let's mount the perfect clock in the middle of the cage, place the cage in the intergalactic space and start the clock. Will it show the same time and tick at the same rate as the clocks outside the cage in the distant future, when the CMB's redshift will be twice as large as it is today? The clocks outside the cage are also started today and they are also in the intergalactic space, next to the cage.

 

[Ibix]

Yes, assuming we can neglect the gravitational effect of the mass of the box itself.

 

[witold]

Extra question: Does the clock placed inside the microwave oven tick slower than the one on the casing, that measures the baking time?

 

[Ibix]

Yes, assuming we can neglect the gravitational effect of the mass of the microwave oven itself. And that the microwave doesn't damage the clock inside.

 

[witold]

Is there a qualitative difference between the Faraday cage with the cmb radiation in the first case, and the microwave oven in the second in terms of the clocks ticking rates? In the first case we can wait for the external cmb's temperature to drop to 0.001K, but inside the cage it will still be 2.7K.

 

[Ibix]

What do you mean by a "qualitative difference in tick rates"? A tick rate is just a number.

Basically, the tick rate of an ideal clock is not affected by the presence of microwaves around it. Two clocks can acquire different tick rates due to inhomogeneity in the matter around them, which is why I assumed we were neglecting the mass of the box/microwave. If you want to put that in the effect would be one part in ten to the twenty-something, and the effect of the box is many orders of magnitude larger than any difference due to the energy of the radiation inside the box, let alone any difference in that die to the different radiation spectra. They might acquire a fraction of a second difference over the period waiting for the CMB temperate to drop by half, but there definitely wouldn't be a factor of two difference in their elapsed times.

 

[witold]

They might acquire a fraction of a second difference over the period waiting for the CMB temperate to drop by half, but there definitely wouldn't be a factor of two difference in their elapsed times.

How about the difference in the ticking rates of the clocks outside the cage today and the clock inside the cage that captured the cmb at the temperature of 3000K at the moment of its emission and it's still with us today, when the cmb's temperature outside the cage is 2.7K? I neglect the gravitational effect of the cage.

 

[berkeman]

It turns out that this OP is a sockpuppet of a temporarily-banned member, so this thread is now closed.