Absolute Zero Velocity - new questions

zenobia357

Most of the (amateur) net scientists seem to agree that absolute zero velocity does not exist. But this doesn't quite make sense to me. I understand that it would be impossible to slow an object to that speed, but I don't understand why there wouldn't be a an opposite to the speed of light.

That is to say, if the speed of light is the velocity at which an object would achieve infinite mass and would become infinitely compressed, etc., why wouldn't there be a speed at which it achieves infinitely little mass and infinite decompression?

Would this be same as saying that as an object approaches absolute zero velocity, it would gradually be changing from mass to nothingness - to empty space itself?

My high school physics teacher told me that you could measure such a speed because everything is always in motion relative to everything else.

But suppose we think of this again with reference to c, the speed of light. If two stars were on a collision course at velocity V, the light from star A would not travel to star B at c+V. It would be fixed at c, no? An observer could infer the speed of A from the wavelength of the light that he or she or it detects with some instrument, precisely because c is fixed. Could there be anti-light, composed of anti-photons that sit at absolute zero speed? Suppose we had an anti-light detector, but that instead of detecting the light hitting our device, we were detecting ourselves hitting the anti-light. The anti-light would be fixed in the same as the light. This
is now totally speculative, I know, but thought experiments can be pedagogically useful.

Maybe another way of asking my question is this: is c really the "speed of light" or is it just the constant of the universe?

Meaning, maybe I should think of the velocity of cosmic objects as the reverse of speeds on Earth. A car's speedometer measures its speed in relation to the planet's surface. There is no theoretical limit to the potential speed that a car could reach until one reads Einsien. Is it that there is no theoretical minimum speed to which one could "slow down" from c?

But again, wouldn't there be less and less mass and less and less compression as the thing slows down?

erikfriend

Short answer: There is a lower speed limit

Long answer:

Absolute zero velocity is only possible if absolute zero temperatures are also possible, which they aren't for the following 2 reasons.

1) If I understand correctly, velocity is included when calculating the energy of a mass. If a particle is at absolute zero velocity, then it stands to reason the particle would no longer possess any energy at all. Perhaps, this is the equivalent of empty space. But is empty space actually possible? If I'm not mistaken, space at the plank length always contains a minimal quanta of energy, sometimes referred to as zero-point energy, and consisting of virtual particles. Non-zero energy = non-zero velocity.

2) An object above absolute zero temperature would always have some finite velocity energy. Cooling an object to absolute zero theoretically requires infinite energy. Basically, it takes too much energy to prevent interactions with the object which impart energy into the object being cooled. It never reaches 0 degrees Kelvin, and therefore never stops moving.

This implies a lower speed limit on objects with an exponential curve of energy requirements as you approach 0, much like the exponential energy requirement at you approach the speed of light.

Please correct me if this is not accurate?

Any thoughts?

zenobia357

I'm afraid that I am in no position to correct you. Your comment/question:

"Perhaps, this is the equivalent of empty space. But is empty space actually possible?"

Is very helpful. It suggests that absolute zero velocity - energylessness - is a sort of unattainable limit.

Thanks.

Absolute Zero Velocity - new questions

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