I Is there such a phenomenon as "micro-frame drag"

[negativzero]

TL;DR Summary

I've read that some energetic electrons are moving at more than half the velocity of light in gold atoms. Does electron velocity in any way affect paths of particles, photons of any frequency for instance, that would amount to frame drag?

It doesn't seem likely given that electrons in copper wire move even faster and i can't find anything on electric circuits creating frame drag. I don't expect anyone to tell me why there is no micro-frame drag . Likely the question itself contains some false assumptions. And thanks for your kind attention.

 

[PeterDonis]

Does electron velocity in any way affect paths of particles, photons of any frequency for instance, that would amount to frame drag?

Do you mean frame dragging as in the kind that was detected for the Earth by Gravity Probe B? As in, the General Relativity effect?

If so, the answer is that electron masses and spins are way, way, way too small (as in, something like 50 orders of magnitude too small) to produce frame dragging. The fact that the electrons are moving at relativistic velocities doesn't change that.

Note, btw, that it is not really correct to say that electrons in gold atoms are moving at relativistic velocities (although a lot of sources will describe it in this sloppy way). The electrons in atoms don't have definite velocities. But they do have definite energies; and the electrons in gold being relativistic means their energies are relativistic (i.e., total energy is significantly more than rest energy).

 

[vanhees71]

The upshot concerning the gold atoms is that you have to use relativistic QT to describe the atomic state. Otherwise you don't even get the correct description of the color of gold.

 

[negativzero]

Thank you for your replies. Can I take from this that unlike quantum gravity, quantum frame drag is not an area of inquiry, especially not in the case of non-massive objects?

 

[PeterDonis]

Can I take from this that unlike quantum gravity, quantum frame drag is not an area of inquiry

I'm not sure what you mean by "quantum frame drag". Your original question said "micro frame drag", which I took to mean the frame dragging that appears in classical GR around a rotating massive body. But that has nothing to do with anything quantum.

Since any quantum gravity theory will have to reproduce the predictions of classical GR in the regime where the classical approximation is valid, any quantum gravity theory will predict the usual classical GR frame dragging in cases where it occurs. Whether there would also be some quantum form of frame dragging, different from that, is impossible to say until we have an actual validated quantum gravity theory.

 

[negativzero]

Again, thanks. I've been looking around at what is available to quantum pictures and what is not. Along that line I've wondered about the "quantum nature of the vacuum" and if that has anything to do with the "quantum nature of space" or if space is considered as a geometric feature that's not quantifiable?
I hope I'm not straying too far from the original topic and if this thread is discontinued I'm fine with that, and gratified.

 

[PeterDonis]

I've wondered about the "quantum nature of the vacuum" and if that has anything to do with the "quantum nature of space" or if space is considered as a geometric feature that's not quantifiable?

In quantum field theory as it currently exists, spacetime is not quantized; it's treated as a fixed background geometry.

However, since quantum fields carry energy, we expect them to act as sources of gravity and therefore to affect the curvature of spacetime. So it seems like a correct theory should include some way for the curvature of spacetime to have quantum properties as well. That is a key motivation for the search for a theory of quantum gravity. But we don't have one yet.

 

[negativzero]

Your comments are illuminating. My thinking is stuck here on a, "What if?". What if there is no quantum of space? Having little imagination, all I come up with is that space must be purely a geometric result of mass energy. When I write, "stuck", I refer to the fact that I come to this vague conclusion that no physicist would agree with, and a niggling question, "If space requires the presence of mass energy then, what is 'presence'?" The notion of presence seems to have space nested in it somewhere. It would be intellectually convenient if space was like a 3D graph paper, not made of cubes, but of the tiniest tetrahedrons mapping out the paths and intersections of particles. That would be a simpler geometry I expect.

 

[PeterDonis]

My thinking is stuck here on a, "What if?".

Please review the PF rules on personal speculation.

The OP question has been answered. Thread closed.