4 ms·

It would still slow down. The blackbody radiation output by the wheel would cool it down, and in the same way, all the electrons the wheel is made out of will r

It would still slow down. The blackbody radiation output by the wheel would cool it down, and in the same way, all the electrons the wheel is made out of will radiate energy as they are spun. (Spinning charges are constantly accelerated by centripetal force, and accelerated charges radiate.) So no, 2nd law of thermodynamics means you can't even keep pace, you are always losing energy. So how can these scientists claim to have invented perpetual motion?

neatze 5y ago
This is how I am reading it as an wheel analogy; 1. Maintaining vacuum state costs energy. 2. Using energy you can change wheel rotation from clock wise to counter clockwise. 3. By using energy when changing wheel ration, wheel rotation energy is not effected. I am almost sure it is false thought :)
space_fountain 5y ago
Hum, guess I'm definitely exposing my lack of physics knowledge, but my understanding was that entropy is only guaranteed to increase or stay the same in any isolated system. That the inequality is >= not >. If so while like this exact example might not work, there isn't anything clearly wrong with something that just has repetitive motion
drdeca 5y ago
The wheel has an overall neutral charge. Does this change whether it emits anything from these charges rotating? If we are modeling thing with classical electromagnetism (I don’t understand enough to attempt to apply quantum mechanics to this), we can treat point charges as having a Dirac delta function for their charge density function. If you take linear combination of Dirac delta functions, with each having a positive or negative coefficient, and these being roughly evenly spaced out in a fixed region (e.g. the wheel shape), and take the limit as the magnitude of the coefficients goes to zero while the number of deltas goes to infinity (with the two being inversely proportional), shouldn’t the correspond signed measure converge to the zero measure, so, a charge density function of zero? So, shouldn’t a macroscopic object (which has a very large number of atoms) be well approximated as having zero charge density? Of course, this is only an approximation, it doesn’t have exactly zero net effect on the electric field, but if it is a good approximation, especially at a distance, I would think that would suggest that such an object accelerating should produce at least less EM radiation than a similar object with a large net charge? But, I’m reasoning heuristically atm, and am not being especially careful, so I could very well be wrong here.

neatze 5y ago

This is how I am reading it as an wheel analogy; 1. Maintaining vacuum state costs energy. 2. Using energy you can change wheel rotation from clock wise to counter clockwise. 3. By using energy when changing wheel ration, wheel rotation energy is not effected. I am almost sure it is false thought :)

space_fountain 5y ago

Hum, guess I'm definitely exposing my lack of physics knowledge, but my understanding was that entropy is only guaranteed to increase or stay the same in any isolated system. That the inequality is >= not >. If so while like this exact example might not work, there isn't anything clearly wrong with something that just has repetitive motion

drdeca 5y ago

The wheel has an overall neutral charge. Does this change whether it emits anything from these charges rotating? If we are modeling thing with classical electromagnetism (I don’t understand enough to attempt to apply quantum mechanics to this), we can treat point charges as having a Dirac delta function for their charge density function. If you take linear combination of Dirac delta functions, with each having a positive or negative coefficient, and these being roughly evenly spaced out in a fixed region (e.g. the wheel shape), and take the limit as the magnitude of the coefficients goes to zero while the number of deltas goes to infinity (with the two being inversely proportional), shouldn’t the correspond signed measure converge to the zero measure, so, a charge density function of zero? So, shouldn’t a macroscopic object (which has a very large number of atoms) be well approximated as having zero charge density? Of course, this is only an approximation, it doesn’t have exactly zero net effect on the electric field, but if it is a good approximation, especially at a distance, I would think that would suggest that such an object accelerating should produce at least less EM radiation than a similar object with a large net charge? But, I’m reasoning heuristically atm, and am not being especially careful, so I could very well be wrong here.