Does a rotating object lose energy over time...

Does a rotating object lose energy over time? If you spin a top in an otherwise empty infinite space how long will it spin for?

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don;t know, I'm a brainlet.
but i think it losses energy

no, there's a thing called inertia.

Objects at rest tend to stay at rest. Objects in motion tend to stay in motion. It will probably keep spinning in your hypothetical space which I’m assuming you’re supposing has no gravity acting on it. The problem is this becomes hypothetically impossible because of the effect of dark matter which we can measure the gravity of but otherwise can not detect. You could theoretically hypothesize a region of spacetime without the effect of dark matter but now you’re taking about something that probably doesn’t exist.

>dark matter is a prerequisite to space existing

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Yes because the components of a spinning object experience centripetal acceleration - this means that things like charges in the top are being accelerated and producing electromagnetic radiation, which slowly makes it lose rotational energy.

It would emit infrared radiation.

Friction

Why would gravity affect rotational motion? Aren't the air resistance and friction between the spinning object and the surface the only forces that slow it down?

If there are no other forces acting on it then it will rotate forever.

If your infinite empty space has nothing else in it but the top, there is nothing to compare its rotation against so it cannot be proven to be spinning.
"If a tree falls in a forest and nobody hears it, does it make a sound?"

Can we test this theory by putting a deaf guy in a forest and wait for a tree to fall? Has anyone tried it?

It wouldn't work because deaf people can feel vibrations. It's just a thought experiment.

What about a deaf guy who is also paralyzed so he can't feel anything? Is that even possible? I guess it'd be hard to prove he's really deaf too since some people fake it for disability money, or might think they're deaf but actually have imperceptibly functional hearing. I'll think more about it and get back to you.

Alright, make way brainlets, scientist coming through.

The question at hand is whether the rotational energy of the top will turn into any other type of energy over time.

According to classical mechanics, the answer is no, because of conservation of momentum. In the absence of any other factors, classical mechanics tells us that it will never stop spinning, as long as you've set it to spin on a stable axis.

Quantum mechanics says that, if the materials in the top have enough energy, then they may emit broadband quadrupolar radiation, which will in the process diminish the rotational energy of the object. This is not likely to be significant for a top, but will be substantial for say a neutron star (see period decay of pulsars for an example).

General relativity says that, if the shape of the object is asymmetric or time variant about its axis of rotation, it will emit gravitational waves which will slow down its rotation rate. Again, this will likely be negligible unless the object is very massive.

Materials science says that, if the material of the top is not perfectly rigid, then the material will deform over time, increasing its moment of inertia along its rotational axis and slowing its rotation. For an example, see how the Earth is elongated along its equator.

Chemistry and statistical mechanics say that, assuming a regular top under regular conditions in intergalactic space, the materials comprising the top will most likely decompose well before any of these effects come into play.

So, tl;dr: no, the top will not stop spinning.

Didn't he pass away recently?

So that's why Veeky Forums was freaking out recently. We lost our best shot at learning what happens when trees fall in vacant forests.

If you assume angular momentum is conserved, then the top spins forever.

Each point on the obect is accelerating so it has to lose energy.

assuming it's a perfect vacuum then no it will never stop spinning

It will spin until its batteries die. How long that takes depends on what types it uses and how efficiently it uses them.

Tiny imperfections in the top cause one part of it to be pulled differently then another part causing drag.

thanks elon

If the top is levitating in a vacuum it will spin until it is disturbed by an outside force.
If the top is in a vacuum chamber spinning on a tabletop it would depend on the amount of friction between the top and the surface it's on, the less friction the longer it will spin.