[hamdani yusuf (OP)]

Your fallacy is in confusing gross motion of a body with thermal motion of the particles inside it..

What's the fundamental difference between gross motion and thermal motion? If you can answer this question, then this thread can be satisfactorily closed.

[alancalverd]

Thermal motion is the displacement of particles within[ a body relative to each other and (in the "one particle " case, or) the boundaries of the body.  Gross motion is the displacement of the entire body relative to other bodies.

[Bored chemist]

What happens to its angular momentum? Will it be conserved?

Yes.
And I didn't need to read the rest of your post.

Are you sure that the laser doesn't carry away some of the system's angular momentum?

Not if it's set up to point away from the system's centre of mass.

[Bored chemist]

You can't ask how something happens without concluding that the thing happens.

A conclusion is

a judgment or decision reached by reasoning.

the necessary consequence of two or more propositions taken as premises

You are confused between conclusion and proposition.

You are muddling the question of "does this happen?" with the question of "how does this happen?".

The second only makes sense if you already concluded  that the answer to the first is yes.

[hamdani yusuf (OP)]

You are muddling the question of "does this happen?" with the question of "how does this happen?".

The second only makes sense if you already concluded  that the answer to the first is yes.

In mathematics, there's an example for this kind of argumentation.
The question is : is there an infinite number of prime?
The first step is to assume that there is a finite number of prime.
And then describe its implications. By showing that some of those implications contradict each other, we conclude that the assumption is false.

[Bored chemist]

Yes, but that's not what you were doing.

[hamdani yusuf (OP)]

Yes, but that's not what you were doing.

Do you think the system will not deplete its energy?

[hamdani yusuf (OP)]

Thermal motion is the displacement of particles within[ a body relative to each other and (in the "one particle " case, or) the boundaries of the body.  Gross motion is the displacement of the entire body relative to other bodies.

How about a gas in a container vibrating when a sound wave is passing by? Will it be the same with liquid or solid?

[alancalverd]

You can indeed heat things by shaking them. If the gas or liquid has nonzero viscosity, some of the kinetic energy of shaking the walls is transferred to the fluid. Friction heating of a solid is the same thing - we routinely use ultrasonic welding for plastics.

[hamdani yusuf (OP)]

You can indeed heat things by shaking them. If the gas or liquid has nonzero viscosity, some of the kinetic energy of shaking the walls is transferred to the fluid. Friction heating of a solid is the same thing - we routinely use ultrasonic welding for plastics.

Is the vibration classified as thermal energy?

[alancalverd]

The result of vibration is thermal energy.

[hamdani yusuf (OP)]

The result of vibration is thermal energy.

Before it's converted into thermal energy, vibration wasn't thermal initially.

[alancalverd]

How very true. And before you applied the brakes, the car had kinetic energy, which turned into heat in the brake discs or electrical energy via the regen system. So what?

[hamdani yusuf (OP)]

How very true. And before you applied the brakes, the car had kinetic energy, which turned into heat in the brake discs or electrical energy via the regen system. So what?

What's the fundamental difference between gross motion and thermal motion?

[Bored chemist]

What's the fundamental difference between gross motion and thermal motion?

Direction.

[alancalverd]

By the age of 6 months, a dog knows the difference between inside and outside. You can move around inside the car, but after a few miles of gross motion you get out to pee.

[hamdani yusuf (OP)]

What's the fundamental difference between gross motion and thermal motion?

Direction.

What's the direction that makes a motion thermal, and what direction makes it non-thermal?

[alancalverd]

Thermal motion is random and uncoordinated, which is why things don't accelerate in a single direction when they get hot - that would be gross motion.