Instead of spin I would be leaning more towards rails on a mountain but this requires more space but should be much more easier on payload
from wiki <https://en.wikipedia.org/wiki/Potential_energy> "In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors"
but a spinning disc in a vacuum would maintain energy indefinitely, taken as a whole, and the spinning disc is a stress in itself.
"In physics, the kinetic energy of an object is the energy that it possesses due to its motion."
The spinning disc has energy because of its movement. If it stops spinning (moving) it has no more energy. That is what people refer to when they say kinetic energy.
> In physics, potential energy is the energy held by an object because of its position relative to other objects
That would be when you put the disc on a high shelf and it falls on you.
> stresses within itself
When you take the disk and you bend it into an S-shape and it is trying to spring back.
> a spinning disc in a vacuum would maintain energy indefinitely
Assuming frictionless bearings perhaps. But what does that have to do with anything?
> spinning disc is a stress in itself.
Not in the way physicist think about it. On the other hand, watching a spinning disk is full of stress! Just think of the last scene of Inception.
> Assuming frictionless bearings perhaps. But what does that have to do with anything?
Thanks for this, let me elaborate. First, yes, magnetically suspended. That given, take a box containing some quantity E of energy in the form of petrol or TNT, whatever. Chemical energy.
Next take a box containing aforementioned disk, spinning with an energy also of E.
From the outside there is no observable difference if both they are left sitting on a warehouse floor untouched, however the box with E of chemical energy is potential energy, the box with the spinning disk has kinetic energy, according to your definitions. Yet they are indistinguishable from without. That's my puzzle.
(I'm being slowposted so replies may take a while)
Sorry but I don't see the puzzle. Are you expecting some "different things need to be able to be distinguished when left sitting on a warehouse floor inside a box, untouched" principle?
> I'm being slowposted so replies may take a while.
No worries. And sorry that that happened.
Therefore you can't say which one contains kinetic energy (the box with the spinning disk) and contains the potential energy (the box with petrol in it).
If you can't distinguish kinetic from potential in this circumstance, does the definition of 'kinetic' and 'potential' have any rigorous meaning? I'm fine if they don't, I'm just trying to understand.
They're still different forms of energy even if you can't see which is which from the outside of a (non-transparent) box. Like, if you have a red ball in one and a blue ball in the other, you can't see from the outside which colour ball is in which box either. Does that mean "the concept of colours doesn't have any rigorous meaning"? No, it just means the concept of being in a non-transparent box has the rigorous meaning that you can't see what's going on inside it.
Same here. Energy E will hang around for unlimited time until you extract it. I dunno. Anyway, thanks.
You know what else can't be distinguished when they sit in boxes in a warehouse (just by looking)? Bricks and teddy bears.
Do you find that they also lack a rigorous meaning? :)