Timeline for Would a spinning object like a fan stop faster in a non-gravity environment?
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
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| Sep 21, 2017 at 16:49 | vote | accept | baranbaygan | ||
| Sep 18, 2017 at 23:09 | comment | added | EL_DON | Now that we come to deformation and vibration of the fan, wouldn't a vertically oriented fan supported against gravity be stretched away from / squished toward its axis by gravity at its bottom / top, and wouldn't this deformation be more significant than tidal forces? | |
| Sep 18, 2017 at 18:12 | history | edited | Floris | CC BY-SA 3.0 |
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| Sep 18, 2017 at 14:38 | comment | added | Floris | @EL_DON You are right that there is the assumption in my answer of some loss mechanisms in the solid, and again that if you cannot excite a loss mode, there would be no lost energy; as for the latter part, the existence of vibration in the fan (as it is at non-zero temperature) will probably imply that there is an "effective continuum" of energy states available (if the material is lossy, it will also not be a perfect crystal lattice, so there will be some spreading of modes). I admit that is more intuitive than rigorous... | |
| Sep 18, 2017 at 13:59 | comment | added | EL_DON | @Floris I'm suggesting that the drop in energy might be so low that yes, you might have trouble exciting even 1 quanta of whatever wave you're dissipating energy into (probably some vibrational mode in the fan). So, you could lose 0 energy in a minute. This would not make your answer wrong from a classical perspective, but it's fun to think about. | |
| Sep 18, 2017 at 13:53 | comment | added | EL_DON | Tidal forces will certainly act on the fan, but will they do any net work on its rotational energy if the fan is rigid? I thought deformation of objects like planets due to tidal force was essential to the drag on rotation. | |
| Sep 18, 2017 at 13:53 | comment | added | Floris | @EL_DON are you saying "it cannot be measured" or are you implying "it will lose zero energy"? Because if it loses zero in one minute, it will lose zero in one day, one year, one eternity. And that's patently false. | |
| Sep 18, 2017 at 13:47 | comment | added | EL_DON | The amount of energy lost to tidal friction in 60 seconds for a human scale fan on Earth's surface is so small that I wonder if it's less than the Planck energy. | |
| Sep 18, 2017 at 13:11 | comment | added | M.Herzkamp | Don't forget the barometric pressure gradient, which is absent in zero-g. It might be dependent on whether the fan is upright or flat, and in which direction it is blowing. | |
| Sep 18, 2017 at 11:40 | history | answered | Floris | CC BY-SA 3.0 |