Comment by Terr_
19 hours ago
I'm sure I'm not the only one who thought "why not vacuum", so I went and found the creator's reasoning [0] for why it's not a priority:
> [I]nside the dome the air quickly ends up rotating at the same rate as the rest of the mechanism. It's reaching its design speed with the motor at less than half duty cycle. Even if it were practical to make the whole thing airtight, it doesn't solve a problem that I currently have. The sound it makes doesn't come from inside the dome but from the motor in the base.
[0] https://www.youtube.com/watch?v=pcAEqbYwixU&lc=UgygtRUb6XZyu...
[Self-reply with side-topic] Assuming a rectangular display rotating in standard air... what glass enclosure would be best?
My intuition says "change the sphere to a cylinder", because then we can minimize how much air could be passing around the sides and top of the display-rectangle, potentially curling around and causing turbulence and noise.
However, that introduces a new issue of visibility: Big flat surfaces have different glare/reflection problems than a spheroid does. It may become harder for the user to see clearly, whether from external glare or from internal reflections in a dark room. What if the top face of the glass cylinder was very slightly curved outwards, to avoid the worst-case scenario where you just can't look down into the device from certain angles? Depending on the refractive index of the glass, it could just be a thicker top, so that it doesn't create dead-space on the inside.