4 ms·
Diamond Age also posited ‘aerostats’ - macroscopic diamond structures that are structurally solid, but contain nothing but vacuum, enabling them to be used to
by jameshart 3y ago
Diamond Age also posited ‘aerostats’ - macroscopic diamond structures that are structurally solid, but contain nothing but vacuum, enabling them to be used to generate buoyancy in air. Not sure how realistic the material physics of those is.
- tbrownaw 3y agoApparently this is barely doable with current aerogels: https://www.reddit.com/r/AskEngineers/comments/1c87pum/crush_strength_of_a_vacuum_filled_aerogel_sphere/ https://www.reddit.com/r/AskEngineers/comments/1c87pum/crush...
- fmajid 3y agoWhy choose? There is such a thing as diamond aerogels: http://www.popsci.com/technology/article/2011-05/new-diamond-aerogel-least-dense-diamond-ever-made http://www.popsci.com/technology/article/2011-05/new-diamond...
- Terr_ 3y agoI'm no physicist, but I'm inclined to try some contextual napkin math, and hopefully I won't botch it too badly trying to work on my phone as opposed to proper spreadsheet. If we assume a 1m³ vacuum container at sea level, that's displacing ~1200g of air. So that's the upper mass limit on the diamond container (or foam) for it to be neutrally buoyant. Let's assume the density of diamond is 3.5 g/cm³, which means the volume of diamond "skin" we have to work with is something less than 342 cm³ for whatever gets built. A sphere with a volume of 1m³ has a surface area of ~48,300 cm², which means we can't go thicker than 0.07mm. The most common thickness for mechanical pencil refills is 0.50mm. That said, I'm sure there is some square-cube law business in favor of much smaller chunks, like a bubble-foam of smaller vacuum-cells.