4 ms·
It's very very close to vacuum - 0.015 psi (99.85% vacuum). For all practical purposes, calling it vacuum is very reasonable.
by olegkikin 10y ago
It's very very close to vacuum - 0.015 psi (99.85% vacuum). For all practical purposes, calling it vacuum is very reasonable.
- mikeash 10y agoBeing able to have a leaky tube and use the air for lift seem like practical purposes to me.
- Retric 10y agoAll vacuums are partial. It's not a binary quality, rather vacuums are graded by how close to absolute vacuum they are. Much like 0 kelvin does not exist, but cryogenic systems are making things colder.
- mikeash 10y agoI'm well aware. The traditional evacuated tube is a pure vacuum for all practical purposes, with any remaining air being undesirable and having no important effects on the machine. Hyperloop requires a certain amount of air in the tube.
- Retric 10y agoEarly vacuum systems where actually using steam that was then condensed. So, it's not particularly high and only a 'pure' vacuum for relevant purposes. Don't forget vacuum cleaners are hardly high vacuum systems.
- mikeash 10y agoIs there a point to this besides pedantry? My actual point is that the Hyperloop is something new, not just a rebranding of previous evacuated tube systems. If you have something to dispute that point, then by all means go ahead, but if you just want to quibble over me being insufficiently specific in my explanations then I'll let it be.