Hacker News Reader

Comment by sjackso | Hacker News Reader

I recall reading about the craft using gasoline as an incompressible floatation fluid, but I hadn't realized the scale: 100 tons of gasoline, making up 2/3s of the craft's mass.

View on HN

Basically the equivalent of a lighter than “air” craft but in a different fluid. I wonder if there’s a word for a craft that controls its buoyancy regardless of medium?

An Archimedes craft.

(I made this up just now).

Fluid is a Latin root, so why not "fluidostat" on the model of "aerostat"?

because -stat is a Greek root.

merriam-webster

   borrowed from French aérostat, probably back-formation from aérostatique "of aerostatics," with -stat (after héliostat heliostat) taken as the Greek agentive element -statēs "one who causes to stand" — more at -stat

I've never looked at it this way, but it really is literally an underwater blimp lol.

> I wonder if there’s a word for a craft that controls its buoyancy regardless of medium

sperm whale

I never knew the scale either. But the book says gasoline has a specific gravity of 0.7. So 100 tons will make roughly 30 tons of buoyancy. The negatively buoyant craft is 50 tons so combined with the air inside that is probably the displacement required to make it positive

Reply on news.ycombinator.com