NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Liquid metals for artificial horizons.
From: George Huxtable
Date: 2002 Apr 1, 08:52 +0100
From: George Huxtable
Date: 2002 Apr 1, 08:52 +0100
Rodney Myrvaagnes said, about liquid metal for an artificial horizon- >You could trade the problems of mercury for adifferent set of challenges >by using NaK, the eutectic alloy of sodium and pottassium, >which is liqud at room tempereature. It is highly reactive and must be >kept from the atmosphere, so you horizon would have to have >an optically flat sealed roof with an inert atmosphere inside. > >If you accidentally broke it, you would cause no longterm environmental >damage. In the short run, the extremely rapid production of >salts might get you a bad burn, and/or damage something else nearby. > >I wouldn't try this at home myself, but if you work in a lab equipped to >handle such materials you could think about it. > >Ha anyone tried making a prismatic horizon that dangles like a damped pendulum? > ================ There exist other alloys, less reactive than Sodium-Potassium. There's a mix of Gallium-Indium-Tin that's liquid at indoor room temperatures, though I am not sure how it would fare outside in winter. And I can't say how poisonous the constituents of that alloy might be. It develops a dullish tarnish on the surface, so is less bright a reflector than a recently-cleaned surface of Mercury, but is much lighter in weight. I have used it for other purposes, but not as a mirror. For what it's worth... George Huxtable. ------------------------------ george@huxtable.u-net.com George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. Tel. 01865 820222 or (int.) +44 1865 820222. ------------------------------