David Thompson


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June 22, 2007



Re: Liquid mirrors for lunar telescopes.

Surely it wouldn't be too hard to heat up the Mercury? Perhaps this would mess up any infrared work but so?


And there’s the issue of payload weight to consider. I’m not sure how much mercury would be needed to make a mirror of sufficient size – possibly up to several metres across – but mercury is much heavier than the “ionic liquids” being worked on. And, of course, much more toxic.


Oh and here's the welsh alternative to pencil carving!


WRT Mercury mirrors.

a cubic meter of mercury weighs 13,545 (.850)KG

a 6 meter diameter mirror has a surface area of 28.27 meters

so 5 centimeters of depth would need 1.41 cubic meters of mercury weighing in at 19,149.9942 Kgs

OK it might be easier to extract mercury from lunar soil instead!


Thanks for the calculations. I’m guessing 1.41 cubic metres of mercury is not only weighty but expensive too. And it’s a matter of deep personal shame that I was unaware of the existence of Welsh love spoons.

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