Re: vacuums and tank clocks
Hi, conventional wisdom had a dewar flask as the best insulated enclosuretoggle quoted messageShow quoted text
as the vacuum did not conduct, and the silvered side had very low emmissivity
to reduce radiation.
But there may be a new technique of using aerogel as an insulant.
Although the material does not have zero emissivity, there are so many
particles that have to emit and absorb in sequence that the transmission
via radiation becomes quite low. (T1**4 - T2**4)**n) as n gets great
and the difference gets small the transmission gets small. Conduction via
air always was small if convection was impossible.
I bought some of this material used for insulating refrigerators on boats,
but as yet have not been able to evaluate it.
On 30 Aug 2019, at 11:19, Brooke Clarke <firstname.lastname@example.org> wrote: