--- In OliveStarlightOrchestra_at_yahoogroups.com, David Coons
<yahoo_at_a...> wrote:
> I believe a parabolic surface can actually be formed
> by starting with a crude near-parabolic bowl, filling
> it part way with a hardening polymer, then spinning
> it 'till it dries. Then you have to mirror-coat it.
> But it's probably something more easily purchased from
> a stock house like Edmund Scientific, which is now:
> http://www.edsci.com
Excellent... a nice website for browsing.
> They also sell fresnel lenses in various sizes, which
> also concentrate solar energy quite well and are
> damned more fun to play with, like at Cassini parties,
> where you can watch small children sear the flesh of
> their siblings. JT might use them for lighting cigars,
> probably even by moonlight. :)
Ah yes... fresnel lenses were also on my list of things
to investigate.
> The more efficient large solar concentrator arrays are
> actually rows of parabolic troughs, with motorized sun
> tracking elevation control and blackened pipes running
> along the focus line. JT might use these for lighting
> a bunch of cigars at once for *his* next party..
Yep - looked at those as well -- way to complex and expensive
for my little "world's cheapest pool heater" experiment.
> Then there's always google.
Never leave home without it. :-)
Received on 2004-06-11 22:14:28