[extropy-chat] Suicide the Green way

[Anders Sandberg]

Landis has done some work on alternative materials for solar sails,
focusing on dielectrics:
http://www.niac.usra.edu/files/studies/final_report/4Landis.pdf

Robert Bradbury wrote:
> This makes sense to me but manipulating the amount of material required
> for
> a useful solar sail with holes in it is presumably a rather dicey task.

True. Even unfolding the darn things have proven hard. I'm rather fond of
the idea of using a plastic backing that evaporates in UV light, but I
don't know if anybody has even got it to work.

> (Anders jumping off the diving board into the deep end of the pool which
> has
> had the water drained from it when he wasn't looking...)

Oops! Time to try to develop levitation! :-)

> Offhand, does anyone know why boron doesn't reflect light?

Isn't this due to the pi bonds in the atom sheets? A EM wave arrives, sets
the mobile electrons in movement and is absorbed. But this would only work
for the sheet allotrope, the rhomboedral ought to have other optical
effects. Does anybody know what color it is?

As for non-aluminium, according to Landis people looked at beryllioum but
it wasn't so good. And it is hard to get many stable metals on the top of
the periodic table. Landis also points out that for the laserdriven sail
low resistance may actually beat lightness. Maybe we will go to the stars
on gold foil?

-- 
Anders Sandberg,
Oxford Uehiro Centre for Practical Ethics
Philosophy Faculty of Oxford University