[extropy-chat] Suicide the Green way

[Anders Sandberg]

Michael M. Butler wrote:
> On 11/20/06, Anders Sandberg <asa at nada.kth.se> wrote:
>> A good aluminium sail is supposed to have half wavelength holes
>
> Interesting. I hadn't heard that. Source, please?

I saw it on Wikipedia, http://en.wikipedia.org/wiki/Solar_sail
I think it follows quite naturally from electromagnetic considerations.
The more sail material removed, the lighter the sail, but  high frequency
radiation get through the narrow holes. If the spacing is a half
wavelength then you get particularly good reflection. Playing around a bit
with http://www.falstad.com/ripple/ seems to support this.


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