[ExI] Arkyd

Anders Sandberg anders at aleph.se
Tue Jun 4 18:56:54 UTC 2013

On 2013-06-04 18:41, Kelly Anderson wrote:
> But being in space, you don't get the diffraction of the atmosphere... 
> Shouldn't a 20cm space telescope be able to see much more than one on 
> the ground?

The resolution of a telescope depends on how wide it is. If you have 
several openings far away (like connected telescopes across the globe) 
you can get a synthetic aperture that is very hi-res. Atmospheric noise 
however blurs everything beyond a certain resolution.

But the *sensitivity* depends on how large the "light bucket" is: the 
total area collecting light. 20 cm is not much at all, plenty of 
amateurs have that. You can get a better picture by looking longer, but 
the signal/noise ratio only grows with the square root of time. So 20 cm 
is not going to be doing anything radical compared to existing 
telescopes, image-wise.

Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University

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