[extropy-chat] sjbrain calcs

Robert J. Bradbury bradbury at aeiveos.com
Sat Dec 20 17:30:55 UTC 2003



On Fri, 19 Dec 2003, Spike wrote:

> I don't have the specs from the Lockheeed SIRTF, but my intuition
> tells me any instrument of the 1 meter class would not have anywhere
> near the resolution needed to distinguish a Jupiter-like SBrain
> (SJBrain?) from its star, even if the SJBrain-star pair is in the
> immediate neighborhood.  Damn.  {8-[

Spike, you have lost me.  Is an SJBrain just a cloud of dust-like
particles in orbit around a star the size of a JBrain?  (Though
Anders JBrain described in his paper is more Earth-sized than
Jupiter-sized so I guess the size of a JBrain depends on who
is designing it...)

If so I don't think you should knock SIRTF too soon.  Both the
Terrestrial Planet Finder and Darwin plan to do most of their
work in the IR frequency range because the signals from planets
are much easier to differentiate from stars because more of the
energy coming off of stars is coming off as visible and UV.

You have to remember that SIRTF has a spectrograph as one of
the instruments -- it remains an open question whether the
IR from a planet (or an SJBrain) will produce enough of
a bump in the IR spectra of the star that it could be noticed.
But if you combine it with a variation of the current planet
finding technique so that one sees regular variations of
the IR spectra as the planet or SJBrain orbits the star
then that is going to have the astronomers scratching
their heads...

Robert





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