Worlds Largest Telescope?

AndersBrownworth writes "With a unique take on "Distributed Computing", the PhotonStar Project aims to search for laser transmissions from extra terrestrial life by harnessing amateur astronomers who have an optical telescope with a laser detector, a GPS and a computer with a net connection. I think it would be interesting to get a large number of computer controlled optical telescopes together that have GPS and CCD capabilities and build the world's largest optical telescope. The concept wouldn't be much different from New Mexico's VLA Radio Telescope. Given the falling prices of computer controlled optical telescopes, a project like this might not be far off."

Comments

Yes, it WOULD be different

[wowbagger]

quoth the submitter:

The concept wouldn't be much different from New Mexico's VLA Radio Telescope.

Actually, it would be. The VLA works because all the signals are brought together and correlated - they are carefully time synced (to the nanosecond) and then combined.

The same trick in the optical domain is called interferometry, and requires that the actual LIGHT from each 'scope be brought together - you need not only the brightness (which a CCD would record), but the phase and polarization of the signal (which a CCD won't record).

So you cannot use an array of 'scopes world-wide to create a virtual array.

What you can do, and what optical SETI is all about, is to have each scope looking at a different star (or star field) at each time.

In a way, comparing the two is like comparing a 64-way NUMA cluster to a Beowulf cluster - one will work well with one big program of many threads sharing data (NUMA/interferometry), and one will work well with many small independent programs (Beowulf/optical SETI).