suitti (suitti) wrote,

Moore's Law for Telescopes

Moore's law for computers says that every 18 months, the number of parts on a computer chip doubles. And this has been going on for a long time. Keep in mind that it doesn't take many doubles before something very small is very large. If you put a penny on one square of a chess board, 2 on the next square, the last square in the row has 128 pennies, and the row has $2.55 in total. It takes $184,467,440,737,095,516.15 to fill the whole chess board.

A couple years ago, i computed the Moore's Law for telescopes. For end points, i used the 1609 1.5 cm Galileo telescope, and the 1992 10 meter Keck telescope (first light with all the segments). Telescopes increased in diameter by a factor of 666x and doubled in size only about 8.58 times over 383 years, giving a telescope diameter doubling period of about 44.6 years. Has the pace increased lately?

Of course, diameter gives resolving power, whereas area gives light collecting. And interferometry should be taken into account for resolving power. The Kecks have 100 meter separation, and the light collecting area of a 14 meter scope. Interferometry started there in 2001, giving a very quick jump for 'diameter'. Size matters, but what size matters to you?

I can hardly wait for space based interferometers at optic wavelengths. In space, you can pretty much always take a longer exposure. And, you could have kilometers or megameters of separation. With radio, VLBI has achieved something like 10-15 microarcseconds resolving power, and with patience determined proper motion for M33. What could you do with a 2 AU optical interferometer? Parallax for any star in the Milky Way? Parallax to M31?
  • Post a new comment


    default userpic