gistfile1.txt

(10:54:19 PM) Loren Bruns: The VLT (Very Large Telescope), when configured in optical interferometry mode with all 4 telescopes working together, gives it an angular resolution that can resolve an object of what scale on the moon?
(10:54:30 PM) Aphyr: oooh, interferometry
(10:54:42 PM) Aphyr: Let's go with... rubix hypercube.
(10:55:15 PM) ***Aphyr actually does some math
(10:55:35 PM) Aphyr: OK, 4 8 meter telescopes
(10:55:55 PM) Aphyr: in interferometry mode they are 25x finer resolution limit
(10:56:21 PM) Loren Bruns: Oh, you're actually looking things up.
(10:56:26 PM) Aphyr: the diffraction limit for an 8.2 meter mirror is...
(10:56:26 PM) Aphyr: uhh
(10:56:38 PM) Loren Bruns: I just figured you would guess and I would tell you.
(10:56:43 PM) Aphyr: wavelength over n sine angle?
(10:56:51 PM) Aphyr: 2n sin alpha
(10:57:02 PM) Aphyr: n is roughly 1 for air
(10:57:06 PM) Loren Bruns: But keep going.
(10:57:13 PM) Aphyr: we'll pretend here to get a worst case limit, that the moon is in atmo
(10:57:50 PM) Aphyr: fuck what is alpha... arrgh it has been so long
(10:58:23 PM) Aphyr: oh that's right
(10:58:26 PM) Aphyr: nobody in astro uses units
(10:59:04 PM) Aphyr: optical wavelengths are 500nm
(10:59:22 PM) Aphyr: so 1.22 * 500nm / 8.2m
(10:59:39 PM) Aphyr: That's 7.43 * 10^-8
(10:59:46 PM) Aphyr: the moon is...
(11:00:04 PM) Aphyr: at apogee, 400,000 km
(11:01:08 PM) Aphyr: 7.43 * 10^-8 radians * 400,000 km = 29.75 meters
(11:01:09 PM) Aphyr: hmm
(11:01:12 PM) Aphyr: that seems really big
(11:01:16 PM) Aphyr: did I do my angular math right?
(11:01:19 PM) Loren Bruns: Divide by 25
(11:01:21 PM) Aphyr: ah
(11:01:25 PM) Aphyr: so 1.1 meters
(11:01:32 PM) Loren Bruns: Jesus christ.
(11:01:33 PM) Loren Bruns: YES
(11:01:36 PM) Loren Bruns: OK
(11:01:37 PM) Loren Bruns: YOU WIN
(11:01:37 PM) Aphyr: is that right?
(11:01:45 PM) Loren Bruns: It's between 1-2 meters
(11:01:47 PM) Aphyr: NICE
(11:01:51 PM) Aphyr: BACK OF THE ENVELOPE WIN
(11:02:00 PM) Loren Bruns: What was your gut instinct?
(11:02:04 PM) Aphyr: a rubix cube, haha
(11:02:09 PM) Loren Bruns: Oh, hah