"gswork" came up with the following after drinking 15 cups of coffee and
then turning his brain loose:


Using a bit of mathematics i have been looking into degrees,
arcseconds and so on.

Having verified the moon to be .5 degrees, and the sun to be about the
same - and this agreeing with books - i was happy that i was doing the
right thing.

When getting say x2 magnification does that mean we see the moon as if
it was 1 whole degree? it ought to follow.

I used the same calculations on nearby stars to fully appreciate why
we just can't see them as disks through telescopes, i roughly
estimated that seeing Sirius A as a disc roughly the size of the moon
would require x300,000 magnification (but i may have that wrong):

360 / 2Pi =57.3 (used later)

Moon degrees = 57.3 * arctan(diameter/distance) (thats roughly
3476/384000)
= just over 0.5 degrees

Sirius A degrees = 57.3 * arctan(1390000km/8.6ly)
(ly=9,460,530,000,000km)
= 0.000001645 degrees
multiply that by 300,000 to get just under .5 degrees!


Been reading quite a few of Brian Tung's posts, eh? ;o)


--
Martin
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