Moon points to the sun

The idea: The moon tells which way the sun is.
[The usual warning - Sun looking without sunglasses burns off bits of the inside of your eye. Permanent unhappiness. :(]

Here is the moon in the sky...

How the moon is lit tells which way the sun is...

[The usual warning - Sun looking without sunglasses burns off bits of the inside of your eye. Permanent unhappiness. :(]

Big Oops. Most of these examples are pointing UP. Down would have been better, ie night with sun down behind earth, as that is the interesting case. Oops.

But "why doesn't it work"?

Why doesn't the moon seem to point straight at the sun? Why does it seem to point off to the side?
A demo: With your knuckle by your eye, sight along your finger and point it at something. Then move your head to the side. Your finger will now no longer appear to be pointing directly at the something. It will however tell you the direction from your head to the thing. Ie, it tells you which way to look. (As long as the thing is relatively distant.) The same with the moon.

Links

Virtual Reality Moon Phase Pictures
Earth and Moon Viewer

Comments encouraged. - mcharity@lcs.mit.edu.
[Musings][Top]
History:
1998.Jul.10  Added link to `Earth and Moon Viewer'.
1997.Mar.11  Added Links and link to "Virtual Reality Moon Phase Pictures".
1997.Jan.23  Hacked in parallax "why doesn't work?" note.
1997.Jan.19  Created.
Notes: Hand is better without arrow. Shadow useful. Adding boundary dots to prototype will avoid autocrop alignment problems. Was a bit sloppy with angles. Add a cylinder object in foreground? Could angled shoulders to define arm horiz plane. Head tilt to match elevation. Sunglasses as appropriate.:) Perhaps a visor to give directional hint? Could also rotate body (shoulders and feet placement) to give direction. Erg - most cases should have been DOWN! Lower hemisphere spin and bob. Need to find shadow night substitute. Virtual roof w shaddow?