All good stuff, and I think there could be an element of each of the points raised at play at the same time. The one that hasn't been mentioned, just for the fullness of the discussion
, is the effect of the refraction of the light passing through the atmosphere. In theory it should slightly magnify the size of the image of the moon, but with a similarly technical experiment some years ago I convinced myself it wasn't significant.
May the atmospheric magnification is just about cancelled by the increased distance (earth's radius)??? Trust Pythagorus to be involved... he probably knew more than we give him credit for! ... and we all thought he was a bit of a square...
The interesting part of this discussion for me is the one of perception. I had previously linked the "it looks big near the horizon because it's close to things we are familiar with, but high in the sky it isn't" case, but I hadn't thought in terms of relative position to the observer.
As part of teaching map reading and navigation, we also teach judging distance. Part of that is understanding perception. Things look further away when:
- looking up at them;
- when laying down (and looking along the ground is the usual scenario);
- when looking across a gap (say a valley).
They look closer when:
- looking down at them;
- when all the ground between the observer and the object is visible.
Hmmm... My advice for a really impressive moon rise? Picture this: ocean cruise, deck chair aligned with the position of moon rise, supine position on the chair, drink of your choice in each hand
(balance is important!)
Cool thread guys! I'll have to try looking at the moon thought my legs too! Sounds like a worthy experiment.
I hope your pinky was calibrated?
Al.