Re:Is it possible for a lunar eclipse to occur before sunset?
by tobr on Friday January 06, 2023 @02:49AM
(#34272073)
So are you saying that the offset of 1 Earth/soccer ball radius is helping or hurting? It’s still seems to me like it’s just getting in the way. (Though I guess the ant wouldn’t see much of anything if it was down in the grass.)
Re:Is it possible for a lunar eclipse to occur before sunset?
by IanCal on Friday January 06, 2023 @05:18AM
(#34273050)
It helps you see things either side of the ball if you're offset from the centre.
Forgive the hasty diagram but https://imgur.com/a/aoZIZTs
The Earth is entirely in-between the wildly out of scale Sun and the Moon, but a giant standing on the "top" of the Earth can see both.
A huge distance is actually a helping factor in this case. A 1.75 meter person can see 4,700 away before the horizon curves out of view. That means (ignoring the bending of light by the atmosphere still) the viewing angle allows for 1 meter "down" every ~2,685.7 meters out. The radius of the Earth is ~6,371,000 meters so to be able to see the middle of an object from ~the radius of the earth "down" with that viewing angle would require the object to be a minimum of ~2,685.7 * 6,371,000 = 17,110,594,700 meters away. That's a minimum distance of ~0.11 AU so the person would only get a partial view of the moon but a full view of the sun because the moon -isn't- far enough away! Well technically the Earth could rotate slightly farther while having the middle of the sun still visible but I'm too lazy to calculate if it's actually enough, my hunch is no. If you wanted to see the middle of the moon and the middle of the sun (with no bending by the atmosphere) during an eclipse you'd have to be near the top of Everest while it happens to be exactly rotated between each.