How and why do eclipses occur, and how come we can observe them from Earth?
According to Sun, Moon, & Earth, “The Sun is four hundred times larger than the Moon, yet four hundred times farther away…” Thus when we look at the Moon it appears the same size as the Sun.
This ‘coincidence’ continues to fascinate me. When I mentioned it to a scientist friend, he pointed out that the Moon’s distance from the Earth varies slightly, and that this enables eclipses to be seen from many locations. If it were always the same size, eclipses could only be total, not partial or annular, and could only be seen from a spot on the Equator. I don’t know how he feels about it, but I regard it as a wonder of proportion.
A proper understanding of proportion is key to life on Earth. According to Praveen Mohan, the Sun’s diameter divided by the Earth’s, and the Moon’s diameter divided by the Earth’s, approximate to 108, and that this number enables life. This is a deep subject!