What Happens During Eclipses

I was at Columbia university the other night, one of the best places to see the eclipse in NY City.  i discovered that the AAA (not the car stuff, Amateur Astronomy association) gathered there that night to see it.

now i don't care how smarty pants ivy league Columbia is, you know how many of them there didn't know what the hell goes on during an eclipse? a lot. didn't know anything.

basically: an eclipse is like a shadow cast from Sun to other body. you ever hang in the shade? well that building, tree etc is eclipsing the Sun. by the way, notice that the shade isn't pitch black? similar principal to why the Moon isn't pitch black during the eclipse: there's still Sun shine around, just not as direct. same deal in space (you ever see a photo of a total solar eclipse? even though it's total, you still have to wear special glasses because of the overwhelming sunlight).

anyway in a lunar eclipse the Earth appears to cover the Sun and cast a shadow over the Moon. we see that shadow over the Moon. since the Earth is much bigger than the Moon, it's more likely to see a lunar eclipse than a solar, and over a greater area (like the whole moon)

in a solar eclipse, since the Moon is smaller, it casts a much smaller shadow over the earth, hence a smaller area gets a solar eclipse, and for a much shorter time, and there are more likely to be partial ones etc. from Earth, the Moon covers the Sun. during a lunar eclipse, from the Moon, the Earth covers the Sun.

so again that's what happens: a body covers another body in front of the Sun, and casts shadows.