which of the eclipses show that earth is a sphere and why?

Question

THE FIRST PERSON WHO ANSWERS THE QUESTION CORRECTY I WILL AWARD BEST ANSWER. PLEASE SITE YOUR SOURCES AND NO STUPID ANSWERS OR YOU'LL BE IGNORED!

Answer 1

One of the oldest proofs of the Earth's shape, however, can be seen from the ground and occurs during every lunar eclipse. The geometry of a lunar eclipse has been known since ancient Greece. When a full Moon occurs in the plane of Earth's orbit, the Moon slowly moves through Earth's shadow. Every time that shadow is seen, its edge is round. Once again, the only solid that always projects a round shadow is a sphere.

Answer 2

Most basic astronomy books state that the Lunar eclipses show that the earth is spherical. However, all a lunar eclipse shows is that the shadow projected by the Earth has a circular shape (showing the Earth's cross-section is circular).

It is only by observing lots of lunar eclipses with the Moon at various angles in the sky (from one eclipse to the other) that we can conclude the earth is spherical.

Otherwise, it could be a cylinder that happens to have its axis oriented on the line joining Sun-Earth-Moon every time there is a lunar eclipse.

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If one were able to determine the exact shape of the Moon's shadow on Earth's surface, and its evolution over time, one would see that the shape varies: It is a perfect circle at mid-eclipse if totality occurs exactly at the zenith of the mid-point of the path of totality on Earth's surface.

At any other place, the shape of the shadow will be somewhat oval as two effects tend to distort it: the angle that the Sun-Moon line makes with the location's vertical, and the curvature of earth's surface. The first one can be easily calculated, leaving only the effect of the shape of the surface. From that, we could calculate the curvature of Earth's surface and conclude (after many solar eclipses) that the Earth is spherical

In the old days, it was impossible to obtain the instantaneous shape of the shadow. (That is why most books still insist that only lunar eclipses can show the shape of the Earth). Nowadays, we can see and measure the shadow from satellite pictures.

I do not know of anyone who has actually done the calculation (probably because we would not learn anything new).

Answer 3

Since someone already answered correctly, I'll go with stupid.

The answer is Unicorn.