That CAN'T be true! / Re: Why do people persist, in the 21st Century, in claiming the Earth is flat?« Last post by Janus on Today at 20:59:50 »
I recently saw an argument that tried to use the recent solar eclipse to "prove" the Earth wasn't round.Quote from: RDIf Earth was a giant disc, lunar eclipses wouldn't be much different.I agree - you can't unambiguously determine the Earth's shape from one eclipse.
But the ancient Greek astronomers pooled knowledge from many eclipses of the Moon. These projected the Earth's shadow from many different directions - and they are all circles.
The only shape whose shadow is a circle from every direction is: a sphere!
It went something like this:
Science says that the light from the Sun travel in parallel lines such as shown in this image explaining the seasons of the Earth:
However, during an eclipse it says that it comes in at angle like shown in this image:
Thus they claim that science contradicts itself.
The problems with this argument are twofold:
1) Science doesn't claim that all the rays of light from the Sun are parallel to each other, just nearly parallel. There is ~1/2 degree difference between rays coming from opposite limbs of the Sun, (which is just too small to show in images like the first one)
2) Images like the second one are never drawn to scale in terms of the sizes of the object with respect to the distances between them. It is just not practical to do so. For example, if the Earth were represented by a circle 1 inch across, then the Moon would be a circle ~5/16 in across and 30 inch away, and the Sun would be a circle ~3 yards across and nearly 1000 ft away. And with this "to scale" image, you would have the nearly parallel Light rays from the Sun producing a total eclipse shadow on the Earth just like the one we see.