Why is the casting shadow of the moon only 70 miles wide?
A casting shadow is always bigger or at least equal size to it’s object. but never smaller.
And the size and sharpness depends on the distance between the light source and the object.
So how come the casting shadow of the moon during an eclipse on the earth's surface is only 70 miles wide?
While the moon itself has a diameter of 3,476.28 km!
The answer to that question is one word.
The first person who can prove the answer gets a 100% upvote.
To enter upvote and resteem.
UMBRA
I'm not first to answer but I'm resteeming and answering this anyway.
The answer is umbra.
So the answer I was looking for was: Gravity! However since there were only two people who voted and gave an answer that is the direct effect of gravity I will give you both a 50% upvote! Congrats!
Why is the answer gravity? It seems (with my limited understanding) That the umbra is only 70 miles wide while the panumbra is actually bigger. What does gravity have to do with it? Unless you are talking about gravity bending the light slightly but does it really make that much difference?
UMBRA is not the correct answer.