Is it possible that the shadow of The Moon is a single dot during solar eclipse? During a solar eclipse The Moon covers The Sun on some places on the Earth. Now the focal point is a bit above the Earth so the shadow area is about 160 miles.  In history The Moon was a bit closer to the Earth but could there have been a time that the shadow area was just a dot. (probably for just some places as the Earth is not really perfect a sphere and the orbit of the Moon isn't also a perfect circle).
What you are calling a focal point is the end of the umbra, the point at which the umbra changes to the antumbra. In a total solar eclipse, that point is below rather than above the surface of the Earth. An annular eclipse occurs when that point is above the surface of the Earth. The Moon appears to be smaller than the Sun, leaving an unbroken ring of the Sun that appears to surround the Moon.

There are some solar eclipses that transition from annular to total, and from total to annular. A point on the surface of the Earth is exactly at the end of the umbra at those times of transition points in time. At this point in space and time the Moon will appear to be exactly the same size as and exactly in line with the Sun.