One of the problems with having more than one thread containing almost identical material running concurrently is that switching from one to another can cause trains of thought to be lost. For that reason I am moving a question from another thread in which it became lost in a plethora of red ink and exasperation.

Originally Posted By: Bill S.
Thanks for that explanation, Pre.

Would it not be the case that any azimuthal equidistant projection would map as a circle?

If Pre-Earth's (or Earth's) "continents" were close together, they would naturally fall (and fit) within such a circle if the centre of the azimuthal equidistant projection coincided with the centre of the land mass.


Might I add to this:

Originally Posted By: Pre
The AAPG circle corresponds to the boundary of the impacted and non-impacted regions.


True; and the process by which this comes about (as you described) means that it could not be otherwise. With no other possible explanation, what does this prove?

If for example I were to produce an azimuthal equidistant projection centred on the UK, with a radius of about 500 miles; then do the same from the opposite side of the world, such that the two boundaries were co-incident, it could certainly not be inferred that the rest of the world could be fitted into the same space as the UK.

There never was nothing.