Good for Erv, I wish him well in that new endeavor.
Math is a interesting subject and it always seems "they" can get math to check out correctly but when "they" do make it check out it is always with a slight little change that has to be made with regard to distance, time, or speed in a lot of cases, which are all variables. So as long as you have the liberty to change the variables, you should be able to get the math to correspond to what ever it is that a person is trying to prove mathematically.
If memory serves me correctly the distances between the sun, earth and moon have changed at least three different times that I can vaguely remember since we changed from a fixed stationary planet Earth that was the center of our solar system and went to the system we currently have where we are flying through space, orbiting the sun and the moon orbiting the Earth.
I guess the good part is that we could both look at a glass of water that was half full and we might differ on whether it was half full or half empty and that would be based on our perspective. The good part is we both see it and agree it is a glass and has water in it, the rest is just ....