Subject: Re: The shape of a single photon
Physicists (and scientists generally) often make simplifying assumptions to make the math easier. They are incorrect, but often are close enough to illuminate the problem and send one in the direction of an answer.

Isaac Asimov had a great essay in "Fantasy and Science Fiction" called "The Relativity of Wrong".
https://www.sas.upenn.edu/~dba...

A quote from it:
...when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.

So things like "Far Field" and "Spherical Chicken" are shortcuts to simplify the math. Copernicus got most of what he needed by assuming the earth was spherical. If NASA were to use that same assumption astronauts would likely die.

Rgds,
HH/Sean