OK,
here's the square wave as a sum of a sine wave and its odd integer harmonics.
http://en.wikipedia.org/wiki/Square_wave
Incorrect.
This is NOT the square wave as a sum of a sine wave. Nor is it a description of one.
This is a link to the webpage where one can find an
idea about how one can start
describing a square wave as a sum of a sine waves and keep doing it through
the end of days if he/she chooses to keep on doing so.
One with a little brain may start doing so and then stop sometime before
the end of days and say to him/herself: "No way. It can't be done. Forget about it, I have better things to do, spending the rest of my days."
One with a bit more brains can take amoment, think a bit about it and say to him/herself: "Hey, this is a cool idea. Nice thinking, mr. mathematician, but since it can't be done, I would not waste my time trying, and I have better things to do."
Apl, have it ever occur to you that to describe simething it takes two: starting your description and finishing it?

Seriously, man, I respect your devotion to "math and physics" and all that, but you gotta try to stretch a bit wider than that, that is if you really care about
"the truth".
Here's an exercise for you. (It's a fun one.!)
Describe an endless road journey from here to the end of the road.
You can start right now, because sooner - better

In order to make it a bit more fun, you can do it while listening to the music analog or digital or better yet something like a digital version of analog one

, here's a nice tune for
the event with appropriate title (and you can watch something cool as well

):
https://www.youtube.com/watch?v=0OU7Hka_--U