November 30th, 2016 by Steven Pomeroy | 2 Comments | Filed in Physics

Dominic Walliman recently added a video mapping out the various fields of Physics (pun intended!). He describes the video as, “Everything we know about physics – and a few things we don’t – in a simple map.” I think it was very well done, and I think you will agree:

This video was not intended to be a complete overview of the broad landscape of Physics, I am sure; rather, it is a nice introduction to the different components. Indeed, it is a very nice introduction that is only eight minutes long.

I recently made a Facebook post on the Scientific American article New Take on an Ancient Method Improves Way to Find Prime Numbers. The article focused on a mathematicians work in improving the Sieve of Eratosthenes to determine if a number is prime. If you are unfamiliar with this ancient algorithm, then this video will be instructive:

Anyway, this got me into thinking of developing a prime number checking program – but in the opposite direction: using the most basic algorithm to check if a sequence of numbers is prime.

Sounds crazy, right? Well, just hear me out. What I want to do is to develop a cool demonstration that shows each number being tested (the speed of program execution will be a variable, btw), and the result of the testing – whether the number is prime or composite.

Take your calculator – it has to have a factorial function (n!). Punch in 0.5, and then hit the factorial key (n!). Then hit the square function key (x^{2}). Then multiply the result by 4. Do you recognize the final result? That’s right – Pi!!

Check out this video for a demonstration and an explanation: