Playing in Space-time: Observing Billiards Using Space-time Numbers
Channel: Doug Sweetser
Date: 16/01/2017

A small book collection is used to explain the 100 year old problem of getting our explanation for gravity to work gracefully with the rest of physics. We need something old and something new: space-time numbers which are a variation on quaternions. Instead of using four numbers that can be added, subtracted, multiplied, and divided, 4 pairs of numbers are used.

Everyone uses real numbers for physics, as I have. An iPython notebook was created to demonstrate how they could be used to describe billiards. 

iPython notebook online: https://github.com/dougsweetser/ipq/blob/master/q_notebook/billiard_calculations.ipynb
iPython notebook github repository: https://github.com/dougsweetser/ipq/