The video is a quick overview of some of the formulas that enable our world to function. Like citizens of the Matrix, we can't see these invisible math calculations, and yet they constantly take place all around us.
If you have a cellular telephone, you can't see the signal between the cell tower and the phone, yet you hear your friend's voice. You can't see the signal your satellite TV dish receives, yet you watch your favorite team play. And inside your house, the small router next to your computer sends out its unseen WiFi signal to your laptop, ereader or tablet.
Math enables all these invisible transactions.
The video discusses waves because so many things we do involve the sending and receiving of signals in wave form, like radio. To enable this, we needed the contributions of mathematicians Fourier, Bernoulli and d'Alembert, plus Maxwell's work on electricity and magnetism. They in turn used principles of physics from Newton. Each generation builds on the hard work of those who came before.
So next time you use your cell phone, realize that math is useful for all sorts of cool things. And encourage those around you to learn more about math.