# Watch: Space-Time Explained With A Music Box And Möbius Strip

## A snippet of Bach goes a long way toward explaining space and time from a Euclidean perspective.

An image of the Carina Nebula, taken by the Hubble Telescope.

Math is the basis for music, but for those of us who aren’t virtuosic at either, the connection isn’t always easy to grasp. Which is what makes the videos of Vi Hart, a “mathemusician” with a dedicated YouTube following, so wonderful. Hart explains complex phenomena–from cardioids to Carl Gauss–using simple (and often very) funny means.

As Maria Popova pointed out yesterday, Hart’s latest video is a real doozy. In it, she uses a music box and a Möbius strip to explain space-time, showing how the two axes of musical notation (pitch and tempo) correspond to space and time. Using the tape notation as a model for space-time, she cuts and folds it to show the finite ways you can slice and dice the axes. Then, she shows us how you can loop the tape into a continuous strip of twinkling notes:

If you fold space-time into a Mobius strip, you get your melody, and then the inversion, the melody played upside down. And then right side up again. And so on. So rather than folding and cutting up space-time, just cut and tape a little loop of space-time, to be played over, and over.

It’s a pretty magical observation, and it makes even me–the prototypical math dunce–wish I’d tried harder. Yet there’s still time: Hart works for the Khan Academy, a nonprofit that offers free educational videos about math, biology, and more. Check it out.

[H/t Brain Pickings]