The Fourth Dimension
I wrote an iOS app called The Fourth Dimension. It’s an interactive 30 page book that explains what a tesseract is and allows the user to manipulate it in three and four dimensions.
In 1986, when I was 15 years old, I read a Scientific American article about how to write a program to visualize a hypercube, and I implemented my own version in BASIC. The Fourth Dimension is my third iteration of that program. I wrote the iOS version because I wanted to experience what it’d be like to hold an interactive tesseract in my hands on an iPad. While developing the app, I always imagined that I was writing it for the 15-year-old me. I hoped that the app might inspire another generation of kids.
When I launched The Fourth Dimension, word of it spread on Twitter and other social channels. Magically, the right people found out about it, and the app got enthusiastic reviews on The Verge, Cult of Mac, BuzzFeed, and other web sites.
I only expected that I’d sell perhaps 50 copies of this app, since it deals with an obscure math topic. However, I’ve had over 12,000 paid installs to date.
So far the app has a 5 star average from 500 ratings in the App Store. I’ve gotten many wonderful reviews like this:
“Astounding. That some people care passionately enough about tesseracts to go create a
fantastic app for others to understand them is incredible. The app is extremely well
designed, wittily written, and executed with love. That alone is worth buying it, besides
the fact that I learned what the hell a tesseract was.”
— Duncan MacMichael
“Fantastic app. I work at a leading UK university. If only all our material was this well
written and presented. Definitely worth buying and then spending a bit of time with over a
day or two to get your head around the fourth dimension. Great app!”
“Mind blowing! I cannot believe this! It is literally insane! I’m only 15 and I’ve never
really understood the idea of dimension... starting to get the hang of it. Will take the
next few days to figure it out. So what is the fifth dimension?!”
— Robert Lane
That last review really made my day. That was exactly what I was trying to do when I wrote the app.