Until pretty recently, when you wanted to find your way somewhere, you had to pull out a paper map, face it the right way, figure out where you were on the map, and then figure out how to get to your destination. Now we’ve taken all the fun out of it. With the digital maps on our smartphone and computer screens, you just type in your start and end points, and it draws the path you should take. Then geopositioning systems, or GPS, use satellites to find you and plop a blinking dot on the screen to show you exactly where you are. Now when taking a trip by car, thanks to GPS the days of crumpled maps are over. But as we’ll see here, when it comes to timing, sometimes the system doesn’t know everything.
One of the most popular and widespread toys ever invented is the Rubik’s Cube. The mission is so simple: just turn the rows and columns to swap around the pieces and get all six faces to be solid colors. And yet that turns out to be one of the hardest challenges out there – maybe because a 3x3x3 cube has over 43 quintillion possible line-ups of the pieces. Ever since the cube was invented in 1974, over 350 million of these puzzles have been sold; the Cube has inspired people to set all kinds of records, spawning speed cubers, one-handed cubers, and the real geniuses who study the cube, blindfold themselves and solve it from memory. To get a taste of the excitement, let’s look at the math behind cracking the code.
First, a really fun announcement: Bedtime Math is throwing a giant Pajama Party at the new Museum of Mathematics in New York! If you live in the NYC area or will be visiting, on Saturday Feb. 2 kids from ages 3-8 can come to MoMath in their PJs and play home-baked Bedtime Math games. You all get first dibs before this gets announced publicly, so click here to get the details and register!
And as long as we’re talking about math, it’s a great time to ponder the number 2013, our very cool new year. It’s the first year in a long time where all four digits are different – more on that below. Also, because the number 13 is prime – meaning it’s divisible only by itself and 1, and can’t be split into equal-sized groups – 2013 looks kind of yucky and prime also, but it actually isn’t. While the number 13 is considered unlucky by a lot of people, we’re thinking 2013 is going to be a good year.