## World's largest Rubik's Cube you can solve by hand

University of Michigan mechanical engineering students have built "the world's largest hand-solvable, stationary" Rubik's Cube. Fashioned primarily from aluminum, it weighs 1,500 pounds but can be manipulated by one person. The puzzle is available for solving in the campus's mechanical engineering building. From Michigan Engineering:

They realized they couldn’t simply scale up the approach a handheld cube relies on because the friction would be too great. So to keep friction minimal, they devised a setup that utilizes rollers and transfer bearings.

“This is a truly amazing and unique kinematic mechanism that functions as a Rubik's cube,” said Noel Perkins, the Donald T. Greenwood Collegiate Professor of Mechanical Engineering and advisor to the students.

“There is no other human-manipulable cube like this, to the best of our knowledge. That said, it is not technically the largest cube. We're aware of a larger cube that requires the user to literally roll it on the ground to solve and rotate the faces. None of that is required by our stationary design. So to be very precise, it is the world's largest stationary, human manipulable Rubik's cube.”

## Guy solves Rubik's cube in record-shattering 4.74 seconds

Mats Valk used a custom Rubik's Cube tricked out with neodymium magnets to set a new world record for speed cubing: 4.74 seconds. Read the rest

## The math behind solving the Rubik's Cube

In this Scientific American video, Rubik's Cube master Ian Scheffler, author of the new book Cracking the Cube, explains some of the math behind "speedcubing." Scheduler's book sounds fascinating even though the only way I could get my Rubik's Cube solved is to hand it to my 10-year-old son's friend Luc who was the first to dazzle me with the fine art of speedcubery.

From the description of Cracking the Cube:

When Hungarian professor Ernő Rubik invented the Rubik’s Cube (or, rather, his Cube) in the 1970s out of wooden blocks, rubber bands, and paper clips, he didn’t even know if it could be solved, let alone that it would become the world’s most popular puzzle. Since its creation, the Cube has become many things to many people: one of the bestselling children’s toys of all time, a symbol of intellectual prowess, a frustrating puzzle with 43.2 quintillion possible permutations, and now a worldwide sporting phenomenon that is introducing the classic brainteaser to a new generation.

In Cracking the Cube, Ian Scheffler reveals that cubing isn’t just fun and games. Along with participating in speedcubing competitions—from the World Championship to local tournaments—and interviewing key figures from the Cube’s history, he journeys to Budapest to seek a meeting with the legendary and notoriously reclusive Rubik, who is still tinkering away with puzzles in his seventies.

Getting sucked into the competitive circuit himself, Scheffler becomes engrossed in solving Rubik’s Cube in under twenty seconds, the quasi-mystical barrier known as “sub-20,” which is to cubing what four minutes is to the mile: the difference between the best and everyone else.

## Girl, 6, solves Rubik's Cube in 41.56 seconds

Wait for the amazing happiness at the end.

## Watch this man solve 3 Rubik's Cubes in 20 seconds while juggling them

But can he chew gum at the same time? (RuboCubo, via Brad Kreit)

## Watch this guy solve a 7x7 Rubik's cube in record-breaking time

Australian speedsolver Feliks Zemdegs beat the existing world record.

## Video: HOWTO put a Rubik's Cube in a bottle

YouTuber Mathologer shares his technique for reassembling a Rubik's Cube inside a glass container. The secret? Magnets! Read the rest

## WATCH: World record smallest 7x7x7 Rubik's Cube

Puzzle enthusiast Tony Fisher demonstrates a new 3.4 cm-wide cube designed by Matt Bahner. It's half the size width of the original 7x7x7 V-Cube. Read the rest

## The fascination of Rubik's cube

Dan Nosowitz on the obsession with a mechanical toy invented 40 years ago--"simple in theory, it can be tremendously complex to conquer" -- and Google's obsession with it in particular. Read the rest