How Many Moves to Solve Rubik’s Cube?

How Many Moves to Solve Rubik's Cube?Do you remember Rubik’s cube, that frustrating “toy” of the 1980s? The idea was to move the sides around, then restore them to their originalcolors in as few moves as possible. For most people, of course, that restoration proved impossible, and the cube moldered in a closet until being thrown out.

But it’s inspired a pair of graduate students from Northeastern University in Boston. They programmed a supercomputer to discover just how few moves could be used to return the cube to its pristine state. They presented their solution at the International Symposium on Symbolic and Algebraic Computation in Waterloo, Ontario.

The previous best has been 27 moves, but after 63 hours of number crunching, the supercomputer arrived at a solution that, quite literally, went one better – that it can be solved in no more than 26 moves.

Students Daniel Kunkle and Gene Cooperman approached the idea with some creative thinking, which was necessary as the 43 billion billion possible positions of the cube was too massive even for the computer. So they used a two-stage solution.

First they programmed the supercomputer to reach one of 15,000 half-solved solutions, which could then be closed in a few moves. Their results indicated that the puzzle could be solved in a maximum of 29 moves,but in most cases 26 moves or less.

From there they decided to focus on the small number of configurations that would require more than 26 moves to reach a solution. Since there were so few of these, it was possible to use the supercomputer to figure out the answer. Perhaps surprisingly, the computer could solve them all in fewer than 26 moves.

So what’s the point of all this? It brings mankind closer to the so-called “God’s number,” the minimum number of moves necessary to solve any Rubik’s cube. The name comes from the fact that God would only need the minimum number of moves, which theorists feel is in the low 20s.

How Many Moves to Solve Rubik’s Cube?

Emerging Tech

Awesome Tech You Can’t Buy Yet: Robotic companions and computer-aided karaoke

Check out our roundup of the best new crowdfunding projects and product announcements that hit the web this week. You may not be able to buy this stuff yet, but it's fun to gawk!
Computing

Breeze through security with these checkpoint-friendly laptop bags

Getting through airport security is a drag, but your laptop bag shouldn’t be. Thankfully, these checkpoint-friendly laptop bags will get you and your gear to your destination with ease.
Movies & TV

The Mandalorian snags Taika Waititi as the voice of a classic Star Wars villain

The Mandalorian, Jon Favreau's live-action Star Wars series planned for Disney's streaming video service, will be one of the most expensive television shows ever made. Here's everything we know about it so far.
Computing

Problems with installing or updating Windows 10? Here's how to fix them

Upgrading to the newest version of Windows 10 is usually a breeze, but sometimes you run into issues. Never fear though. Our guide will help you isolate the issue at hand and solve it in a timely manner.
Computing

Get ready to say goodbye to some IFTTT support in Gmail by March 31

If This Then That, the popular automation service, will drop some of its support for Gmail by March 31. The decision comes as a response to security concerns and is aimed to protect user data.
Computing

Get the new Dell XPS 13 for $750 with this limited-time deal

Dell is currently running a limited time deal lasting through Thursday, March 28, where you can bring home a version of this year's new XPS 13 for around $750 with the use of a special coupon code. 
Computing

Nvidia faces attacks from AMD, Intel, and even Google. Should it be worried?

Nvidia announced an expanded array of RTX server solutions designed to leverage the power of ray-tracing at GTC 2019. The effort will help Nvidia take on Google's Stadia in game streaming with GeForce Now, and the company's investments in…
Mobile

This is the easiest way to save your iPhone data to your computer

Living in fear of losing your contacts, photos, messages, and notes on your iPhone? Fear no more -- in this guide, we'll break down exactly how to back up your iPhone to your computer using Apple's iTunes or to the cloud with iCloud.
Mobile

Here are the best iPad Pro keyboard cases to pick up with your new tablet

The iPad Pro range can double as laptops, but they do need proper keyboards to fill in effectively. Thankfully, there are loads to choose from and we rounded up the best iPad Pro keyboard cases right here.
Computing

Microsoft’s Clippy came back from the dead, but didn’t last very long

Before Cortana, Alexa, and Siri even existed, Microsoft Clippy dominated the screens of computers in the 1990s to help assist Microsoft Office users when writing letters. He recently made a bit of a comeback only to die off again.
Computing

How 5G networks will make low-latency game streaming a reality

Faster speeds and more bandwidth are some of the many promises that 5G can deliver, but for gamers, the most important thing is low latency. To achieve low latency, carriers like AT&T and Verizon are exploring hybrid models for game…
Deals

Time to do taxes? Save up to 50 percent on H&R Block tax software this weekend

Tax season is stressful, and with new tax laws in effect this year, it's not a bad idea to get some help. H&R Block has you covered: For two days only, you can save 50 percent on its great software so you can file your taxes online and save…
Computing

Stop dragging windows on your Mac. Here's how to use Split View to multitask

The latest iterations of MacOS offer a native Split View feature that can automatically divide screen space between two applications. Here's how to use Split View on a Mac, adjust it as needed, and how it can help out.
Computing

The new iMacs push on iMac Pro territory, but how much power do you really need?

With Apple refreshing the higher-end iMacs with newer processors and graphics cards, it moves closer to the iMac Pro. In this guide, we consider the performance, features, and help make sense of the differences between the two.