JP Brown’s Serious LEGO – CubeSolver

May 29, 2007 | General | By: Mark VandeWettering

One of the mailing lists I’m on pointed out the following project to make a LEGO robot that could solve the Rubik’s cube:

JP Brown’s Serious LEGO – CubeSolver

Very slick, but it mentioned something I found even more interesting: Herbert Kociemba’s algorithm for quickly solving the Rubik’s cube:

Cube Explorer

In his testing, he generated one million random cubes, and tried to solve them using his program. He found no candidates which could not be solved in 20 moves or less. As far as I know (and this might be out of date) there are proofs that 25 moves is sufficient, and there are positions for which 20 moves is necessarry, but it isn’t known what number actually suffices.

I spent six months carrying around a Rubik’s cube back when they were the fad in high school (at least among geeks like me), and ultimately had my own rather pathetic way of solving the cube (it was slow, and usually took me ten or fifteen minutes to do). Fun stuff.

[tags]Robot,LEGO,Rubik’s Cube[/tags]

Comments

Comment from tdl
Time 5/31/2007 at 7:31 am

Wow. That Lego solver is hardcore.

I paid no attention to the Rubiks Cube when it was in any way trendy. But last thanksgiving I picked one up and decided to learn, so now I’m semi-obsessed with it at a time when it’s kitschy at best, and pathetic at worst. But it’s fun.

When I learned how serious some people take it, I joked to a friend, “If I can ever solve it in under 2 minutes, kill me.”

Well, after a few months of casual solving (without focusing on speed), I realized I had gotten it down to 1 min 30 sec. (I wish I could remember who I had told that to! My life could be in danger!) This was with Singmaster’s technique (http://en.wikibooks.org/wiki/How_to_solve_the_Rubik%27s_Cube), which is easy to learn but inefficient.

So now I’m doing what I promised myself I wouldn’t do. I’ve learned a more advanced technique (http://lar5.com/cube/index.html). Since it’s foreign to me, I’m back up to 2.5 or 3 minutes. But I suspect it’ll get me under the 60 second mark before long.

What a weird hobby.