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Rubik's Cube Now Solvable in 20 Moves
A few years ago we reported that it had been proven that Rubik's Cubes could be solved in 23 moves. Well now that number is
down to just 20. Proving it required 35 years of computer time donated by Google to get it done.
The shortest path between any two configurations (be them solved or not) on a graph of all possibilities will be no greater than 20.
Don't have to, World Community Grid has already been doing cancer cure grid computing for years.
This one is complete:
http://www.worldcommunitygrid.org/research/hdc/overview.do
These two are still running:
http://www.worldcommunitygrid.org/research/hcc1/overview.do
http://www.worldcommunitygrid.org/research/hfcc/overview.do
Start with your right arm behind the wearer. Make sure your thumb is on the reinforced section holding the clasp, behind the clasp, on the side to your right. Your index and middle finders should be in a similar position on your left. Squeeze your thumb and the index and middle finger towards each other, while also pressing slightly in (towards you) with your arm. The bra should now be unhooked.
(Lefties use your left hand and switch left and right above.)
35 years is about 300k core-hours, a standard measure of computing resources. This is a big pile of computer time, but is not unreasonable.
So how much does this cost?
A typical supercomputer, Ranger, cost $59 million to build and operate for four years. It's got about 60k cores, so $59 million delivers 240k core-years; they used 35 core-years to do this computation. Doing the division, you get $9000 of computer time -- not all that bad. Plugging in the cost numbers for another production supercomputer, Kraken, gives a slightly lower cost.
No, they've proved that the superflip (the position where all the edge pieces are flipped and the corners and centers are in place) is 20 face turns from solved. Thus before this new work it was already known that the general solution required at least 20 face turns, and this work says that 20 is sufficient. So 20 it is!
That's where you are wrong. There is a lack of resources, funding, and computers cycles. There have been cycles running for years. I know cancer researchers, and I've donated time, money, and my computer cycles
While all research could use more funding, cancer research has to be one of the best-funded research fields out there. It's either that or defense. It lacks funding like I lack funding because I can't buy a mansion.
Could you be more specific as to what those cycles were for? I'm guessing they were for protein folding, which is essential and good research but is not going to directly find a cure. If google had run all it's computers on protein folding, we'd likely be only marginally closer to a cure for cancer.
The limiting factor in cancer research is -not- computing time. A bigger one is the fact that there are many different types of cancer, and the biggest one is that it's incredibly difficult to kill millions of any one type of cell without killing a lot of other cells in a human body. For most of our history, we had no idea how to specifically kill bacterial cells in a human body. It's still an issue.
Great job though moderators, bump up misinformation. You'd rage too if you were 34 and had to deal with this shit. And watch, I'll get marked as Troll again, even though I'm not and have a great post history. Whatever.
You're also going to get modded troll because you were asking for it. If you're 34 you should have at some point learned how to calm down and not take things so seriously.
Actually, this is a much more important result than the summary claims. Until now, there was always a gap between the proved lower bound and upper bound on necessary moves. They now proved that the known lower bound (20, proved in 1995) is also an upper bound (ie. there is no position which requires 21 or more moves to solve) and thus concluded research that lasted for 30 years.
This article could very well be listed on the Slashdot main page, it has nothing to do in Idle. The algorithms that were designed during this research are nothing to laugh at and will surely advance other research fields as well.