[ad_1]
Even on my The sound is undeniable, it's the slippery and slippery sound of a Rubik's Cube that slides to take shape. "This is my first resolution of the day," said Australian speedcuber Feliks Zemdegs, rather sheepishly. He is early in Sydney, where he speaks to me by videoconference from his apartment. On his shoulder, I can see his bed undone. On her: a big pillow, the new Rubik's Cube pillow. He seems not to have been awake for more than 20 minutes. It does not matter: it takes less than seven seconds to transfigure the cube between his hands, from encrypted to resolved.
Zemdegs has many volume records, but is best known for being the fastest 3 × 3 solver: the canonical three-layered Mondrian color cube. (The toy you probably imagine is just one of the mechanical riddles of what's called twisted riddles.) Last month, at a speedcubing competition in Brisbane, he set up a new world record of 5.69 seconds on average. 5, in which the participants each solve five cubes that have been scrambled in accordance with the computer generated instructions. When they finish, the competitors eliminate their fastest and slowest times and calculate the average of the last three. Zemdegs' 5.69-second average was 0.11 seconds better than its previous precedent, which was also a world record. "Since 2010, I broke the record of averaging 5, probably 10 times," he says.
Short records are common in speedcubing, a relatively young sport. (Sport, of course, why not?) The first world tournament was held in 1982, eight years after the cube was invented by Hungarian architect Erno Rubik. There, competitors took a minute to solve the cube. But in 2009, the fastest speedolvers (many of them too young to be driven) unraveled the cubes in just over 10 seconds. And today, the hundreds of the best speedcubers on the planet average less than 7.7 seconds per resolution, with the top 10 all below 6.5.
And yet, improvements are becoming more and more progressive; trace the progression of the cubic records, and the resulting curves are clearly asymptotic. While speedcubers such as Zemdegs are approaching the limits of their finger art, an irresistible question arises: what could this limit be?
It is tempting to solve the problem: divide the most efficient solution for the cube (measured in revolutions) by the resolution rate of a world-class user (measured in revolutions per second). The result would provide a theoretical limit to speedcubing.
The resolution rates are fairly simple: in competition, elite cubers like Zemdegs have on average 10 rounds per second. (It's fascinating to look at and gives the strange impression of agitated spinners.) As for the number of laps required to solve the puzzle, it's harder to pin down.
First of all, it depends on the complexity of the scrambling of a cube. At one end of the spectrum are configurations that require almost no resolution effort. For example, there are 18 starting positions that require a single turn to solve a single face. Such difficulties would probably never be allowed in a tournament. Once again, the chances that they meet at random during a competition are, say, weak.
"There are more than 43 billion ways to scramble a Rubik cube," says computer scientist Tom Rokicki. "It's more positions than grains of sand on all the beaches of the Earth."
Forty-three quintillions – 43 252 003 274 489 856 000 to be exact – is the kind of number that defies analysis. That is why, for many years, no one knew for sure how many movements were needed to solve the most Gordian problems of the cube. But in 2010, Rokicki and a small team of computer scientists convinced Google to let them solve the problem by using the company's computers to find the most effective solution for the $ 43 billion. billion starting configurations. Testing them by exhaustion would have taken decades for a normal computer, but Google's machines reduce computing time to a few weeks. In the end, the Rokicki team proved that each Rubik's Cube problem could be solved in 20 moves and that the vast majority of them could be solved in less.
But the fact that a computer can identify the most effective solution to a scrambled cube does not mean that a human can do it. "No one is able to look at this cube and say, ah, I have 18 movement of resolution, and this one takes me to 17," says Rokicki. "It's just not something humans can do."
Even though humans could identify the most effective solution before performing a single turn, its implementation might not be faster than current speedcube methods, which rely on deep-rooted muscle memory and reflexes triggers of hairs.
This is perhaps the biggest misconception among people who do not know the style of the cube: whoever solves the puzzle quickly does not do it by pure intuition, but with sequences of memorized movements, called algorithms, that they deploy to solve the cube section by section. Elite speedcubers store hundreds of algorithms and practice them in their inactive moments. Know which one to use when recognizing shapes: each algorithm corresponds to a different arrangement of colored squares on the cube. When a speedcuber spots an arrangement that it recognizes, it executes the corresponding algorithm, bringing the cube closer to its problem.
The chaining of algorithms is a skill in itself. The best speedcubers excel in what is called "anticipation", that is to say, the ability to detect the pattern that will occur at the end of the movement they are currently performing. A sort of short-range, forward-looking clairvoyance allows players to plan future algorithms a split second in advance. This minimizes breaks that take a long time and can give observers the impression that a speedcuber solves the cube into an uninterrupted chain of maneuvers. With the help of algorithms and anticipation, the most versatile cubers in the world record on average between 50 and 60 shots per resolution, which they can execute almost without thinking. "In speedcubing, as soon as you stop to think about what you are doing, everything is over," says Rokicki. "It's like dancing in a way, and I know that breaks are an important part of the dance, but if you dance and you stopit's not part of the dance. "
But there is one variable that we still have not taken into account: luck. On rare occasions, by pure luck, a cube will be scrambled to require less movement than usual to be resolved (think 40 to 50 moves instead of 50 to 60). In even rarer cases, a lucky tug will be in the hands of a world class cuber. And, in the rarest cases, Cuber executes his algorithms not only quickly, but transparently, dancing with his solution with almost perfect fluidity. When all these things happen at the same time, an incredible time can seem to come out of nowhere.
That's precisely what happened last May, when Zemdegs made a single resolution in 4.22 seconds then unprecedented. And that's what happened six months later, at a competition in Wuhu, China, a relatively unknown speedcuber, Yusheng Du, solved a cube in just 3.47 seconds.
"To be honest, it was pretty unexpected," says Zemdegs. It was not that he did not think that someone would beat his record ("I'm tired of being broken over the years and I'm pretty numb,"). he said), he did not expect it. fall so fast, or by many. Not since 2008, when the single-resolution record went from 8.72 to 7.08, the world of speedcubing has not seen such a jump.
And yet, Zemdegs knows that there are even faster solutions on the horizon. "My best solution, in practice, is 3.01 seconds," he said, "and I know a few people who have managed to solve the problem of the under three category at home, just a problem. " He believes that in perfect conditions, a person of his level could solve a cube in 2.5 seconds. "The question is right: when will it happen?"
But future records will not only depend on luck. Perhaps there are methods, still to be discovered, that systematically require less than 50 moves – an advance that could allow the record to resolve on average by the middle of the four seconds. The scaling equipment could also be improved; Today, the specially designed gear cubes are easier to twist than the original and contain magnets that help the faces to get in position.
And to hear Zemdegs say it, there will always be room for improvement with regard to the fluidity and speed of the fingers. "You can always be more perfect," he says.
I think that's an error on my side of our video chat. But a seductive, of course.
More great cable stories
[ad_2]
Source link