Four years after a Japanese mathematician announced he'd cracked an epic math problem, his fellow number crunchers are a step closer to deciding whether he got it right. Yes, his work is that complicated. In 2012, Shinichi Mochizuki of Kyoto University, who's known to work in isolation, published a 500-page proof he said explained the ABC conjecture, a renowned math problem involving prime numbers. The problem is few could understand his proof because it required a grasp on Inter-universal Teichmuller Theory—essentially a new branch of math Mochizuki created—and he refused to travel to explain it to the mathematical community, reports Nature. Finally, a breakthrough came last month in Kyoto, where he lives.
During a meeting of four dozen mathematicians, Mochizuki was able to teach his theory to others. As Ivan Fesenko of the University of Nottingham put it on Facebook, some participants "visibly progressed in their understanding" and ended up "tired but happy," per Motherboard. (The latter site gets into the nitty gritty of the "simple-seeming" ABC conjecture.) There are now 10 people who reportedly understand IUT and are working to verify Mochizuki's proof. But it isn't clear how soon that could happen. One number theorist says it could still be years before Mochizuki's theory is proven correct—or not. If he's right, though, it could be "revolutionary," says one mathematician. (Want to be a millionaire? Solve this problem.)