Google's Compute Engine has calculated the most digits of Pi ever, setting a new world record: 31.4 trillion digits. And a musician creates a million hours song from Pi.
Emma Haruka Iwao, who works in high performance computing and programming language communities at Google, used infrastructure powered by Google Cloud to calculate 31.4 trillion digits of pi. The previous world record was set by Peter Trueb in 2016, who calculated the digits of pi to 22.4 trillion digits. This is the first time that a publicly available cloud software has been used for a pi calculation of this magnitude.
Iwao became fascinated by pi when she learned about it in math class at school. At university, one of her professors, Daisuke Takahashi, was the record holder for the most-calculated digits of pi using a supercomputer. Now, y-cruncher is the software of choice for pi enthusiasts. Created in 2009, y-cruncher is designed to compute mathematical constants like pi to trillions of digits. "You need a pretty big computer to break the world record," says Iwao. "But you can't just do this with a computer from a hardware store, so people have previously built custom machines." In September of 2018, Iwao started to consider how the process of calculating even more digits of pi would work technically. Something which came up quickly was the amount of data that would be necessary to carry out the calculations, and store them -- 170 terabytes of data, which wouldn't be easily hosted by a piece of hardware. Rather than building a whole new machine Iwao used Google Cloud.
Iwao used 25 virtual machines to carry out those calculations. "But instead of clicking that virtual machine button 25 times, I automated it," she explains. "You can do it in a couple of minutes, but if you needed that many computers, it could take days just to get the next ones set up." Iwao ran y-cruncher on those 25 virtual machines, continuously, for 121 days.
Now, for Pi Day (March 14), music software programmer Canton Becker has crafted a million-hour song based on Pi that unfolds generatively on a virtual tape deck. Titled "Shepard's Pi," the song combines two of Becker's favorite infinities: Pi, and an auditory illusion called a Shepard tone, which he describes as an "unsettling sonic illusion of a pitch that climbs or descends forever, never reaching a top or a bottom." Found at PiSongs.com, users can tune into "Shepard's Pi" in real time with a custom virtual tape deck. The track itself evolves moment to moment, but the synthesized and sampled tones will be familiar to anyone who has ever listened to the electronic music of Kraftwerk, Tangerine Dream, Aphex Twin, and Global Communication. Far from being a mere gimmick, it is a highly evocative and transporting piece of electronic music, alternately ambient, glitchy, and interestingly rhythmic.
"When users hit 'play' on the virtual tape deck, the algorithm actually 'performs' the piece," the report says. "This way, the 114-year song can fit in just one gigabyte of space, which is mostly comprised of the digits of Pi. The virtual tape deck was also a solution to a built-in quirk of browsers such as Chrome, Safari, and Firefox -- users must click on a webpage to trigger a sound." From start to finish, the song lasts 999,999 hours, "a limitation imposed by only considering the first one billion digits of Pi."