Researchers at the Swiss university Fachhochschule Graubünden claim that they’ve broken the world record for the most calculated digits of pi, a mathematical constant that describes the ratio of a circle’s circumference to its diameter. Usually, when we talk about pi, we talk about the number 3.14, but because its decimals never end, nor do they settle into a pattern, pi’s digits go on, theoretically, forever.
These scientists have not just broken the world record for the most calculated digits of pi, but they’ve smashed it, moving beyond the existing record of 50 trillion digits to reach a whopping 62.8 trillion digits using a supercomputer. They also completed their record run nearly four times faster than the previous one.
But the real question is: why should we care about all of those digits in the first place?
Project leader Thomas Keller is very clear about what this world record represents—and doesn’t. “The number of pi is (except for a few very well-known digits) irrelevant to us and probably to anyone else in science and mathematics,” he tells Popular Mechanics via email. “For us, the record is a byproduct of tuning our system for future computation tasks.”
That part is key, because calculating pi has become a way for computers to flex their computational abilities, as programmers look toward extremely resource-intensive tasks, like modeling the universe or even making high-performance imagined worlds in video games. Scientists can also use powerful supercomputers for practical tasks like mapping the human genome, or crunching all of the world’s known chemical compounds in order to find candidates for new medicines.
So calculating pi itself, Keller says, is a fun and attention-grabbing side effect of supercomputing, rather than a specific goal. Setting the record is cool, but that’s all it is. And in this case, the record came at a much faster speed—good news for the supercomputer.
How do we calculate pi, anyway? Well, this team and the last several groups to break the world record have used a special formula called the Chudnovsky algorithm, developed in 1988. But all the algorithms to solve for pi are working off a hypothetical version of a very real problem. Pi is the ratio of a circle’s circumference to its diameter.
In theory, if you can draw and measure a perfect circle, you can calculate pi by simply dividing one value by the other. In reality, we must have complicated formulae to get the right individual digits that calculate out to as many decimal places as possible. The Chudnovsky algorithm involves the intersection of complex, advanced mathematics you’ll have to dig into on your own (see above).
Back to the new record, though. Because the last several records have all used the same algorithm, any changes in speed represent something in the programming or computing power on display. And for what it’s worth, simply having an algorithm to use is one thing, but how you “implement” that algorithm in code can vary a great deal.
“Speed is not relevant per se in these record runs, as only the number of digits is important for the world record,” Keller says. “But tuning the system to maximum performance is an important aspect of our future calculations in the area of applied research and development.”
This is a really important point to make, because these records are set as the result of careful mathematical thinking, as well as the practical concerns of programming a computer to do what we want. The wrong programming can absolutely sink a project in terms of increasing computation time.
“The unfathomable speed, and the huge numbers a computer can process in a very short time and with incredible precision” surprised even Keller.“”In comparison, in 1874, William Shanks calculated the number of Pi to 707 decimal places. It took him 15 years to do so!” he explains. At the time, Shanks was the fastest “computer” around.
In January 2020, Timothy Mullican—a cybersecurity analyst and entrepreneur living in Huntsville, Alabama—broke the previous world record for the “most accurate value of pi,” a title that he will continue to hold until the Guinness Book of World Records certifies Keller’s attempt. Mullican calculated the value down to 50 trillion digits, upsetting the prior record holders from Google.
As for Keller and company? They’re keeping their full calculation for the number pi under lock until Guinness certifies their record. For now, we know that the last ten digits are 7817924264. Do with that what you will.