March 14th is an annual excuse to celebrate pi, the infamous irrational number, used since ancient times, and a fundamental mathematical constant. It was one of the first big breakthroughs in mathematics, and without its instrumental role in maths and physics, our modern world would be simply impossible.
As an irrational number, the digits of pi continue infinitely with no regular repetition or pattern, so the need for an approximation or a symbol to represent it is crucial. Using the greek letter π to symbolise pi was popularised by Euler in the 18th century, but the concept of pi as the ratio of the circumference of a circle to its diameter has been in use since 1650 BC.
Auditor of Trinity MathSoc and final year theoretical physics student, Liam Kavanagh says the popularity of pi is probably down to it being the first taste we get in school of the complexities and mysteries of mathematics: “It’s one of the first kind of weird numbers that people are introduced to when you’re in school. You go from 1,2,3,4 to fractions, and then all of a sudden you’ve got letters that are representing numbers.”
It’s also one of the first times children come in contact with infinity as a mathematical concept and even as a concept at all: “That’s kind of the interesting thing about it, it’s infinitely long and it doesn’t repeat. And so you can’t write it down in any meaningful way, except to just give it a letter.
The fact that it has its own letter is enough to show that it’s an important number in literally every aspect of maths.”
Pi crops up in so many aspects of everyday life. “Anytime you see a circle or anytime you have a repetition or some sort of cycle it will be related to pi. It goes so far, and it pops up in so many weird and wonderful places that you just don’t expect.” DNA helices, electromagnetic waves, planetary orbits, hula hoop crisps- pi encodes many of the deepest secrets of our universe. This September an interesting planet was discovered, K2-315b, affectionately nicknamed Pi-earth due to its similar size to earth and its orbit every 3.14 days around its star.
Aside from discovering all the uses of pi, mathematicians and computer scientists are still trying to calculate as many of its infinite decimal places as they have the computational resources to, the record currently stands at a staggering 50 trillion. Do we have the need for 50 trillion places of accuracy for calculations using pi? Certainly not, scientific calculator brands only use about 10, engineers are the butt of many a joke for their stereotyped rounding to no decimal places, and even NASA’s jet propulsion labs use only 15 decimal places for spacecraft launch. So why calculate so many? In many ways, our advances in calculations of pi are a benchmark for our scientific and mathematical advancements. We have come far from the days of Archimedes estimating pi by sandwiching a circle between two regular polygons and estimating pi in fractional forms. Though this was groundbreaking in its day, now calculations of pi are carried out by computers using infinite series formulae, which better reflect pi’s infinite nature and better approximate it.
In honour of pi day, Trinity MathSoc will be holding a talk on March 10th at 6.30 pm to discuss the history and wonders of this much-famed number. The talk will be “an accessible introduction to something that is really at the core of pretty much everything in maths” says Kavanagh. Pi is such a universally interesting topic and Kavanagh hopes the talk will appeal to a wide audience: “Even people who aren’t particularly keen on maths would recognise pi. We’re kind of hoping that people who aren’t necessarily in MathSoc, or [studying] maths or theoretical physics, would kind of be happy to engage.”
Kavanagh points out that a real barrier to engagement with STEM societies is the misbelief that you need to be studying a certain course or have a high level of interest in the subject to join or to be comfortable in the society: “I think a lot of STEM societies, in particular, suffer from the perception of being like a closed-off wall.” He cites the large number of students at present and previously who have been central to the society, but who came from very different subject backgrounds. “It’s definitely very accessible, I can promise you that nobody in MathSoc, except maybe one or two people, are maths geniuses.”
“At the end of the day, MathSoc is just like any other society really, it’s just a community of people who have shared interests…It’s just really a group of people who are just interested in having a fun evening, talking about something interesting, and then in a normal situation, you might go off and play some board games or go to the pub.” MathSoc, like many subject-based societies, has to strike the balance between acting as a form of academic stimulation but also social aspects. “There’s definitely people in the society for different reasons. We do try and cater for everyone that’s there.”
Kavanagh remarks that first-year engagement this year has been greater than might be expected, given the daunting experience Freshers face in this virtual-only year. “I was really surprised at how many first-year students in particular actually, went out of their way to try and get involved in societies. Because we would never have been able to get to them otherwise, except that they were the ones who reached out. And once they reach out, they stick around, because they realise that it’s something they enjoy. We try and be as welcoming as possible.”
In the spirit of this, MathSoc has recently opened a maths help room on their discord server to provide another platform for student to student support. “That’s seen a massive amount of new people join in, and they’re there to try and have a conversation with somebody, to try work through a problem that they’re having. It could be from any course, maths is one of those subjects that so many people do… computer science, economics, business, all of the sciences. It’s just as so far-reaching, and everyone needs help with it at some stage.”
So in the spirit of pi day, whether your calculator has been gathering dust since your leaving cert maths exam or whether you’re the next Pythagoras, MathSoc’s doors are wide open.