Adam Savage Book Club: Humble Pi: When Math Goes Wrong In The Real World

welcome to the Adam Savage book club we are in the library of my house only a few short blocks from my cave and me and my assistant Maggie here are asking questions today of Matt Parker of his new book humble pie being released in the it’s just been released in u.s. yeah you’re travelin around barnstorming talking about it Matt I read this a few months ago when you sent me the UK version and I have questions about that but first off like give the broad overview what is this book about all right. I’ve written a previous book which is much more about doing math and I thought you know what it’d be nice to appeal to a wider audience of people and one of my many goals is to get more people more excited about math and I thought you know what people like stories of disasters you’re not living in at the moment it’s it’s it’s entertaining. I thought you know what I’ll find loads of examples of when math has gone wrong and kind of us thinking like there’s. much math people don’t appreciate going on behind the scenes right like you know any kind of industry and format exactly if it goes wrong you know like I say big consequences and. I thought you know what it would be nice to get these entertaining stories of things going wrong and then I can use that as an excuse to talk about the math behind the scenes you know you use this phrase getting people excited about math yeah and the thing is that one thing modern education is really good at is achieving the opposite the best case for a lot of modern conversation education is getting people resigned to me exactly that’s the best option and I think the thing that I found most surprising when I first became familiar with your work a number file which is where I first encountered you is the fact of your genuine excitement and thrill and it it engendered in me the same thing. I was some you know I think a lot of people are surprised to find out that mathematicians aren’t people who are resigned to math at a higher level than exciting because people think mathematicians are just doing like longer and longer tedious calculations well it’s a living batting number file that could only have happened on YouTube where we had absolute free rein because was YouTube and Brady who makes it just he contacted a few of us and was like hey I owned his the thing about numbers and all we did was sit down and talk about what excited us about mathematics and I don’t think maybe careful with the sentence I don’t think mathematicians at that different to normal humans I think they’ve just done a lot more learning and a lot more like it takes a lot of background reading to get into math because everything depends on previous bits but what excites a professional mathematician is the same thing that will excite a normal person what we tried to do was just show that like this is why we love it when the patterns line up where it all works when it’s useful and yeah seems to work well I mean and that’s just the thing is when the patterns line up there are aspects to the landscape of mathematics where you find connections from one end to the other that are still not clearly understood and that makes it a really exciting we think everything’s been discovered but it has it no there’s always always more math and it’s that moment where you suddenly go wait a minute this looks familiar and it looks like a thing that was over here and I mean like you say often we’ve not drew down far enough but often if you can go down and you can kind of abstract it or get more theoretical then you suddenly find there’s this logic that links and turns out they’re both just manifestations of this deeper I mean I would say like truth or something but that’s good well they’re you know and. that’s kind of the dream that those moments where you suddenly realize that these things are connected and you can do that at any level. obviously professional mathematicians are doing it at the forefront of human knowledge but even like I’m a record recreational mathematician right. I mess around with it and even though I’ll be doing something I’ll have a sequence of numbers or something and go wait a minute that rings a tiny bell and that’s kind of an unfair advantage like if you watch someone who’s been doing math for a long time now go oh hang on this is and like I recognize this is Pascal’s triangle right these are the prime numbers and it’s just because you spent. long doing it you you build up this intuition but those sorry just my final story about number files I will be lying in bed watching numberphile videos with my headphones on and my wife will turn to me and go are you crying about math and I’m gorgeous. you talk about a recreational mathematician as a serial recreation list and all this that I know I have in the past joked that what I like to do with the skill is get to learn it until I’m better than most people at it and then I drop the progression.

I am the patron saint of mediocrity plus one and in that vein I’d like to talk about the Parker square which is my favorite part of this book and I think it’s a wonderful a wonderful analogy for iterative learning and thank you. what is the Parker sorry the Parker square this started when because I sit down with Brady who makes numberphile maybe every couple months couple times a year and will form a whole bunch of videos and I’d want it to do one on something that we don’t know yet which I also find the math we don’t know I find that fascinating and because there’s some fairly understandable questions that are easy to parse that are still unanswerable that’s a great thing about math because the simplicity with which you can state the question in no way correlates to how complex the answers can you have an example to the there’s a famous one called the Collatz conjecture which is just one of these sequences if you take a number and if it’s odd you double it and I think or you and if it’s even you you divide by three like there’s two very simple rules which people are now yelling at their screens how much I care about the collets conjecture and. with these two simple rules or every number ends up at one but you can state them very easily. easily I don’t even bother to remember them but proving that that always happens has evaded all mathematicians. every time you try it and for any circumstance it ulam answer but you can’t but why not prove that definitely happens every single time which I find just find amazing and there’s a whole thing of perfect numbers these are numbers where if you add all their factors all the numbers that divide into them you get back then and be started with no one’s ever found an odd number for which that’s true no one’s ever managed to prove it what that there is no such odd number we don’t know we don’t know and the parker square was if you have a magic square. these are where you’ve got a grid of numbers and if you add the columns you get the same total every time you add the rows you get the same total every time the diagonals vary importanly it turns out you get the same total every time and magic squares have been studied for millennia Benjamin Franklin famously came up with a bunch of magic squares Oh recreational mathematicians over the generations have looked at these things and an obvious question is hey there’s a square have we tried square numbers and people have found bigger magic squares with square numbers no one had ever found a 3×3 Magic Square where all the numbers were themselves square numbers you thought that was a worthy challenge I thought I’d give it a go and. I like yourself I’m like I wasn’t like a poly appalling nerd apart I become sufficiently obsessed with a lot of different things poly nerd as opposed to polymath as opposed to play math but that implies too much mastery of the subject sure where’s like you like like I look to solve a Rubik’s Cube faster than 99% of people those remaining 1% are like is taking forever all right everyone else thinks it’s incredible right right I do like mental calculation tricks better than most people but the pros are like this is useless and. I thought I’d pick up programming as a hobby and. I was learning Python fantastic programming language I highly recommend and I thought this would be a good exercise I will see if I can program a way to search for these types of magic. build a program that would run through iterations until hopefully it’s sifted out a magics exactly and that some people think that it sounds like you’ve taken all the creativity out of it was I find programming isn’t incredibly creative well there’s just the actual coding but there’s also thinking how am I going to do this search and. I basically searched square numbers and put them in categories based on what their sum was and they had another program which would go through all these categories and find ones which could sufficiently overlap you did a number file video on programming maths software that I found really impressive for the way it required a specific way of thinking through tackling the problem that’s it’s not trivial and that was my goal because in. many videos I realized I was saying and I programmed this I was like you know I just actually show the process. I started from scratch with a new problem I hadn’t tackled before and in that video I went through and showed how you put the code together for the parker square i wrote the code i ran it and then i analyzed what came out the other and I ended up with this one square which kind of work. in my defense it was pretty good if there were of the nine numbers three of them were repeats and I mean I admit if you start going down that path because I could have just had all ones exactly. I except I was one step along that path in fact it’s symmetric along one diagonal. in some regards I got half a square and just copied it in the other thing also one of the diagonals doesn’t work. one diagonally only one what’s one diagonal huh right there’s a spare one that works as a one diagonal didn’t work and. in the video I’m talking like to Brady who’s filming I’m going through all this stuff and I I get to the point I here’s what I found he’s like no it’s not very good what’s it called I was like I am NOT gonna call it the pocket square because they’re never gonna be like oh something goes wrong and be like a classic pocket square and Brady was like don’t worry I won’t make a big deal of it and. he named the video the pocket square yes he released a line of t-shirts well I was on tour at the time and later on that tour my tour manager shows up with the biggest grin on their face wearing a parka square tisha there are even into math but they just knew that wearing this was a form of casual bullying and. they went with it and there’s mugs and everything and I mean as you said the very beginning I I kinda I was like I’m okay with this I guess it’s fine because I think it’s a mascot for giving it a go and if there’s like one of the morals of the story even before I were at the book but now very much in the book is math is about giving it a go and people remember it from school and think oh it’s all about getting the right answer it’s not math is about trying and playing with numbers and patterns and the bulk of the time you’re gonna get it wrong and every now and then you get a little bit closer well and with all the sciences the deeper you scratch the grayer right versus wrong that cause right this is the everything vens at a certain point yeah and. I was like look at I’m happy for this to be out in the world and just to become this kind of has taken on its own life is a kind of online meme where there’s just this sense now in a certain corner of the internet and people and how many young people watch the videos and they go I’m just this sense of in math it’s okay to give it a go and just because you don’t get it totally correct doesn’t mean that it was okay look eight out of nine that’s totally sufficient for me my god what is that look at 88% my okay all right we got some questions from fans they have been reading the book and these questions are terrific I. someone said how how hard did you work to make the book pie times 100 pages long and I I know from speaking to you that you may have had some ambitions about pagination in the book that the publisher was reticent to to achieve yes yes it’s the nicest way anyone’s put it my publishers had a different phrasing I enjoy messing around with the page numbers and for some reason all books are very locked in how they do patient. if you grab any of the books off the shelf here I can almost guarantee they will have they’re all gonna have odd page numbers on the right yeah and they’re gonna heavy even on the left. yeah open there we go odd on the right even left my previous book I started on pages zero which flips it it means then I’ll it’s always even on the right I’ll another I thought that was hilarious didn’t people did people right but they just kind of they’d start the book and at the very beginning the first page has a zero on it and they’re like oh haha this time I tried two things. the zero is still in there mmm-hmm but also it counts backwards. at the beginning of the book here it like it starts on page 311 and then the next ones 310 and 309 and it continues to countdown and I had. many stories in the book where often in computing a system would be set up where they assign a big number and then countdown routinely often to keep track of time or progress okay and when it hits zero it would then cause the system to crash and. I found there was like an like in Southern California and air traffic route Control Center all their computers turned off because of exactly this problem and they lost contact with hundreds of aircraft this is because they had just left the computer on for too long too long and it hit zero and crashed and this has happened. many situations and often it’s caught or like you say if you restart often enough it fixes the problem. and just as a briefly brief aside I was at a conference a couple weekends ago talking to some security researchers which is always a terrifying comfort oh my goodness yeah but one of the things that I realized in speaking to them it oh right a chip a computer chip is nothing but hundreds of millions of little stop watches like that’s one way of looking at it yeah and then when you look at it like that a timeout error becomes oh of course that what happens from time to time and people often say why are you counting down same thing will happen counting up that’s not gonna fix the problem it still gonna finite amount of space kids what did you want to do the survey show anyway it counts down to zero then it crashes the page the page numbers and if you spotted this because right in the back where it gets boring they roll over to just over four billion I’ve got a 32-bit encoding on my page numbers but the actual question here is it starts on 314 and that was half happy accident half I using up more goodwill with my publishers cuz I had to put a note to explain that they’re going backwards those would be glorified that it cuz if there are any complaints or people return the books or complain to Amazon that there’s a mistake BOM like it just get bamas on just shut it down oh really and my publishers were just. nervous that would happen. the compromise was a note it literally says please don’t take it back for a refund this is the Librium but the the 10th I’m sorry a hundred times pi that’s on 314 when I realized it was gonna be closed I just said look early on when we’re typesetting I mean it’s gonna be close do you mind if we basically shuffle back where zeros gonna be and then normally they wouldn’t number this page like this is a totally blank normally the page numbers would start like here I said look would you mind rolling where it starts back a little bit. it starts at 3:14. it was it a half happy accident half half by design that’s fabulous on page one here’s I love this on page 197 you do the McDonald’s updated calculation for the meal subsection you’ve count two pics of three meals as six wouldn’t it be three times three equals nine was that one of the intentional errors in the book how do I love you challenged by your face I love my fans. much. I get. many emails from people who found mistakes in videos and books it’s a good thing I’ve kind of made that on-brand for me now maybe you’d be amazed just my thing. specifically this was there was an advertising campaign McDonald’s around the UK in 2002 and they promised more combinations of food than they could possibly deliver they had eight items on their menu and they promised over 40 thousand possible combinations forty thousand three hundred and twelve to be specific and there’s it’s. like the way they got that number how they got it wrong they there was an a people complain to the Advertising Standards Authority we girls had to go to court I’ll show they’re working out and I think that you showed that they were really they were working towards a genuine answer and some good faith yes oh yeah and they and I totally get where it happened because there would have been brainstorming how are we going to get the McDonald’s advertising account I know one of these look at the combinations and that they did what you’d kind of half remember from school right now whenever no one double-checked it and and this incorrect number ended up in the advertising campaign I just thought I would explore hypothetically what are the bounds on a reasonable meal. as if they had a genuine mathematician in the room as they were brainstorming exactly you have counseled and you could have because you can’t just work it out how many ways can you choose a number of items from eight options I thought no no let’s think about as accuses a lot of doubles in that when you do what exactly I was like well hey what if it was actually a meal what if you want to have a thick shake for a starter and a dessert or this or that right and. I went through to this calculation the specific question here is I have done six will have I done done three it was the complaint of two pairs of three meals as six you count two pics of three meals as a. I’ve done three choose two what have I done check us check those live on the state what page number they will compare 197 one nice it’s thank you by the way William on Twitter and YouTube for because I’ve got a sneaking suspicion they are right meal options here we go here we go okay. I’m allowing people to have a no main one of those three options or two of those if they’re really hungry. what have I done right. they think I should have allowed this to be picking the same thing twice versus choose two of these people have no main one option one of the three yep I think they’re right I think they’re right but it was no that’s not an intentional err okay I think yeah I think the rest of this video should me be me double-checking this calculation now okay I will I will I will check that thoroughly later at the back of the book I have a long list of people who sent in legitimate Corrections and if they’re the first person to send in a correction and I change it their name goes in the next edition.

I’m I fully embrace people pointing out my mistakes yeah I don’t know why I’m saying that don’t yeah yeah. honestly if you find it send it in and in the back here in the acknowledgments there’s a growing list of people who here they are who a zero-day discoveries. little securities joke – for you oh yeah and then you can see now there’s like it’s over two lines of people who sent in our Corrections that I’ve made. and again all my videos online start with underneath them in the description is a section for corrections oh wow they’re by default and starts by saying none yet let me know if you spot any and then they gradually fill in. brilliant um I love this question from Neil Russell on YouTube he says I’m a teacher from Scotland here Adam and Matt what do you think is the key to helping change the next generation their fear of maths as a teacher I constantly see students write off maths in an early age because they’re stuck in the belief that only certain people can do it any tips on how to capture their imaginations and to inspire them. that they can enjoy it I’m curious what is your origin story of the first time you found maths thrilling has an interesting question I’m probably would have been too young to remember mm-hmm I was very fortunate in that my dad was an accountant and my mum was a librarian for the most part and from a very early age I was given math problems to do at home before I went to school really and. I the first family recreation yeah yeah exactly and they tricked me they were like hey this is fun it’s like in the treats math and the first opinion I remember having about math is that I preferred addition – subtraction but I realized all the subtraction ones I could turn them in a little plus symbols and then do the adding up right it was I found it. pleasing and when I went to school I had this rolling start of her a math where was everyone else and and I saw this one as a teacher. which was a high school math teacher for four years at parent-teacher night you I would see parents say to my face with their kid next to them oh I was never good at math. of course my kids not good at math and like don’t give a teenager an excuse to not learn ever like they’re gonna take that and run with it and the difference like even just that when you start learning math having the attitude of oh this is difficult yeah I’m not good at it versus this is fun I’ll give it a go it makes all the difference and as soon as you get behind in math it gets harder to catch up and kind of the point and this is not going to solve their problem enthusing young people well I think is the major issue is people who who struggle with math look what the people who do a lot of it or enjoy it or do it for a living and think wow they must be really good at math they must come to them naturally and that’s not true the people who were into math are the people who enjoy the fact that it’s difficult they enjoy that they have to struggle with it that’s part of the appeal and it’s not don’t get me wrong it helps that if you immerse yourself in it you get very good at it and you build a bit of an intuition around it in the same way that the crossword puzzles are difficult and. doing is difficult these are these are things we use the challenge our brains the the the realization I think that everyone I’ve met who loves maths loves it because they see they see something unknown unknown about it yeah right like that’s the in school when you teach it as a bunch of tests and things to memorize you’re teaching it as facts that you either know or don’t know it’s binary but the reality is way more and the reality is don’t get put off when you struggle because you’re always going to struggle and you’re teaching everything a brain the human brain is not good at math naturally but it’s very good at learning it but the learning is a struggle and it takes effort and you’re going to make mistakes and I think the secret is to not be disheartened by that but to enjoy the journey of your adding to your you know toolkit of problem solving and thinking techniques. I remember for me I actually have very specific pairing of things that happened I was uh in a freshman in high school and no no no no excuse me it was middle school’s seventh grade right now that I remember the teacher and it was one of those logic puzzles of you know Mary works three days a week Brian drives to work and is all these disparate facts and somehow you have to find that commonality and the teacher gave it to us to work on for a period all of us failed and then the next period was spent looking at it algorithmically and I found myself fascinated that the way to solve these things was not you couldn’t just build an equation to solve for it you actually had to build an equation start plugging in numbers and screwing up to kind of see the direction or trajectory you wanted to go in cut to about six or eight months later some friends of my parents showed up and they gave me this puzzle that was a series of radio levers on platters with different cut holes in them and the puzzle was to get the levers which all started on the outside of this puzzle to the inside of the travel and it was all clear and I was looking at it and I could see that there was a plus one aspect to the stacks of things and I realized that the same algorithmic thinking I had learned from this word puzzle applied to this and like 12-year old me wasn’t thinking that I like maths but I was like oh this is figure one i sat there with a piece of paper and I started to draw what I could see the structure and then I saw the bus lit like an hour there you go it was and there were like 19 million combinations and I was like right but it’s just an order plus. we can exclude a lot of them and for me that that moment of taking on the difficulty and coming to a solution using something that came from a place that didn’t seem like it had a connection was deeply thrilling and that almost answers the question it’s how do you recreate that in a classroom for kids right and and that’s the challenge and a lot of teenagers I mean you can motivate them because there’s an exam coming up or something but it’s difficult and in the UK and Australia we’re out of time both we are. low on enthusiastic math teachers right because if you get a math degree there’s a lot you can do with it option is not becoming a schoolteacher and. we kind of rely on people who become math school teachers because they think it’s a good thing to do which is not a good way to start an interest rate and. we just haven’t got enough enthusiastic teachers because the creativity and effort required to give students that kind of epiphany moment where they is they’re just learning the tools of math they get to see how they used that’s that’s when you get a kid did you did you have any go to like catch your attention lectures that seemed to resonate with your kids I used to do a lot on magic tricks right. there’s a lot of self working card tricks our friend Richard Weissman is a wonderful collector exactly and. and. I keep like I had a lot of friends who are magicians. I think a good good balance there’s a real crossover between mathematicians and magician really is there really is there’s a lot and. I loved contracts as a kid and. now all these self working ones their mathematical yeah almost by definition yeah and. I would get self working card tricks and I would get students to reverse-engineer how they work and then they could then use that to make their own culture oh right and. the extra layer of because it what I love about it is if you just memorize the steps you can do that trick that’s a bit like how most people learn math they memorize the steps they can do that specific problem but if you understand the logic behind it you can then bend it to your will you can change it you know what with a new trick and as an analogy for learning math I was like God whatever what I’ve moral to the story and kids love like you say you’ve got an exam you’re gonna need to learn this or one day you’ll have to get a mortgage things that really excite teenagers yeah whereas if you learn this right now you can annoy your friends and family instantly you’ve got him on board absence and yet you’re still getting the same critical thinking problem solving puzzles spotting patterns yeah I like that yeah that’s a great intersection I got I’ll flag it up because obviously I’ve written a book that you pay money for we wrote a free pdf download guide to using math magic tricks to teach math. I’ll we can in the comment down below fabulous it’s all there this okay here’s from Johnny DL on YouTube says the book contains a chapter that touches on the Millennium Bridge and the Tacoma Narrows disaster famous Washington Bridge that you’ve seen footage of buckling in the wind Mythbusters we tried to test the myth and struggle greatly as I recall and the course is asking if I have any thoughts since my second attempt and do you have any advice on why our first test failed. badly oh I know why I why our first test failed. badly and the difficulty the thing that I learned in testing this is you probably know is that bridges are way over designed oh yeah bridges are massively massively redundant Lee designed to be like way more like when I’m when I’m like lifting something with rope I’m always looking for a four-to-one safety advantage which means I want all of my equipment to break at four times the maximum weight I’ll be using that makes me feel comfortable and that’s what you call a live load something that swings if it was a static load I might go with a three to one but bridges are built at like a ten or twenty or fifty to one mechanical advantage I remember I did a little bit of civil engineering when I was at university and one of the unit’s we would spent ages with the calculations working exactly how much load all the parts could take and I used to love it getting right into the details right you get to an answer there like right now just slap another zero on the end and there’s your number like all that working out – just like magnet multiply to increase it and that’s what you built yeah and. for us the difficulty we had at testing is building a bridge that’s right on the edge of falling apart. you could test what makes it fall apart is actually its own engineering challenge that’s really quite difficult I did some lectures recently with Hanna Frey who does numberphile there’s a thing in the UK called the Rasta tution Christmas lectures there every year their science lectures Hannah and I did them just gone and we wanted to show the Millennium Bridge during this wobbling thing and there was no way we can make our own rig. we borrowed one from the research people at Cambridge University yeah and rigged up this massive thing that they had spent ages honing and building and the platform was able to move in one direction and we put treadmills on it and then we got people walking on trails and that’s and that is what we found then showed this one specific move great execution yeah laughter that did it well it’s tough because when did you have you had steps going up and down we had steps going up it was actually a huge argument from Jamie and I right and I don’t mean to unpack it here but I will just for a second which was Jamie built these robots which were exceedingly cute and hilarious because what they were was a air ram that worked as a semicircle it. it was a pneumatic cylinder that turned a quarter turn when you activate it and. we had a boot on each one and it would do this but my problem was the periodicity was never to be accurate to the millisecond because of the amount of a loss of feedback with air you needed a mechanical and we had this huge huge argument about it if he won the argument because we would do that for each other but then later on when it didn’t work I was pissed yes yes that’s f odd because obviously I’ve worked with a lot of people and of always you gotta wonder do I want to later on be able to say oops sorry or told you. and. one of the things that I had in my head that I’ve learned over the years is if someone says to me something spectacular ly not the right idea I think to myself do I need to solve this problem right now or will the world solve this problem yes for we universe closed this book and waiting for the world to solve it has been a real Grayson with the problem we found the reason we put humans on treadmills is specifically we were looking at the Millennium Bridge which is bright his bridge and Millennium Bridge the feedback loop was such that when people felt the bridge moving their method of attempting to stop it was actually exacerbating the problem that’s never a problem it was this feedback loop and the Millennium Bridge was very well engineered for the kind of up and down stepping and it was this unexpected side-to-side that was like about a Hertz or yeah a human walking is about a Hertz pendulum side to side and when the bridge was moving you get like this it’s like being on a ship right you can’t you start you start stepping into the participate where the moon gets going and that meant that more people do that they’re adding energy to the system and that causes more people to fall in step which adds energy and eventually you get look like a third of the people on the bridge we’re all working walking in perfect unison incredible to watch and that was enough to make it move about 10 centimeters and. they had to close it is there is there any news footage where you can clearly see it yes yeah align this footage they found and to recreate it they got people and they gradually had more and more people and March them backwards and forwards across the bridge to test a test at and the the rig we were using for the Christmas lectures was part of that research but the people who built it don’t want to be mean to the one company that made the Millennium British or because other bridges have had this problem there but for the grace we what makes a work though is it’s the human closing the feedback loop and even on because it was a bridge in a town called Salford outside Manchester which was the the original one with the troops marching and I think if you’ve got any kind of mechanised attempt to recreate that you’re gonna lose the human closing the feedback loop it’s because it’s a moving target you can try and do it at a rigid periodicity you could have been run find a harmonic yes but humans don’t work that way and that and I and even the ones on the bridge the victory stories they started whistling a tune and they all started they all started brain like going really going for there was a hilarious that the food bridge was moving. they all deliberately start walking at that. this is akin more to pushing someone on a swing which isn’t a regular periodicity but it is it’s not exponential but it carries right that way yeah okay yeah. it you need something in there which is going to knit self to that resonant frequency and then because humans will will lean into these things literally and figuratively that works you can do it the other way where you just happen to hit it and there was a building in South Korea around 2011 forever correctly where’s the thirty eight or nine storey building and people at the top one day found the whole building was moving and they evacuated think it was an earthquake it wasn’t it was an exercise class on the 12th floor you happen to exercise two snaps I’ve got the power and that I’m not gonna sing at your other music factory is very similar no snap snap I’m sorry oh wow we have approached snap X animation point is the band there you go Kayla that’s the correct pronunciation and the frequency of that happened to match the frequency which this building this was a torsional instability. the building was twisting along it’s kind of sent up. when is somebody gonna figure out like attach a pencil or the corner of the building and somehow figure out that that is some way to determine pi Oh another question a look at your face is awesome right there because actually maybe you’ll be up for this there’s you know the amount of compressive force to make a beam buckle know. it’s we’re depends upon okay the actual calculation for the compressive force for buckling a beam has a PI in it oh here. in theory I’ve been IMing and hiring about this for years if you had a beam like it like a very thin rod fixed at one end and you knew its properties very accurately you could calculate pi by the amount of force required for it to buckle. this is what we’re getting into is this wonderful esoteric Oh about math which is that there are weird and amazing ways to calculate pi that the deeper you look into it the more they will blow your mind and it involves like throwing sewing needles on to a grid is a possible way to determine pi there are ones about i mean someone was just telling me one last weekend that was. surpassingly strange my I can’t even remember it because it was really late at night when I was told it but like you go down this rabbit hole and it gets as deep as you want to get and that’s why it’s a very good example again of most people think math and by extension pi is just about calculating circles or memorizing the digits it’s about you know just this tool what you’re going to use them on very specific example but actually mathematicians like PI would not be the poster child of math if it was just circles it’s the fact that it appears in. many unexpected situations and. I’m always looking for weird places where PI pops up and then using it to calculate it and my favorite is the period of a pendulum the equation for that has a PI in it. if you get a pendulum which the length of it is 1/4 the acceleration due to gravity it takes exactly PI seconds for it to swing.

I put a PI on strings guys right and then I calculated PI by swinging a PI good times I love it I think this is a great last question Thomas Morningstar on YouTube says how do you think people should address mistakes Wow yeah I mean learning from them I guess that sounds. obvious when I say it it’s like the pocket square I embrace the fact that was wrong and I think it’s useful and that’s a big that’s a very scientific stance right you want as a casual mathematician but as a scientist by bent you you want to have your mind changed you want the data to bring you the information whether it matches what you previously thought or not right against our human nature yeah we strive to update what we believe based on new evidence and. if we have a mistake or something doesn’t whether we expect we should not only update that we should tell the people about it and I alluded to this in the book because I don’t want to get into any legal trouble but I part of running the book was talking to people I knew or approaching people and trying to get their examples of where math has gone wrong in their industry and. many times time and time again I couldn’t get any examples because they weren’t allowed to share them they won’t let them make them publicly available because of our reticence to show mistakes and also because often the engineering company for the case of engineering problems will be hired by the architects or I forget the order in which these things happen but the the people in charge will have all these non-disclosure agreements with everyone else involved and no one is allowed to say we messed up this was wrong or even we learnt this right and and this was wrong information is exposure exactly and. for the cases where I personally knew people and they had told me their mistakes like over a drink that we were just talking about the day at work they told me this went wrong this went wrong when I went back to them to say hey I’m writing a book they were like who you are like there’s no way you can use these stories and. I think that is a major problem it specifically in engineering where problems aren’t shared well and you know that’s the opposite of the of the of the edifice of science right everything is shared one of the things I love about the videos that Brady makes and I didn’t realize it until two things happen one Brady came to San Francisco we had him on the podcast and when I said you want to be on the podcast he said you know that I don’t know anything about math right that’s true and I was like no I didn’t know that because his questions are. terrific as he asks them and sometimes his questions are the answer is I don’t know why he might ask you a question that’s past the limit of your knowledge and I find the good humor with which his interview subjects respond to be wonderful and also his openness of like well I could still ask meaningful questions even though I don’t understand the starting principles if our kind of career model is poly nerd Brady is the I’m gonna claim the poly idiot I think that’s he doesn’t like he’s got an interest but doesn’t know the details about a lot of areas and. he’s perfect at asking these questions and he’ll get right to the hey but what about this and well I don’t get this bit or and it’s and he’s usually reading my mind at that point because I have the same exact question is the perfect he’s this is where a lot of technical YouTube videos will fail Brady is some audience member in the room who just knows what everyone who’s watching it is thinking and then ask that it is. important to have that there’s a video that’s going around recently on YouTube about math and I found it inscrutable and it made me a little sad because I really wasn’t understanding their starting propositions and I was like what is the pro the problem is they don’t have Brady asking any base level questions the most important ones exactly yeah it’s such a good job and it’s important to show number one that with all these math thinks you can asks there’s no silly questions no there are what about this where’d that come from doesn’t that mean this which is fine which is why I take any correction I get seriously I’ll flip through I’ll find it and check if I got it right or wrong and secondly the people the interviews a little bit of selection bias here sure tend to be people who are very happily say I don’t know yeah or or either this two different flavors have I don’t know there’s I don’t know but it exists and I’ve forgotten it oh I don’t know but I could look it up and then there’s I’m not sure and then there’s human kind just does not know and and all of those are interesting to be honest hearing any one of those from a teacher was surprising to me and one of the very first teachers sorry one of the very first teachers to say to me in response to a question I don’t know was I’d literally felt like I’d unlocked a key to something because that was a phrase I heard from a teacher and. I think that’s one thing going back to the earlier question about inspiring kids tell them the limits of your knowledge I used to love teaching the higher year high school years when I was teaching in the UK because I’d well Keenan would have the problem and I go well let’s work it out together right and I I’ve you dit as involving them in the process and showing them other people call it lack of lesson preparation but go through it together and get stuck it would all sit back and like this is like small classes yes. I fully accept you very rarely get this luxury mm-hmm because. many lessons you’ve got like 30 students that you’ve got to get the whole cohort working together and all advancing to hit a test-fire date. the luxury of I don’t know let’s all learn it together totally yeah and I. I have all sorts of great things to say about education but no real pragmatic ways of putting them into practice I love the luxury of this guy I don’t know and we’ll work it out together and get stuck and come out of being stuck in a lesson one of the best producers I had on Mythbusters was my friend Alice and Alice was a very much a lay person who did not understand a lot of the science behind complexities of the things that Jamie and I were testing and thus she would not let us call a piece to camera done unless she understood what the hell we were talking about over and over and over again and it was such a fantastic education she was being the audience and thus we learned the the hardest and the best way how to phrase something. that everyone could understand everyone needs a Brady we really do we really do Matt um I am. excited that your barnstorming around the country promoting this I loved this book sorry I keep touching my mic I loved this book I’m very excited to promote a science book that goes into an area most people think is beyond them to find thrilling adventures Wow thanks. much I mean I’m. pleased that you’ve enjoyed it it was a lot of work hopefully we’ll get more people more excited about math links to buy this are below and if you have any other questions where can people find you online I’m on Twitter stand-up maths and on YouTube of course numberphile we mentioned and my own stand-up mass Channel if you go on there I’ve got some videos about stuff in the book if you ask any questions I’ll try and answer them thanks Matt see you soon thanks everybody