Wrong, But Useful

In this, the final episode of WBU, @reflectivemaths and I discuss: @samuel_hansen's antiracism post((get well soon, Samuel)). Dave and I both assert that Black Lives Matter and acknowledge that we have a significant amount of work to do to create a just society. In a whiplash-inducing change of tone, tooth fairy maths Multiplayer Nim (‘unlucky 10’) The Million Game from @drewfoster Dave seems to have a thing about noughts and crosses The Mathoff is over: thanks, everyone! Now, more than ever, would a decent text book be the answer? The chaos game in a hexagon Social distancing in 3D Via @christianp: Simon Plouffe has found a sequence of 565 primes in 'geometric progression' (meaning they're the closest integers to the first 565 terms of a geometric sequence) Some quotes from past blog posts: Dave insults mechanics, then gets stroppy about Colin insulting stats In this month's podcast, @reflectivemaths and I discuss: Colin's book being available to buy Colin gloats about Spoof My Proof and Dave chews on sour grapes Colin has laser eye surgery and doesn't care about Dave's health... ... but does care about 20481 A final puzzle: It usually takes me eighty minutes to run my Sunday running route, but if I wear my running hat, it takes one hour and twenty minutes. Why? Thank you for listening loyally, especially to those who've co-hosted and interacted with us. It's been an entertaining journey. Right. How do we get into pretending this didn't happen? The post Wrong, but Useful: Episode 80/80 appeared first on Flying Colours Maths.

In this, the penultimate episode of Wrong, But Useful, we’re joined by @karenshancock (who is Karen Hancock in real life). We discuss: A scoring system for an online quiz round. The Big Mathoff What is a surd? Currently reading Ratio by Michael Ruhlman - a cookery book that starts from the principles Some Noughts and Crosses variants https://twitter.com/mburnsmath/status/1248330254281662464 www.marilynburnsmathblog.com/five-twists-on-tic-tac-toe/ nrich.maths.org/1199 Core maths festival (via @mathsTechnology/Tom Button) For any given cubic if a line intersects it at three points then the sum of the x-coordinates of these points will be constant. An infinite monkey music bot A fractal Odds and Evenings and Mathematical Objects Ending the podcast The post Wrong, But Useful: Episode 79 appeared first on Flying Colours Maths.

In episode 78 of Wrong, But Useful, we're joined by @c0mplexnumber, who is Clarissa Grandi in real life. Full show notes will follow later. The post Wrong, But Useful: Episode 78 appeared first on Flying Colours Maths.

In this month's Pi Day Special episode, we're joined by @aap03102, who is Chris Smith in real life. We discuss: Negative primes Surdoku (look in issue $2^5$) Chris's dark past Chalkdust book of the year Book (or writing) ideas (I’m trying to compile a big list of maths things I - or anyone - could write about. If you have such an idea, let me know and I’ll stick it on the list.) Chris's Pi Day antics Katherine Johnson has died, aged 101 A COVID-19 lesson plan and dataviz. Distance-time graphs The post Wrong, But Useful: Episode 77 appeared first on Flying Colours Maths.

What's this? Didn't we have a WBU last week? We did indeed. Only we cut out a section of our conversation with @dr_teeluck about APR to keep the episode length (somewhat) reasonable. Here it is as a special bonus episode for your enjoyment. The post Wrong, but Useful: Episode 76b appeared first on Flying Colours Maths.

In this episode of Wrong, But Useful, we’re joined by @dr_teeluck, who is Dr Vijay Teeluck in real life. We discuss: sunrise (posts by @colinthemathmo and by me got the same answer, someone else disagrees, nice thing to explore) favourite numbers a lovely post by @samhartburn about tetrahedra fitting through each other bridges (why are the bricks not parallel with the road?) The R0 value of the coronavirus Internet once again astonished that multiplication commutes Perfect espresso formula In communicate the bloody thing properly news: $|-1|-2|-3|$ thread here “Ten times greater” “Ten times smaller” Zero point seventy-five per cent via @peterrowlett: 30 A*s in one class via @peterrowlett: Funding boost via @peterrowlett: call for hosts for Carnival of mathematics via @evelynjlamb: Google ngrams shows a dramatic spike for ‘enneagons’ (and other-gons) around 1820. Why? Watch out for a special mini-episode next week! The post Wrong, But Useful: Episode 76 appeared first on Flying Colours Maths.

In episode 75 of Wrong, but Useful, we talk with @astrastefania, who is Stefania Delprete in real life. We discuss: Dreams about Maths and doing Maths in lucid dreams Goodreads maths reading challenge Newsletters I like: Stuff Evelyn Wants You To Read by @evelynjlamb and and Fair Warning by @SophieWarnes Is a parallelogram a trapezium? (via @cshearer41) via @jamesgrime: The bullseye illusion RI Christmas lectures with @fryrsquare How do you describe Confidence Intervals? How damaging is to say “I’m 95% sure that mu is between ‘here’ and ‘here’ “? We reference The Maths of Life and Death. via @MrShepherd Maths (Lee Shepherd): "This may be a really stupid one but please enlighten me as I've been thinking for a few weeks to work it out. If irrational numbers are infinitely long, does pi contain the value e in its decimal? Do they converge at some point?" via @johndcook: A simple unsolved problem: Are there infinitely many positive integers n such that $tan(n) > n$? via @wtgowers: Pretty accessible explanation of how to solve a cubic Via Adam Atkinson: how much would a suitcase of gold weigh? Pizza Hut’s 41% off food in January Drawing a perfect circle Questions I wasn’t expecting … When you’re numbering a list for a random sample, do you number across or down? and … Why isn’t stabbing my pen into the page ‘random’? What can I do with a pricing gun? Where did Lagrange come from? The post Wrong, but Useful: Episode 75 appeared first on Flying Colours Maths.

It’s time for the @BigMathsJam Wrong, But Useful! @stecks (Katie Steckles): Brouwer’s Fixed Point Theorem: “they said it’s a theorem, so I’ve got to believe it.” Mentions @jamesgrime. @christianp (Christian Lawson-Perfect): ordering cards to generate a fractal sequence. @peterrowlett (Peter Rowlett): transforming numbers problems into graphs. Mentions @alexcorner and @wtgowers. @dragon_dodo (Dominika Vasilkova): the Weierstrass function @scroggs (Matthew Scroggs): @oddsandevens’s fractional origami. Yuen Ng: Miscancelling fractions @pecnut (Adam Townsend): @astrastefania’s redesign of the the musical stave. @smokeyfurby and his handler (Belgin) enjoyed @samhartburn’s cake, based on @becky_k_warren’s Big Math-Off entry - scroll down! @njj4 (Nicholas Jackson): A bit about Emilie du Chatelet. Adam Atkinson: On randomly-moving knights. The post Wrong, But Useful, Episode 74 appeared first on Flying Colours Maths.

In this month's episode of Wrong, But Useful, we talk to @AJMagicMessage, who is Andrew Jeffrey in real life, and one of the driving forces behind Maths Week England, which in 2019 is November 11th to 15th. Apologies for a few issues with feedback in this episode. Dave takes full responsibility. We discuss: Number of the Podcast: 1089 How to get involved in Maths Week England Game Theory (especially isomorphic games) and ncase.me/trust (via @LorHRL Hannah) Reading: @benorlin’s Math[s] with Bad Drawings and @robeastaway’s Maths on the Back of an Envelope. Via @robeastaway: further thoughts on rounding Via @peterrowlett: problem-solving in the new A-level Should you tie your shoes on the travelator, or on a standard walkway? Shorts: Big MathsJam bookings Via @octonion (Christopher D Long): "I'm also curious if Haken and Appel's original computer code for the Four Color Theorem from 1972 is still available, and if it can be run on modern hardware. It'd be a sadly missed opportunity for scientific history if it were somehow lost." Carnival of mathematics 175 Election coming up. We want to see your bad graphs! Puzzle feedback: Late solution to the square-colouring puzzle, from Sam Steele, our favourite Antipodean listener in Carrum Downs, Australia. No answers to the pillar problem yet. New puzzle: (via @cshearer41) Find the sum of the infinite series $frac{1}{2} + frac{1}{4} + frac{2}{8} + frac{3}{16} + frac{5}{32} + frac{8}{64} + frac{13}{128} + dots$ (i.e. Fibonacci on the top and powers of 2 on the bottom). Next month is the Big MathsJam special! * Edited 2019-11-08 to fix LaTeX The post Wrong, But Useful, Episode 73 appeared first on Flying Colours Maths.

In this month's podcast, we're joined by @CoreMathsCat, who is Catherine van Sarloos in real life. We discuss: Number of the Podcast: 179 (balloons) Maths Week England is mid-November (11-16th). Catherine is involved in running a contest for it! Via Peter Rowlett: Women’s names Via Adam Atkinson: rounding up or rounding away from zero or rounding to even? Reading books: we're all getting our teeth into Rob Eastaway's Maths On The Back Of An Envelope and Kit Yates's Maths Of Life And Death. Cat is also reading Invisible Women by Caroline Criado Perez. The Pink Tax How much does nursery cost? A jury awarded damages of $8 billion against Johnson and Johnson - as Rob Eastaway says, enough that the victim could budget $300,000 a day if he lives to be 100. Shorts: New Chalkdust out now Sums of cubes news: they found 3 between recording and going live! George Osborn Crinkle Crankle walls Perfect circle drawing Words from obsolete technologies (inspired by clockwise/anticlockwise) Puzzle feedback from last time: We missed a lovely answer to the probability machine puzzle from @chrishazell72, who worked the ratio out at about 55-45. Gold star for Adam Atkinson who said he’d expect 100/e, about 37 squares not to be coloured in. (I think I’ve missed some other stars in my mentions.) New Puzzle (via @davidKButlerUoA): In the middle of my room, there is a pillar. Its cross-section is a square with sides of 1m. I want to draw a circle of radius 2m around the pillar. Obviously I can’t get to the centre to put a compass there - how can I draw my circle accurately? The post Wrong, But Useful: Episode 72 appeared first on Flying Colours Maths.

In the 71st episode of Wrong, But Useful, we’re joined by @nookiedv, who is Anouk de Vos in real life. We discuss: Number of the podcast: 1729, a fairly uninteresting number. Sums of cubes updates: 33 42 3 is also interesting as there are two solutions but it’s unknown if there are more (posed in 1953) - since recording, 3 has been found again! The Collatz conjecture: maybe it isn’t true? Process approaches 1 for nearly all starting points (Terry Tao) Numberblocks, Sumaze primary, and DragonBox GeoGebra Number of Core Maths students increased last year Pitching core maths? Reuben’s homework - Round three dice Puzzle feedback: Gold star for Adam Atkinson who got 4/9 as P1’s win probability. I evaluated a double integral. Silver stars for our favourite listener in Carrom Downs, Australia, Sam Steele and @schwartzstack, who both gave the right answer for the wrong reasons (higher mean doesn’t mean more likely to win). New Puzzle: (via @david_cobac You have a 10 by 10 square grid. A number from 1 to 100 is selected and the corresponding square is coloured. This is repeated 100 times. On average, how many squares do you expect to be not coloured in? The post Wrong, But Useful: Episode 71 appeared first on Flying Colours Maths.

In this episode, we're joined by special guest co-host @sophiebays, who is Dr Sophie Carr in real life, and the world's most interesting mathematician1. We discuss: The Big Internet Math-Off. My favourite pitch wasn’t really in the contest! I also liked Alex’s wobbly table and Anna’s FURNACE. Number of the podcast: 24. The Winton Centre Quick Quiz for Legal Professionals from @dspiegel. Maths Scholarships The £50 note. The Maryam Mirzakhani Prize in Mathematics. The Isaac Newton Institute’s summer puzzles Eliasson exhibition at Tate Modern What has 4 letters, sometimes 9 letters, but never has 5 letters. A claim by Claire’s Accessories. Catriona Shearer’s book is available on Amazon: Geometry Puzzles in Felt Pen. Puzzle feedback from last time: The average distance of two points in a unit square. No solutions received! (It’s 0.5214 ish, the result of a tricky double integral.) New Puzzle via @ghast_neoh: There are two players, and a machine that outputs a random number between 0.0 and 1.0 when you press a button (inclusive, chosen uniformly and independently, from the reals, etc). Player 1 pushes the button twice, and multiplies the two outputs together to get a score (e.g. 0.45 x 0.9=0.4). Then player 2 pushes the button once, and squares the result to get their score (e.g. 0.67 x 0.67 = 0.4489). The higher score wins. Which player wins more often? apparently there are caveats. The post Wrong, But Useful: Episode 70 appeared first on Flying Colours Maths.

In this episode, we're joined by @christianp, who is Christian Lawson-Perfect in real life, our first returning special guest co-host1. We discuss: The Big Internet Math Off and associated stickerbook 99 variations on a proof by Philip Ording The Art of Statistics - Learning from Data by David Spiegelhalter Maths on the back of an envelope - Rob Eastaway 1 in 8 men believe they “could” win a point against Serena Williams. Green number lines via Adam Atkinson: Zachtronics games are now free for school use. Also, "Baba is You" is fun. Mathematical objects podcast Via @peterrowlett: The Talking maths with your kids hashtag #tmwyk That said, I think @draon_dodo has been involved in two previously. The post Wrong, But Useful: Episode 69 appeared first on Flying Colours Maths.

In this month’s thrilling installment of Wrong, But Useful, we’re joined by @c_j_smith, who is Calvin Smith in real life. We discuss… Number of the Podcast: 5 Are Fish and Chip shop owners good at maths? Two maths puns and a maths joke Are there ‘popular’ books that ‘lead you in’ to mechanics? An application of the sum-of-squares problem Via @PaulsPrattle (Paul O’Malley): “If you were the ruler of the universe tomorrow what would be the objective in secondary mathematics learning for all kids everywhere?” Via @aap03102, (Chris Smith)’s newsletter: some love for Simon Plouffe Via @christianp: The Big Mathoff is running again Puzzle feedback from last time: We hadn’t seen any solutions when we started recording, but some have come in since - we’ll mention those next month. However: Chris pointed out a tweet from @mathsjem (Jo Morgan) showing the clock-hands puzzle in Thompson’s Practical Algebra, published in 1878. New Puzzle: There are 3 lighthouses. The first shines for 3 seconds and then is off for 3 seconds. The second shines for 4 seconds and then is off for 4 seconds. The third shines for 5 seconds and then is off for 5 seconds. Initially, all three come on together. When is the next time they’re all on at the same time? The post Wrong, But Useful: Episode 68 appeared first on Flying Colours Maths.

In this month's Wrong, But Useful, we're joined by @sheena2907, who is Sheena in real life. We discuss: Sheena's Number of the Podcast: 3,212 Board Games - Number Fluxx, Prime Climb Magic: The Gathering is undecidable! Oxbridge Time surprises The oddness of the Fibonacci sequence The heights of women Big MathsJam Down Under Population modelling in the Marvel universe The IMU committee for women in mathematics newsletter Elwyn Berlekamp has died How do you see means? The Superpermutation Search Via Jeremy Cote: "I've actually seen [J] in a textbook I've used for my real analysis course, but in that case, it was to represent the natural numbers (1,2,3,...). The book is called Introduction to Analysis, and can be found here. Other maths podcasts: a list; MathsAt; MakeMathMoments. Puzzle feedback: No stars of any description for the Crystal Maze problem. New puzzle: At 3:00, the hour and minute hands on a clock form a right angle. What is the next time that happens? The post Wrong, But Useful: Episode 67 appeared first on Flying Colours Maths.

In this month’s episode of Wrong, But Useful, we’re joined by @cshearer41, who is Catriona Shearer in real life. We discuss: LaTeX (time to fight again) Mathematical sign language More interesting ‘bad graphs’ than the obvious howlers you usually see on the internet. Via @peterrowlett: Some people think statistics has too much significance, and it’s hard to disagree. Chalkdust article by @loopspace about Catriona's other, almost-mathematical, hobby, bellringing! @mathsobjects, a new podcast from @stecks and @peterrowlett. Any other cases of mathematical discoveries that looked different at the time? Does your road have a house 13? 136 votes: yes 56%, no, not long enough 20%, no missed out 24%. Escape room advice - don’t use algebra (via @ProfSmudge) What’s $frac{3}{4}$ of $frac{2}{3}$ - is this surprising or obvious? Shapes with different shadows Stephen Wootton tweets: @WrongButUseful regarding tax there is also the interesting case between £100k - £120k where the tax free allowance is reclaimed thereby giving rise to an effective tax rate higher than the highest rate of income tax! Keep up the podcasts, thank you. via Adam Atkinson: a picture of a 24-hour clock (photo by Daniele Aurelio of Pavia Mathsjam) Adam found a book from the 50s or 60s which called the set of integers “J”. “Have you or your loyal listeners ever run into this?” @divbyzero asks: Technical math terms the general public uses in a nontechnical way: inflection point (a turning point), squaring the circle (difficult task of reconciling two very different things), in the Venn diagram of _ and _ (in the intersection of), exponential growth (grows fast). Others? Puzzle feedback from last time: Gold star for @MarHarStar This month’s puzzle: In a game show, you have four distinct tokens you have to arrange in an unknown order. Every time you guess, you are told1 how many are in the correct position. What strategy gives you the correct answer in the fewest guesses? by way of FIRE The post Wrong, But Useful: Episode 66 appeared first on Flying Colours Maths.

In this month’s Wrong, But Useful, we’re joined by @televisionduck, who is TD Dang in real life. We discuss: Chalkdust Issue 091 Fun spring cover with Harris spiral, Horoscope is back!, New academic webpage checklist (c.f. Colin’s old webpage, @standupmaths interview, top ten regulars, etc. Write for them! Talkdust, second best podcast: it’s about maths, puzzles, making the magazine, interviews. Number of the podcast: 42. Sums of cubes and open questions Pi day Apologies about audio last time. Dave’s fault. Superpermutations and Humble Pi Balancing pi on a beam One weird trick to deal with percentages The Queen Elizabeth Prize for Engineering for 2019 has been awarded to engineers Bradford Parkinson, James Spilker, Hugo Fruehauf and Richard Schwartz for their foundational contributions to the creation of GPS. The prize, worth £1,000,000, celebrates the global impact of engineering on humanity. Sumaze Primary, L; Martello Towers; Bloxors Dave is wrong about LaTeX It’s a magazine for the mathematically curious, apparently. Never heard of it. The post Wrong, But Useful: Episode 65 appeared first on Flying Colours Maths.

In this month’s episode of Wrong, But Useful, we’re joined by @DrSmokyFurby and his handler, Belgin Seymenoglu. Apologies for the poor audio quality on this call. Dave’s fault, obviously1 . We discuss: The Talkdust podcast (via Adam Atkinson): Life insurance Superpermutations: new record for n = 7 in the comments on a YouTube post @pecnut and @mscroggs have a LaTeX package that puts hats on things Desmos adding support for distributions and all sorts @mdawesmdawes’s QUIBANS website Dave has been playing the game The Mind (Via @peterrowlett), 318,000 combinations of pringles Dave gave a talk in Exeter and will hopefully give one in Bristol in June. Humble Pi by @standupmaths – book launch on March 2nd in London, tickets selling fast sold out. You can join the waiting list here. @honeypisquared (Lucy)’s new podcast – Mathematips We’ve been shouted out in @aap03102 (Chris Smith)’s newsletter, and on @missradders’s padlet – thanks! Tax – round up or not? Rotationally symmetric equations (@robeastaway and @peterrowlett): here, here, and Elliot’s versions here Puzzle feedback from last time: Gold star for @chrishazell72: for showing that $(a-b)^2 + (b-c)^2 + (c-a)^2 + (a+b+c)^2 = 3(a^2 +b^2 + c^2)$, and that the first child is 6, younger (2yo) born when elder was 3. New Puzzle (via @cmonMattTHINK): Find the line that touches $y= x^4 – x^3$ at two distinct points. Avoid calculus if possible. Narrator: it was not, in fact, Dave’s fault. The post Wrong, But Useful: Episode 64.md appeared first on Flying Colours Maths.

In this month’s installment of Wrong, But Useful, Dave and I are joined by @honeypisquared, who is Lucy Rycroft-Smith in real life. We discuss: Mathematical board games, including The Mind Camel Cup Qwinto Number of the podcast: Lucy doesn’t like numbers so we don’t have one. Does your collection of maths people exclude anyone? Lucy went to Big MathsJam this year. Bowled over by the time taken to make sure people felt included. Clearly an intentional, thoughtful approach. Is stats actually maths1 ? Reference to Sara Hottinger – Inventing The Mathematician Christmas books: Colin – Factfulness by Hans Rosling Lucy – Perils of Perception by Bobby Duffy Dave – The Indisputable Existence of Santa Claus by Hannah Fry and Thomas Oleron Evans Some deserved applause for @fryrsquared’s Zeeman medal and @stecks’s appearance on QI Via Adam Atkinson – Money Box. £35 000 per year for life or £480 000 now? The great makeup heist Postal systems and nutri-grain Quick bits: New largest Mersenne prime: $2^{82,589,933}???1$. Prizes listed here for any Mersennaries out there. via @christianp: Plouffe’s prime-generating function via @chrishazell72 – Sibahle Zwane ‘answers complex arithmetic questions in seconds’ (Is he as good as the article seems to think?) via @fenneklyra: Follow up on “Guess who”: There are 24 people on board, and I had a typo, the first question narrows it down to 12 which means it IS the most efficient one cause you will always have narrowed it down by half. Not sure it’s allowed via @peterrowlett: Thirdsday via @christianp: A lot of mathematical mortality recently – including Jean Bourgain, Peter Swinnerton-Dyer, Elias Stein and Sir Michael Atiyah. via @peterrowlett and @robeastaway: Rotationally symmetric equations. See also here and here via @fermatslibrary: Pizza Puzzle feedback: @schwartstack and Adam Atkinson both found answers in the region of $3.5?times?10^{38}$, rather than quadrillions. Gold stars all round. On looking into it more, the Fantasy Flight Games site claims 104 septillion (still several orders of magnitude too small.) This month’s puzzle: Prove that 3 times the sum of 3 squares is the sum of 4 squares. This month’s second puzzle: A parent buys a pack of 24 candles. On their first child’s first birthday, they use one candle; on the second, two candles and so on. At some point, a younger sibling arrives, and the candles are used in the same way. On one of the first child’s birthdays, the parent finds they have exactly the right number of candles left for that birthday. How old is the first child, and how old were they when their younger sibling was born? QTWTAIN The post Wrong, But Useful: Episode 63 appeared first on Flying Colours Maths.

In this month’s episode of Wrong, But Useful, we’re joined by @ch_nira, who is Dr Nira Chamberlain in real life – and the World’s Most Interesting Mathematician. Nira is a professional mathematical modeller, president-designate of the IMA, and a visiting fellow at Loughborough university. We discuss Nira’s entry in the Aperiodical Maths-Off. I mention a simulation of the Schelling model. Number of the podcast: 2, the percentage of the top rate of National Insurance. The Big MathsJam Special and Big MathsJam itself. Dave has a circle question that stumped his students. Nira turned the tables on some future teachers by making them simulate Aston Villa’s season. Ouch. A thread from @creeepyjoe about communication and collaboration – with an insight into Nira’s Mathematics Attack Room. Colin mentions the German €20 note, but meant the old DM10 note. @fenneklyra’s Guess Who questions: “White hair OR red hair OR glasses? Yes: Red hair or hat? No: Blond or hat? Then there are only 6 left of which you can make out the next question yourselves” @stecks was on @myfavethm to talk about the fold-and-cut theorem. Nira points to a tweet from @probabilityfact pointing out that 87% of Americans can be identified by the combination of ZIP code, sex and birth date. What’s the opposite of inside-out? @fotsn have put out a new audiovisual offering called You Can’t Polish A Nurse Nerd. Dave thanks Adam Atkinson for his help on percentages. Puzzle feedback: gold stars for @schwartstack, @chrishazell and loyal antipodean listener Sam Steele, who each worked out $P(X=5) = frac{1}{120}, P(X=4) = 0, P(X=3) = frac{1}{12}, P(X=2) = frac{1}{6}, P(X=1) = frac{3}{8}, P(X=0) = frac{11}{30}$. This month’s puzzle: Dave is playing Keyforge, in which a deck consists of 36 cards: twelve from each of three distinct clans. There are 51 distinct cards available for each clan (repeats are allowed), and seven clans. The makers quote quadrillions of possible decks; is this plausible? In my Maths Attack Room recording a podcast with the @WrongButUseful Team. Love talking everything #mathematics. Thank you @icecolbeveridge for the invite! Look out for this episode next week. pic.twitter.com/4Ik04wsmds — Dr Nira Chamberlain (@ch_nira) December 8, 2018 The post Wrong, But Useful: Episode 62 appeared first on Flying Colours Maths.