The Greatest Maths Mistakes | Matt Parker | Talks at Google

When math goes wrong, things can get expensive. Or absolutely hilarious. For this talk we invited KZbin personality (Numberphile, standupmaths), math communicator, comedian, and one third of the Festival of the Spoken Nerd, Matt Parker, to share his favorite math mistakes from his new UK #1 bestseller, "Humble Pi - A Comedy of Maths Errors".
Matt exposes errors on the Two Pound Coin, very specific rules for trains operating in Switzerland, and how simple unit conversion slip ups can cost billions of dollars. He also discusses the infamous 256th level of Pac-Man and answers audience questions about more hilarious mathematical failures.
Get the book here: goo.gl/G4kqw6

[@bbmikej]

A note about how aviation looks at mistakes in the US: we have a great program called the ASAP program where if you generally make a mistake (ie not intentionally breaking a rule or being negligent), you can self report to the FAA. They then look at it with representatives of the company and the workers union to determine if it was actually a mistake without a name attached to the report to keep it anonymous. If it was determined to be a mistake and the ASAP is accepted, the FAA cannot take action against the person who made the mistake. The number of people willing to admit to mistakes has increased since implementation and industry wide training has gotten better because of this.

[@mattsadventureswithart5764]

Still fail to use metric, though...

[@bbmikej]

@@mattsadventureswithart5764 we actually use both systems daily. Knots and nautical miles for speed and distance, feet for altitude, miles for reported visibility, and pounds for weights. And while you are trying to talk down on the US for not being metric, European rules mandates imperial measurements also. While kilos are used for weights and meters used for visibility, feet is used for ceilings, knots for speeds, and nautical miles for distances.

[@acruzp]

I love the aviation industry.

[@carlcederqvist3108]

we have a similar system in Sweden for people working in healthcare called Lex Maria.

[@alansmithee419]

@@bbmikej "we actually use both systems daily" *proceeds to list only imperial units*

[@blackpenredpen]

What an honor to be mentioned by you, Matt! Thank you!

[@srikrishna_97]

Do you know Matt personally?

[@yoavcarmel1245]

i was searching for a comment about your channel. glad to see you watched it

[@davids.9789]

Yoooo!!!

[@karelvanderwalt3625]

big fan

[@blackpenredpen]

Thank you!

[@Stubones999]

What about the math error at the Savannah River nuclear plant that was regularly cracking the pressure vessels. Everyone kept checking the materials used, and engineering practices, but no one verified the actual operating pressures of the vessels, and it turns out that they ran for 40 years at 115% power levels because some engineer had a slide-rule error during its initial construction documentation.

[@nicholasvinen]

I don't understand how this was never upvoted. It's a great example.

[@kyoopihd]

"Pounds... per......... bushel, or something..." xD

[@Anklejbiter]

Fun fact : you can measure acceleration in pounds per kilogram

[@sergey1519]

@@Anklejbiter F = ma. So i guess you can also measure it in kilograms(of force) per kilogram. So it's just unitless

[@GodlikeIridium]

Imperial units are just bad... They are useless and make math really hard for no rational reason. The SI System makes sense. SI is way superior to imperial. Metric ftw

[@johnnyplays2843]

Yo stfu British man

[@pfeilspitze]

@@Anklejbiter Only if you're using "pounds" incorrectly. In lbf/kg, certainly, but just "pounds" are a unit of mass.

[@hakarthemage]

imagine going to your tutor and saying "Sorry my PHD exploded"

[@JohnJones1987]

9/10 they will tell you it didn't and it's still totally publishable, but you're just gonna need another 1 year of unpaid work.

[@timonix2]

@@JohnJones1987 PHD students here are paid though. They might need to do some explaining on why they need another year. But they will still get paid for that extra year.

[@JohnJones1987]

@@timonix2 yeah but your paid barely enough to live, and the work is 16hr a day every day. Its in everyones interest to extend the PhD, as postdocs cost more.

[@mabhatter4294]

Roger Hallam, a founder of extinction rebellion is doing a Phd in Civil Disobience. Some people should never meet.

[@ajkimphan1176]

The train thing.. I call that "Fix by post-it" Like when you know that a program crashes if you click a button, but instead of fixing the program, the boss tells you to send an email to everyone, instructing them to put up post-its to their screens saying "don't press that button"

[@Jkirek_]

"It was an orbiter, not a lander" I think the craft itself disagrees with you there, Matt. It definitely landed, albeit at a high velocity downwards.

[@thechemuns74]

Parker lander?

[@IceMetalPunk]

Is that kind of like how a fish on land is breathing for a few minutes?

[@berenicesaquet1870]

funny one

[@VainoOskariAstala81]

Aerobraking supplemented with lithobraking.

[@garrydamrau9809]

It's not a crash, it's a rapid unscheduled disassembly.

[@DavidSoderstrom]

I'm at peace when Matt's head line up with the monitors edge in the background.

[@emmettfountain8658]

David Söderström I’m gonna be looking at nothing but that for the rest of the video now

[@davidmeijer1645]

Me too! I was neurotically watching that the whole time and then I read this?!?!! Do you twitch yours legs as the gaps in the dotted lines on the highway pass from view under the hood.of the car?

[@sk8rdman]

I do this sort of thing every time I watch a video like this, where a person is meandering in front of some sort of display. There's always some sort of way that I want for them to fit into the image, and my eyes are constantly looking for it while I listen to the talk. I guess it has something to do with our brains liking patterns and things fitting into other things. I think that's part of what makes Tetris such a satisfying game to play.

[@pmcgee003]

@@sk8rdman Mattris?

[@KikiTay]

Darn, now I'm super aware of it now! 😂

[@ChrisBigBad]

The train thing.. I call that "Fix by post-it" Like when you know that a program crashes if you click a button, but instead of fixing the program, the boss tells you to send an email to everyone, instructing them to put up post-its to their screens saying "don't press that button"

[@arnoldhau1]

Well it is not really a practical problem, because due to the manual coupling and mixed traffic dominated by passenger trains there are simply no trains that long for various reasons (they are simply not allowed onto the network). Also, those kinds of things are sometimes quite old and very expensive to change as they solution has to be "safety approved" using a very expensive process, it is not at all like just replacing a bug in software. So, if it where a real risk it would not exist. But still, from a modern point of view it is a very strange solution.

[@IceMetalPunk]

True story here: the application my team develops had a bug where, for one client, addresses were being validated on the API service end, and if the address was invalid... it just didn't update. But the API didn't tell the app that it failed; it returned a success code. So the app responded as if the address updated, even though it didn't, and that would break things if it was the first address on file for the customer. I, being a front-end UI developer, reached out to someone on our API services team to explain the problem and ask him to assign a fix for it to one of his developers. His response? "No, we don't need to fix that; just make sure the client doesn't enter invalid addresses, and it'll be fine." That was my first experience with your "fix by Post-It". And I was like... "so we have to tell our clients they can never make any typos or risk corrupting their customers' account data?" Some people. SMH.

[@jeffsergeant]

Or the most annoying user interface feature.. leave the button, but give the user an error message saying not to press the button.

[@arnoldhau1]

@@jeffsergeant Yes those are all horrible ideas. I do not say the solution of that axle counter was good, but lets not forget we do not tak about a normal software solution here, but about an old embedeed system that had to pass rigurious saftey checks, I do not even think it really has software in that sense.

[@iamlikemex]

@@IceMetalPunk ideal solution is two-fold; client validation in conjunction with correct success codes from the API response. That way you can have dynamic feedback in the UI preventing them from putting the wrong sorts of things and providing some helpful feedback, but the security of ultimately relying on the same validation server-side. Would be interested to know why you couldn't sync the data back from the server again though to put both client and server back into the same state? That would solve potential issues further down the line, for example server-side data processing and calculated fields. I know this is an entirely uneccessary reply, but I've had a year out of back-end development and that comment just reignited my passion for software development and bug fixing for some strange reason.

[@samreid6010]

28:05 bit of a correction: that happened to the USS Yorktown, which at the time was a Ticonderoga class cruiser. The story changes a bit every time I hear it but essentially some sailor was working on the radar, typing in gates so that it doesn’t flag every seagull or cloud as a target. One of the gates didn’t apply in this situation so he put a zero in it. If he had left it blank or written null or anything else, the computer had a check to filter out non number inputs. However, the check read 0 as a valid number to enter into its equations, at which point it divides by zero and the system, running Windows NT, freaks out and shuts down. This computer not only ran the radar, but also propulsion and navigation. The ship ended up dead in the water for about three hours

[@samreid6010]

@@user-wt5bu9jm3u this was the cruiser Yorktown, not the carrier. It served from 1984 to 2004, windows nt came out in 1993

[@oliversissonphone6143]

He says the Mars Climate Orbiter was "over 10 years ago".. he wasn't wrong though - it was Sept 1999!

[@kidcrow1393]

13:46 the lone star joke he threw in there was brilliant.

[@HotelPapa100]

"That's such a Switzerland solution to the problem" So true it hurts.

[@troubadourperegrinus]

True Swiss would be a different rule for each Kanton

[@sagov9]

"the plate's undone by a lone star", completely missed by the audience

[@lesliekilgore648]

if it wasn't an American audience, or specifically one American audience familiar with Texas, they'd have missed it also. MP did a Royal Institute talk on KZbin here: kzbin.info/www/bejne/bHvadoyXos-LpqM where he used the license plate from Texas. it was a British audience, they all missed the joke too.

[@samwilson5544]

Enlighten us, what's the joke?

[@BrutalBeast666]

@@samwilson5544 The Lone Star State is the official state nickname of Texas.

[@juliaying26]

I CAME DOWN TO COMMENT THIS

[@stuckonautomatic]

How do you know? It's not exactly a laugh out loud joke.

[@tommykarrick9130]

I love the long build up to the guy just giggling “They killed an elephant with cocaine”

[@uk1988tb303]

I was waiting for something like, ‘well, you can imagine how much cocaine an elephant 🐘 trunk could vacuum up’.

[@Markle2k]

I can't find anything about elephants and cocaine, just humans ODing on elephant tranquilizer, and poor Tusko who was given a massive 3000x overdose of LSD

[@uk1988tb303]

Markle2k. Whoa, what a way to go. Super consciously aware every cell in its body is a separate universe, and its body in totality is the multiverse 🤯 ... and Pink Floyd are quite decent actually ...

[@Markle2k]

@@uk1988tb303 Alas, not poor Tusko. Seizures and intense distress marked the last hour and a half of his life. However, about 10 years later, two elephants were given more appropriate doses and seemed to enjoy themselves.

[@BogdanSass]

@@Markle2k There are so many things wrong here... 1) The sources I could find say "3000% overdose" (which is very different from "3000x" :) ) 2) while there are some drugs where the dosage is calculated by body surface area, neither cocaine nor LSD is among them - in fact, if you look up the LD50, it is given in mg/kg for both 3) it is still unclear whether it was the LSD that killed Tusko, or the combination of drugs - the test was repeated later (Siegel, 1984) with the exact same dose (.1mg/kg) of LSD alone, and the elephants survived

[@lunasophia9002]

"I'll be around." No, Matt, you'll be a Square. Not apologising for that.

[@sebw89]

@Stefan Dingenouts Exactly what I thougt, too :D

[@osotanuki3359]

And not a perfectly magical one, at that

[@SimonGronlund]

One of the more funny long nerd talks I have seen in full in a long time. What disturbs me is that companies are reluctant to give away how mistakes were made. I think companies easily could obfuscate sensitive portions but still give away generic parts of the error. That would help not only the company itself but human beings as such. But sadly, often cause of errors are not even communicated within the company itself :-(

[@gejyspa]

In re: spacecraft -- About 35 years ago, while in college, I was working in a cooperative education job for eight months at RCA Astro-Electronics. The department I was working in was updating testing software created for the TIROS-N satellites for the Advanced Tiros N satellite, which had more instruments on it. The point of the testing software was to make sure that the instruments wouldn't shift too much during launch. To do this, they would measure with lasers the precise location of the instruments on the spacecraft put on a shaker table simulating launch, vibrate and then remeasure the positions, and put all the figures into this program to check if it was in specs. Well, on modifying the program (in FORTRAN, btw), I notice that it had a subroutine to calculate the difference between signed numbers. And here's how it did it: First it took the absolute value of the difference of the _absolute value_ of the two inputs, and then if the inputs had different signs, put a minus in front of the result. Essentially Z=ABS(ABS(X)-ABS(Y));If ((X0) ) or ((X>0) and (Y

[@uk7179]

Thanks for sharing your story...

[@leonardusdesignleonardusde3479]

I have a similar story I worked for rca electronics in the eighties as an onboard sw engineer . During spacecraft operation I analyzed the performance of momentum unloading procedure of one of their telecom satellites erratic behavior was observed and after reviewing the control software I found an error in the digital filter implementation a truncation error in the filter caused instability in performance . Numerical accuracy was improved by implementing 24 bit accuracy and consecutive spacecraft functioned as expected Problem solved! A really interesting assignment at the time

[@santimonto26]

If Matt does write a sequel to this book, it better be called "Humble Tau", or I'll be triggered.

[@jbt-qu6lm]

@BLAIR M Schirmer Good take but I don't think this is the right comment

[@trashj8778]

That would sound like a Woo-Woo lifestyle book though.

[@itskdog]

That would go against everything Matt stands for in his mathematical constants.

[@Peter_1986]

He sometimes seems to pretend that he is about to start talking about Tau in some of his videos, but then he always goes back to Pi. =P Like for example he can say that he should probably not write one period as "2×Pi" just to make you start thinking "he is gonna mention Tau...!" but then he immediately adds something about including all the integer number of periods other than just 2×Pi. I guess that that's his way to say "fuck Tau, I won't even talk about it even when it might sound like I am about to do that".

[@tiokronor]

And at some point in the future, his memoir "Humble i".

[@dhpbear2]

30:45 - There's a more acute example than the 'millennium bug': Loudspeaker driver manufacturers would rubber-stamp each of their drivers with the year and month of manufacture. They encoded the year using ONE digit! One couldn't tell if a certain speaker was made in 1955 or 1965!

[@thebonesaw..4634]

I absolutely love learning about unforeseen consequences. I'm not sure how varied a maths version of that would seem from the more general "maths mistakes", but it sounds like a book I'd love to read.

[@DStecks]

When I was in my first year of computer programming in college, my instructor used the Ariane 5 Flight 501 as an example of the importance of writing good code. The way he recounted the story was that the rocket got about 5km in the air and then turned left.

[@philipoakley5498]

I worked with guys who were nearly on that (actually did Ariane 4, and the post-match Ariane 5 review). It's always the dull stuff that catches you. "For the want of a nail"

[@salmjak]

”Funny story about trains, people die aaand... Pacman!”

[@dhpbear2]

55:20 - "To err is human; to blame it on a computer is even more human." :)

[@gheckolock81]

They don't find it easy, they are just people who enjoy how difficult it is. -How did you get so wise Matt

[@mailleweaver]

"...until you notice that one semicolon." Spot on. Just a couple weeks ago I wrote a script to do something in the cabinet design software I work with, and I couldn't figure out why this one line didn't seem to work. Luckily (?) it is a very forgiving system and let the rest of the script run even with a problem in that line so I didn't notice it for a while. Once I did figure out the line wasn't working I spent hours poking at it: double checking the variables that fed into it, looking for holes in the logic of its formula, rewriting the same formula in different ways, and even trying completely different approaches to accomplish the same thing, but nothing worked. I eventually gave up on it and continued on with the rest of the code. Later on my eyes happened to pass over that line and notice that the comment at the end of the line didn't have the one semicolon in front of it that it was supposed to. Semicolon added, boom it works. In a way it was good that happened, because one of the alternate approaches I developed trying to fix it was a lot more graceful and made it easier to add another feature later. It was still stupidly frustrating, though.

[@taylorsmurphy]

This is a great argument for having fussy systems. The shortcuts and little tricks it doesn't let you get away with, also stops that full day job of finding out the mistake. I have done the same kind of thing countless times when messing around.

[@cliftonkor1030]

Have u tried using lint? Lol

[@DanielTheDev]

A bit late to the party, but 27:30 I was on that mission! Two weeks in Hawaii due to the software bug.

[@Flyingdingii]

So? Did you hear the Windows Start Up sound?

[@DanielTheDev]

@@Flyingdingii Negative. I was a flying crew chief on one of the KC-10s that dragged the F-22s around. I just heard them talking about it during refueling. Some went to Midway and most made it to Hickam. Interestingly, there were Japanese protesters waiting for us to get to arrive in Japan, protesting the arrival of the F-22s. I expect a few of them thought we turned around intentionally. When we finally made it a couple weeks later, there were no protesters to be seen.

[@enotdetcelfer]

"That's how anonymous I can make your stories if you see me after" rofl

[@rohitagarwal329]

Matt is awesome. Also, as an AV aficionado, I appreciate the uniformity of the matrix display behind him.

[@peteconrad2077]

The first complete cell above the podium (from our left side view) has a slightly non uniform join with the cell above it toward the left of the common boundary. Sorry to spoil it for you.

[@TheManLab7]

55:33 I think "Mentour Pilot" is probably one of the best one's out there and he actually talks about the swiss cheese model. Which I think's funny, but it's actually really informative. 🐘😂🤣🤦🏻‍♂️ 43:50 It was actually LSD that killed the elephant and it was called Tusko.

[@agvulpine]

I would like to ask Matt, what I think the final question-asker was actually trying to ask, and that is: "What seems to be the most recurring 'maths in engineering mistake' that humans just can't seem to learn from, and are doomed to repeat?"

[@eswing2153]

And after recovering from having his humour thrown in his face he delivered a pretty decent back-peddle answer.

[@aok76_]

13:50 that joke went under the radar xD Nice one!

[@danielbosshard7768]

I came here for this

[@alexanderbehr3969]

26:56 Fly-by-wire is the other way round, it’s the type of aircraft that has the controls connected to a computer :)

[@zJoriz]

I'm actually surprised he said the pilots managed to get the F-22s back to base without its systems on. But maybe it was just the navigation system that quit? I've seen footage of an early F-22 testing a touch-and-go maneuvre and the flight systems denying the 'go'-part of that, resulting in a (very expensive) belly flop.

[@KrolKaz]

Mr.Parker is a world renowned mathematician, speaker, artist, and philanthropist.. basically he's much smarter than you or I could even imagine so I will take his word for it 🤗

[@alexanderbehr3969]

@@zJoriz fly by wire has three or four different modes, depending on the manufacturer. If the full envelope protection quits, it drops down to the more basic modes, still allowing control but with none of the fancy corrections the computer would normally provide. However I could imagine fighter Jets being pretty much unflyable with just „raw input data“ controls, as their CG is very far aft, to create both more manoeuvrability and instability. ie: you pitch up and the plane pitches up uncontrollably.

[@rediornot811]

I am a retired US Air force Master sergeant, we were stationed at England Air Force Base 1985-89, the moved my family into base housing the first year and we were in a 3bdrm unit multi-family complex. The downstairs was all out of proportion. The plans for the two-story units did not have stairs to get to the upstairs. These were drawn in later and kitchen pass-through goes into the living room

[@EebstertheGreat]

It's approximately correct that for the most part, dosage scales across species not with body mass but body surface area (or the 2/3 power of the mass). The truth though is even more complicated, as typical power laws used to fit effective doses for many species have exponents between 0.5 and 1, typically around 0.75. Among humans, the dose for many drugs depends on body fat content, so dosage is often quoted in mg/kg, but that's still not strictly accurate. Linear scaling with mass certainly can't be used to extrapolate doses from a 70 kg human to a 5500 kg elephant.

[@andymcl92]

Interesting :)

[@musikSkool]

Or bullet diameter or ft. lbs. for hunting. HUGE debate.

[@EebstertheGreat]

@@musikSkool I don't think it's similar. Consideration of caliber and gunpowder mass and such for hunting will depend on the ballistic details of the gun and the target. The stopping or killing potential will certainly depend on the animal, but it will depend on things like the density of the skin (zeroth power of mass), distance from skin to vital organs (

[@musikSkool]

@@EebstertheGreat I was thinking that things don't always scale directly. A BB gun will kill a mouse, but scaling that up could lead us to think we need a cannon ball for an elephant. The natives still throw spears, a few dozen or so usually do the trick. Mathematically way more energy than a well placed, legal, piece of metal uses.

[@EebstertheGreat]

@@musikSkool True, bore definitely doesn't scale linearly with the size of the target. Shooting a mouse with a BB gun, most of the energy is lost just getting through the tough skin, which is not as tough as a wildebeest's or whatever, but is not too far off the average for mammals. But if you're hunting an elephant, you don't really want to knock it down dead just like that anyway, because to do that, you really would need a pretty big boom. Not a cannon, granted, but still something bigger than the 2 bore elephant guns people used to break their wrists firing. You want the elephant to bleed to death slowly. You do not, however, want your partridge to bleed slowly as it flies away. I mean, to be clear, I don't want elephants to bleed to death slowly. That's horrible. But I'm assuming a poacher would want that to happen.

[@stuartmcconnachie]

20:10 and now we have another reason to call it the “cluster mission”.

[@3mon3y94]

I'm a simple person: I see Matt Parker, I watch the video and click like.

[@MCDexX]

I think the guns being mis-aimed was in the Falklands, and rather than being coriolis-related, it was to do with how that far south, your map projections start to get really warped. If I recall correctly, they worked out firing trajectories on a flat 2D paper map, not taking into account that lines of equal longitude (the vertical lines in a grid map) converge more and more sharply the closer you get to the pole. The artillery projections were calculated on a flat map, the shells landed in the wrong place, and I believe they killed their own troops. (...and everybody died.)

[@rickmacdonald5575]

That makes more sense, I was thinking intuitively (and maybe wrongly, I don’t know) the Coriolis Effect is not really even significant enough to make a really fatal error even in the case of something that calls for relatively high precision like nissile/projectile firing trajectory.

[@macdjord]

@@rickmacdonald5575 Coriolis effect is something you have to take into account, but only if you're doing long-range sniping (where centimeters matter) or very long range artillery (where the ranges are long enough that you can actually miss entirely if you don't).

[@fshjdkfhasdkfhsd]

We choose to do maths....not because they are easy but because they are hard.

[@robertrstevens]

Yes every single one of these maths is hard. THIS math is, THAT math is ... yes all of them are - all 73 of them.

[@Christian-UNICI2I]

@@robertrstevensdid you know that 73 is the 2nd most commonly chosen number when people are asked to pick a random number between 1 and 100? The only number picked more often is 37

[@cmwslw]

What an entertaining and educational talk! Thanks for talk and I hope to read the book some day.

[@zachb.4429]

I love how these grown men know what a Parker square are and even have the shirt. So funny!!

[@Kiteboardshaper]

Just excellent Matt, love your work

[@JMUDoc]

In the first _Sonic the Hedgehog_ (Megadrive) it takes eight hits to kill the final boss. You can hit him _nine_ times... but the "boss hit counter" underflows to -255. Good luck getting another 263 hits on him before the (10 min) timer runs out.

[@PyrusFlameborn]

Omg, the check is equals 0 instead of equal or less than, isn't it?

[@pooyataleb2514]

"if you support me on Patreon that's how I waste your money" I died

[@schenckinator5427]

Probably a little bit late on this, but the German Solution for 8 Bit Axis Counters is even more hilarious: We limit the Number to 250 so that they never roll over (the counters, not the trains) even if a extra engine is needed because the main one broke down (we've got almost only engines with 4 axis here)

[@johnjoseph9823]

Thank you Matt. I love Maths and this kind of stuff.

[@isilder]

The pictures of cogs is always something to do with the question, "that might work or it might not work.. things have to be done right or it doesnt work " .. its part of the message.

[@jaybertulus]

dont degrade yourself like that. you fill an important spot on YT, and reach a lot of people. love your 4D graphics in your 1st book, would love to see more 4d content

[@ohalloranpeter]

nomen nominandum It's not degrading. It's British. 😉

[@DeputatKaktus]

Self deprecating humour is quite a British thing. Nothing wrong with that. In fact, I find it quite sympathetic.

[@joedrave945]

He’s Australian

[@mathias3721]

@@joedrave945 But he lives and works in Britain and has done so for years

[@maikjoseph]

@@mathias3721 Tbqh aussies, and much of the rest of the world have a native understanding for that type of humour. I doubt he evolved it only after having moved

[@StoicTheGeek]

re: stars in the moon, the artist was perhaps referencing Coleridge (you know - for the kids): "'Till clomb above the eastern bar The hornèd Moon, with one bright star Within the nether tip" - The Rhyme of the Ancient Mariner, Samuel Taylor Coleridge

[@howardtreesong4860]

This was a great talk. Fascinating to listen to.

[@UnknownCat2]

Great to hear that Brody gets a mention!

[@nicosmind3]

No mentioning Brady though

[@andymcl92]

Bradley

[@timbeaton5045]

@@andymcl92 Shame that Dirk at Veristablium didn't get a mention, though.

[@iipetopuah]

Check about a man who made a car plate with "NULL" on it to avoid fines, and then system did send him a huge amount of fines that wasnt detected right on camera an head NULL on the line of numberplate

[@iski4317]

lol! Maybe he can wiggle his way out of all of them, even the correct ones?

[@DadgeCity]

*and had

[@johnhaines4163]

For the Swiss axle counter issue, I wonder if that prohibition came from an actual incident when a train disappeared from the system or if someone foresaw the potential problem when the system was originally specified.

[@naffnafff]

The latter. I work for the DB (German railroad), we have the same regulation, since there are still some old signal boxes on the system working with those old axle counters. Newer systems can count up to 4096, I think. When technological advancements were made in railway technology, trains in Europe became longer. And someone was smart enough to point out that if a train would consist of more than 255 axles, it would reset those old counters. The regulations are still in place, they're right next to me in the shelves I keep my paperwork in :P

[@Urhixidur]

@17:45 "Pushing against" a gyroscope will only allow you to change your orientation, it can't change the trajectory. Wikipedia: "Specifically, software that calculated the total impulse produced by thruster firings produced results in pound-force seconds. The trajectory calculation software then used these results-expected to be in newton seconds (incorrect by a factor of 4.45)-to update the predicted position of the spacecraft."

[@reorg]

I heard of one about the Navy needing a special nut for one of their ships engines, the engineers order the nut and then we're very anoyed when it was taking so long to come, any way after several months the nut arrives on a flat bed and it absolutely huge, seems the Navy gave the measurements in meters instead or milimeters

[@dnisbet71]

12:41 there is also a star right next to Ernie's pyjamas, in front of a hill, dangerously close to Earth. Nobody noticed?

[@xToredus]

Love it :-D. Cheers from Switzerland ;-)

[@paulgiaccone6115]

I think you mean cheese from Switzerland ;)

[@ApemanMonkey]

You better watch your axles!

[@Ghandralph]

There is one problem with the story about the swiss axle counters (32mins into the video). While technically true and the regulation obviously existed it had no practical relevance. A train of 256 axles would on average equate a total train length of ~1600m. In Switzerland no train is longer than 750m, there where very few limited experiments with 1500m trains. So in the real world the phantom trains as described in the regulation and portrayed in the video would not exist. Still a nice find by Matt Parker who's videos I love ...

[@985476246845]

If someone wanted they could make trains with half the axle distance and make it fuck up, but that would be illegal.

[@DerKiesch]

You have to think about this like about the Ariane IV vs. V problem: It's not about the problem being able to occur now, it's about documenting that there might be a problem under certain conditions that might or might not happen in the future just to make sure that when something changes people are at least aware that there is a problem.

[@naffnafff]

While you are technically correct, there are no TRAINS longer than 750m, it is still allowed to have SHUNTING operations with units of wagons longer than that, which is occasionally necessary at freight yards. - A locomotive driver from Germany

[@stewartcampbell1786]

Great talk however I would like to take issue with the title ‘maths mistakes’; most of these feel a lot more like software testing mistakes than maths mistakes. I speak as someone who studied maths and later became a test manager for a number of companies. In the past I also worked for the European Space Agency on the Meteosat project and have vivid memories of a live stream of a Meteosat launch when the satellite itself failed and wondering if I would still have a job. On leaving ESA I was also test manager on a project to provide a tracking system for Ariane 5 which would blow the rocket up if it went off course (it was a replacement system for the one that blew up the specific Ariane 5 rocket in your talk). Examples of testing failures I used to quote (although I can’t remember the original source now) were, the Hoover free flight offer where they hadn’t correctly assessed the value of their offer and were inundated with claims, a soft drink promotion with too many winning cans, and a Y2K problem (which actually triggered before 2000) where a stock control system read a date in 2000 as out of date, sent the supposedly out of date stock for destruction and reordered new stock ad infinitum.

[@chrthiel]

Will the sequel be called Humble Tau?

[@985476246845]

That would have to be Steve Moulds book

[@The_Bit_Player]

I can't believe this guy never mentioned any of my Math exams.

[@emberthecatgirl8796]

“Fly-By-Wire” is *actually* where you don’t control the surfaces directly via hydraulics, but instead use the controls to input desired movement into the computer, that then shifts your control aurfaces while accounting for factors like wind or weight distribution or stuff.

[@trueriver1950]

12:25 stars shining through the moon. The earliest example I know is in Coleridge's Rhyme of the Ancient Mariner, where there is a crescent moon with "one bright star within the nether tip"

[@awkweird_panda]

I pre orderer this. Its an amazing read. Loved it

[@duality4y]

Matt: "All that because a couple of lines of code" Me: intensely stares at a couple of lines of code on my second screen.

[@immortalsofar5314]

Similar to phantom trains, I had a crashing problem with the "home of the future" on startup that I couldn't repro. On my machine it worked fine, in the test lab there was no problem and when the home was closed and I could test it, it never happened. Then a new guy joined the team and was being shown around the home - it occurred and I started to narrow down the source in the code. When he left, it stopped happening but I knew where it was. I started the system, no problem. I restarted it and ran through the house - it crashed. There was a race condition on the motion detectors! The fix (given that the code was locked down, thereby locking in the bug) - when you start up the system, stand very, very still! Borland C for DOS had an interesting rollover bug in the undo buffer. If you accidentally hit 2 keys at once at exactly the moment when the buffer was supposed to roll over, instead of having a history of 255 characters, it thought you had 254 characters in the keyboard queue and replayed them - including block begin, page down, block end, block delete, save file. That was a frustrating 30 seconds watching it irreversibly destroy my code!

[@ancbi]

43:43 love the first 'question'.

[@joannaa1724]

Great last question. I wish we'd know if Google's postmortem of mistakes blames the human (as like medicine) or blames the system (as like aviation)? Good point that if blame the people then never learn from the mistake. As the system is the issue.

[@DavidGuild]

It's very much the second one. If a human makes a mistake the focus is on why they thought that was the right thing to do and/or why the system didn't prevent them from making the mistake. I wish I could give details, but NDAs etc.

[@dementedchicken1]

Blameless postmortems are essentially industry standard at this point too

[@Tocsin-Bang]

I had a maths teacher called Parker before Matt was born. I failed O level maths three times. I later did a far more advanced maths course and exam five years later and scored 98%. I later taught maths.

[@robertrstevens]

Correction: You later taught MATH; i.e. MATHEMATICS. So, it's MATH - just as it's ARITHMETIC and not ARITHS. Saying maths or ariths makes you look like a schmuckS. Got it? Alright then! (Just Kiddings!)

[@linuslundquist3501]

@@robertrstevens What are you gonna do about it, throw tea in the ocean?

[@Braamsery1992]

I watch this, genuinley stopped it right now, because a few seconds ago he said, last story, then Q&A. Checked how long I watched it and almost 40mins gone by. Awesome :D

[@fiveoneecho]

But everyone knows Duna's atmosphere starts at 45km! MCO should have been fine!

[@AXEUROLder]

They had the realism overhaul mod installed

[@gerrymcerlean8432]

I hope you've already found this out, but "fly-by-wire" is the opposite of what you said. In FbW, pilot initiated actions are sent (by 'electrical' wire) to a computer which then carries out the required actions (via 'electrical' wire) using electro-mechanical actuators.

[@Crlarl]

Matt, fly-by-wire means that the controls are electrically connected instead of physically by cables and rods.

[@agentxp]

43:55 those two in the background move in perfect sync for a bit lol

[@MitchCrane]

@57:21 The sunlight and shadow on that building in the upper right of the screen behind Matt looks like an Amiga mouse pointer.

[@pawoo666]

pounds per bushel xD

[@jeffirwin7862]

Is that pound force per bushel, or pound mass per bushel? Please clarify.

[@Alorand]

@@jeffirwin7862 Obviously Pound Sterling per bushel.

[@Peter_1986]

Matt always says funny things that make you wanna laugh.

[@lauraireson6358]

+

[@Sam_on_YouTube]

Matt: More detail than normal. Me: I already heard this story.

[@spdcrzy]

"Aviation is phenomenal in terms of how they deal with mistakes" Boeing: HA!

[@osotanuki3359]

Matt: I didn't think this was gonna be-- That one dude: AHAHAHAHAHAHAHA Me: Oohhhhh boy

[@AmandaKaymusic]

Funny, logical and informative. Another enjoyable share. Thank you. "They are just people who enjoy how difficult it is." A quote for many genres that search for more knowledge.I am sad the man who was graceful enough to step aside for the last question was not part of the clip. What was his question?

[@jordimartinez4295]

I worked in aviation for many years. There was a system where you could report the mistakes you made anonymously. Once a year it was released internally so you could read the reports about things that went wrong and grow your mind about different scenarios you could have never imagined.

[@mattbox87]

Perth? Oh! I loved you before I knew you were Australian, but now I'm sold for life. Love from Melbourne.

[@ShinySwalot]

His reaction to the cocaine elephant 😂😂

[@PeterNancarrow]

5:20 - So when are you going to release your cook book ? ;-)

[@HenryLoenwind]

yeah, I want to properly cook celebrities, too... scnr

[@musikSkool]

As long as he measures the flour in cubic feet, and milk in troy ounces. Hmm, water could be measured in cubic miles. I just love precision, don't you?

[@laban123321]

in that case use "Bizarre Units used by Scientists - Sixty Symbols" "watch?v=hsEB65Q4kHI" they already started

[@newbarker523]

Should he do such a book it simply must be called "Humble Pie".

[@bikerchrisukk]

Step Daughter is keen on maths, unlike me - have just bought your book. Good job!

[@peter_smyth]

41:27 Where the join is in the rows of screens, the hyphen in the URL is hidden.

[@griefgrief]

at 43:51 the two people on either side of elephant cocaine guy laugh and move forward in the exact same way

[@mission772]

Something in the matrix has changed

[@towlie911]

I’m whelmed

[@bhskgywjf]

@13:45 that's why it's the "lone star" state

[@feoranis26]

When he said you could see stars through the moon I zoomed in on the white portion and tried so hard to see stars through it like it was transparent LOL

[@pretendawatch]

"You can tolerate a lot for a single year"... 2020: Uh oh...

[@erilassila409]

I'm a simple person: I see Matt Parker, I watch the video and click like.

[@edwardweisberg4369]

Great speech!

[@CarrionMaw]

"Does anyone else know the other spacecraft-rocket mass mistake?" Too soon, dude!

[@thomasgrubert7819]

Wild guess: The trivial error leading to an aesthetic difference = Facial animations in Mass Effect Andromeda

[@um02122]

The maths can save your life by helping you avoid geometric anomalies: vicious circles, love triangles and square heads.

[@Anantcool5]

Nice way to interact and to get stories fromcrowd-sourcing for the sequel! ;) (Later saw him mentioning the same in the 41st min)

[@tomtrask_YT]

21:09 - UCL, not UCLA as the subtitles state (it's clear from the subsequent description but still, he was also clear when he said UCL)

[@CoolAsFreya]

Ex Teachers can become some of the best educational KZbinrs, so good at speaking and explaining

[@thomasbender2036]

When you mentioned the Sesame Street book, my first thought was "There are stars in front of the hills!"

[@zevo9314]

"i havent come across that, thats great" the elephant might disagree

[@Toastybear1]

I don't feel like the audience are appreciating this guy enough!!

[@GardIsPureOwned]

I immediately thought of the Parker Square, sorry mate

[@nickp7526]

You beat me to it, take my like.

[@reformCopyright]

1:18 was basically "inb4 Parker square".

[@DownhillAllTheWay]

I can't give a reference to it, but there was once a motor torpedo boat on exercise, probably 30 years ago, testing a new kind of torpedo. They got the torpedo armed and lined up, and at that moment, the test was called off, and the boat turned around to go home - then blew up. Lives were lost. In the final analysis, the torpedo had a fail-safe mechanism in it, that would cause the torpedo to self-destruct it went off course in the water and turned around to face a friendly boat. It was still armed, and the turn-around sensor had done its job.