Using an Out-of-Control Car to Calculate π.

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  • เผยแพร่เมื่อ 27 ธ.ค. 2024

ความคิดเห็น • 1.2K

  • @standupmaths
    @standupmaths  ปีที่แล้ว +2455

    UPDATE: If we had used 26/38 exactly were would have π = 3.136421 which is basically 3.14. (I stand by my 3.12 but I am kicking myself.)
    Yes, yes, it's not Pi Day for a few more days. As always: I try to get the Pi Day video goes out a few days early so teachers have time to plan their Pi Day activities. And leaving it until Monday next week felt too late.
    So, ah, what are we all doing for Pi Day this year?

    • @jackeea_
      @jackeea_ ปีที่แล้ว +96

      I'll be wondering what's so special about 14.3!

    • @legofan2284
      @legofan2284 ปีที่แล้ว +199

      Given pi = 3.112, the viedo release isn't that badly timed

    • @SoftwareSimian_
      @SoftwareSimian_ ปีที่แล้ว +58

      Calculate pi by pi day release dates.

    • @hallohoegaathet7182
      @hallohoegaathet7182 ปีที่แล้ว +30

      On π day i am going celebrate my birthday

    • @TheDoh007
      @TheDoh007 ปีที่แล้ว +3

      I'll probably be giving pepper to a friend xd

  • @PopeGoliath
    @PopeGoliath ปีที่แล้ว +3308

    Every time someone says "we can ignore" or "lets not worry about", an angel takes away a digit of precision.

    • @murk1e
      @murk1e ปีที่แล้ว +170

      Fortunately ♾️-1 = ♾️

    • @ultimateo621
      @ultimateo621 ปีที่แล้ว +11

      Nice

    • @Rabbit-the-One
      @Rabbit-the-One ปีที่แล้ว +54

      Let's not worry about that though.

    • @Rabbit-the-One
      @Rabbit-the-One ปีที่แล้ว +16

      @@murk1e where'd you get that fancy infinity? Is that like a deep cut emoji near the bottom? All I have is the ∞ from the = long press.

    • @Raulxz
      @Raulxz ปีที่แล้ว +9

  • @jacobdgm
    @jacobdgm ปีที่แล้ว +996

    Fun fact: It's important that the undisclosed location was in North America. Due to the Coriolis Effect, skidding cars spin in the other direction in Australia/South Africa/etc.

    • @Khaim.m
      @Khaim.m ปีที่แล้ว +209

      Somewhere out there, someone believes you.

    • @andrewdescant
      @andrewdescant ปีที่แล้ว +115

      Fun fact you need to use the chiral version of Pi in the southern hemisphere

    • @bsharpmajorscale
      @bsharpmajorscale ปีที่แล้ว +37

      What happens with skidding cars at the equator, then!? :P

    • @jacksonpowers4459
      @jacksonpowers4459 ปีที่แล้ว +115

      @@bsharpmajorscaleCars do not spin at the equator.

    • @bsharpmajorscale
      @bsharpmajorscale ปีที่แล้ว +29

      @@jacksonpowers4459 That's what I thought, but I wanted to confirm it. Very linear.

  • @johnchessant3012
    @johnchessant3012 ปีที่แล้ว +506

    Fun fact: The value of pi for 2023 matches the one for 2019 to three decimal places.
    2019: pi = 3.11791
    2023: pi = 3.11712

    • @oskarthompson3789
      @oskarthompson3789 ปีที่แล้ว +111

      The the real value of pi must be 3.117505 +- 0.49, amazing

    • @robertthompson3447
      @robertthompson3447 ปีที่แล้ว +4

      How does this, not have more likes!?!

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว +66

      Good to know that pi isn't changing too rapidly over time. I hope next year most of the digits I memorised will still be correct.

    • @robbiemer8178
      @robbiemer8178 ปีที่แล้ว +10

      @@oskarthompson3789 Come on. You know the real value of pi was in our hearts all along...

    • @randomizednamme
      @randomizednamme ปีที่แล้ว +4

      @@robbiemer8178is that a suggestion for next year’s calculation?

  • @mauri7959
    @mauri7959 ปีที่แล้ว +1613

    After so many Calculator Unboxing videos, Matt still uses the phone calculator

    • @standupmaths
      @standupmaths  ปีที่แล้ว +664

      The ability to screengrab is just too convenient! It's not for a lack of other calculators in my office.

    • @iamdigory
      @iamdigory ปีที่แล้ว +174

      @@standupmaths you gotta go hardcore and use a circular slide rule for pi day

    • @CaioTrinchinato
      @CaioTrinchinato ปีที่แล้ว +48

      Go abacus or go home! LoL

    • @Petch85
      @Petch85 ปีที่แล้ว +18

      Honestly, all youtuber's need merch and he already have Maths Gear so he should just bite the bullet and make he's own graph calculator and include screengrab. Maybe add spreadsheet capabilities and color screen for the graphs, use USB to charge the replaceable battery and have a nice keyboard and make sure that it can write the equations probably. There have been no new innovation on the calculator market since the mobile phone. I am still using my two old trusty voyage 200 and I think it is time for something new.

    • @PopeGoliath
      @PopeGoliath ปีที่แล้ว +5

      @@standupmaths maybe you could unbox a capture card for your calculators?

  • @Karagoth444
    @Karagoth444 ปีที่แล้ว +312

    Matt: Happy Pi Day
    But it's not Pi day yet?
    Matt: calculates Pi to 3.117, posts video at 3am on 0311 AU eastern time
    I stand corrected

    • @nitehawk86
      @nitehawk86 ปีที่แล้ว +16

      The other pi approximation day.

    • @the4spaceconstantstetraqua886
      @the4spaceconstantstetraqua886 ปีที่แล้ว

      Nice coincidence

    • @nomadMik
      @nomadMik ปีที่แล้ว +2

      As I say every year, π is closer to 22/7 than 3.14, so he's really just humouring his US viewers by posting the videos four months early. The fact that professionals are bumbling with feet and pounds and miles mean they may as well be using 3.12 for π in the US… or 7/22… 😏

    • @adamplace1414
      @adamplace1414 ปีที่แล้ว

      ​@@nomadMikyes, the imprecision of 0.3048 metres and 0.45359237 kg is the real problem..

  • @gcewing
    @gcewing ปีที่แล้ว +72

    I'm imagining an xkcd based on this. "The pi button on my calculator is broken, so whenever I want to calculate the area of a circle I have to put my car into a skid."

  • @ckq
    @ckq ปีที่แล้ว +1244

    You would've got 3.136 if you didn't round 26/38 as 0.68 13:15

    • @standupmaths
      @standupmaths  ปีที่แล้ว +935

      OH DANG YOU'RE RIGHT

    • @cragonaut
      @cragonaut ปีที่แล้ว +185

      What would happen if the 15 approximation hadn't been used in preference over the real value?

    • @ratboy2713
      @ratboy2713 ปีที่แล้ว +400

      I'm waiting for the day when Matt discovers significant digits and stops prematurely rounding everything off

    • @ncrshane1919
      @ncrshane1919 ปีที่แล้ว +169

      @@cragonaut Punching it in with 14.962 instead of 15, and going with the better 0.684 coefficient of friction gets you pi as 3.128 rounding to 3 decimal places.

    • @wertacus
      @wertacus ปีที่แล้ว +13

      ​@@ratboy2713 that comment made me laugh so hard! The irony 😅

  • @djsmeguk
    @djsmeguk ปีที่แล้ว +402

    So, when is Matt going to use his previous approximations of pi to calculate pi again?
    By the way, not using the simple average way. Rather, treat his values as normally distributed and calculate pi by reconstructing the Gaussian curve and solving for the area under is as sqrt(pi)

    • @PopeGoliath
      @PopeGoliath ปีที่แล้ว +8

      I'm here for it

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +9

      How exactly does your method work? You can't reconstruct a gaussian curve because you only have the observation, not the probability of getting each observation

    • @cinemaker321
      @cinemaker321 ปีที่แล้ว +10

      ​@@freshrockpapa-e7799 I think they may be talking about Maximum Likelihood Estimation (MLE). There are some good videos explaining on it on YT.

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +12

      @@cinemaker321 that would result in the same pi estimation as just making the average...

    • @Houshalter
      @Houshalter ปีที่แล้ว +5

      Probably a log normal distribution. Maybe even something weirder since some calculations get lots of digits and some very few.

  • @munjee2
    @munjee2 ปีที่แล้ว +834

    3.1023 is quite the Parker approximation of pi

    • @scottmclaughlin1410
      @scottmclaughlin1410 ปีที่แล้ว +7

      I was just wondering what he was saying that for

    • @Neefew
      @Neefew ปีที่แล้ว +20

      It's definitely closer than some of his previous approximations

    •  ปีที่แล้ว +21

      2.0230310 is quite close as well

    • @jessehammer123
      @jessehammer123 ปีที่แล้ว +11

      Huh? He estimated 3.117, not 3.1023.

    • @ArcheoLumiere
      @ArcheoLumiere ปีที่แล้ว +15

      ​@@jessehammer123 r/woosh

  • @DeathClawz
    @DeathClawz ปีที่แล้ว +530

    How my brain viewed Matt's drawing:
    2:26 Car from above
    2:28 Car from side (I expected a round view of the tire)
    2:40 I think Matt has gone insane before finally realizing it's a head-on view (or a rearview tbf, is a rearview a head-off? 🤔)
    Keep up the vids, interesting as always :)

    • @RMDragon3
      @RMDragon3 ปีที่แล้ว +20

      Same!!

    • @bcpatter68
      @bcpatter68 ปีที่แล้ว +4

      Ditto!

    • @texasranger7687
      @texasranger7687 ปีที่แล้ว +2

      Same

    • @hypoaktivnaovca
      @hypoaktivnaovca ปีที่แล้ว +13

      No, a rearview is a mooning 🙃

    • @BTGTB
      @BTGTB ปีที่แล้ว +1

      I was doing the same thing.

  • @Halinn
    @Halinn ปีที่แล้ว +148

    Looking forwards to "calculating pi by taking the average of all the times I've calculated pi"

    • @wynoglia
      @wynoglia ปีที่แล้ว +4

      It'll be glorious in 20 years time

    • @vigilantcosmicpenguin8721
      @vigilantcosmicpenguin8721 ปีที่แล้ว +7

      The series of values of Matt's calculations diverges to pi.

    • @Huntracony
      @Huntracony ปีที่แล้ว +10

      Average is easy. I want the most likely value of pi assuming the guesses follow a normal distribution.

    • @sarahgargani5836
      @sarahgargani5836 ปีที่แล้ว +5

      i was curious to see what his current average is: 3.186.

  • @lak395
    @lak395 ปีที่แล้ว +45

    Folks, find yourself someone who looks at you how Matt looks at 3.117

  • @ocicrab
    @ocicrab ปีที่แล้ว +40

    Next year, you should try using the buckling equation. It gives the maximum load that a column can support before buckling. F = pi^2 * E*I / L^2, where E is the Young's modulus (material property), I depends on the size and shape of the cross section, and L is the length. The equation is slightly different depending on how the two ends are supported. There are also the beam bending equations which relate the displacement of a cantilever beam to the amount of force applied (displacement of the end = F*L^3 / (3*E*I) ), so if you don't have E and I, you can calculate (E*I) from displacement of a cantilever beam and plug it into the buckling equation.
    I just ran an experiment with angel hair pasta, where I measured force vs. displacement of a bundle of 20 angel hair pastas using a kitchen scale to calculate E*I (divide by 20 to get a single pasta). Then measured the buckling load for individual pieces of angel hair of various length by pressing it onto the scale until it broke. My estimate for pi was 2.675, less than 15% error with only 6 trials.
    I can imagine a fun video where you have a bunch of students run the same experiment with different pasta (spaghetti, fettucini, etc.), and then bring in some heavy machinery to run it with metal rods/tubes.

    • @Salien1999
      @Salien1999 ปีที่แล้ว

      My intuition says something a little less brittle would work better, but I could be way off. Regardless, that's an interesting idea.

    • @mikasa3427
      @mikasa3427 ปีที่แล้ว +1

      That equation is an upper bound and very sensitive to imperfections so it's always going to give you a large(ish) underestimate no matter how many times you run the experiment.

  • @ColinGLogan
    @ColinGLogan ปีที่แล้ว +124

    All those imperial units... *shudder*.
    Your sacrifice is appreciated, Matt

    • @paulcrumley9756
      @paulcrumley9756 ปีที่แล้ว +4

      In North America it was more likely "conventional units," which predate so-called "Imperial Units."

    • @Chris-hx3om
      @Chris-hx3om ปีที่แล้ว +4

      No, they're North American units, which don't even match Imperial! 🤦

    • @ColinGLogan
      @ColinGLogan ปีที่แล้ว +6

      @@paulcrumley9756 Well, "predate" isn't the correct way to describe it - the introduction of imperial units occurred 1826, and that of the US customary system in 1832 - but yes, they are technically not directly related, both were separately derived from the prior "English units" system, albeit in very similar manners.
      My comment is technically wrong, so fair enough for the correction, but in my defense, I'm from the UK, so the bad units were always called imperial when I was growing up, and it was a joke lol.

    • @0LoneTech
      @0LoneTech ปีที่แล้ว +2

      I was thinking maybe these wouldn't be the really bad ones (like hole gages). Then I checked... there's a factor 11 in the number of yards per mile, and it's 15% off from a nautical mile. WTF.

    • @josephmelnick3446
      @josephmelnick3446 ปีที่แล้ว +10

      What?! No scores of furlongs per fortnight speed measurements?!?!
      ... using Roman numerals?!?!
      ... in base 60?!?!
      ... in Braille?!?!
      Tsk, tsk, tsk.

  • @Verlisify
    @Verlisify ปีที่แล้ว +26

    "I think that might drag my average track record closer to pi"
    I can't wait for next year's video to be 'finding pi by averaging pi attempts'

  • @nsub1
    @nsub1 ปีที่แล้ว +247

    If you use another decimal point of precision for the coefficient of friction you get 0.684, which yields an even better approximation of 3.135!

    • @akabami2161
      @akabami2161 ปีที่แล้ว +26

      r/unexpectedfactorial

    • @SgtLion
      @SgtLion ปีที่แล้ว +1

      Snap

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +5

      That's not how precision works...

    • @lboijens2173
      @lboijens2173 ปีที่แล้ว

      684

    • @phiefer3
      @phiefer3 ปีที่แล้ว +6

      @@freshrockpapa-e7799 What do you mean? That's exactly how precision works.

  • @Stephen-Fox
    @Stephen-Fox ปีที่แล้ว +20

    Unicar might be the most terrifying concept for a vehicle I've ever seen.

  • @Platanov
    @Platanov ปีที่แล้ว +33

    Pi Day is like Groundhog Day, except instead of setting the start of spring, we're setting the value of pi for the year.

    • @nitehawk86
      @nitehawk86 ปีที่แล้ว +1

      Also its like the movie Groundhog Day where we keep doing the same thing over and over (calculating pi), and things going wrong.

    • @Horseshoecrabwarrior
      @Horseshoecrabwarrior ปีที่แล้ว +2

      "Okay everyone, this year pi is equal to four!"
      *A roar of complaints and cursing from mathematicians, engineers, and other pi users everywhere*

  • @joshuapaulwhite
    @joshuapaulwhite ปีที่แล้ว +77

    As a chemistry professor, not showing units during dimensional analysis is killing me! Love the videos

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว +6

      I refuse to follow SI advice to put a thin space between a number and a unit because I feel so strongly that the two are not separable.

    • @barneylaurance1865
      @barneylaurance1865 ปีที่แล้ว +5

      @@nicholasvinen I feel the same about numbers and currencies for sums of money. I'm always wanting to keep them together in an object when I'm working on computer programs - but a lot of programmers are willing to pass them around the program separately and just hope they'll always remember not to put a number together with a currency that doesn't belong to it.

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว

      @@barneylaurance1865 yeah, that's a recipe for mistakes. I agree that currencies are basically like units. The number without it has no real meaning any more.

    • @bluerizlagirl
      @bluerizlagirl ปีที่แล้ว +2

      @@nicholasvinen I grew up with mechanical typewriters and then fixed-width fonts on character-mapped displays, i.e. not having any way to create a thin space, so it's natural to type the unit butted-up hard against the number even if that is not the way I would hand-write it.
      But I also think of the prefix as belonging more to the number than the unit. For instance, 170cm. can be thought of as (170 centi) metres, with "170 centi" being just a funny way of saying 1.7. (OK, this gets awkward with mass ..... we would have to rename the kilogram, and then the renamed gram would have milli in it, and maybe the cooks would be annoyed, which probably why it wasn't done before.)
      Casio calculators actually used to have an "ENG" button, short for "Engineers' notation" which would adjust the mantissa of a number upwards or downwards (depending if or not you pressed "INV" beforehand) to make the exponent a multiple of three and therefore align with a named prefix, e.g. 06 = mega, 03 = kilo, -03 = milli, -06 = micro &c. So if you get an answer of 5.89e-7 you can render this as 589e-9 or 0.589e-6. (And many other, less-sensible ways of writing it!)

    • @QuantumHistorian
      @QuantumHistorian ปีที่แล้ว +5

      Technically, you shouldn't show units during dimensional analysis. Units are, though related, not quite the same thing as dimensions. Dimensions (in the context of dimensional analysis) are things like length, time, mass, while units are meters, miles, seconds, hours, kilograms, pounds, etc... So you can't attach actual numerical values to dimensions (because of the lack of unit), but the whole purpose of dimensional analysis is a sanity check that an equation isn't nonsense equating apples and oranges, so that doesn't matter.

  • @ponyote
    @ponyote ปีที่แล้ว +192

    I had wondered where the 'spherical cow' part would come in, then you explained that it is a single tire car. :D

    • @TorutheRedFox
      @TorutheRedFox ปีที่แล้ว +1

      @PeachCrusher69 i mean the triangle wave on the NES is supposed to be "close enough" to a sine wave (it isn't)

    • @trulyinfamous
      @trulyinfamous ปีที่แล้ว +2

      ​@@TorutheRedFox it works better than a sine wave because of the overtones caused by the uneven jagged edge of the triangle. The NES triangle is meant for lower tones and goes out of tune quickly at higher tones, and low notes of a pure sine wave are very difficult to hear without good speakers. It wasn't really meant to work like a sine wave.

    • @MaryAnnNytowl
      @MaryAnnNytowl ปีที่แล้ว

      ​@@trulyinfamous that's... a bit difficult to believe, as drastically different as the two are.

  • @Sam-lr9oi
    @Sam-lr9oi ปีที่แล้ว +69

    I'm actually a Volvo enthusiast so that car drawing works very well for me

    • @endersdragon34
      @endersdragon34 ปีที่แล้ว +1

      It's a Parker Car

    • @KSignalEingang
      @KSignalEingang ปีที่แล้ว +2

      They're Boxy, But They're Good

    • @ERNesbitt
      @ERNesbitt ปีที่แล้ว

      @@KSignalEingang Yes! Someone else who's seen that movie!

    • @MaryAnnNytowl
      @MaryAnnNytowl ปีที่แล้ว

      ​@@KSignalEingang didn't that movie bomb? Assuming it's the one I think it is, of course. Dudley Moore as the lead, IIRC. It's been so freaking long since I even thought about it, I might be wrong.

    • @KSignalEingang
      @KSignalEingang ปีที่แล้ว

      @@MaryAnnNytowl I don't know how well Crazy People did at the box office, but I suspect more people know that quote than have seen it..which is a shame, it's a really funny film.
      (Ok if I'm honest most of the good jokes are in the first half. Still! Def'ly underrated.)

  • @chipgruver2911
    @chipgruver2911 ปีที่แล้ว +81

    Should we update Pi Day to March 12th this year? We need to hurry and make the official announcement!

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว +5

      It's the 22nd of July, duh.

    • @SeanCMonahan
      @SeanCMonahan ปีที่แล้ว +5

      π = 3.10 based on this video's release date

    • @MaryAnnNytowl
      @MaryAnnNytowl ปีที่แล้ว +2

      ​@@nicholasvinen LOL, another day to celebrate maths? Let's do both! Both is good!

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว +1

      @@MaryAnnNytowl 22/7 would be a good day to celebrate approximations.

    • @rhialtothemarvellify
      @rhialtothemarvellify ปีที่แล้ว +1

      Obviously, pi day is 31-4 (since there is no 3-14 because we have only 12 months)...

  • @SoleaGalilei
    @SoleaGalilei ปีที่แล้ว +4

    The calculation was nice and all, but I was most fascinated by learning about Eric's job! I'd never realized that was something people did for a living. I love hearing about unusual careers.

  • @dk6024
    @dk6024 ปีที่แล้ว +12

    Kudos to your guest for saying 'formulae'.

  • @jackielinde7568
    @jackielinde7568 ปีที่แล้ว +47

    Eric: "Surly somewhere there's Pi,"
    Me: "There's always Pie, and never call me Shirley."

    • @samarvora7185
      @samarvora7185 ปีที่แล้ว +3

      Surely you can't be serious...

    • @mattb5816
      @mattb5816 ปีที่แล้ว

      ​@@samarvora7185 They're not serious, they're Shirley.

    • @jackielinde7568
      @jackielinde7568 ปีที่แล้ว +5

      @@mattb5816 Samar got the joke... and probably watched the movie, too. Gotta love ol' Leslie Nielsen

    • @samarvora7185
      @samarvora7185 ปีที่แล้ว +4

      @@jackielinde7568 I just wanna tell you both good luck. We're all counting on you.

    • @jackielinde7568
      @jackielinde7568 ปีที่แล้ว +5

      @@samarvora7185 Looks like I picked the wrong week to quit amphetamines.

  • @Scum42
    @Scum42 ปีที่แล้ว +6

    Oh man, I love the [undisclosed individuals] at [undisclosed location]. They're so friendly!

  • @ErlendBarkbu
    @ErlendBarkbu ปีที่แล้ว +18

    When you pressed the equal sign I went “Oooh!” loud enough to make my son ask what’s up. I had to tell him that Matt got pretty close to pi and he was impressed.

  • @Demonblade36
    @Demonblade36 ปีที่แล้ว +146

    Happy Parker-Pi day everyone!

    • @DotArve
      @DotArve ปีที่แล้ว +12

      Parker-Pi = 3.1

    • @robertthompson3447
      @robertthompson3447 ปีที่แล้ว +2

      I was wondering why this video was released early. 🤦‍♂️

    • @Dvard
      @Dvard ปีที่แล้ว +2

      Happy Mario Day

  • @psychosis7325
    @psychosis7325 ปีที่แล้ว +3

    This was just too awesome 😅 I'm a mechanic and tyre specialist by trade and super nerd by heart so I was on the edge of my seat the whole way and the ending did not disappoint. Love that rounding killed your average too 🤣👌 as before I started watching with kids I quite literally gave them a talk and said more than a couple decimals is useless for all but going to mars and gave an example of being off a little at short distance but still hitting an edge, then another one far away where you would miss by a star shot at same error margin 👏 I want Pi day every day now 😊

  • @almaraNZ
    @almaraNZ ปีที่แล้ว +3

    Dude. Your videos are literally my favourite bedtime stories and I have been /waiting/ for this one. Had a burnout week and for some reason thought pi day was 3/3 so I've been holding out on the edge of my seat since before then

  • @oxilite
    @oxilite ปีที่แล้ว +25

    Thanks for the early reminder that pi day is coming up!

  • @ajm7375
    @ajm7375 ปีที่แล้ว +3

    Your videos made me love math!!! I catch myself teaching my daughter and little cousin math tricks and watching their brains figure it out looking off into space is the coolest thing ever. Matt you’ve inspired so many I feel it’s my job to pass the torch along. Keep making us say wow! Love your channel

  • @WRSomsky
    @WRSomsky ปีที่แล้ว +1

    As a physicist, a few nits: 1) The force of friction is pointed inward, not outward. It *is* the centripital force; it doesn't *balance* it. 2) The coefficient of friction is usually represented as mu.

  • @douglasboyle6544
    @douglasboyle6544 ปีที่แล้ว +4

    I like the real-world application, thanks Eric for bringing this to us this Pi Day!

  • @bluecat2991
    @bluecat2991 ปีที่แล้ว +37

    You really went "sphere in a vacuum" on this one and I love it.

  • @AussieFlyer86
    @AussieFlyer86 ปีที่แล้ว +23

    Hey Matt, as an idea for pi day next year; the max slope of the lift coefficient for an ideal 2D wing is 2*pi.

    • @nicholasvinen
      @nicholasvinen ปีที่แล้ว +3

      So, Tau?

    • @bluerizlagirl
      @bluerizlagirl ปีที่แล้ว +1

      @@nicholasvinen Depending which part of Greece they (or whoever taught them to speak Greek .....) are from, some people pronounce it Tav.

  • @theblindspot985
    @theblindspot985 ปีที่แล้ว +16

    I really thought when Matt said he was at an undisclosed test track he was gonna pull the old top gear bit where he says exactly where it is.

  • @logicalfundy
    @logicalfundy ปีที่แล้ว +4

    It's not out of control! It's doing exactly what he wants it to do! 😉
    Also, pretty impressed you managed to get two digits of accuracy out of that.

  • @Sirby
    @Sirby ปีที่แล้ว +2

    I was wondering why the PI day video was up on 3/11, then I burst up laughing when the 3,117 result came up.
    Of course I then realized this was not in fact related but I would totally back the idea that PI day is just whatever day you end up calculating each year!

  • @cloneclone5341
    @cloneclone5341 ปีที่แล้ว +23

    12:59 you know things get serious when Matt uses the Scientific Mode

  • @wearloga
    @wearloga ปีที่แล้ว +1

    I'm absolutely amazed that the result was so 'precise' given the amount of rounding and the uncertainty of the measurements.

  • @adamplace1414
    @adamplace1414 ปีที่แล้ว +6

    Now that we've seen the preview for Fast and Furious 3.14, I can't wait for the theatrical release!

    • @vigilantcosmicpenguin8721
      @vigilantcosmicpenguin8721 ปีที่แล้ว +1

      The critics don't love it. They have qualms with the pacing; it just goes on forever.

  • @KerryHallPhD
    @KerryHallPhD ปีที่แล้ว +2

    LOL at measuring the circumference when you had to set a rope to the length of the radius.

  • @abigailcooling6604
    @abigailcooling6604 ปีที่แล้ว +14

    Love it when my interests of maths, cars and Matt calculating pi in weird ways come together! I am always surprised by how often pi turns up in equations that at first glance seem to have nothing to do with circles.

  • @DylanMatthewTurner
    @DylanMatthewTurner ปีที่แล้ว +1

    I think I've got one for you next year.
    π appears in the Coloumb constant, k=1/4πɛ0, which appears in the force of charges on each other: F=(kQq)/r^2
    So you could build a small ion engine that'll create ozone, which will push away from the differently charged engine and could push a small piece of paper. Measure how much the paper moves to calculate force from the ions and work backwards to get to k and then π! Makes a great demo
    Perhaps you could find a way to do a similar thing with a particle accelerator as well. That would make a cool vid

  • @singerofsongss
    @singerofsongss ปีที่แล้ว +3

    This is the second Pi Day video I’ve seen put out a few days early for teachers. LOVE that! :)

  • @venkatachalamgomathi8873
    @venkatachalamgomathi8873 ปีที่แล้ว +2

    I love how you removed your cap at the beginning as a cue to the driver

  • @albertlyngpetersen8702
    @albertlyngpetersen8702 ปีที่แล้ว +3

    As a physicist, I really think you should measure each of the uncertainties and find the total uncertainty using the error propagation law. This way you get a feel of how luck-based you accuracy is.

  • @waltermeerschaert
    @waltermeerschaert ปีที่แล้ว +2

    When considering the errors inherent with your measurements, you can calculate the expected error of the answer, and it seems you actually nailed it. You can say the same thing about most of your π-day calculations.

  • @shootingthebreeze4972
    @shootingthebreeze4972 ปีที่แล้ว +6

    Hi Matt. US collision reconstructionists may use 'f' for the coefficient of friction, but in the UK we use mu and sensible metric units. Didn't want everybody to think that we were making up our own names for the variables and not using SI units! Happy Pi Day. Thanks for what you do in showing maths (yep, with an 'S' on the end) in real world situations.

  • @eeebird
    @eeebird ปีที่แล้ว +2

    10:15 "I don't want to alarm you but for the historical level of precision from my calculations we're good!" 🤣🤣

  • @DragCadRacing
    @DragCadRacing ปีที่แล้ว +5

    I was slightly nervous too, Matt! I'm always excited for these annual videos.

    • @DragCadRacing
      @DragCadRacing ปีที่แล้ว

      ... After hitting "send", I realized that maybe there's a way to calculate pi using the fact that Pi Day comes around once a year??

    • @josephmelnick3446
      @josephmelnick3446 ปีที่แล้ว

      ​@@DragCadRacing Does it involve furlongs per fortnight in the circumference of the year?!?!

  • @dougmanatt4317
    @dougmanatt4317 ปีที่แล้ว +2

    This is an engineering discussion, if it were a physics discussion, the car would be spherical.

  • @steveparker9361
    @steveparker9361 ปีที่แล้ว +3

    3.30 So Matt's drawing an MGf skidding round a corner. Something that particular car is very good at: been there, done that!

  • @sammarks9146
    @sammarks9146 ปีที่แล้ว +2

    I’m glad you returned home for your derivations. It’s not safe to drive and derive.

  • @RabbitStu-M7UTS
    @RabbitStu-M7UTS ปีที่แล้ว +3

    ❤ that you posted this on the date you calculated pi to be.

  • @swiftbird4846
    @swiftbird4846 ปีที่แล้ว +1

    Happy Pi Day everyone. Another brilliant effort. Mathematicians of yesterday could only dream of such a sophisticated method.

  • @deanfielding4411
    @deanfielding4411 ปีที่แล้ว +4

    I love the creative ways you find Pi.

  • @J0EK1NG
    @J0EK1NG ปีที่แล้ว

    9/10 PI calculation. -1 for using f for coefficient of friction instead of µ

  • @srwapo
    @srwapo ปีที่แล้ว +5

    The speedometers in my cars are about 5-10% fast. Dropping that 25 mph by 5% seems to get you so much closer!
    (I'm doing the math in my head, I could be wrong, haha)

    • @hoebare
      @hoebare ปีที่แล้ว +1

      The discrepancy in your cars' speedometers could be because your speedometers were calibrated for larger wheels. To go the same speed a smaller wheel has to turn faster than a larger one would, and the speedometers are based on wheel rotation speed (sort of).

    • @srwapo
      @srwapo ปีที่แล้ว

      @@hoebare No, the wheels and tires are the stock size. And the odometers have read accurately! Seems to be a German car thing (VW and BMW), my folks' cars have always been accurate (Honda, Subarua, Kia...).

  • @Almrond
    @Almrond ปีที่แล้ว +1

    I was wondering why this was early, then I read the description. Thanks for being great not just to students, but to teachers as well :)

  • @ecyor0
    @ecyor0 ปีที่แล้ว +3

    Next year, Matt calculates Pi by herding border collies with squeaky toys.

  • @ACuriousTanuki
    @ACuriousTanuki ปีที่แล้ว +2

    This was a really fun collab and celebration of pi. Kudos to Eric for reaching out!

  • @thehuggz-i9k
    @thehuggz-i9k ปีที่แล้ว +53

    Is today Pi day? No... Was this supposed to be auto released on Tuesday? Yea, probably. Did I watch and enjoy anyway? Most absolutely!

    • @sergey1519
      @sergey1519 ปีที่แล้ว +19

      maybe he calculated it to be 3.10 this year?

    • @thehuggz-i9k
      @thehuggz-i9k ปีที่แล้ว +1

      @@sergey1519 Well, to be honest, not done watching yet, but I'm half expecting 3.1 to be the result of his calculation HERE!

    • @adamsbja
      @adamsbja ปีที่แล้ว +11

      If I remember from past years he likes to get them out early for use in classrooms and such.

    • @Aquanz0r
      @Aquanz0r ปีที่แล้ว

      Parker Circle

  • @wrex509
    @wrex509 ปีที่แล้ว

    Whoever came up with this idea deserves a raise. That was such a fun experiment.

  • @xb70valkyriech
    @xb70valkyriech ปีที่แล้ว +18

    "It's not just drifting, I'm actually doing math"

    • @josephmelnick3446
      @josephmelnick3446 ปีที่แล้ว +2

      "Remember kids, the only difference between screwing around and science is writing it down." Adam Savage, Mythbusters

  • @artswri
    @artswri ปีที่แล้ว

    Very cool computational experiment! And no serious injuries as a bonus! Thanks to all!

  • @clementlebeau484
    @clementlebeau484 ปีที่แล้ว +14

    I hate all the imperial units in these formulas, but apart from that, very nice approximation!

    • @stevewandel9317
      @stevewandel9317 ปีที่แล้ว

      agree. Wonder if there's a metric equivalent

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +2

      ​@@stevewandel9317 dude it's the exact same thing in metric

    • @stevewandel9317
      @stevewandel9317 ปีที่แล้ว

      @@freshrockpapa-e7799 I kind of glossed over the bit where g for gravity was being screwed around with. Probably don't need to do anything for metric as everything is base 10

    • @gakulon
      @gakulon 6 หลายเดือนก่อน

      ​@@stevewandel9317You'd still need to deal with base 60 when converting meters per second into the (most likely) kilometers per hour measurement from the car

  • @likebot.
    @likebot. ปีที่แล้ว

    The formula and measurements in this science leaves no decimal places of accuracy, yet it's good enough to determine the speed of a vehicle with stunning accuracy. Being off 2 or 3 mph at highway speeds is very impressive.

  • @SJohnTrombley
    @SJohnTrombley ปีที่แล้ว +3

    I'd love to participate in calculating pi by hand, but the odds are against it happening in the US, and I can't afford to travel internationally. Have fun everyone that can afford to participate.

  • @KoRntech
    @KoRntech ปีที่แล้ว

    Thank you for coming across the pond to -5 UTC enduring our freedom units, to our First in Flight state as I watch from my chilled Birthplace of Aviation state.

  • @JohnLeePettimoreIII
    @JohnLeePettimoreIII ปีที่แล้ว +3

    2:25 to a topologist, a car with 2 open windows is a teacup.

  • @matthewellisor5835
    @matthewellisor5835 ปีที่แล้ว

    Eric, that sled looks far nicer than the half-bag of concrete poured into a chunk of tire that they made me build and then carry and drag around for three weeks.
    Turns out that gently-used, nearly level, dry, asphalt road-surface still is around μ = 0.7.
    Thanks for the memories.

  • @PronteCo
    @PronteCo ปีที่แล้ว +5

    The true PI-day celebration would be inventing time travel and going back to March 14 1592

    • @rmela4501
      @rmela4501 ปีที่แล้ว +2

      At 6:53:58 am

  • @BetweenTheBorders
    @BetweenTheBorders ปีที่แล้ว

    Honestly, you got two digits of precision out with two digits of precision in. Anything beyond that would've been luck, so good job.

  • @gleedads
    @gleedads ปีที่แล้ว +3

    Also, as a physicist, it causes me physical pain that you drew the friction force in the opposite direction to the mv^2/r. The friction force *is* the centripetal force (it is the force acting on the car that points towards the centre of the circle). It doesn't oppose the centripetal force. There is no actual force called "the centripetal force". We need some force to "be centripetal" for the car to turn, and in this case it happens to be friction that is playing that role.

  • @Nooticus
    @Nooticus ปีที่แล้ว

    I’m absolutely not a Maths person at all, but I really enjoy watching your Pi video each year!

  • @platypi_otbs
    @platypi_otbs ปีที่แล้ว +4

    That was impressively close, Matt.
    I just did my π day calculation using the time stamp of when I paused the video and saw my name on the screen. And my result was spot on.
    Time of my name appearing N = 17:10 or 1030 seconds
    Total time of the video T = 17:23 or 1043 seconds
    An arbitrary scale factor A = 10
    A×N÷T= 10×1030÷1043 = 9.8754 rounded to 4 decimals
    Is that close to a familiar number? Throw in a square root for no reason other than it makes my last 30 minutes seem productive.
    √9.8754 = 3.14 rounded to 2 decimals
    That, my friends, is how to calculate π using serendipitous data and an arbitrary methodology. Which came from finding the percentage just for fun and noticing it was close to 10π²

  • @cubicinfinity2
    @cubicinfinity2 ปีที่แล้ว

    I really like this tradition of stupid/silly/ridiculous/interesting ways to compute the floating point representation of pi each yeah.

  • @timroot-shoshin4287
    @timroot-shoshin4287 ปีที่แล้ว +13

    The former physics teacher in me is screaming at you for not keeping your units in your equations. Yes, it takes more room, but then you don't lose track of anything. :beaming_face_with_smiling_eyes:

    • @MathNerd1729
      @MathNerd1729 ปีที่แล้ว +4

      Yep! And Matt should have written 3600/5280 in his explanation instead of 5280/3600; writing the units would've made that clearer

    • @danielschuett
      @danielschuett ปีที่แล้ว +2

      ​@@MathNerd1729 When he read the units out loud without writing them down, it irritated me so much that it took me a minute to realize he had it upside down. It always helps to look at the units first to see where which variable goes.

  • @okRegan
    @okRegan ปีที่แล้ว

    ive heard the word skidding more times in these last two weeks than in my whole life put together

  • @bosstowndynamics5488
    @bosstowndynamics5488 ปีที่แล้ว +4

    Did you compensate for the error in the speedo? Modern cars almost universally read fast so the car probably was going slightly slower than it seemed (which would have made the result slightly larger, and slightly closer to Pi).

    • @michaelharrison1093
      @michaelharrison1093 ปีที่แล้ว +3

      That was a US vehicle and hence the speedo reads correctly. It would be different if it was a British or European vehicle

    • @alexandruandercou9851
      @alexandruandercou9851 ปีที่แล้ว

      Actualy the speed should be slightly above 26 like 26.067

    • @bosstowndynamics5488
      @bosstowndynamics5488 ปีที่แล้ว

      @@michaelharrison1093 I'm sure the discussion I saw on this mentioned US vehicles were affected, but I could be wrong

  • @Hamuel
    @Hamuel ปีที่แล้ว +1

    Man I rewatched all the pi day videos to get myself hyped for this year's, not realizing that this one came out this year.

  • @KyotecYT
    @KyotecYT ปีที่แล้ว +5

    1 digit is a good enough approximation!

  • @DuelScreen
    @DuelScreen ปีที่แล้ว

    This was a good Pi Day video. Good job and thanks to Eric both for suggesting this and helping you make this video.

  • @StefanRau
    @StefanRau ปีที่แล้ว +23

    Happy Engineers-Pi Day!

    • @MortalCosta
      @MortalCosta ปีที่แล้ว +2

      There hasn't been a truer comment to date

  • @JoshSmith-db2of
    @JoshSmith-db2of ปีที่แล้ว +1

    Something to add to the CORRECTIONS section in the description: the conversion factor at 4:48 should be 3600/5280, not 5280/3600.
    I discovered this because I was curious if using the more precise value of 14.962 rather than 15 would improve the approximation of pi, so I was trying to reconstruct the calculation. Using 14.962 rather than 15 and exactly 26/38 for mu (I refuse to believe it's f), I got pi = 3.1285.

  • @BTElectric
    @BTElectric ปีที่แล้ว +34

    I don't think today is pi-day lol

  • @theanyktos
    @theanyktos ปีที่แล้ว +1

    Ok, had to check the date real quick, but I'm not complaining about an early pi day video!

  • @juho1069
    @juho1069 ปีที่แล้ว +11

    Never seen anyone use imperial units for physics calculations. It was... horrifying.

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +2

      It's very common actually and not an issue at all as long as you're consistent, knock it off

    • @Chris-hx3om
      @Chris-hx3om ปีที่แล้ว +2

      @@freshrockpapa-e7799 Why? imperial is a horrid system when trying to do calculations like this. And it's not 'common'. Most scientists use metric, even those in 'Murica!

    • @clausanders2886
      @clausanders2886 ปีที่แล้ว

      @@freshrockpapa-e7799 With this kind of units, you'll end up with any result you want. Add 2 cups of flour and 1 cup of water, 1 teaspoon of yeast and a pinch of sugar. Mix everything and wait a day or so. Ball it and stretch it to 12" and call it a pie.

    • @freshrockpapa-e7799
      @freshrockpapa-e7799 ปีที่แล้ว +1

      ​@@Chris-hx3om uh, no it isn't, if you can't figure out how to use another system of units you clearly shouldn't be working in stem

    • @Chris-hx3om
      @Chris-hx3om ปีที่แล้ว +3

      @@freshrockpapa-e7799 Oh, I can work in either unit set (and I'm frequently forced to), and because of that I know just how difficult US imperial is! When will Murica join the rest of the world and ditch those archaic units?

  • @sadmanislam5111
    @sadmanislam5111 ปีที่แล้ว

    @Stand-up Maths I love your annual pi series. It’s always great to see what ways you use to calculate pi each year.

  • @osmium6832
    @osmium6832 ปีที่แล้ว +4

    5:57 Ok, this must be some European slang, but "speedo" means something completely different in the US. Combine that with the fact that you mention "skid marks" in the same sentence, which is slang for something else, and you've got a recipe for a lot of students completely distracted from the math you're trying to demonstrate.

    • @sayorancode
      @sayorancode 11 หลายเดือนก่อน

      don't worry they are not old enough to know yet

  • @ManInJapan
    @ManInJapan ปีที่แล้ว

    My wife and I bought our first house and when asked to pick a closing date, March 14th was an actually reasonable option so... We're celebrating Pi day with a house!

    • @ManInJapan
      @ManInJapan ปีที่แล้ว

      Now that I think about it, we have the final walkthrough on the 12th, which is 3.12 and therefore very 2023 Pi indeed.

  • @kylegonewild
    @kylegonewild ปีที่แล้ว +4

    "It's Pi Day 2024 and we've calculated Pi in many different ways so far. Today we're sacrificing the unworthy to the God of Math who will approximate Pi for us, a Parker Pi if you will, and they just happen to live here, in this active volcano! It's sure to be a hot episode if I do say so myself. 😏"

  • @da_Space_Cowboi
    @da_Space_Cowboi ปีที่แล้ว

    So cool i absolutely love the different ways you can experimentally derive pi!

  • @klamsy7249
    @klamsy7249 ปีที่แล้ว +3

    I wonder how close will you get to π, if you take the averages of the results from your previous π-days.

  • @rickseiden1
    @rickseiden1 ปีที่แล้ว +1

    I've been waiting for this video for a month now. It's the annual, "Matt figures out PI" video!

  • @jajssblue
    @jajssblue ปีที่แล้ว +4

    I thought I had lost a week! 🤣

  • @jasperdegrood
    @jasperdegrood ปีที่แล้ว

    So cool! Loved the video! 😃Creative and exiting with the fast car. No worry's about the 26/38 thats all cool. Even cooler is that you approximated Tau. Clearly using 2Pi and the radius and by the magic of dividing Pi popped up! see you all june 28 th.