Cursed Units

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  • Опубліковано 22 гру 2024

КОМЕНТАРІ • 6 тис.

  • @robertyang4365
    @robertyang4365 Рік тому +9895

    I love how it feels like the background music is equally upset about all of this as the narrator

    • @ramonbril
      @ramonbril Рік тому +376

      I believe it to be specially arranged but the musician likes just as much to talk as the vocal host :D

    • @RainaRamsay
      @RainaRamsay Рік тому +8

      +

    • @RuthlessDutchman
      @RuthlessDutchman Рік тому +382

      "Background music was me improvising on a piano." The man's a savant and narrates the video with his voice and his fingers

    • @v01dv01d
      @v01dv01d Рік тому +46

      Also as loud. Which is annoying. I can't focus of what is said during the video :(

    • @bluestaraquamarine9214
      @bluestaraquamarine9214 Рік тому +30

      @@v01dv01d yeah I thought that too, but the content what worth the watch. 3:30 is what got me turning my volume down and using CC for a better viewing experience. I like how expressive the piano is but not the volume of it in contrast with information is hard to understand already and listening closely is harder when volume isn’t balanced properly.

  • @AntonioZL
    @AntonioZL Рік тому +16200

    The hubble constant being simplified to Hertz and then it's inverse ending up as an approximation of the age of the universe absolutely blew my mind.

    • @jeroenritmeester73
      @jeroenritmeester73 Рік тому +1772

      I was so disappointed to learn that the numbers being close to each other is pure coincidence.

    • @mousemaps9168
      @mousemaps9168 Рік тому +946

      @@jeroenritmeester73 I'm not so sure it is. The basic reasoning is sound even though it assumes a linear expansion which is a big simplification.

    • @user-xg5dw2gm8f
      @user-xg5dw2gm8f Рік тому +581

      they arent unrelated its an estimate assuming the hubble constant remains the same of when all galaxies were in the same place (the big bang) it just so happens the hubble constant hasnt always been consistant and the speed of the universe expanding has increased

    • @АйбулатИсхаков
      @АйбулатИсхаков Рік тому +106

      It blew my mind so hard that at very that moment I liked, shared and subscribed to this channel

    • @purpleshaft234
      @purpleshaft234 Рік тому +149

      I was alone in my apartment
      I screamed "holy f***"
      This was phenomenal

  • @strawmann9183
    @strawmann9183 Рік тому +2819

    "I personally find square roots cursed" ~Pythagorean Cultist, most likely

    • @mursuhillo242
      @mursuhillo242 2 місяці тому +6

      So cursed, apparently, that it even weeded out the comments, along with the other roots.

  • @jaywu1951
    @jaywu1951 Рік тому +4412

    In middle school I wondered why rain was measured in mm instead of something logical like litres/m^2 until it clicked and I realized they are the basically the same unit.

    • @MogR91
      @MogR91 11 місяців тому +309

      took me 34 years to figure that out :D

    • @Rabid_Nationalist
      @Rabid_Nationalist 11 місяців тому +290

      Damn, you just made me realize that..

    • @cinchez007
      @cinchez007 11 місяців тому +228

      daaaaaayummm it also boggled me why rain is measured in mm or inches. It makes sense now that volume/area is just a unit of length. Weird. Thanks for this info that I may never have to use. haha

    • @lucianfox
      @lucianfox 11 місяців тому +30

      @@cinchez007ohhh is this how it worked ? I didn’t realise that. Liter by itself didn’t seem like m^2

    • @lucianfox
      @lucianfox 11 місяців тому +113

      I thought they kept some kind of measuring jar and measured the height of the water collected in that jar

  • @ptorq
    @ptorq Рік тому +7540

    In my PChem class the instructor made the error of saying he didn't care what energy units we used on a test. He really meant it didn't matter to him whether we used joules or calories, but I took him at his word and turned in my test with all the energies expressed in liter-atmospheres.

    • @the-pink-hacker
      @the-pink-hacker Рік тому +709

      Do you do good on the test?

    • @ptorq
      @ptorq Рік тому +3032

      @@the-pink-hacker Yes, he was a man of his word. He did privately express regret to me for phrasing it that way.

    • @kai325d3
      @kai325d3 Рік тому +1493

      @@ptorqThat man took one look at your tests and instantly regretted everything

    • @ryanflynn611
      @ryanflynn611 Рік тому +564

      OMFG liter-atmospheres has me dying😂😂

    • @kvetchenfinks7044
      @kvetchenfinks7044 Рік тому +750

      Should've gone all out and done it in tablespoon-torre

  • @evinism
    @evinism 10 місяців тому +1551

    The little detail of the piano seemingly following a random walk on a whole tone scale while random walks are being discussed is amazing

    • @losthor1zon
      @losthor1zon 8 місяців тому +31

      Schoenberg would be proud

    • @sbef
      @sbef 5 місяців тому +12

      I disagree. There is a reason background music is bland and boring, because it should not be the focus. Chromatic improvisation on a piano is the opposite, as the dissonance is unexpected, thus extremely distracting. This is the jazz nerd equivalent of doing a science video with Wake Me Up Inside blaring in the background.
      The fact that many are fine with it, either are deaf, or are not actually paying attention, which is a shame because the topic is super interesting.
      tl;dr: this video would've done better without any music
      EDIT: ah damn, the newer video doubled down with this musical nonsense.

    • @evinism
      @evinism 5 місяців тому +72

      @@sbef lol u could have said you found it distracting without calling everybody who doesn't mind deaf

    • @SanojBerg
      @SanojBerg 5 місяців тому +6

      Also going up at “increasing” and down at “decreasing” (15:50)
      Edit after starting the second part: To be clear, I also love those details 😅

    • @destroyer68175
      @destroyer68175 5 місяців тому +44

      @@sbef "There is a reason background music is bland and boring, because I am bland and boring" fixed that for you.

  • @parkerkincaid1031
    @parkerkincaid1031 Рік тому +2184

    Calculating the Hubble constant as a music note (all notes are just frequencies) gets us an E 67 octaves below middle C.

    • @cheeseplated
      @cheeseplated 10 місяців тому +200

      Reminds me of the video "a joke about measurement" by Jan Misali, some really cursed units there

    • @GerinoMorn
      @GerinoMorn 9 місяців тому +84

      we are just harmonics, maaan

    • @Aurora.Astralis
      @Aurora.Astralis 9 місяців тому +16

      @@cheeseplated I forgot about that video, I need to watch it again

    • @cantileveredapotheosis
      @cantileveredapotheosis 9 місяців тому +35

      I would like to listen to your note, but I suspect that it would be multiple instances of the universe I would have to suffer through in order to assemble enough peaks and valleys in order to reach an assemblance of hearing it.

    • @phillyphakename1255
      @phillyphakename1255 8 місяців тому +7

      I need to make this an art installation.

  • @NevinBR
    @NevinBR 8 місяців тому +2170

    The sun appears to move through the sky at a rate of 15 minutes per minute.

    • @robertarvanitis8852
      @robertarvanitis8852 7 місяців тому +209

      Earth revolves 360° around its axis in 24 hours. 360° is 21,600 arc-minutes. 24 hours is 1,440 time-minutes.
      Your 15:1 arc over time is itself a fine "cursed unit."

    • @mortgageapprovals8933
      @mortgageapprovals8933 6 місяців тому

      @@robertarvanitis8852 First one about the bird poop is malformed. Does not take into the account size of poop and
      I could lay in my backyard and get pooped on or go to middle of the arctic sea and never get pooped on.
      I see bird poop on my car almost every day. And I see many cards in my hood with bird poop. So clearly we are not waiting 195 years per poop.
      You're taking the average of "never" and frequent and providing a useless and meaningless number.

    • @ChannelTerminatedbyYouTube
      @ChannelTerminatedbyYouTube 6 місяців тому +26

      Rate is (360×60)/(24×60)
      Or, 15

    • @ChannelTerminatedbyYouTube
      @ChannelTerminatedbyYouTube 6 місяців тому

      ​@@robertarvanitis8852 it's rotates ig not revolves

    • @greenmist75
      @greenmist75 6 місяців тому +45

      So just 15 then lmao😂

  • @noscar3557
    @noscar3557 Рік тому +4331

    3:33 "using kWh is like using km.h^-1.min" that's basically what we do by measuring distance using light years

    • @meifray
      @meifray Рік тому +217

      and in such scale,it do make sense sometime,like when you are calculating electricity bill of a factory,just like measuring distance between stars...

    • @SioxerNikita
      @SioxerNikita Рік тому +188

      Interestingly enough, when we get to proper spaceflight, it would make for more sense to use light speed measurements in general, like 2.2 Light Seconds, especially if we use laser weaponry.
      You A) get the measurement of a distance. B) you get the delay for how long ago the measurement was made.
      So in the example of 2.2 Light Seconds, you know they are 2.2 Light Seconds away, you also know that the delay of the measurement is at minimum 2.2s old. If you use laser weaponry, you will also intuitively know that you have to compensate by about 4.4 seconds, as the information is 2.2 seconds old, and if you need to hit it, you need to take into account that you also take around 2.2 seconds to hit.
      Especially useful for military applications.

    • @sankang9425
      @sankang9425 Рік тому +145

      @@SioxerNikita Inevitable transition from metric to planck units incoming in the next millennia?

    • @SioxerNikita
      @SioxerNikita Рік тому +26

      @@sankang9425 Definitely not XD

    • @agiri891
      @agiri891 Рік тому +38

      @@SioxerNikita yeah then we would have like 9.43 * 10^32 units or something like that

  • @cvl14
    @cvl14 Рік тому +3270

    I've seen in the notes of a friend of mine attending a urbanism class the unit "people/dumpster", which was used to measure how many people would be served by a single dumpster in a particular area. The first time I saw it I found it very funny, I read 500 people/dumpster as 500 people crammed into a single dumpster

    • @gametimewitharyan6665
      @gametimewitharyan6665 Рік тому +64

      That is indeed very funny 😂

    • @Gabsboy123
      @Gabsboy123 Рік тому +46

      But wouldn't this just assume that all users of a single dumpster would generate an equal amount of garbage each?

    • @DustyHoney
      @DustyHoney Рік тому +65

      @@Gabsboy123Considering how many US cities suffer from trash overflow, I would assume that this measurement does _not_ take people who create more trash into account.

    • @chaotickreg7024
      @chaotickreg7024 Рік тому +75

      ​@@Gabsboy123It sounds like an average. For every random person with a dropshipping business putting tons into the trash, there's a vegan committed to making no trash. They balance out eventually, especially if we're talking about a group of 500 people.

    • @christophernoneya4635
      @christophernoneya4635 Рік тому +38

      Person per toilet is even more complicated. There's a whole equation needed, it's also split per gender with up to 2/3 of male toilets being converted to urinals which makes it even more annoying

  • @joostvisser6508
    @joostvisser6508 Рік тому +2740

    I needed to pause for a second when you revealed that the Hubble constant can be measured in Hz. That is truly cursed

    • @Thetarget1
      @Thetarget1 Рік тому +63

      It makes sense from Hubble´s law: v = H*r. r has unit meters, so H needs units s^-1 to give v the units m/s.

    • @kailaine3974
      @kailaine3974 Рік тому +128

      the moment i saw inverse seconds i had to pause the video and take a breather. funniest shit ive seen all week

    • @sage5296
      @sage5296 Рік тому +20

      i mean this is basically the frequency in which the universe expands, similar to how an APR interest rate would work, since %growth is unitless so it’s just 1/time as well

    • @42Mrchadman42
      @42Mrchadman42 Рік тому +11

      I just assumed that it was the "red shift" offset. Like, the Hubble constant is how much (on average) redder the light from other objects in the universe are compared to their true color.

    • @SpaceSoups
      @SpaceSoups Рік тому +11

      It made my head hert

  • @Subcontrabassoon
    @Subcontrabassoon 10 місяців тому +225

    I've watched this video more times than I would probably admit, and "Hertz?!" gets me every time. What a gem of a video.

  • @Tandanuu
    @Tandanuu Рік тому +8576

    Another great unit for power can be found on energy efficiency labels for light bulbs here in the EU. It's specified in kWh/1000h :D

    • @rlachiecyce
      @rlachiecyce Рік тому +2605

      wow by writing it like kWh/kh we can literally reduce it to W

    • @jan-lukas
      @jan-lukas Рік тому +936

      ​@@rlachiecycethat's probably why they chose that exact one, while also making it obvious for the people used to kWh

    • @stefanalecu9532
      @stefanalecu9532 Рік тому +741

      As a fellow European myself (and to explain the reasoning behind that unit for non-EU people):
      If you have a lightbulb that will be on for quite a long time (1000h isn't hard to achieve in a year or so if you keep it on for maybe 3h/night) and thus I care about its energy efficiency, but guess what units are on my energy bill... That's right, kWh, so since 1000h is a minimum reasonable lifespan of a bulb, it isn't as dumb as you might think.
      Of course, we also have W (and at least on this side of Europe where I am from I've mostly seen them advertised as W), but oh well

    • @UnePintade
      @UnePintade Рік тому +283

      ​@@stefanalecu9532 1 kWh/1000h = 1W

    • @TheMariofan222
      @TheMariofan222 Рік тому +154

      Watt do you mean?

  • @TheLoneWolfling
    @TheLoneWolfling Рік тому +3053

    My favorite is s^-1 / s^-1, where the units don't actually cancel.
    (One is a frequency, the other is an _angular_ frequency, and so is off by a factor of 2pi.)
    In general, anything involving radians is 'fun', because people declare it to be unitless and then omit the unit, and then get really confused.

    • @AimeeColeman
      @AimeeColeman Рік тому +326

      This always annoyed me, because degrees and radians are definitely units, and by declaring their unitlessness, it's easy to get confused when reading about models in papers where you're not familiar with the field's standards as to whether they're talking about radians or degrees. This issue comes up a lot in crystallography modelling, where the angle standard in physics is radians, but in measured X-ray diffraction data, it's degrees, and models either choose one or the other.

    • @mreese8764
      @mreese8764 Рік тому +66

      The same happened here with the gravitational constant at 9:30. Google covered it wrong. It went from 1/s to Hertz and multiple the unitless constant "revolution" without stating it. So, converting back to 1/s would introduce the 2pi or 360° factor incorrectly.

    • @mrWade101
      @mrWade101 Рік тому +50

      @@AimeeColeman ° is the symbol for degrees and rad for radians. Isn't it pretty standard to write rad/s for angular velocity?

    • @朕是神
      @朕是神 Рік тому +163

      It's dimensionless, not unitless.

    • @TheLoneWolfling
      @TheLoneWolfling Рік тому +8

      @@朕是神 Indeed!

  • @JohnDixon
    @JohnDixon Рік тому +1448

    I once had a physics problem recommend writing the charge of an electron as "1 electronvolt per volt" in order to help the units cancel nicely. I'll never forget staring at that problem and just thinking, "Huh, well I guess that's technically true"...
    Now that I'm an astronomy grad student, I see shit like "solar masses per year" and "joules per square centimeter per second per Hz" and it doesn't even seem out of place.

    • @A-lik
      @A-lik 11 місяців тому +71

      As someone with no degree and only an interest in astronomy, solar masses per year doesn't even sound remotely cursed. Am I missing something?

    • @christianclark2656
      @christianclark2656 10 місяців тому +47

      @@A-likprobably not. It’s just “solar masses” isn’t a unit we use every day 😂

    • @CatFish107
      @CatFish107 10 місяців тому +42

      Gotta convert to something relatable, like the universal news units of school busses( large mass), football fields (intermediate lengths), and aircraft carriers ( real big mass).

    • @MrShadow1617
      @MrShadow1617 10 місяців тому +48

      @@CatFish107Well, those sound less "relatable" and more "american"...

    • @1unar_eclipse
      @1unar_eclipse 9 місяців тому +34

      ​@@MrShadow1617Americans will use anything but the metric system

  • @michaelwoodhams7866
    @michaelwoodhams7866 10 місяців тому +208

    Back when I was an astronomy grad student (c1990) one of my professors told us "a barn megaparsec is a teaspoon". I quickly responded "That can't be right - maybe 0.6 teaspoons?"
    The reasoning being: I knew a parsec was 3 x 10^something meters, a teaspoon was 5 ml = 5 x 10^something m^3, and a barn was 10^something m^2. So taking on trust that the powers of 10 cancelled as he claimed, there was still a factor of 3/5 left over.
    A bit later, I showed him on my shiny new HP48SX calculator, which could attach units to quantities and do conversions, that multiplying a megaparsec by a barn and converting the result into teaspoons indeed gave a result of about 0.6.
    That HP48SX's units functionality was absolutely wonderful for an astronomy grad student.

    • @HobbitJack1
      @HobbitJack1 5 місяців тому +11

      I'm an Astrophysics undergrad student (and researcher), and I've got my HP-48GX on my desk next to me!

    • @michaelwoodhams7866
      @michaelwoodhams7866 5 місяців тому +9

      @@HobbitJack1 Back in the day, I wrote a program to turn the top five rows into a giant CST menu. It was very handy for keeping all the odd units and constants astronomers use close at hand.

    • @HobbitJack1
      @HobbitJack1 4 місяці тому +4

      @@michaelwoodhams7866 Absolutely! It's super useful.

    • @philiphunt-bull5817
      @philiphunt-bull5817 4 місяці тому +1

      This is an incredible story, thank you for sharing

    • @HobbitJack1
      @HobbitJack1 4 місяці тому +7

      Just did the calculation (on my 48GX!): One barn-megaparsec is 0.62604tsp.

  • @skurella
    @skurella Рік тому +1179

    The craziest unit I’ve ever worked with is an Erlang, which is equal to 60 minutes per hour. You read that right. It’s used by telecommunications engineers to describe the capacity of trunk phone lines (i.e. between exchanges) to carry multiple voice calls simultaneously. If you group 10 regular phone cables together, it will have a capacity of 10 Erlangs. Long live engineering.

    • @EdKolis
      @EdKolis Рік тому +60

      I guess you could use it to measure the rate at which time flows in different gravitational fields?

    • @B1SQ1T
      @B1SQ1T Рік тому +353

      Every 60 seconds a minute passes in Africa

    • @Mr.Nichan
      @Mr.Nichan Рік тому +54

      You could call that a dimensionless number (ratio of spoken time to real time, or (usually average) number of calls at once) if you wanted to. I think there are a lot of numbers like this you could rewrite with "cursed" units for clarity if you wanted to.

    • @godofmath1039
      @godofmath1039 Рік тому +22

      So just 1, basically

    • @Noname-py3uu
      @Noname-py3uu Рік тому +11

      @@EdKolis seems possible, but only if you fix the hour to 1 earth hour

  • @beriukay
    @beriukay Рік тому +972

    The musical companionship to the monologue is frickin' amazing. I noticed it early on, but at the random walk, I decided I had to comment on it

    • @AstralPhnx
      @AstralPhnx Рік тому +16

      I love it when music does this it's great

    • @SmashCrunch
      @SmashCrunch Рік тому +7

      Lol I am looking at the comments for this with the video paused at the random walk moment

    • @cxvz5576
      @cxvz5576 Рік тому +4

      @@SmashCrunch I gotchu, 16:01

    • @thatoneofficialpianist
      @thatoneofficialpianist Рік тому

      same, this is crazy

    • @vvsganti
      @vvsganti Рік тому +5

      @@thatoneofficialpianist Background music was me improvising on a piano. he said this in the description

  • @Space_Kalak
    @Space_Kalak Рік тому +1095

    The most cursed unit I came across in my physics degree was for the frequency spindown rate of a pulsar, measured in seconds per second (or, every second, how many seconds longer each rotation of the pulsar increases by)

    • @TotallyDapper
      @TotallyDapper Рік тому +256

      If the spindown rate of the pulsar was accelerating, you could measure that in seconds per second per second. How many seconds per second slower the pulsar is spinning every second.

    • @DuetJay
      @DuetJay Рік тому +160

      @@TotallyDapper I feel like we could throw "seconds" as an angle measurement in there too, somehow.

    • @gptgpt-xh7bx
      @gptgpt-xh7bx Рік тому +71

      @@DuetJaylongitude/latitude seconds are equivalent to arcseconds but measured and represented as seconds, so yes

    • @Neo-vz8nh
      @Neo-vz8nh Рік тому +47

      Janky if you convert it is J/s/m^2/Hz, and so s=1/Hz, it remains only J/m^2.
      When I did this, my supervisor wasn't happy.

    • @chrisclark6154
      @chrisclark6154 Рік тому +5

      Ah the good old Pdot. Dispersion measures for pulsars are another weird one.

  • @n8moore3
    @n8moore3 10 місяців тому +21

    I stand by this statement with 100% confidence, this is the best video on UA-cam. I can watch it so many times and it never gets old. This needs to be a series…

  • @Treblaine
    @Treblaine Рік тому +647

    How can the "thin tube of fuel" be so simultaneously cursed and brilliant at the same time?

    • @MogR91
      @MogR91 11 місяців тому +27

      do you also see all the cars passing by led by their own fuel line now? :D

    • @bobthegamingtaco6073
      @bobthegamingtaco6073 9 місяців тому +20

      It's like trolley wires but made out of dinosaur juice lol

    • @avroarchitect1793
      @avroarchitect1793 8 місяців тому +7

      crossectional consumption rate.

    • @matthewhall5571
      @matthewhall5571 6 місяців тому +4

      It makes perfect sense. You are just using a different more roundabout way of measuring the flow rate of fuel to keep it running.

    • @deadlylaigrek
      @deadlylaigrek 6 місяців тому +4

      That tube is also predestined and shows where you will go due to time travel. For more information, watch the documentary "Donnie Darko"

  • @BonJoviBeatlesLedZep
    @BonJoviBeatlesLedZep Рік тому +604

    Dimensional analysis kind of saved my butt in high school physics and even some college physics. When you understand unit multiplication, I find it WAY easier to remember equations. Sometimes you can derive unit breakdowns in the exam and get a eureka moment which makes you remember the equation from your studying.

    • @CarpetOfStars_98
      @CarpetOfStars_98 Рік тому +24

      It's insanely helpful. I'm studying physics and I do that all the time.

    • @jordanledoux197
      @jordanledoux197 Рік тому +38

      I did this in high school physics too. I was in AP calc at the time, so rather than spend time studying, I used calculus on the tests to re-derive the equations from dimensional analysis, because that way I basically only had to remember calculus which I needed to do for my other class anyway.

    • @linkhyrule5800
      @linkhyrule5800 Рік тому +13

      Dimensional analysis turns out to be a nontrivial part of our understanding of *quantum field theory*, so this feeling never goes away even at the highest levels of physics :p.

    • @souImenace
      @souImenace Рік тому

      Same here, it saved me in a lot of tests cause I couldn't remember the equations so I would just derive the equations based on the units

    • @Spicymuffins89
      @Spicymuffins89 Рік тому +3

      In a dynamics test I had forgotten the formula for final velocity given distance and acceleration so I used dimensional analysis to recreate it on the spot. I did however forget the 2.

  • @victorbarreto8599
    @victorbarreto8599 Рік тому +1028

    A long time ago I used to translate documents from English to Spanish. More often than not, they were of a technical nature. And often I had to review and fix someone else's work. One day I had to review someone else's translation of some very specialized industrial paint. The work also involved converting from customary units to SI. The original instructions indicated the lowest and highest temperatures at which the paint could be applied. And these had been properly converted from Fahrenheit to Celsius. But there was another important parameter provided by the instructions. For the first 24 hours after applying the paint, the ambient temperature should not fluctuate by more than 20F°. This had been duly converted to -6.7C°. So "for the first 24 hours the temperature should not fluctuate by more than -6.7C°". Whoever did this did not have a technical mind and did not understand that the 20F° referred to a relative change and not an absolute temperature. The correct value was about 11C°. The temperature should not fluctuate by more than 11C° over the first 24 hour period.

    • @Cerafem
      @Cerafem Рік тому +62

      This reminds me of the basic issue of people having trouble with things like 30 or 0 degrees F being cold, so what is twice as cold??? But really we compare those to the reference 'room temp' where we are comfortable, not the numerical 0 (and I suspect the relationship is rather nonlinear to boot).
      So in your problem, they needed to know the difference in temperature from 0-20 degrees F, which meant calculating both and subtracting, or if they understand that this is a scaled difference, all they actually had to do is multiply by 5/9 since C and F differ by a constant ratio, plus an offset.

    • @kosmologist
      @kosmologist Рік тому +10

      duly

    • @Xnoob545
      @Xnoob545 Рік тому +93

      This confusion would all be solved with kelvin

    • @johncain59
      @johncain59 Рік тому +11

      @@Xnoob545 there's no such thing as cold but I can work out what's half as warm. Wow its a bit cold.

    • @BillDavies-ej6ye
      @BillDavies-ej6ye Рік тому +21

      @@Xnoob545 Or for Fahrenheiters, Rankine. Why don't people have names like Macquorn Rankine anymore?

  • @thatginger8897
    @thatginger8897 7 місяців тому +22

    In materials science, fracture toughness is measured in MPa/sqrt(m). If you account for the fact that Pa are N/m^2, you can end up with the unit N/m^3/2, which I’ve always found to be super cursed.

  • @5ucur
    @5ucur Рік тому +1226

    I can't remember any cursed units, but I gotta comment on how excellent the piano accompaniment was. The discordant sounds when you mention something confusing, the dramatic build-up as you build up to a conclusion, the sudden stop when you drop a surprising fact! Top-notch.

    • @DevinDTV
      @DevinDTV Рік тому +2

      it's so bad

    • @deanyona6246
      @deanyona6246 Рік тому +52

      Don't forget the step up and step down when talking about the chance of the diffraction changing and the piano music being a musical random walk when talking about random walks!

    • @mustang1912
      @mustang1912 Рік тому

      He didn't even touch the planck equation

    • @xenomaster7263
      @xenomaster7263 11 місяців тому +2

      It definitely adds a great touch, reminds me of how Untitled Goose Game uses its soundtrack

  • @sheikchilli8670
    @sheikchilli8670 Рік тому +864

    in chemistry, pH is the negative logarithm of the concentration of protons in a solution, and concentration is basically the number of particles in a volume. most equations using pH aren't that cursed, but i was never really able to figure out an intuitive way to understand the dimensional analysis of the henderson-hasselbalch equation

    • @red5t653
      @red5t653 Рік тому +130

      It comes from the fact that strictly speaking, generally the concentrations of protons in a solution is in fact quite low, so of course you're dealing with negative powers of 10
      Hence, to make pH a sensible unit, and to reduce the scale in such a way as to be interpretable, you first take the logarithm, but that's a negative number, and you can't HAVE negative scalar units, so you then negate it.
      If there's enough protons in solution to suggest that there is indeed somehow one mole of loose protons per liter of solution, AKA 1 M, or pH = 0, or there are somehow so few protons per liter of solution that there's one mole of hydroxide ions instead, then the solution is likely so caustic as to be nigh-on uncontrollable without highly specialized and study equipment, thus handily explaining why pH is generally not measured once you go below 1 or go above 14.

    • @HeavyMetalMouse
      @HeavyMetalMouse Рік тому +51

      Ultimately, it only really works because 'concentration' can be a dimensionless constant - Number of Protons per Number of Total Particles (mol/mol). The issue is that we measure concentration as mol/L. The only way to make that dimensionless so that the logaritm can log it without issue is to have an implied scaling constant of 1 L/mol on that concentration (instead of pH = -log(a), you have pH = -log(ka), where k = 1 L/mol). If we were to rescale this so that we were measuring concentration as mol/mol (dimensionless), we introduce a new scaling constant is the volume per mole of the solution (pH = -log(kma), where a is now our dimensionless concentration, and b is the mol/L of the solution, while k = 1 L/mol), and so varies based on the solution. Since most acid/base work is done in liquid water, 1 mole of water is 18 grams, which is 18 mL liquid water, so b = 1 mol/0.018L = 55.6 mol/L or so.
      Rewriting so as to only have one scaling constant, we have pH = -log(na), where a = concentration in moles per mole, and n ~= 55.6 dimensionless, for no real reason except to keep the final answer (also a dimensionless value) consistent with the existing pH scale. In theory, you could redefine pH to not need that constant - the constant factor only serves to shift the final number by about 1.74ish. A 7 pH would end up being a 'pH' (normalized to mol/mol) of 8.74 or so, which is less pretty, I guess.
      Which variation is 'more right' comes down to which option makes it easier to compare activity in different kinds of solutions (not just water). In this case, mol/L sort of makes sense as a 'how much activity by volume of liquid', but on the other hand, chemistry is done stoichiometrically, so you're more likely to want to know how much 'activity by mole of solution' you have, I would think. On the other other hand, 'activity by volume' is probably more readily accessible to a non-chemist, so is more comprehensible to the layman. So I don't really know.

    • @stratonikisporcia8630
      @stratonikisporcia8630 Рік тому +32

      pH = - log(mol / L) = log(L) - log(mol)
      Considering L = 10^-3 m3, we can write:
      pH = log(10^-3 m3) - log(mol) = log(10^-3) + log(m3) - log(mol), therefore:
      pH = 3log(m) - log(mol) - 3

    • @ゾカリクゾ
      @ゾカリクゾ Рік тому +8

      the explanation I received is that there is an implicit "unitary concentration 1 mol/litre" inside of the logarithm or something like that.
      This is to cancel out all units, since logarithms (and trig functions) cant have units in their arguments.
      Specifically in logarithms and exponentials, it's always a ratio of something against something

    • @StrangyENPP
      @StrangyENPP Рік тому +4

      Excuse me, the pH wasn't measured by the activity of a component in the solution?

  • @emmeeemm
    @emmeeemm Рік тому +554

    The most cursed units I've seen are "Hertz per dioptre". The dioptre comes from optics, measuring the optical power of a lens, and it's equal to an inverse meter. So, Hertz per dioptre is (s^-1) / (m^-1), which is speed if you flip the fraction to eliminate the negative exponents.

    • @adiaphoros6842
      @adiaphoros6842 Рік тому +28

      The speed of what is frequency per optical power measuring? I could conceivably see this unit in a graph that tracks the optical strength of a lens depending on light frequency in Hertz. Diopter is the inverse of the lens’ focal length, so it's focal lengths (of a lens with a certain optical power) per period (of light with a certain frequency) in this context.

    • @alysdexia
      @alysdexia Рік тому

      @@adiaphoros6842 length → width, span; travels → goes, fares, wends

    • @charliewright2667
      @charliewright2667 Рік тому +7

      Beer's law similarly has (M^-1)(cm^-1) for the molar absorption coefficient. k in a third order reaction would be (M^-3)(s^-1)

    • @emmeeemm
      @emmeeemm Рік тому +9

      @@adiaphoros6842 Brace yourself, because this answer might shock you.
      This is a unit for the speed of ANYTHING with a velocity.
      (s^-1)/(m^-1) = m/s. "Inverse seconds per inverse meter" equals "meters per second", which is a pretty common general unit of speed in physics.

    • @adiaphoros6842
      @adiaphoros6842 Рік тому +12

      @@emmeeemm It can’t just be anything, since the context of the units needs to be considered. In this case, the context is optics because “(light) frequency” and “optical power” are commonly used units. So, in that context, the speed of what is being measured?

  • @phoenix4010
    @phoenix4010 Рік тому +8

    props to the music in this video!!!! It very well ties together the background ambience with the words being spoken. I particularly love the example of the random walk in the section on PMD

  • @Thrustmaster64
    @Thrustmaster64 Рік тому +438

    I just love how, when you were talking about random walks, you were also playing a hexatonic random walk on the piano! Great soundtrack, clear explanations, 10/10!

    • @MB-yf4lt
      @MB-yf4lt Рік тому +59

      10/10! is a very low score...

    • @khandmo
      @khandmo Рік тому +2

      @@MB-yf4lt 100% is low?

    • @sams_enfp
      @sams_enfp Рік тому +50

      @@khandmo 10 divided by 10 factorial (10!) is 3628800, so 10/10! is about .00000276, or .000276%, which is very low.

    • @Sup3rman1c
      @Sup3rman1c Рік тому +8

      @@khandmo If i told you your mom is a 1 would you take offense?

    • @wyattstevens8574
      @wyattstevens8574 Рік тому

      ​@@khandmoJoke went over your head

  • @clairekopenhafer8272
    @clairekopenhafer8272 Рік тому +640

    As an astronomer I am delighted to see the cursed units of the Hubble constant featured. Also, the 2 AU distance between measurements in January and July is resolved by taking half of the angle between those two measurements. The January and July measurements make an isosceles triangle that you then slice in half to make right triangles. This phenomenon of apparent position change is called parallax!

    • @hqTheToaster
      @hqTheToaster Рік тому +13

      Since you like cursed units, here is a cursed unit of volume: (Hubble Length*Acre/(Barn ^ 1/2) *(1 gallon)^(1/6)* (1 rod)^(1/2)/(1024)^16) ~ 2 cu in.
      And you can raise it to the 1/6th and divide by Milliparsecs squared, and pass an Earth Day as a duration to get a different, very fast growing Earth Days per square root ~1.1 in. per Milliparsec squared. A cursed unit you could use for... cooking checking... using solar panels and a goofy hourglass setup.
      Yeah, units get really cursed if you want them to.

    • @nadavslotky
      @nadavslotky Рік тому +19

      Whence, parsec: *par*allax distance per arc-*sec*ond

    • @joshuaychung
      @joshuaychung Рік тому +5

      Do we account for the fact that we're in an elliptical orbit around the sun? Theoretically, the January/July measurement would be a little different from say a March/September measure.

    • @fury_blade9303
      @fury_blade9303 Рік тому +12

      @@joshuaychung Well, I would assume they only take measurements in the months where the earth is 1 AU from the sun. Makes you wonder why AU is a unit when the earth’s distance from the sun is not always the same depending on where it is. The ellipse is probably not that big of a difference.

    • @johndododoe1411
      @johndododoe1411 Рік тому +3

      ​@@fury_blade9303AU is the radius of a perfect circle with the same year length .

  • @screwaccountnames
    @screwaccountnames Рік тому +740

    The bit about fuel consumption has an interesting update with the transition to electric cars:
    The specific energy consumption of an electric car can be given in kWh/km, which translates to 3600 kJ/km = 3600 J/m = 3600 Newtons. And it has a neat interpretation: It's the average force (air resistance, friction etc.) holding your car back over the distance of the trip (some overhead for onboard electronics notwithstanding).

    •  Рік тому +22

      This explanation feels wrongs. The energy efficiency of a car does not only depend on external losses like air resistance. In fact, air resistiance and frictions can be considered constant, depending on the actual car design and implementation details.

    • @MarkFobert
      @MarkFobert Рік тому +42

      ​​​@ but these resistances change with different driving conditions (speed, headwind, ...). I would also expect electrical and mechanical efficiency to change with variables such as temperature.

    • @MrHankeyYT
      @MrHankeyYT Рік тому +28

      @ That's why it is not an explanation but rather an interpretation: Assuming that all losses were created by air resistance then it would have the exact force of your energy consumption.

    • @juanausensi499
      @juanausensi499 Рік тому +64

      @@MrHankeyYT I think it's a valid explanation too. Those newtons are the total forces the engine needs to overcome, including air resistance, wheel friction, and also internal resistance of the engine itself.

    • @MaxwellTornado
      @MaxwellTornado Рік тому +6

      At that point it's just an aerodynamics value.

  • @emilgrnlund5747
    @emilgrnlund5747 11 місяців тому +72

    Permability coefficient Pm which is: 10^-13(cm^3*STP)(cm)/(cm^2*s*Pa). Ohh and STP is 101,3kPa.
    The unit is from material science, seen in the book Callister

    • @kexcz8276
      @kexcz8276 6 місяців тому

      Material science? 💀 I wanted to study that ngl XD

    • @whynot9421
      @whynot9421 5 місяців тому +4

      You made the next vid, replace Pa with cmHG

  • @mariohuttel1822
    @mariohuttel1822 Рік тому +342

    Noise (density) of electrical components e.g. operational amplifiers is usually given in nV/sqrt(Hz).That's my all-time favorite.

    • @leyasep5919
      @leyasep5919 Рік тому +7

      still it quite makes sense.

    • @Ugnaski
      @Ugnaski Рік тому +1

      Is it similair to the dispersion mensioned in the video? As in how many volts of noise are generated in a certain bandwitch?

    • @Simon-ps3oj
      @Simon-ps3oj Рік тому +8

      so... nV√(s)?

    • @fisk7aal
      @fisk7aal Рік тому +14

      Hello there fellow EE. I was looking for this one

    • @GegoXaren
      @GegoXaren Рік тому

      That made me laugh.

  • @JackBarlowStudios
    @JackBarlowStudios Рік тому +185

    I once saw (in an old technical report from Oak Ridge National Lab) thermal conductivity written in units of BTU/hr/ft/°R, and I still haven’t recovered.

    • @carlosvasquezjr92
      @carlosvasquezjr92 10 місяців тому +2

      °R?

    • @cyberneticsquid
      @cyberneticsquid 10 місяців тому +34

      @@carlosvasquezjr92I presume it's degrees Rankine (Fahrenheit offset so 0°R is absolute zero)

    • @yablecki
      @yablecki 10 місяців тому +34

      It's actually crazier than that. Thermal conductivity is usually expressed in BTU*in/(hr*ft^2*°F). That is, the number of BTUs that will conduct through a material that is 1 inch thick, 1 foot square, and has a 1°F difference in temperature between the hot and cold side in 1 hour.

    • @vaderdudenator1
      @vaderdudenator1 8 місяців тому +2

      @@yableckiI hate that

    • @uNiels_Heart
      @uNiels_Heart 8 місяців тому +4

      Actually, both °R and °F are a very colloquial way to write that part of the unit. Technically correct would be R (without the ° symbol), i.e. just Rankine, as that signifies a temperature difference on the Fahrenheit scale (the same way a temperature difference on the Celsius scale would be K, Kelvin, without the ° symbol).
      °R (with the degree symbol) would be an absolute temperature with its zero point at "absolute zero", the lowest temperature possible. It's the same with the Celsius scale, where °K would be an absolute temperature with its zero point at the lowest temperature possible.
      And both °F and °C never go without the degree symbol, as they're both absolute temperatures, never temperature differences. (However, with a zero point at a physically silly - but useful in practice and more tangible for human consumption - temperature.)

  • @bitbyt3r
    @bitbyt3r Рік тому +1814

    By far my favorite cursed unit in electronics is Ohms per Square. It's used to measure resistance of flat copper planes (such as in a printed circuit board). It turns out the length and width of the square cancel out, so the square is unitless. Any square you draw on a copper plane will have the same constant resistance regardless of size.

    • @jnawk83
      @jnawk83 Рік тому +120

      the thickness of the copper is the only remaining variable.

    • @MrNicoJac
      @MrNicoJac Рік тому +66

      Wait, so that means that you want as few squares as possible, in order to minimize resistance? 🤔

    • @TheZoltan-42
      @TheZoltan-42 Рік тому +54

      Are those Parker squares or city squares? :)

    • @bitbyt3r
      @bitbyt3r Рік тому +144

      @@MrNicoJac Pretty much, yeah! If you have a long thin trace it'll have higher resistance because you have to draw a bunch of tiny squares in series to cover it. A thicker trace means each square covers more of the distance since both the length and width can expand to fill the wider trace, and thus the overall resistance is lower for the same length of trace.

    • @ShreyasPethe97
      @ShreyasPethe97 Рік тому +42

      Yesss !
      Just today I had to redo some of my older experiments for a paper involving a four probe sheet resistance and I was just thinking about what an actual bullshit 'Ω/sq' is, and then this video pops up on my way back ! 😂😂😂

  • @marope
    @marope 10 місяців тому +11

    This video has been on my youtube suggested list for some time and finally I decided to watch it today...
    YT algorithm was right!
    Not only I really enjoyed the video but also I realized that I had the same questions and reactions myself about these cursed units. Good work.

  • @Fireworker2K
    @Fireworker2K Рік тому +2038

    There's an XKCD comic with a cursed measurement resulting from unit conversion. The unit is meters and Randall Munroe called it the "Oily House Index (OHI)".
    He noticed that real estate prices are stated in dollars per area while oil prices are dollars per volume.
    By cancelling these two units against each other, you get the OHI measured in meters. He then graphed it over time and some economical events even showed up (housing crisis, oil crisis, etc).
    The "intuitive" representation of the OHI would be: if I sold a piece of real estate and bought crude oil from that exact amount of money, how high could I fill the property with the oil I bought?
    Its absolutely lovely and the corresponding comic is one of my absolute favorites.

  • @toast99bubbles
    @toast99bubbles Рік тому +321

    In university, I had some work that was calculated in minutes per hour. We were doing a group project on how many toilets a building needed, estimating the time of a trip to the toilet, estimating the nukber of people in the building and estimating the number of toilet trips per day to try and estimate the amount of minutes of toilet usage per hour. One model had 2650minutes/8hours which became 331.25minutes/hour and then further simplified to 5.5208minutes/minutes.

    • @tomjackal5708
      @tomjackal5708 Рік тому +13

      incredible lmao

    • @chemtrailsmoker9852
      @chemtrailsmoker9852 Рік тому +37

      Couldn't you just interpret this as 5.5208% of work time spent on toilet breaks?

    • @toast99bubbles
      @toast99bubbles Рік тому +24

      @@chemtrailsmoker9852 I guess that's one way to interpret it. Although we mostly wamted to work with it to model theideal number of toilets for the building. I think it was something like 1 toilet per 20 people, plus an accessible toilet on every floor.

    • @djaydeved
      @djaydeved Рік тому +5

      @@toast99bubbles im no maths geek but this gave me a good laugh!

    • @mrsimitschge3958
      @mrsimitschge3958 Рік тому +6

      Do I interpret correctly, that you do not have enough toilets?

  • @petrie911
    @petrie911 Рік тому +988

    Unlike SI, CGS does not have a separate unit for charge. Instead it has the statcoulomb, a derived unit equal to 1 sqrt(g cm^3)/s. To add to the cursedness, it's not dimensionally consistent with the coulomb. The conversion factor depends on the context of the quantity it's measuring.

    • @mibber121
      @mibber121 Рік тому +102

      CGS is an entire cursed unit system in the first place

    • @TimothyRE99
      @TimothyRE99 Рік тому +16

      Better than having to use vacuum permittivity and permeability constants. Makes dimensional analysis a whole lot easier.
      Hardly any reason to ever convert charge itself, anyway, and CGS is consistent with SI on stuff like Energy.

    • @Saturnius
      @Saturnius Рік тому +27

      @@TimothyRE99 That's like saying working with g the gravitational field strength is tedious. Constants in physics having units is nothing new.

    • @thekonkoe
      @thekonkoe Рік тому +20

      I remember too many problems where cgs helped cut through the tangle and clarify the problem to think it’s completely useless. That said, the statcoulomb is pretty cursed.

    • @TimothyRE99
      @TimothyRE99 Рік тому +10

      @@Saturnius But why use an extra constant when you don't need to?
      There's a reason natural and Planck units exist.

  • @redstonewolfx
    @redstonewolfx 2 місяці тому +6

    8:30 the 2 is because 1 au is the distance from the earth to the sun (radius of orbit), but the second reference point isn’t the sun, it’s twice as far away - specifically, on the other side of the sun, or twice as far away (the diameter)

    • @c.jishnu378
      @c.jishnu378 Місяць тому

      Bro he knows.

    • @imbob99999
      @imbob99999 14 днів тому

      ​@@c.jishnu378Then why does he say he doesn't know where the 2 factors in?

    • @c.jishnu378
      @c.jishnu378 14 днів тому

      @imbob99999 that's the point of the whole video, instead of making units that make everything as simple as possible, these people some hundred years back chose to make the definitions as simple as possible inadvertently making their practical and some times theoretical uses way more complicated.
      He is saying that because obviously one would be much more simpler for practical purposes but because of the lousy definition everything has become complicated.

  • @PeterBarnes2
    @PeterBarnes2 2 роки тому +2782

    The music adds a lot of value to the presentation here. It's cool that the topic is interesting enough, but having an inherently emotional component validate the audience's interest in a topic, in particular by matching a reasonable emotional understanding, kept me hooked in. Sort of like helping you suspend your disbelief, but without the disbelief because the thing in itself is science.

    • @KaidenBird
      @KaidenBird Рік тому +109

      It really feels like an unnamed goose from an unnamed game will come and steal the text on the screen... and maybe a bell

    • @vanleeuwenhoek
      @vanleeuwenhoek Рік тому +8

      Mr. Rogers' Neighborhood

    • @RomainQ
      @RomainQ Рік тому +40

      I thought it was a tad too loud, distracting me from the voice.

    • @angkhangnguyen5017
      @angkhangnguyen5017 Рік тому +8

      what's the piece's name

    • @albertnewton8296
      @albertnewton8296 Рік тому +25

      The random walk section was funny

  • @LordHonkInc
    @LordHonkInc Рік тому +395

    I remember the first time I thought about how strange unit cancellation is was when I learned that you can measure rainfall as either liters/meter², which is basically (0.1 meter)³/meter² or 1/1000ths of a meter, or 1 millimeter. So if you're expecting five millimeters of rain, that's just five liters per square meter of ground it's falling onto. Super obvious in retrospect, but it confused the heck out of me as a kid.

    • @Themoonisachees
      @Themoonisachees Рік тому +41

      which incidentally is how you can "easily" measure rainfall: put out a 1m^2 pan outside, and measure how high the water is in the pan at the end of rain. in your example, it would be 5 milimeters. in fact, because of unit cancellation, you can see that any pan would have 5 mm of water on average.

    • @Queue3612
      @Queue3612 Рік тому +13

      So thats what that means, i thought they left some sort of rain catcher out and measured how much it filled, which always confused me as to how small of a number it was

    • @onecommunistboi
      @onecommunistboi Рік тому +26

      ​@@Queue3612 That's exactly what you do, but you do not measure how much it fills but how *high*. That way you do not have to specify how big the container is.

    • @Daniel-yy3ty
      @Daniel-yy3ty Рік тому +10

      @@Themoonisachees damn. I went and wrote a comment saying that measuring height is container agnostic, only to read the last line when I was done >_>
      On the other hand, if you don't have a ruler but you have a scale the size of the container matters

    • @eldarliis8788
      @eldarliis8788 Рік тому +1

      Wow. I never thought about that.

  • @stickmanonastick6089
    @stickmanonastick6089 Рік тому +1683

    Can we appreciate the music in this video? Like, I've genuinely never seen someone have reactive, living music that plays with and compliments the video, rather than a few standard, unchanging backing tracks. It's so creative, I love it!

  • @Lellba47
    @Lellba47 8 місяців тому +1

    Can we talk about how the background music matched his speech intensity? That music - content synchronization is amazig! Congrats!!

  • @carrotspace8593
    @carrotspace8593 Рік тому +65

    Saying "this video is getting too long" is the UA-camr equivalent of the Teacher saying "That's outside the scope of this course"

    • @MakotoUeno
      @MakotoUeno 27 днів тому +1

      "Left as an exercise for the reader"

  • @crazyfunguy2107
    @crazyfunguy2107 Рік тому +888

    My AP physics teacher once told us a story about how one student would always write his test answers with ridiculous units just to make our teacher check the conversions to make sure he got it right.
    After beginning E&M and encountering the unit of "Ohm" for the first time, and him telling us "1/Ohm" was allowed to be written as "Mho", I got inspired to do something stupid just for fun.
    Long story short, after consulting the year's worth of notes to find the right connections, I found that all units can be written in terms of "Mho", with my favorite example being meters.
    c^2s/KgMhom=m, or Coulumbs squared seconds per Kilogram Mho Meter is equal to meters. The part about this both my friends and teacher thought was the most cursed, was the fact that meters appears its own definition of itself, which is just plain stupid.

    • @wayneyadams
      @wayneyadams Рік тому +101

      I never had a student do that, but my solution would be to call the student to my desk and have him explain what his unit meant and why he used it.

    • @gideonz74b
      @gideonz74b Рік тому +119

      1/Ohm is Siemens... But I like Mho better.

    • @bjornfeuerbacher5514
      @bjornfeuerbacher5514 Рік тому +80

      I. e. c²s/kgMho = m², i. e. m = c sqrt(s/kgMho). So you can actually avoid that the meter appears on both sides.

    • @denelson83
      @denelson83 Рік тому +40

      Nowadays the "mho" is known as the siemens.

    • @DimkaTsv
      @DimkaTsv Рік тому +36

      Let's be completely honest. Meter IS derivative of itself, which was tied to physical world occurrences to have ability of consistently reproducing value within laws of our universe.
      Any measurement value is such, because it relied on people defining it in the first place and there were no good ways to create absolute measurements back then.
      And, as meter is one of the key values, as everything can be tied to meter, it is reasonable to assume you can actually derive meter or second from combinations of basically any existing metric values as well.

  • @hadz8671
    @hadz8671 Рік тому +247

    A rule of thumb in surveying is that the elevation of a horizontal line of sight changes by 8 inches per mile-squared. This turns out to be the reciprocal of the diameter of Earth.

    • @flerfbuster7993
      @flerfbuster7993 Рік тому +33

      Oh I know that unit from back when I used to look at flat earth videos for fun lmao

    • @sternmg
      @sternmg Рік тому +34

      The elevation drop is pretty much "the same number" in SI, for once(!), namely ≈ 8 cm/km². That's because, in the spirit of this video, (1 mi² × cm)/(1 km² × inch) = 1.02 ≈ 1, dimensionless.

    • @xenontesla122
      @xenontesla122 Рік тому +2

      @@sternmgThat’s an amazing coincidence!

    • @KeithBoehler
      @KeithBoehler Рік тому

      @@flerfbuster7993 Is that where they get that from? Flat Earth is the only context I have ever heard that.

    • @swaree
      @swaree Рік тому +3

      Matt Parker did a video on that and he obtained the same number

  • @ChristianStout
    @ChristianStout 6 місяців тому +3

    "Dimensional Analysis" got me through several midterm exams, and I didn't even know what it was called!

  • @wwiwwin
    @wwiwwin Рік тому +506

    For my cursed unit I'm gonna go with a plain old meter... USED FOR TENSILE STRENGTH OF A MATERIAL. I don't remember the exact equation, but basically it answears the question of "how many meters of a wire made form a specific material would it take to deform plastically under it's own weight". It's quite nice for aerospace science and other science branches where weight is important, because it combines strength properties with density of a material.

    • @pushatsinfrared
      @pushatsinfrared Рік тому +74

      Strain = Change in length / length. Thanks A-Level Physics for ruining my life.

    • @Jaymac720
      @Jaymac720 Рік тому +16

      In every engineering setting I’ve encountered, we’ve used the Young’s Modulus, aka modulus of elasticity which is in units of stress, ie GPa or psi

    • @nanamacapagal8342
      @nanamacapagal8342 Рік тому +20

      ​@@pushatsinfrared strain is a dimensionless unit?

    • @iowasovereign2237
      @iowasovereign2237 Рік тому +11

      ​@@nanamacapagal8342 Yes, it is.

    • @pushatsinfrared
      @pushatsinfrared Рік тому +1

      @@nanamacapagal8342 Yes

  • @norgard7518
    @norgard7518 Рік тому +315

    POV: You are solving a physics problem and see GPa for the first time as a unit of tension

    • @comparatorclock
      @comparatorclock Рік тому +24

      I hate that I understand this joke.

    • @seesaw41
      @seesaw41 Рік тому +9

      Pascal as a tension unit? What?

    • @harrygenderson6847
      @harrygenderson6847 Рік тому +47

      Funny, in engineering I encountered GPa as a unit of stress 🙃

    • @Blackspidy619
      @Blackspidy619 Рік тому +19

      ​@@harrygenderson6847 man, thinking of my studies in engineering is putting me under 4.20 GPa

    • @carultch
      @carultch Рік тому +12

      @@seesaw41 A tensile stress unit. Usually it is MPa for stress, and GPa for Young's modulus, since that's the order of magnitude we generally expect for these concepts.

  • @gizmoguyar
    @gizmoguyar Рік тому +154

    "Volts per square root hertz" often pops up in audio amplifier specs. My understanding is that this is fairly common when dealing with power distributions. Same thing for shock and vibe testing where power spectral densities are specified in units of G^2/Hz as a function of Hz.

    • @alonewanderer4697
      @alonewanderer4697 Рік тому +10

      That unit is often used to work with thermal noise, so what I get from it is that sqrt(unit) is expected to show up whenever dealing with probabilities (such as noise or random walk in the video)

    • @Amir_404
      @Amir_404 Рік тому +9

      You beat me to it. Another cursed unit in the audio world is decibel. I mean think about it, it is a ratio so no unit isn't actually needed and we always use it in its deci(1/10th) form no matter the context; it is even common to see mdB used which is like saying microcentimeter. To make things worse, it is also common to reference off standards that are just assumed and not always agreed on. So in an audio system, you might have amp gain measured in db(log scaled input voltage/output voltage) feeding into a speaker which produces db/V(but in this case, db is the log scaled ratio of volume vs a standard sound[20 micropascals]) as well as a signal-to-nose-ratio(SNR) which is also measured in dB(log scaled signal/noise).
      It wouldn't be so cursed if people didn't insist on using dB as both a method of comparison(what it mathematically is) and a unit(by comparing against unofficial standards).

    • @thecodeking91
      @thecodeking91 Рік тому +3

      ​@@Amir_404 I want to measure using the unit bel now

    • @pairofrooks
      @pairofrooks Рік тому

      ​@@thecodeking91 ah, bells are a unit of house buying currency in Animal Crossing

  • @joparicutin
    @joparicutin 9 місяців тому +8

    This guy is a genius. He explains as good as it gets and meanwhile makes piano music that goes with the feeling of what he is saying. Subscribed.

  • @LMD100797
    @LMD100797 Рік тому +395

    My parents had to ask what comedy show I was watching when I kept laughing and wheezing at this video. The silence pause after you introduce each cursed unit is phenomenal, it's like you have to stop for a few seconds to massage your temples and be like 'ugh this again' before continuing. Instantly liked and subbed, I need more of this.

    • @mikez1328
      @mikez1328 Рік тому +22

      I think the music is also a big part in it. It fits every moment very well and amplifies the comedic value

    • @wayneyadams
      @wayneyadams Рік тому

      Unfortunately, too many people mistake this video for a serious science video. I'm giving him the benefit of the doubt in assuming he meant it to be humorous, because it is certainly not serious science.

  • @danielhidefjall5060
    @danielhidefjall5060 Рік тому +245

    I really love how the piano music follows the story! It adds so much!

  • @Epicman227
    @Epicman227 Рік тому +244

    Finally, an outlet for the weirdest unit I came across in college. Sheet resistance, the measurement of electrical resistance of thin films of uniform thickness, uses a unit that is so cursed it has stuck with me for nearly a decade at this point, that being "ohms per square". This unit is referred to as such because, while bulk resistivity is measured in ohm*meters, which is actually stated as ohm*m^2/m (ohm*area/length), you then ALSO divide it by its sheet thickness, giving you straight ohms again. However, to designate the maddening process you've been through, it is designated as "ohms per square". Link here for more reading: en.wikipedia.org/wiki/Sheet_resistance

    • @shehranazim4784
      @shehranazim4784 Рік тому +34

      I'm doing PEM fuel cell research and this unit was pissing me off to no end until I finally figured out wtf it means...

    • @apinkchameleon
      @apinkchameleon Рік тому +28

      I LOOKED AND IT'S AN ACTUAL SQUARE LMAO

    • @Murks33
      @Murks33 Рік тому +28

      Holy fuck there's Ω/ロ notation for it. (The square I used here is a Japanese letter I cba looking up a square symbol)

    • @rubenbohorquez5673
      @rubenbohorquez5673 Рік тому +20

      Electrical/electronic engineers are masters of using cursed units to designate stuff, at this point I've abandoned any hopes of ever doing a proper dimensional analysis and just look at the formula long enough until I'm convinced the units _probably_ line up lmao

    • @MrTiti
      @MrTiti Рік тому

      you have the same in the resistance of heat of materials, isntead of metres. its hard really hard but the same

  • @Azeria
    @Azeria Місяць тому +4

    We use miles per gallon in the UK but due to the unique way the Imperial system works, it’s not the same gallon as the Americans use. This means there are roughly 1.2 gallons per gallon.

    • @visionaervilz
      @visionaervilz Місяць тому +1

      the metric system - my beloved - has a stroke rn

  • @Darkstar2342
    @Darkstar2342 Рік тому +596

    After our physics teacher taught us about dimensional analysis in school, I never had to remember all these many complicated formulas again. It felt like enlightenment! I only remembered some basic formulas (F=m*a etc.) and in every test I simply derived the more complicated formulas again. It made everything so much easier!

    • @marmaladetoast2431
      @marmaladetoast2431 Рік тому +13

      same. i just follow the units

    • @RyanBrockey
      @RyanBrockey Рік тому +54

      This is what I teach to my students! Stop memorizing and just practice dimensional analysis until you're confident with it. It'll help you actually understand the relationships between the values.

    • @andreaspeters8602
      @andreaspeters8602 Рік тому +23

      @@marmaladetoast2431 me too. Although I sometimes forget dimensionless factors like 1/2 or 2Pi...

    • @nicholasreale7998
      @nicholasreale7998 Рік тому +25

      My friend in college forgot ohms law during an electronics test. He used a few of our phisics 2 formulas to derive it. I still don't know if he was right or just got lucky, the prof wrote a bunch of question marks then circled ohms law on the formula sheet. (Yes he was being completely dumb)

    • @NotGarbageLoops
      @NotGarbageLoops Рік тому

      @@nicholasreale7998 * physics

  • @murica7096
    @murica7096 Рік тому +165

    megaJansky per Steradian (10^-26W/m^2/Hz/sr) is a particularly cursed one I found while working on a power radiometer for radio astronomy. A jansky corresponds to the power per telescope dish area per hertz (flux density) and steradians the observed circular arc of the sky (rads^2)

    • @thenickstrikebetter
      @thenickstrikebetter Рік тому +13

      That does seem pretty Jansky

    • @stratosoundvox
      @stratosoundvox Рік тому +24

      None of these words sound real lmfao 😂

    • @OnboardG1
      @OnboardG1 Рік тому +11

      That’s the new Final Fantasy end boss’ final form.

    • @Smonserratm
      @Smonserratm Рік тому +2

      I had forgotten about the Jansky 💀

    • @theupson
      @theupson Рік тому +3

      "it's a perfectly cromulent word"

  • @monkeybusiness673
    @monkeybusiness673 Рік тому +176

    5:40 Oh yes! I have taught physical chemistry at the university for quite a while, and dimensional analysis got very important pretty often. Students would divide quantities instead of multiplying, getting completely nonsensical results; but just evaluating the units of everything can reveal the error. I am glad my physics teacher back in high school drummed this into us relentlessly.

    • @starfishsystems
      @starfishsystems 11 місяців тому +5

      It's a great sanity check on any sort of ad hoc calculation from physical measures in daily life.
      For example, my wife and I live off grid, and we're going to be upgrading our domestic propane system end to end in the coming year. We will have to rethink the consumption rate of our appliances and determine the capacity of lines to supply them.
      Even before we get to drawing up a consumption budget, it's very helpful to think about the units of measure. Appliances here may be rated in either peak BTU/hour or equivalent Litres/hour, or more rarely kJ/h or Watts, as well as thermal efficiency. Line capacity will be a function of cross section and pressure, also possibly taking length into account. Tankage is rated by either weight or volume.
      So already there's a comfortable sense that peak L/h can be the common currency in drafting the budget and sizing the lines and regulators and tanks. We haven't cited a single number, and yet we have a good preliminary grasp of what we'll be talking about when we get together with the gas fitter. No doubt there will be some regulatory constraints, the need to work within standard pipe sizes and whatnot, but we have an easy conceptual framework to make sense of all that.
      It may also be that the trades have a preference for converting directly between particular units. That can seem cryptic at first encounter, but already having a dimensional analysis makes it much easier to follow. In short, it's an extremely valuable form of literacy.

    • @lucykitsune4619
      @lucykitsune4619 8 місяців тому +2

      This is what I keep telling the second semesters I'm supervising for 2.5 ECTs: Solving this homework is simple:
      Step 1: Google every formula that might be relevant and note it down
      Step 2: Figure out how to get from what units you start with to where you want to end up
      Step 3: Calculate the unit to make sure you don't end up with a hamster whose mass is measured in km²/C
      Step 4: Calculate the order of magnitude and ask yourself "Does it make sense for this hamster to have a mass of a few 10^36kg?"
      Step 5 (optional): calculate the numeric value

    • @ptorq
      @ptorq 6 місяців тому +2

      It's amazing how many chemistry and physics problems can be reduced to just "dimensional analysis" and I used to try to impress that on the students in my chemistry recitation sections. What does the problem give you? Mass. What does it want you to find out? Volume. What do you know that relates mass to volume? Density. Boom, problem solved, the rest is just arithmetic.

    • @PlutoDarknight
      @PlutoDarknight 5 місяців тому

      ​@@lucykitsune4619 km²/C is a beautiful unit arrangement

    • @camahama70
      @camahama70 2 місяці тому +1

      As a physicist I passed physical chemistry thanks to knowing dimensional analysis (and rate equations). Still no idea of the chemistry.

  • @OptimusPhillip
    @OptimusPhillip Рік тому +5

    The 2 factors in quite simply. Basically, as the base of the triangle doubles, the vertex angle doubles as well. So a parsec is equivalent to the height of a triangle with a base of 2 au and a vertex angle of 2 arcseconds.

    • @DrDeuteron
      @DrDeuteron 6 місяців тому

      can't an AU cubed be converted into a year squared per (inverse, maybe) kilogram?

  • @ShamelessDuck
    @ShamelessDuck Рік тому +371

    The way you use music in this video (and I presume, in your other videos too) is perfect. Music is often used and made with a sort of standalone role, as if the whole purpose of it is to just listen to it. Sure, in movies, games, theatres and a lot of other form of art it plays a role of enchancing the emotion, but so rarely it is used in learning processes for that purpose. Using it like you did here is precisely what we often overlook in how we learn things. And it is crucial that you didn't just use some off the shelf piece but actually made it like a soundtrack for this particular video. This is just great and I appreciate it very much.

    • @benjamindesjarlais5713
      @benjamindesjarlais5713 Рік тому +21

      Especially when it got to the random walk bit and the music turned into stepwise staccato notes! It was all so good

    • @cblrtopas
      @cblrtopas Рік тому +4

      Yeah, how did he do that? Is he a pianist in addition to being an engineer.

    • @99jdave99
      @99jdave99 Рік тому +7

      I personally found it extremely distracting and pretty annoying. It's cool and all, but imo this is the kind of content I want to be focusing on the presenting material , and the music is consistently pulling me away from that (as I'm a musician so I'm subconsciously analysing it as it goes along, and each time it changes (which happens when the info is changing in this vid especially), my mind goes to that for a couple seconds; I have to either fight that impulse or rewind the video a lot as a result...).

    • @ShamelessDuck
      @ShamelessDuck Рік тому +8

      @@99jdave99 to each their own, I guess. As you are a professional musician and automatically focus on music more then the main content of the video I'd say it's more of a compulsion than a normal way to perceive such stuff. Some people of different professions can't de-focus from their field when they find it's footprints in other types of content, or when someone talks about something completely different. Don't take offense, I truly mean nothing bad, but there are a certain type of scientists, that can't help but tell you why and how some piece of science fiction is not realistic, and how they should've made it differently, as if they cannot enjoy sci-fi without constantly thinking about their work. It either means you are extremely passionate about your stuff, which is good and you'd most likely be able to give it more of your time than others, or there is a problem in how you view your profession. I don't know if it is a term in English, but in Russian we say it's a "professional deformation". And to be professionally deformed is to carry over some traits and particular views on things that are useful and ubiquitous in your field into other spheres of your life, where those traits are usually problematic to you or your surroundings.

  • @tijn0236
    @tijn0236 Рік тому +572

    I really like how you use music/sound to help the video more. Its not just background noise, it really fits

    • @DasIllu
      @DasIllu Рік тому +45

      flying over the comments i just thought "Uhm, Music divided by Sound, now thats weird..." until my brain broke out of this spiral of madness.

    • @BibleBlack667
      @BibleBlack667 Рік тому +4

      No. It's really fkn annoying.

    • @vedantsharma6206
      @vedantsharma6206 Рік тому +15

      @@BibleBlack667 to each their own

    • @BibleBlack667
      @BibleBlack667 Рік тому

      @@vedantsharma6206 Indeed

  • @ianbaram3043
    @ianbaram3043 Рік тому +93

    the most cursed units for me are inverse centimeters, which are used for a sort of frequency because they're the inverse of the wavelength, but they're called wavenumbers and have a factor of 2pi thrown in, and they're also used for energy because you can convert a wavenumber of light to an energy in joules or eV pretty easily, and then physical chemists get excited and start just doing literally every single unit in inverse centimeters

    • @kantinbluck
      @kantinbluck Рік тому +11

      Spectroscopists are a plague. I had to recall that RT thermal energy was roughly 200 cm-1 and that it corresponded to the much nicer 25 meV to remember the "conversion"

    • @kzalesak4
      @kzalesak4 Рік тому

      I wholeheartedly agree. Inverse centimeters are absolutely terrible. Luckily for me, nm is the standard for the near-IR so we get to work with beauties

    • @jeffreysoreff9588
      @jeffreysoreff9588 Рік тому

      and it is a _named_ unit. 1 cm^-1 is a kaiser. Visible is from 13 kilokaisers to 26 kilokaisers. Just think of 10kK as an inverse micron...

  • @mohammadjadallah9813
    @mohammadjadallah9813 5 місяців тому

    I love how this video compartmentalizes math and science by going to the core of it all which is units and it talks about the weird cases. For someone that struggles with science and units in general, this video can sure help them out by letting them know some units are for sure "weirder/cursed" than others and yet they still, of course, make sense.
    Seriously this content is helpful to many!!!!

  • @legoneurt
    @legoneurt Рік тому +185

    Weirdest unit I encountered was the Fracture toughness constant, which has [MPa m^0.5] as units

    • @adriathan1994
      @adriathan1994 Рік тому +26

      And at the same time [N m^-1.5] which is so cursed when you convert some millimeters to meters for the stress.

    • @jonathanatherton9628
      @jonathanatherton9628 Рік тому +3

      I used to despise the entire field of Fracture Mechanics because of MPa m^0.5… Until I had to start playing with T m^0.5 (Tesla root metres) in my Honours thesis…

  • @Sigrund
    @Sigrund Рік тому +207

    The unit barn (b) which is 10^-28m^2, which is still used as a unit for a cross sectional area of a target, usually used in the creation of new elements where barn came from the phrase "couldn't hit the broad side of a barn"

    • @L1ama
      @L1ama Рік тому +70

      The more cursed version of this is that particle accelerator data collection is measured in inverse femtobarns

    • @HouseBricksDoor187
      @HouseBricksDoor187 Рік тому +20

      barn/b is just arn

    • @pr0hobo
      @pr0hobo Рік тому +34

      there's also a BarnMegaparsec which is a unit of volume. its the volume of a prism with base area of one barn and height of one megaparsec, used to measure the volume of space that a particle of cosmic radiation traverses in its long travels.

    • @jorandax9059
      @jorandax9059 Рік тому +15

      @@pr0hobo It's about 3.08 milliliters.

    • @logion567
      @logion567 Рік тому +2

      physicists sometimes takes jokes a bit too far lmao

  • @mario7501
    @mario7501 Рік тому +174

    If you could only remember one thing from high school physics, it should be dimensional analysis. It's gonna be useful for the rest of your life.

    • @tytrater2136
      @tytrater2136 Рік тому +15

      So many little problems in life can be solved with a dimensional analysis exercise in like 10seconds. But when you do that people think you’re a god damn wizard or something

    • @ggkol8745
      @ggkol8745 Рік тому +2

      yeah we never had that. Maybe that's why I like learning about this stuff, because I hated most everything else in school and this didn't get ruined

    • @V-for-Vendetta01
      @V-for-Vendetta01 Рік тому

      facts

    • @Cerafem
      @Cerafem Рік тому +1

      The best use of dimensional analysis imo is to find out that you modeling the whole thing wrong, especially when working with imperial vs SI distances raised to powers, etc.

    • @Big_Red1
      @Big_Red1 Рік тому

      My highschool physics and chem teachers 100% drilled dimensional analysis into our heads. I'm pretty sure they colluded on that fact. Also, for AP chem, the teacher would randomly ask students question about ions if he saw you in the hall and tally the total right/wrong answers to buff or nerf his curve for the final exam 🤣. People took it very seriously as his class was super hard.

  • @alexandergrozz9418
    @alexandergrozz9418 2 місяці тому +1

    This is absolutely fantastic. I love the dynamic music. It reminds me of the excellent video essay on the music of Wii tanks (I know it sounds silly but trust me, this is a massive compliment). The music was certainly custom made for the video, and it's great. Subscriber well earned!

  • @BalladeN4
    @BalladeN4 Рік тому +164

    As someone who majored in both engineering and piano as an undergrad, I absolutely love this backing track!

  • @julius2175
    @julius2175 Рік тому +336

    In my photovoltaics lecture I really hated kWh/a (Kilowatt hours per year). The justification, which kinda makes sense, is, that you can see from the unit, that the value you are looking at signifies energy generated (or consumed) averaged over a whole year (with its different seasons etc.). Still, it seems stupid to me to have a time unit divided by a time unit.

    • @suomeaboo
      @suomeaboo Рік тому +31

      That's even worse than kWh (energy * time^-1 * time). This one's energy * time^-1 * time * time^-1.

    • @comparatorclock
      @comparatorclock Рік тому +34

      @@suomeaboo sooo.... J/s?
      wait that actually makes perfect contextual sense...

    • @kofer99
      @kofer99 Рік тому +12

      @@suomeaboo well the unit makes sense culturally, we get our electricity bill yearly ( more or less you pay some estimate per quarter but it is always corrected at the end so doesnt matter), now on that bill it states you used e.g. 2500 kWh, therefore for a solar panel it makes sense to know how many kWh it generates per year to quickly figure out how much money you would save per year and if it is worth it. (of course for solar panels there are other factors and costs like batteries and stuff since you probably arent using all the energy during the day and so on)

    • @thisfr0
      @thisfr0 Рік тому +5

      The EU energy efficiency labels (for some products, like displays) are even weirder: the average consumption is stated as xyz kWh per 1000h. Weird way to write it consumes xyz watts...

    • @vylbird8014
      @vylbird8014 Рік тому +3

      The reason for kWh at all is because it makes accounting easier. Take the wattage in KW, multiply by the price of electricity, you have your hourly cost.

  • @ItsMoorbinTime
    @ItsMoorbinTime Рік тому +234

    I just finished my first year in a university Particle Physics degree and I have a great addition: magnitude - a measure of brightness . This comment will only discuss apparent magnitude (so distance between observer and body can vary), absolute magnitude (M) is a measure of apparent magnitude when the body is at exactly 10pc away.
    The Greeks originally classed stars in 6 magnitudes, the brightest were m=1 and the dimmest were m=6. They aimed for each grade in magnitude to be merely twice as bright as the previous grade. Nowadays we've quantified magnitude into the formula: m = -2.5 log(F) + c. F is the flux (W m^-2) at the star's surface and c is complicated... The result of this modern equation is that if star A has magnitude 7 and star B has magnitude 6, that means star A is 2.5 times dimmer than star B.
    However, since we have more advanced apparatus for observing the sky, more stars have been discovered which are brighter or dimmer than the original 6 grade system (m = 1 to 6). This leads to very bright stars having a magnitude of 0 or even negative numbers! Alternatively we can have very dim bodies with magnitudes near 20.
    To make all of this worse, you need to consider that to observe something, you are detecting wavelengths of light that body is emitting. With this knowledge, let's discuss what c is in the magnitude equation. Consider some bands of light: U, B, V, R, and I. Ultraviolet, blue, visible, red, infrared. Different bodies may be brighter in some bands than others e.g. a star may emit more infrared light and thus have a smaller magnitude in the I band than the V band. The variable 'c' in the magnitude equation must be chosen such that it is m=0 across all bands. For most of my exam papers, the star chosen was Vega. Once you have chosen a reference magnitude/body, all subsequent calculations must use the same c if you want to compare any of them to each other. The result is an incredibly cursed, negative, non-linear, dimensionless system of measuring brightness. Could we not just have used the candela or something?

    • @davilimalol4612
      @davilimalol4612 Рік тому +32

      The funniest part of this whole story is that this convoluted system was made exclusively to be convertible to a brightness ranking from antiquity, which is so far removed from us that modern astronomers probably don't even know it other than as some thing that used to exist.
      (Disclaimer, I don't have a particle physics degree or much knowledge of luminosity related stuff lol)
      If we wanted to make a measure related to how much light you would detect at some distance maybe we could use photons per square meter at 10 parsecs or whatever distance of the star. After looking up how many photons hit one square meter of the Earth's surface which is apparently 3.8*(10^21) photons, I divided by 4.25 trillion (10 parsecs' worth of AU squared) to get 900 million of the Sun's photons inciting on a square meter sheet at a 10 parsec distance from the Sun in any given second, or an absolute magnitude for the sun of log 8.95 photons/m^2, and in my hypotherical scale stars would range from around magnitude log 6 (1000 times dimmer than sun, lowest bolometric luminosity I found for red dwarfs) to mag log 15,5 photons/m^2. (~5 million times brighter). Fairly complicated explanation but the photon is an absolute unit, so at least that much isn't arbitrary.
      Edit: After looking it up, it appears that the original figure of 3.85×10²¹ photons I encountered comes from people calculating how many photons of green light (which is what light the sun emits the most) would equal the 1400 joules of energy per second that a square meter of ground receives in the Earth, so my scale is in relation to 500/550 nanometer wavelength photons in specific, which keeps in a good deal of cursed-ness is kept in the details of my hypothetical brightness scale as that would mean my scale which is supposed to be for absolute and relative magnitude apparently has a bolometric correction effect built into it because it's measured in terms of Sun-like green photons.

    • @frogflint4371
      @frogflint4371 Рік тому +18

      and you didn't even mention that that flux is subject to another weird unit cancellation: W m^-2 = kg s^-3 !

    • @aloysiuskurnia7643
      @aloysiuskurnia7643 Рік тому +13

      ​@@frogflint4371 that unit must have a very ugly interpretation, if it has one at all lmao

    • @divyanshsingh1078
      @divyanshsingh1078 Рік тому

      clear your doubts and read it again, you must have failed

    • @theupson
      @theupson Рік тому +1

      @@frogflint4371 that one is hilarious. it does kind of illustrate the dishonesty of these tricks though. a joule of thermal energy per square meter of pizza per second is coherent. converting a joule of thermal energy to a kg of... something times a square meter of something else per square second is dodgy as hell, and canceling a square meter of undefined something-else with a square meter of pizza is just outright fraud.

  • @SF-fb6lv
    @SF-fb6lv 9 місяців тому +1

    That was SUCH a well-put-together presentation in all ways! My favorite cursed unit is Specific impulse, Isp. Essentially a whole bunch of units get cancelled out until the final dimension is 'seconds'. That's it 'seconds'. Super unintuitive. Sometimes its better to NOT cancel everything out...

  • @CrunchRosey
    @CrunchRosey Рік тому +512

    In my nuclear education (I promise this isnt that boring) we had to do a lot of unit conversion, and to teach us how to do them well we had a sheet of obscure units broken down into their metric derivatives. Basically on that sheet was the "Miner's inch" and it became a meme between the boys because, y'know, yeah... If you were curious, its a measurement of volume/time.

    • @thebiggaklipa
      @thebiggaklipa Рік тому +19

      How much a man can........ If you catch my drift😂

    • @retiredmushroom
      @retiredmushroom 11 місяців тому +13

      ​@@thebiggaklipa It'd be crazy if it also depended on the mass of what ever caused the 'enlargement' too.

    • @caseyriley1014
      @caseyriley1014 10 місяців тому +62

      "I promise this isn't boring"... they say to all of us nerds who just watched a 20 minute math video for humor

  • @302ci1968
    @302ci1968 Рік тому +77

    My father used to say: "always check the units". It helped me being a bit above average in my physics courses at university. Keeping the units in every step helped me not to be too lost in my own calculations.
    Your examples are fantastic, thx !

    • @MogR91
      @MogR91 11 місяців тому +3

      One of my best teacher got mad when he realized we weren't taught to think in units when solving equations "It makes it so easy!" he yelled. I've been checking my units all the time since then but gotta admit that getting in the game late can be veeeery confusing like when juggling with angular speed in rad/s... o.O and finding out that basically radians aren't real... or having to prove to myself in a middle of an exam that a Joule is a W/s so a Watt is a kg.m^2/s... Not the most efficient way to solve something I should have prepared instead of playing skyrim

    • @dielaughing73
      @dielaughing73 11 місяців тому +5

      Yep, retain units throughout and always write conversion factors out as longhand fractions like in Randall's example at the beginning. Can't go wrong then.
      I mean you can, you can always go wrong, but at least it won't be because you didn't write down units.

    • @vdd1001
      @vdd1001 5 місяців тому

      Conversion factors come in clutch, I write them out always, otherwise I make some dumb mistake like saying 1 day is 3600 seconds and the entire calculation from then on is wrong

  • @radioaktivman8661
    @radioaktivman8661 Рік тому +409

    my math teacher once said: "science is just guessing, just really really smart guessing". and its the most funny, yet accurate thing ive ever heard from any teacher

    • @bipl8989
      @bipl8989 Рік тому +4

      You got half right. Guessing is the hypothisis. Proving it is science.

    • @arcuz7862
      @arcuz7862 Рік тому +30

      @@bipl8989 You got it wrong. Doing stupid shit is stupid shit. Once you start writing it down it becomes science. Simple.

    • @pendarischneider
      @pendarischneider Рік тому +11

      @@bipl8989 Half right (so maybe we are down to quarter right now?) Yes smart^2 Guessing is the hypothesis, Science is proving it wrong, and Confidence in the hypothesis increases the more times competent people fail to prove it wrong. Only in mathematics can we prove the hypothesis (aka assertion/conjecture) is correct.

    • @Tower_Of_Chaos
      @Tower_Of_Chaos 11 місяців тому +4

      ​@user-xh9pt8zu2l
      No, the original commenter is correct. You see nothing can really be proved regarding the really world since there is always some uncertainty in the accuracy of our observations. Therefore science isn't about proving things exactly, just finding patterns that match reality very well. You can see this in how new developments in science often overwrite previous theories, such as newtonian mechanics vs gr

    • @viliml2763
      @viliml2763 11 місяців тому +3

      @@bipl8989 You can't prove anything in science, only disprove

  • @USSWisconsin
    @USSWisconsin Місяць тому +2

    1:01 and here in canada it goes between miles/gallon and L/100KM depending on who you ask and where in the country you are

  • @waynebutane1338
    @waynebutane1338 Рік тому +196

    I had a similar experience when we tried out ChatGPT 4 and asked it to calculate something for us. It kept referring to pressure as "meters", but the answer it got was correct. When we asked it why it uses meters are pressure, it said that it uses "meters of water" as a pressure unit...

    • @maartenbeute6742
      @maartenbeute6742 Рік тому +44

      reminds me of mmHg which is a written abbreviation for millimetres of mercury: a measurement used to record blood pressure:

    • @jeremyburby7132
      @jeremyburby7132 Рік тому +14

      If I remember right, you have a U shaped tube that's closed on one end, and open on the other, and you apply the pressure to the open end, and the pressure you measure is how far the water level on the closed end moves. We used inH2O as units in one of my labs

    • @theexchipmunk
      @theexchipmunk Рік тому +8

      But that unit in that context would be incomplete. It would need to be water colum in meters under earth gravity. Because water pressure dpening on depth is connected to the gravity of the object it´s on, or in short, the weight of it.

    • @MrSamsamsammy
      @MrSamsamsammy Рік тому +14

      That is absolutely a unit! I work with a lot of natural gas generators for my job, and frequently take pressure readings. Natural gas runs in most houses ~ 1/4 of a PSI, or .0172 bar. To be more precise, we use the unit “inches of water column”
      It’s amazing you can get enough power to run 20 houses at once with less pressure than is at the bottom of a glass of water

    • @TheNheg66
      @TheNheg66 Рік тому +7

      Not that strange tbh. I see pressure measured as height of a fluid column pretty regularly

  • @Acre00
    @Acre00 Рік тому +81

    I remember in my engineering class we had an answer to a problem measured in "dozens of slugs per day", slug being the SAE unit of mass. That was an interesting result

    • @olmostgudinaf8100
      @olmostgudinaf8100 Рік тому +25

      The old school hackers will be familiar with the "jargon file" (you can still look it up on the internet). It refers to, amongst others, deliberately arcane units like nanoparsec per milliforthnight, roughly an inch per second.

    • @PlutoDarknight
      @PlutoDarknight Рік тому

      ​@@olmostgudinaf8100Or Barn-Megaparsec, which is a volume of roughly ⅔ of a teaspoon

    • @dillonryan285
      @dillonryan285 Рік тому +6

      It gets weirder when you realize that a dozen slugs is called a blob. So your answer was in units blobs per day.

    • @Acre00
      @Acre00 Рік тому +1

      @@dillonryan285 That is awesome. I don't even think our engineering teacher knew that

  • @ReySilverskin
    @ReySilverskin Рік тому +440

    One thing that I always chuckle at is that torque can theoretically be measured in joules.

    • @MogR91
      @MogR91 11 місяців тому

      I hate you

    • @MogR91
      @MogR91 11 місяців тому

      @@mguddeti Except Torque isn't a form of work? Is It? It can't be... "Work" is Energy, It's the result of the action of a force inducing deplacement. The units are the same but the thing they measure isn't.
      For Work we consider the distance travelled by the object because of the force applied to it, If the object doesn't move It didn't recieve Energy. (unless it deforms or warms up or emit light or wathever ^^')
      But for Torque, we consider the distance from the force application point to the center of rotation of the object. Torque exists without displacement. you can apply a Torque without spending energy if nothing happens to the object.
      And this "rotational Inertia" equation is kinda misnamed because it's simply newton's second law F=ma applied to rotation it doesn't measure rotational energy. "Rotational kinetic Energy" does E = 1/2 * I * w^2 but Yes, this again has the same unit, Joules xD
      @ReySilverskin you truly are evil hahaha
      I'll keep using N.m for torque

    • @mguddeti
      @mguddeti 11 місяців тому +82

      Here’s a proof for those wondering:
      Torque => F * d => ((kg * m) / s^2) * m => (kg * m^2) / s^2 = Joules.
      Here’s the proof using the rotational inertia equation:
      Torque => Ia => (kg * m^2) (rad / s^2) => radians are unit-less so => (kg * m^2) / s^2 = Joules
      However, even though it’s possible to measure torque in joules, it doesn’t have the same intuition as energy, as torque is just the rotational version of force, which just by chance has the same units as energy, but it shouldn’t be thought of as that.

    • @Georgewilliamherbert
      @Georgewilliamherbert 11 місяців тому

      @@mguddeti Rotation energy is another form of energy, as with kinetic or potential energy etc…
      For extra fun, rotate or move fast enough that you need the lorenz transforms…

    • @Tower_Of_Chaos
      @Tower_Of_Chaos 11 місяців тому +19

      I mean most of those implication arrows (=>) should just be equal signs. "Implies" or "=>" is used when you have two statements, such as x = y => x+1 = y+1 rather something like 1 => 2-1

  • @noahduncan4095
    @noahduncan4095 8 місяців тому +3

    I love how the music during the random walk part feels like a random walk itself

  • @rafaelvaliati3728
    @rafaelvaliati3728 Рік тому +97

    There are a few papers on the fractal nature of some day-to-day objects, like paper balls. We use this experiment for our undergrad students to learn log-log linearization. What is interesting is that you find the mass is proportional to the diameter^n, where n is a real number between 2 and 3 for paper balls (usually around 2.3). Then, since M = k*D^2.3, the unit for k is kg/m^2.3, which is some sort of "fractal density".

    • @lunam7249
      @lunam7249 Рік тому +1

      🥇👏👏🥇👏❤️

    • @noatrope
      @noatrope Рік тому

      Is that related to the Hausdorf dimension?

    • @Xnoob545
      @Xnoob545 Рік тому +7

      So, paper balls are 2.3dimensional?

    • @lunam7249
      @lunam7249 Рік тому +4

      @@Xnoob545 yep!, your grade for the class is A+

    • @lqr824
      @lqr824 Рік тому

      @@Xnoob545 not quite. If you find that MODELLING them as a fractal gives you some insight, of course you can do it, but the fractal dimension for a "crumpled" 2D object (theoretical sheet of paper) will be greater than 2 but less than 3. (It approaches 3 as the paper ball approaches being a solid ball.) We can also see that if you have a line that is a fractal. Lines are 1-dimensional but once you make a fractal line it kind of starts to fill up area. The furrier and crazier it gets, the more area it fills up, and we say its dimension is increasing. A maximally furry fractal line would approach being a solid sheet of something, so approaches being 2D.

  • @Morgernstein
    @Morgernstein Рік тому +42

    I like slugs, "A slug is defined as a mass that is accelerated by 1 ft/s2 when a net force of one pound (lbf) is exerted on it." I just remember opening up an old textbook and it talked about how the some 60's jet weighed about 900 slugs and being a little sleep deprived I just burst out laughing on the quietest floor of the library.

    • @darioabbece3948
      @darioabbece3948 Рік тому

      Isn't a slug a generalization of g?

    • @pjl22222
      @pjl22222 Рік тому +5

      No. A slug is the imperial unit of mass. It is "equivalent" to a kg since they are both units of mass in their respective systems. The pound is technically a unit of force but it's also used as a unit of mass (lbf vs. lbm) since people who work in imperial units tend not to be quite so pedantic. But then again metric people tend to use kg as a unit of force as well as a unit of mass. After all, when is the last time you heard someone give their weight in Newtons?
      A mass of 1 slug weighs g pounds (32.2 pounds) just like a mass of 1 kg weighs g Newtons (9.81 Newtons) on Earth at sea level.

    • @bp495599
      @bp495599 Рік тому +1

      My favorite unit is horse power hour, but slugs are cool too

    • @Barnaclebeard
      @Barnaclebeard Рік тому

      @@pjl22222 People don't measure their weight in Newtons because it changes constantly depending on your velocity and frame of reference. They just say weight when they mean mass. But in certain situations where the distinction matters (eg, climbing) people really do measure their actual moment to moment weight in a system in N and kN.

    • @pjl22222
      @pjl22222 Рік тому +1

      @@Barnaclebeard Unless you're leaving the surface of the Earth your weight isn't changing more than a miniscule amount that is probably less than the precision of the scale being used to measure it.

  • @coolbrotherf127
    @coolbrotherf127 Рік тому +95

    I used to work installing optical fiber and not only do the cables have impurities, they also end up being installed in all kinds of crazy ways with a lot of bends which also scatters light. Fiber being as fast and consistent as it is even with all those things working against it is really cool.

  • @osmeridium
    @osmeridium 9 місяців тому +1

    Great channel! 3B1B vibes. Really cool improvisation, man. Hugely underappreciated, I'm sure.

  • @CAAStudios
    @CAAStudios Рік тому +139

    The most cursed unit I've ever had to work with is Rankine, where some very old documentation on refrigeration used Rankine for all of it's temperature references. Rankine is the Kelvin of the Fahrenheit scale. R°=F°+459 and some change.

    • @Alpheamus
      @Alpheamus Рік тому +3

      That's super cool :)

    • @nekomi_ch
      @nekomi_ch Рік тому +3

      Wait what there is K for F?

    • @naverilllang
      @naverilllang Рік тому +21

      personally I think we should call this scale "Melvin"

    • @maxhorsford7800
      @maxhorsford7800 Рік тому +4

      @@nekomi_chsure, why not? It wouldn’t be as useful cause Fahrenheit isn’t used in science much but the same rules would apply to F as C

    • @r0cketplumber
      @r0cketplumber 11 місяців тому +5

      I have to deal with legacy NASA documents (and engineers) for launch vehicle certification. Rankine rankles.

  • @Mew__
    @Mew__ Рік тому +37

    Electron-volt really does deserve a spot here.

    • @eekee6034
      @eekee6034 Рік тому +7

      Especially as you can convert any unit to eV and eV to any unit. That was proven in the 00s. The immediate result was half the science and engineering students started converting everything to furlongs per fortnight.

    • @ExodiumTM
      @ExodiumTM Рік тому +2

      ​@@eekee6034 what do you mean "any unit"?

    • @eekee6034
      @eekee6034 Рік тому

      @@ExodiumTM any unit of measurement. grams, metres, kelvin, seconds, metres per second, any others I can't remember just now, and any unit that can be converted into these.

    • @ExodiumTM
      @ExodiumTM Рік тому +1

      @@eekee6034 I searched it and didn't get any relevant results?

    • @eekee6034
      @eekee6034 Рік тому

      @@ExodiumTM Search results can be pretty bad these days, especially for uncommon knowledge which sounds like commonly known things, if that makes sense. I'm not sure what tips to give. I can't find anything myself today, but I'm too tired to look properly.

  • @JoelDowdell
    @JoelDowdell Рік тому +156

    Not the most cursed unit I've encountered, but strain is worth mentioning.
    Put simply, if you put a material under tension (or compression) it will expand (or contract). For the tension case, the ratio of the material's new length to its old length will usually be some number very close to, but slightly larger than 1. If we subtract 1 from this number, we have a measure that starts at 0 when you apply no force and increases linearly for a little while (for "normal" materials). This measure is strain. If you consider the units, you have length/length, which is unitless, so subtracting 1 from it isn't nearly as insane as it might look. But then you find that it's not uncommon to report strain in units of mm/mm or inch/inch.
    I'm reminded of radians, which are technically unitless, but in practice are written as "rad", because it makes the bookkeeping easier.

    • @maartenbeute6742
      @maartenbeute6742 Рік тому +6

      i thought radians were also technically distance/distance, since its defenition is the length of a part of the circumference of a circle devided by the radius of the circle.
      i know you would never write an angle like m/m or smth, but i thought it was funny that both of your mentioned units could be defined by this m/m

    • @Crazy_Diamond_75
      @Crazy_Diamond_75 Рік тому +4

      They're only unitless if you're only considering fundamentals as "true" units.

    • @falkez1514
      @falkez1514 Рік тому +3

      the torque distribution unit is pretty cursed as well: Nm/m
      this type of stuff i usually just dont mind understanding because its just a matter of keeping things tight lol

    • @taiyoqun
      @taiyoqun Рік тому +2

      "How many mm/mm?" Is a question that could kill a robot honestly

  • @MarcCastellsBallesta
    @MarcCastellsBallesta 2 місяці тому

    As a physicist, this video was a pleasure to watch.
    Cursed units? Pressure. Pascals, Torr, bar, psi, etc. Well, maybe the conversion to each other is what's cursed.
    A couple of things to mention: some fluid dynamics parameters have funny dimensional units. And the second one had a chapter/lecture on its own when I did a MSc in mathematical modelling: nondimensionalization. Even the teacher had issues with the name. It was like a game of moving around constants and variables until having an equation without dimensions.
    Thanks for making this video. It was beautiful.

  • @nightlord531
    @nightlord531 Рік тому +194

    One cursed unit I hated at uni was the barrer, often used in membrane engineering. As defined, 1 barrer = 10^-10 * [( cm_STP^3 * cm ) / ( cm^2 * s * cmHg )]. When the units are so awful, we have to invent new ones to try and handle it!

    • @tykjpelk
      @tykjpelk Рік тому +22

      cmHg? Not mmHg like normal people? Or mmmHg like vacuum people?

    • @FelineBlender
      @FelineBlender Рік тому +47

      ​@@tykjpelkit's the alto clef of barometry

    • @rykehuss3435
      @rykehuss3435 Рік тому +5

      @@FelineBlender we dont like the alto clef

    • @klaasbil8459
      @klaasbil8459 Рік тому +2

      Similar to permeability (of rock samples, for instance) which is measured in m^2 when expressed in SI units. Since the values in m^2 are usually unwieldingly small, the Darcy or even millidarcy is more often used, one Darcy being about equal to 10^12 m2

    • @funtitan4378
      @funtitan4378 Рік тому +5

      @@klaasbil8459 and even smaller than the Darcy is the Barn, clocking in at about 100 square femtometers. It’s used in nuclear chemistry to measure the cross section of individual nuclei. And it’s not even a physical cross section, it’s a probability measurement!

  • @Thetarget1
    @Thetarget1 Рік тому +154

    I did my master´s in theoretical physics, so for the last few years I mostly used natural units, to the degree where you tend to forget that there even are units involved. But if you think about it, a unit system where hbar = c = 1 is incredibly cursed if you try to convert back to SI (but nobody ever does that).

    • @eddyunterseher4430
      @eddyunterseher4430 Рік тому +9

      Currently I am writing a paper about that because I love the cursed physics and math behind such stuff

    • @doctorbobstone
      @doctorbobstone Рік тому +5

      Even though I understand why people would want to use natural units (or other units which simplify their customary work) I find dimensional analysis so useful for ensuring you get the right answer that a system where you tend to forget the units seems like it would make certain types of mistakes way easier to make.
      Some engineers I've worked with tend to do similar things where they routinely normalize their equations to make things unitless or they just ignore units while calculating and attach them at the end. It also feels similarly error prone.

    • @simonmultiverse6349
      @simonmultiverse6349 Рік тому

      I had a crazy teacher who wore dark glasses (tim buc 3) luckily I was still able to finish my doctorate in rocket science, meaning jet engine internals: thermodynamics and fluid dynamics.

    • @imbaby5499
      @imbaby5499 Рік тому +1

      I remember a funny answer on physics stack exchange about the conversion back to SI units which described how god might convey to Noah how much wood to buy for his ark but I can't find the link unfortunately.

    • @JohnDlugosz
      @JohnDlugosz Рік тому +1

      @@doctorbobstone Yes, you want units to help you verify your algebra, even when you don't actually have units in this formal system; e.g. radians. In one of the Lockdown courses (I don't recall if it was Brian Green or Sean Carroll) he get to Natural Units, and then keeps going to Planck Units. Just like Time is equal to Space (length) once you eliminate the conversion factor of c, you can remove units entirely, as everything is either equivalent to Energy or inverse Energy.

  • @arthurhubert4849
    @arthurhubert4849 Рік тому +167

    If you want complicated SI unit, most of the unit in electronics are absolutely horrible, like the Farad (for capacity of condensator) : F = 1 m−2. kg−1. s4. A2

    • @rosiefay7283
      @rosiefay7283 Рік тому +12

      But whatever units you have, the dimensional analysis is the same, so if you think the farad's horrible, that's not SI's fault.

    • @arthurhubert4849
      @arthurhubert4849 Рік тому +2

      @@rosiefay7283 I m not sure of what you mean exactly

    • @markmarketing7365
      @markmarketing7365 Рік тому +14

      And then there's V/sqrt(Hz) for noise levels (???)

    • @transimpedance
      @transimpedance Рік тому +6

      @@markmarketing7365 Noise units are definitely cursed. All consequences of defining noise as the “power” in a 1 hertz bandwidth. The worst is it’s not a real power, but the power spectral density of the noise signal, so it’s V^2 / Hertz. Oh you want a unit that lets you compare amplifiers? Ok plot V/sqrt(Hz), divide it by the gain A(f), integrate over all frequency, and then turn it into the RMS voltage of a fictitious input voltage. 🎉

    • @ahdog8
      @ahdog8 Рік тому +4

      i think the idea of "capacitance" is just so abstract that the units can't help but be ugly

  • @jdf17
    @jdf17 Рік тому +2

    While working in a lab that did contact testing, we would frequently do thermal conductivity testing. W/mK is nice and easy. But every so often, we'd get someone who wanted imperial units... usually if they wanted R-value for an insulation. The imperial units for thermal conductivity are BTU*inch/hr*ft2*F and it always drove me nuts to see two different length units in that trainwreck.

  • @juliannim6843
    @juliannim6843 Рік тому +16

    Once worked with "millitmeters of mercury minuts per liter", now that is one cursed unit!

  • @yoavboaz1078
    @yoavboaz1078 Рік тому +334

    Ever since I heard about about kWh for the first time i was obsessed with it since I found it to be so dumb. I didn't find anyone else getting annoyed by it until now. Thank you for finally discussing how absurd it is

    • @eckligt
      @eckligt Рік тому

      Consider also the "kWh/a" (a=annum=year) that others have mentioned or "TWh per annum" that I described in my comment. It's a total farce, and harmful.

    • @fisk7aal
      @fisk7aal Рік тому +19

      Thank God I have a friend in a random internet stranger. I always said that it is stupid to first you divide by time only to multiply with time later. Did we not learn to shorten down fractions? How can a math / phys teacher ever accept an answer given in kWh?!

    • @TheMonkeystick
      @TheMonkeystick Рік тому +44

      From an engineering perspective, a power plant is more concerned about average power consumption over time. If a factory needs to run 8 hours a day and consumes 1600 kWh, then it will consume an average of 200KW of a plant's bandwidth. These conversions are of course doable in Joules, but it's a lot cleaner and easier to reason with if you just stick to kWh rather than converting to and from Joules all the time.
      It's also why lightyears/light-seconds is a thing: (300e8 m/s) * years is the same as 9,46e15 m, but in astronomy it's convenient to have a measure based on relativistic speed since it's a commonly desired conversion.
      tl; dr it's a convention borne from conversion convenience

    • @Flutesrock8900
      @Flutesrock8900 Рік тому +6

      I have a Masters degree in physics and absolutely detest that unit. I also teach high-school physics and it is quite difficult to help students understand it, which I honestly cannot fault them for.

    • @Murzac
      @Murzac Рік тому +39

      Really if you think about it, there's a very simple reason why things have ended up this way. It's the one variable that doesn't comply with the SI prefixes in the whole thing: time. That's it. 1 Watt for 1 second is exactly 1 Joule. 1000 Watts for 1000 seconds is exactly 1 MJ. But the issue is that 1000 seconds is a completely arbitrary 16 minutes and 40 seconds. Instead we use 1 hour, which is 3,600 seconds, which is why we end up with the 3.6 factor from kWh to MJ.
      It's all because we never got around to metrifying time. Which tbh is understandable because our circadian rhythm and the sun doesn't give a shit if 86.4 ks is an awkward amount of time.
      Moral of the story: mixing metric units with non-metric units is cursed.

  • @grillmaster95
    @grillmaster95 Рік тому +23

    As a meteorologist, units of reflectance are a little funny, mm^6/m^3. It takes on a log relation whenever people use it so it comes out as dbZ, where db is decibels and Z is the reflectivity factor.

  • @masterjojo78
    @masterjojo78 6 місяців тому +1

    I had once a practical course during my masters degree where we did compare to calculation methods. One was straightforward without any major problems. The other methods somehow involved a change in exponent during evaluation, leading to a parameter to the power of 0.8-0.9. This results than also in the unit of this parameter to have the same changing exponent.
    As I found out, this blew not only my mind, but also the mind of the person holding the practical course.

  • @Rudxain
    @Rudxain Рік тому +131

    Imagine how cursed it would be to have "e" as an exponent, and Pi as a log base

    • @jotch_7627
      @jotch_7627 Рік тому +15

      log functions are all identical save for a constant scaling factor, so a log base of pi would probably be a *more* useful interpretation than a natural log combined with a scaling factor involving both e and pi

    • @christianullrich2923
      @christianullrich2923 Рік тому +85

      XKCD has got you: "If you ever find yourself raising log(anything)^e or taking the pi-th root of anything, set down the marker and back away from the whiteboard; something has gone horribly wrong."

    • @trevorx7872
      @trevorx7872 Рік тому +10

      @@christianullrich2923 there's an xkcd for everything

    • @supercr33p3r7
      @supercr33p3r7 Рік тому +3

      Finna have a brain aneurysm

    • @pietergeerkens6324
      @pietergeerkens6324 Рік тому +5

      @@trevorx7872 Is there an XKCD for "there's an XKCD for everything"?

  • @Sordorack
    @Sordorack Рік тому +132

    I always like to remind myself that radians and by extension degrees are taken from the circumference of a circle devided by the radius. Because of that their actual SI units are "length/length" or in other words, they are dimensionless, which will always be a weird property for a unit to have for me ^^

    • @MoritzFriedemann
      @MoritzFriedemann Рік тому +10

      Circumference devided by the radius is just a constant (2 pi)

    • @geoffreyentwistle8176
      @geoffreyentwistle8176 Рік тому +14

      A circle always has a radius of 57.3 degrees. XD

    • @Noname-67
      @Noname-67 Рік тому +11

      mol is literally just a number

    • @pfcrow
      @pfcrow Рік тому +4

      I came to the comments just to make sure someone had brought up radians. Weirdest units ever. Well, except maybe for Smoots.

    • @WofWca
      @WofWca Рік тому +4

      Percent is also dimensionless. So if you mix 33.(3)% of O2 and 66.(6)% of H2, you get 66.(6)% of H2O

  • @himanbam
    @himanbam Рік тому +18

    Jan Misali made a video where he derived a new set of standard units that were pretty cursed. Like instead of distance and time he used units of velocity and frequency with the speed of light c and middle C (256ish Hertz). But all the math works out.

    • @theexchipmunk
      @theexchipmunk Рік тому +2

      You can to a lot of convoluted bullshit with math. In part that is also where math becomes pretty fun, because it can feel like magic to take some seemingly random stuff and pull something that you wouldn´t think by guessing could be calculated out of it. Makes you feel a bit like a wizard.

  • @DerekCooper_
    @DerekCooper_ 9 місяців тому +3

    The “What If” book for Christmas is too real 💀💀💀