World's Roundest Object!

  • Опубликовано:  4 года назад
  • The world's roundest object helps solve the longest running problem in measurement -- how to define the kilogram.
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    A kilogram isn't what it used to be. Literally. The original name for it was the 'grave', proposed in 1793 but it fell victim to the French Revolution like its creator, Lavoisier. So begins the tale of the most unusual SI unit. The kilogram is the only base unit with a prefix in its name, and the only one still defined by a physical artifact, the international prototype kilogram or IPK.

    But the problem with this definition has long been apparent. The IPK doesn't seem to maintain its mass compared to 40 similar cylinders minted at the same time. The goal is therefore to eliminate the kilogram's dependence on a physical object. Two main approaches are being considered to achieve this end: the Avogadro Project and the Watt Balance.

    The Avogadro project aims to redefine Avogadro's constant (currently defined by the kilogram -- the number of atoms in 12 g of carbon-12) and reverse the relationship so that the kilogram is precisely specified by Avogadro's constant. This method required creating the most perfect sphere on Earth. It is made out of a single crystal of silicon 28 atoms. By carefully measuring the diameter, the volume can be precisely specified. Since the atom spacing of silicon is well known, the number of atoms in a sphere can be accurately calculated. This allows for a very precise determination of Avogadro's constant.

    Special thanks to Katie Green, Dr. David Farrant, the CSIRO, and the National Measurment Institute for their help. Thanks also to Nessy Hill for filming and reviewing earlier drafts of this video.

    There is debate as to whether this is truly the roundest object ever created. The Gravity Probe-B rotors are also spherical with very low tolerances such that they may in fact be rounder.

    Music by Kevin McLeod ( Decision, Danse Macabre, Scissors
  • ОбразованиеОбразование
  • Длительность: 11:44
  • veritasium  science  physics  Perfect  sphere  kilogram  avogadro  avogadro project  redefining the kilogram  kilo  metric system  silicon  silicon sphere  silicon-28  silicon 28  watt balance  bipm  history of the kilogram  grave  units  SI units  definition  gram  mass  quantity  weight  weights  kilograms  csiro  kilogram of the archives  kilogramme  definition of the kilogram  unit  perfect sphere  roundest object  world's roundest object  kilogram definition  

Комментарии: 30 471

  • Catlord
    Catlord Час назад

    Anyone else just see a cube map?

  • The kid :3
    The kid :3 Час назад

    I Think i learned more from this video than all of 7th grade

  • Isaac Gonzalez
    Isaac Gonzalez 2 часа назад

    Fushigi ball

    VKJ TECH 2 часа назад

    it is so confusing

  • Devansh Mendiratta
    Devansh Mendiratta 6 часов назад

    0:00 to 0:20 Listen with eyes closed

  • Sammy The Cute Puppy
    Sammy The Cute Puppy 8 часов назад

    The song is like roblox, flood escape

  • josh Brz
    josh Brz 8 часов назад

    I want to hit it once with an icepick then put it in an unbreakable glass case and just leave it infront of those scientists

  • bcherbs
    bcherbs 10 часов назад

    the natural water drop has this beat hands down!

    EMAXD 10 часов назад

    Geez why is your face so close to the camera in the first part?

  • Blobfish Gamer
    Blobfish Gamer 10 часов назад

    I will be very careful..
    *drops on ground and makes huge dent*

  • Nathan Thomas
    Nathan Thomas 18 часов назад

    Peel enormous sidewalk pile vary middle hand horizon obviously.

  • ANice Gamr
    ANice Gamr 20 часов назад

    high ass quality from 2013 then again its Veritasium

  • DoctorCockter
    DoctorCockter День назад

    World's best anal bead

  • Arnav Sharma
    Arnav Sharma День назад

    Is not still slightly off as no one knows the exact value of pi which is needed to count the atoms

  • Gold man
    Gold man День назад

    The song is drom a Dutch theme park

  • Rama Pasupula
    Rama Pasupula День назад

    9:05 I thought that was sodium...

  • khuzaima Abbasi
    khuzaima Abbasi День назад

    you mean the mass of a kilogram is the number of atoms in the sphere into the Avogadro constant?.Dude you lost me somewhere in the video.

  • TheCreeperMineZ
    TheCreeperMineZ День назад


  • Billy Lauwda
    Billy Lauwda День назад

    The roundes object can be usefull more then just measuring kg, could be used to decrease drag in a rotating machinenary

  • Bruce Aiken
    Bruce Aiken 2 дня назад

    The Earth is round? Since when? That is a physical impossibility!

  • hernanc
    hernanc 2 дня назад

    Such a costly thing resting on just three feet and then on a square base that is hardly big enough to hold it. What happens if it just bounces off into the table and the into the floor? OMG!!

  • Johnathan Hall
    Johnathan Hall 2 дня назад

    In the thumbnail u look like the white snoop dogg

  • otaku1014
    otaku1014 2 дня назад

    "but why would you invest one million euros and thousands of manhours perfecting a pure polished silicon sphere?"


  • DunkeiMonkey
    DunkeiMonkey 2 дня назад

    I'm too stupid for this video.

  • nick4life2020
    nick4life2020 2 дня назад

    Boonk gang that shit😂

  • triple aa
    triple aa 2 дня назад

    If he dropped it............

  • Spectre The Online Bounty Hunter
    Spectre The Online Bounty Hunter 3 дня назад

    Le Grand K

  • xXFuriousFoxXx
    xXFuriousFoxXx 3 дня назад

    It's not perfect. Ughhh so close to round 14m if it was multiplied millions of times? Too much lol.

  • Ingþór Ingólfssson
    Ingþór Ingólfssson 3 дня назад

    Think I have the answer why all the kilograms had different weights when they were sent back.... if there is a change in the weight of the earth, gravity becomes more powerful and everythings get heavier.... so a new island made from volcanic eruption and changes in the core of the earth adds some mass to it - enough to add 0.000000049 grams to a kilogram...

  • Jacob Arquiza
    Jacob Arquiza 3 дня назад +1

    Roundest object? - My Belly

  • martin menke
    martin menke 4 дня назад

    Isn't a soap bubble more spherical?

  • Parabalani
    Parabalani 4 дня назад

    It can't really be round anymore. As soon as someone took it into their hands they bended it by an extremely small amount. Also at the same time they took away some atoms from the ball

  • roblox gaming tutorials
    roblox gaming tutorials 4 дня назад


  • Andrei Gabriel
    Andrei Gabriel 4 дня назад

    The first 30 seconds are just like a beginning of a porn video.

  • Mort Goldstien
    Mort Goldstien 4 дня назад

    How many licks does it take to get to the centre?

  • Mort Goldstien
    Mort Goldstien 4 дня назад

    I searched Go-low circle in Bonn Germany and found this video....

  • Mort Goldstien
    Mort Goldstien 4 дня назад

    They haven't seen my balls

  • godly04
    godly04 4 дня назад +2

    Imagine how OP this thing would be in bowling.

  • waggy boy
    waggy boy 4 дня назад

    YEah boi CSIRO for the win

  • Sin Tunstall
    Sin Tunstall 4 дня назад

    The ultimate fushigi ball.

  • Nick 99
    Nick 99 5 дней назад


  • Brad Munro
    Brad Munro 5 дней назад

    still don't make sence why they making a pure silicon sphere. don't we know the weights of all atoms so why not do 1kg / silicon atom weight

  • B. Pornchaser
    B. Pornchaser 5 дней назад

    I still don't get why you actually need a physical object just to calculate it. I mean, math books would be incredibly heavy if that would be the case.

  • Homo Sapiens
    Homo Sapiens 5 дней назад

    2:18 - *Insert Lenny face here*

  • Titan
    Titan 6 дней назад

    Hello and welcom to da hydraulic pres chanel

  • Music God
    Music God 6 дней назад

    Lol 2017 UPDATE!

  • Sara Makes Art
    Sara Makes Art 6 дней назад

    I honestly never thought that what the world's roundest object is was something I needed or wanted to know, but this is a great video with an interesting history lesson.

  • Exploding Labs
    Exploding Labs 7 дней назад


  • xAvalancheGD
    xAvalancheGD 7 дней назад +1

    I think we all know what's rounder :>

    • xAvalancheGD
      xAvalancheGD 7 дней назад

      The word rounder of course.

  • William Rees
    William Rees 7 дней назад

    Aight so you think you can pronounce French? You think you're better than me? I'll tell you what since you're so much better than me why don't you take two scoops of ice cream and I only get one....

    You're not better than me

  • Spaldam's Adventures
    Spaldam's Adventures 7 дней назад +1

    So where they successfully in redefining the kilogram?

  • Santa Tv
    Santa Tv 7 дней назад

    i know this video is old , but when he asked her why sphere , she replied that it's easy to calculate the volume of a sphere if you know the diameter , but do we know exactly the value of pi ????

  • Btfahle Brendan
    Btfahle Brendan 8 дней назад +1

    imagine how embarrassing it would be if he droped it.

  • Menthol Kratom
    Menthol Kratom 8 дней назад

    this guy looks high all the time

  • Danger Falcon
    Danger Falcon 8 дней назад

    how stoned am i? why am i watching this?

  • Danger Falcon
    Danger Falcon 8 дней назад

    how stoned is this guy?

  • Hunter Powers
    Hunter Powers 8 дней назад

    I think she likes you.

  • John cena
    John cena 9 дней назад

    meh, i've seen people more round than that piece of over priced junk

  • killerlite1
    killerlite1 9 дней назад

    what am i watching and this comment section is cancerous

  • reytheGEMini
    reytheGEMini 9 дней назад

    Just imagine what that lady would do to him if he dropped it... To be continued?

  • Enrico Zagnoli
    Enrico Zagnoli 9 дней назад


  • Korkuslorkus
    Korkuslorkus 9 дней назад


  • Hyperion
    Hyperion 10 дней назад

    The world's squarest triangle.

  • Fraser5
    Fraser5 10 дней назад

    billcry the science boi

  • Ash _Gamez
    Ash _Gamez 10 дней назад

    I hear Orphs soundtrack.

  • Henry Markle
    Henry Markle 10 дней назад

    Thank you so much for the video.

  • James Gorman
    James Gorman 10 дней назад

    Whom is round and to what does he object?

  • Tildin2006
    Tildin2006 10 дней назад

    Dude it is 2017

  • Tildin2006
    Tildin2006 10 дней назад +3

    He didn’t touch it because of gloves

  • بندر عبيد
    بندر عبيد 11 дней назад

    it's not round

  • roy boese
    roy boese 11 дней назад

    Only problem is that after a few months in a vault someone will drill holes in it and replace its guts with tungsten bars.
    probably the same dude who does the gold bars...

  • TheInkinJapan
    TheInkinJapan 11 дней назад

    Your "jokes" make it more difficult to watch- not easier. Please stop.

  • Linuxx
    Linuxx 11 дней назад

    this guy is extremely excited to see balls and a girl i bet he has not been laid to date.

  • Joris Lemoine
    Joris Lemoine 11 дней назад

    Is it just me, or does he look a little tired? Take a small break, dude! Have a nap ;).

  • Jasmina Ed
    Jasmina Ed 11 дней назад

    My balls are rounder

  • Mianroca
    Mianroca 11 дней назад

    I like how happy he is when he sees the ball. You can tell how much love and passion he feels for stuff like this

  • ༺Dlj༻ ༺Dᴇᴍᴏɴɪᴄɪჯ
    ༺Dlj༻ ༺Dᴇᴍᴏɴɪᴄɪჯ 12 дней назад

    Nervous laugh ~ Hahehhuhahh... It's slippery..HAHEUHEUHEUhuhuha ;}

  • DanCrusade
    DanCrusade 12 дней назад

    so you ever want to just go into a seperate universe where you can do certain things in your life and they dont have consequences? like, feel this thing and then just throw it at a wall, and watch everybody's reactions for about 30 seconds then go to another thing, example the guy who is in an actual romantic relationship with his car, you smash it. i just have this weird thing of seeing how people react when i tell them something or do something.

  • Blaze Nelson
    Blaze Nelson 12 дней назад

    Would have been great if he started doing Fushigi tricks with it...

  • Jon Moore
    Jon Moore 12 дней назад

    1:09 I dont get it

  • Cherry Stone
    Cherry Stone 12 дней назад

    watch the video with your eyes closed it sounds likes he's grabbing her tits lol

  • TheNachina
    TheNachina 12 дней назад

    could always change the definition of the kilogram to 55.5 recurring mols of h2O at 4 degrees celcius.

  • Tank HeavyBlast
    Tank HeavyBlast 13 дней назад +3

    For the last time you dumb peeps, Earth is oval not round

  • Видео Аудио
    Видео Аудио 14 дней назад

    this is strange)

  • Everything Viral
    Everything Viral 14 дней назад

    wtf did i just watch

  • Zippy Tornado
    Zippy Tornado 15 дней назад

    One of the roundest objects is my balls

  • Jose  Pereira
    Jose Pereira 15 дней назад

    Gostaria de saber mais sobre o assunto

  • saday saday
    saday saday 15 дней назад


  • Daddy
    Daddy 16 дней назад

    His reaction when he picked it up pissed me off. That damn ball feels like any other ball . Calm it down

  • Nicholas Cabrera
    Nicholas Cabrera 16 дней назад

    Whew, they better watch out with all of the chemistry in the lab.

  • Benjamin Lehman
    Benjamin Lehman 16 дней назад

    How do you manage to get into these places? Like the seed vault.

  • Mutha Flela
    Mutha Flela 16 дней назад

    I have come on youtube to watch some deadlifts wtf am I doing here ? and why have I seen the whole video ?:D

  • Fridgemusa
    Fridgemusa 16 дней назад

    Katie wants the D :P

  • Fridgemusa
    Fridgemusa 16 дней назад

    Wouldn't variations in the Earth's gravitational pull account for the change in the mass?

  • MajorJim!
    MajorJim! 16 дней назад

    The earth is not a perfect sphere.

  • Letta Aulet
    Letta Aulet 16 дней назад

    woooooowwww...amazing. would this be similar to going from paper to digital? from object to concept. nice. <3

  • Quizzy 72
    Quizzy 72 16 дней назад +1

    are we talking about the circle or kilograms

  • Shubham Saini
    Shubham Saini 16 дней назад

    Why are we born on this earth

  • Atemu
    Atemu 17 дней назад

    so has the kilogram been redefined in 2014?

  • Kalle-Aleksi Vainionpää
    Kalle-Aleksi Vainionpää 17 дней назад

    Meanwhile americans still using the imperial system