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: 31 073

  • Cale Howe
    Cale Howe 9 часов назад

    So is there a platinum measuring tape/ micrometer somewhere locked in a vault? That thing must be worth at least TWO of these ball things.

  • Bianca Valentino
    Bianca Valentino 11 часов назад

    What a’re pretty cute.

  • Christopher Martinez
    Christopher Martinez 13 часов назад

    I'm pretty sure that's just a sphere that is expensive for no reason......what's the point of making this?????

  • Domi B.
    Domi B. 14 часов назад

    wait your llowed to touch this?

  • epicmariogameplayer
    epicmariogameplayer 14 часов назад

    The song is Kevin Macleod - Decisions :)

  • ScienceFoundation
    ScienceFoundation 16 часов назад

    But it's still dependent on the number of atoms of a certain element in a given space

    This solves nothing.

  • Ty's Kingdom
    Ty's Kingdom 16 часов назад

    I see a boobie 2:18

  • olivier k
    olivier k 17 часов назад

    How round is it compared to a neutron star? Ive heard that a neutron star has mountains and valleys of about 4 mm but is is only 15 miles across or something

  • Rubina Malik
    Rubina Malik 19 часов назад +1

    Okay who else paused the video at 2:18
    Looking at the tits

  • TinyLittleYoutuber
    TinyLittleYoutuber 23 часа назад

    Oh my god

  • Alban Pema
    Alban Pema День назад

    WilL iT BleNd

  • Spice For Spice
    Spice For Spice День назад

    now turn it inside out

  • Tani Bee
    Tani Bee День назад

    Can anyone translate this to german and tell me the main informatins?

    Wir haben dazu einen Physiktest und ich hab kein Plan was das heißt😂😂💕

    • Tani Bee
      Tani Bee 20 часов назад

      Hmm thanks😂❤ i forgot that

    • Цзин Кэ
      Цзин Кэ День назад

      U wot? There are german subtitles.

  • Dragon Whisperer
    Dragon Whisperer День назад +1

    When you look at that sphere front on, the way the reflection of the light bends the closer you get to the edge sort of reminds me of the way the light bends the closer you get to the edge of a black hole.

  • MetalGuitarBoy
    MetalGuitarBoy День назад

    1000 Degree Knife VS. ......

    World's Roundest Object!!!

  • The Director
    The Director День назад

    Cover it in vantablack and you got a black hole

  • nugnug635
    nugnug635 День назад


    A what balance?

  • Daniel SOP
    Daniel SOP 2 дня назад

    1:23 high af

  • Abhilasha Yadav
    Abhilasha Yadav 2 дня назад

    how to check that this is the roundest object ?plz reply if u have any answer ...

  • perno grafy
    perno grafy 2 дня назад

    I thought my dad's head whas the roundest, guess this thing won

  • Mr Awesome
    Mr Awesome 2 дня назад

    im glad im never gonna hold it lol i know id drop it

  • Tom Bomb
    Tom Bomb 3 дня назад

    ya that is the second roundest cuz m'balls are the first XD

  • Lukson
    Lukson 3 дня назад

    Well youre wrong my balls are roundest object in the world.

  • rabie4x4
    rabie4x4 3 дня назад

    I woulda accidently dropped it and it woulda rolled straight into the worlds grindiest object...

  • Falcon Baker
    Falcon Baker 4 дня назад

    Why don't they just define it as what it was originally defined as and not spend all this time and money into it

  • RED Productions
    RED Productions 4 дня назад

    Did they ever figure it out?

  • MrPlayDay
    MrPlayDay 4 дня назад

    kilagrame of stiw or a kilograme of feaythers

  • Monkey .D. Luffy nolan
    Monkey .D. Luffy nolan 5 дней назад

    whats with all the halo music

  • Titanic
    Titanic 5 дней назад


  • MetaDecker
    MetaDecker 5 дней назад

    The world's flattest object is the Earth

  • AJ Melamud
    AJ Melamud 6 дней назад

    worlds most expensive fushigi

  • Kaiden's World
    Kaiden's World 6 дней назад

    You can't get rounder than round

  • morgan harris
    morgan harris 6 дней назад

    The roundest object is any sphere

  • Jory Porteous
    Jory Porteous 6 дней назад

    That's a fushigi.

  • ana laura guimaraes wahasugui
    ana laura guimaraes wahasugui 7 дней назад

    Hii Dereck! I’m Brazilian and I’m studying at Escola Sesc de Ensino Medio. Me and my colleagues watched your videos and liked all of them - mainly which ones that you sing haha, you are amazing!
    In my school, every year since 2008, the students have “the science week”, which is one of the coolest week at our school. The science teachers gives us a lot of challenges in these days and as we are doing them, we are getting points for our class. Our last challenge is make a science question to you! And here it is: how do you feel about all of the students around the world that watches your videos and understand - and beyond that, like- physics as well?

  • LbMeKing
    LbMeKing 7 дней назад

    I slipped looking at it.

  • Tibbs Productions
    Tibbs Productions 7 дней назад

    Vsuace wanna be

  • The GamingAntPlays
    The GamingAntPlays 7 дней назад

    Hey thats my first name give it back! (1.52)

  • alissa spoons
    alissa spoons 7 дней назад

    "It's priceless..."
    I give you 3 bucks

  • Savage Life
    Savage Life 7 дней назад +1

    It's not round inof for me to be in pressed

  • Alessandro Napolitano
    Alessandro Napolitano 7 дней назад

    Danse Macabre👌

  • Steven Littleton
    Steven Littleton 7 дней назад

    So the equipment used to create "the perfect sphere" haven't made anything else? No... My neighbor... God rest his sole... Made spheres in this same manner out of all kinds of things (not silicon though) as a hobby. Explain to me how this is different?

    • Ryan MacNeill
      Ryan MacNeill 7 дней назад

      this is smoothed the the atomic level, your neighbour only smoothed it till it was smooth to the touch.

  • kalle halmela
    kalle halmela 7 дней назад

    That was intresting... Thank you

  • David A
    David A 7 дней назад

    aaaaand it didn't happen until 2018

  • Levi The Pumpkin
    Levi The Pumpkin 7 дней назад

    Just looks like a circle why do people call moving circles spheres

  • ZorthoTV
    ZorthoTV 8 дней назад

    Roundest object sitting on the most precarious stand ever made

  • Bianca G
    Bianca G 8 дней назад

    Has this happened in the end?

  • Ani the arctic fox
    Ani the arctic fox 8 дней назад +1

    It’s just a ball.

  • Grim Reaper
    Grim Reaper 8 дней назад

    I thought my gf's titties were the roundest, guess i was wrong.

  • Y07H-Glendon LAI
    Y07H-Glendon LAI 8 дней назад


  • the corbin show
    the corbin show 8 дней назад

    I'll just spit on it

  • Connor Komuro
    Connor Komuro 8 дней назад

    Why is this so round. It is just like every sphere

  • pumaburro1
    pumaburro1 8 дней назад

    I'm interested in this topic, could you contact me?

  • MrSottobanco
    MrSottobanco 8 дней назад

    Ms. Katie Green has a great body.

  • MrSottobanco
    MrSottobanco 8 дней назад

    Can you give us an update?  Did it become the new standard?

  • warbreakr
    warbreakr 8 дней назад

    Spongebob's circle set the definition of round. this video comes in second

  • Man Like Gov
    Man Like Gov 8 дней назад +1

    maybe washing them before the weigh in is what changed the mass lol

  • LeDoggo
    LeDoggo 9 дней назад

    *holds a ball* THATS AMAZING

  • skullstabber9
    skullstabber9 9 дней назад

    I think the weight of something should be defined as a concept, a precise measurement but instead they waste one million euros and countless man hours to make something that's entirely useless. That's just really stupid.

  • MegaVidManiac
    MegaVidManiac 9 дней назад

    Yea, True level bitch! - Rick Sanchez

  • Alex Black
    Alex Black 9 дней назад

    Rick Sanchez will break in and change it to 0.

  • Jacob Hood
    Jacob Hood 9 дней назад

    4.2 degree celsius ;)

  • Fosi94
    Fosi94 9 дней назад +1

    7:25 I will redefine your constant

  • janosik
    janosik 10 дней назад

    well nobody cares i came to only see the object i dont care about weight omg

  • Saltura Gold
    Saltura Gold 10 дней назад

    *touches it*

    *MoRtY oRgAsM*

  • SS-50-CAL 3232
    SS-50-CAL 3232 10 дней назад +2

    This dude's eyes are awfully red! 😧

  • Terry Strieder
    Terry Strieder 10 дней назад

    Experiencing True Round

  • Jack Williams
    Jack Williams 10 дней назад

    Grave (grar - vay)

  • Mu'adz Bahari
    Mu'adz Bahari 11 дней назад +2

    Dude, get some sleep

  • Wj11jam
    Wj11jam 11 дней назад

    Does light cause any force to be applied to objects?
    Couldn't you base weight off of that force? Then it'd be calculated based on light.

  • Tiikoni
    Tiikoni 12 дней назад

    I felt worried when they wave their hands around it at 9:22, while that priceless thing is on a stand that looks like it is almost over the edge.

    KELERENG RECORD 12 дней назад

    wow..lihat nih ada cewek sangek lo

  • Ricky Williams
    Ricky Williams 12 дней назад

    It's spherical! SPHERICAL!!!!

  • TurboKai
    TurboKai 12 дней назад

    Is that a sphere from doom 1?....
    A different one: the lady at the beginning seems a bit let's say "touched on erotic side".. like she later says OBJECT....just my impression... so who says ladies only like money or muscles... just get a sphere with a specific amount of atoms... BAM...

  • Rajat Roy
    Rajat Roy 12 дней назад

    Someone has been salty on paris ...

    MALLEP 13 дней назад

    Actually it's the second roundest object in the world, the first one is my girlfriends butt...lord thank you.

  • Innocuous_Cat
    Innocuous_Cat 13 дней назад

    It’s 2016 xD re defined yet?

  • moakley
    moakley 13 дней назад

    hey that's bronte grave yard =)

  • Nicholas Krastev
    Nicholas Krastev 13 дней назад

    This guy is stoned

  • Jon Aram
    Jon Aram 13 дней назад

    You thought I wouldn't catch that saint saens? Wrong!

  • Learnzz
    Learnzz 13 дней назад

    If scientists are so smart why are they not rich being billionaires

    • Learnzz
      Learnzz 9 дней назад

      The rich entrepreneurs might not get A's but they are very smart if not smarter. It's just not book smart but also street smart. Like trump just offered to take an Iq test battle against Rex tillerson, trump can't spell good but

    • Brandon Daniels
      Brandon Daniels 9 дней назад

      Building wealth does not directly correlate very well with academic intelligence/ability. The book _The Millionaire Mind_ by Thomas Stanley researches this topic. In a nutshell, many A and B students go on to have prestigious jobs at great companies. What people fail to notice is that many of the great companies are owned by D and C students. Building wealth requires a great deal of social intelligence and financial intelligence, which are qualities that are not as highly prized in the American educational system (compared to intellectual ability).

    BOB ROSS 13 дней назад

    Please give me shiny

  • Psychic Hedgehog
    Psychic Hedgehog 13 дней назад

    "You can't have a unit that changes its value!" Tell that to currency

  • Psychic Hedgehog
    Psychic Hedgehog 13 дней назад

    He doesn't know the French pronunciation of K... this shouldn't be the type of thing that triggers me XD

  • Yours Truly
    Yours Truly 13 дней назад

    I love danse macabre

  • Alex Boshey
    Alex Boshey 13 дней назад

    So your saying if i touch something you could make it hevier

  • J Doggy dog
    J Doggy dog 13 дней назад

    Why can't I have your job.

  • The Real 2nd Earl of Rochester
    The Real 2nd Earl of Rochester 14 дней назад

    Radiometric decay?

  • DraconusGT
    DraconusGT 14 дней назад +1

    Anyone reminded by that rick and morty episode when morty standed on the flatest surface and he feels stronger and healthier? Also, 2017!!!!!!!!!!!!!!!

  • Free Hhhh
    Free Hhhh 14 дней назад

    Come on it ain't rocket science sike

  • Matenesis Vlogs
    Matenesis Vlogs 14 дней назад

    I don’t get the 14 m apart thing.

  • Noah! Retford Stephens
    Noah! Retford Stephens 14 дней назад

    Lol just makes me think of the flat surface on rick and morty

  • gowri prasad
    gowri prasad 14 дней назад

    How many of you feared by music when he entered into graveyard😂

  • 01a2Bc3DeF
    01a2Bc3DeF 15 дней назад

    Minor error
    1kg sphere of silicon-28 is about 2.15*10^28 atoms not 2.15*10^25 atoms

  • iamtherealkek -
    iamtherealkek - 15 дней назад

    I wondere if his IQ score is passing the standards

  • Joker Sound Studios
    Joker Sound Studios 15 дней назад

    When he holds it it looks like it is still and only his hand is moving.

  • ImClutch TV
    ImClutch TV 15 дней назад +3

    Make it and orangey yellow color and put some red stars on it. welp that reminds of a dragon ball 😂

  • Pickle Rick
    Pickle Rick 15 дней назад

    looks like my ballllzzzzz , woahhh

  • G S
    G S 15 дней назад

    why they put a million euro ball in a little tripod, that it's an a little table? it's looks all to easy to mess up.

  • Joey O'Neil
    Joey O'Neil 16 дней назад

    if you tampered with the big k, there would be *mass* confusion.