Do We Need a Negative Leap Second?

1 318 Shikime 133 mijë

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Did you know that last year we had 28 of the fastest days ever recorded? Earth's rotation can be affected by a number of things, and scientists think we might someday need an unprecedented adjustment: deleting a second!
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  1. SciShow
    6 ditë më parë

    Go to​ to try out Brilliant’s Daily Challenges. Sign up now and get 20% off an annual Premium subscription.

    1. Yeetur McBeetur
      Yeetur McBeetur
      4 ditë më parë

      @Mor Rari damn 😞

    2. Mor Rari
      Mor Rari
      5 ditë më parë

      @Yeetur McBeetur nah

    3. Yeetur McBeetur
      Yeetur McBeetur
      5 ditë më parë

      @Mor Rari can I trade ur tinfoil hat for one?

    4. Mor Rari
      Mor Rari
      6 ditë më parë

      @Yeetur McBeetur dont worry be happy, flux is cheap

    5. Yeetur McBeetur
      Yeetur McBeetur
      6 ditë më parë

      @Mor Rari my flux capacitor is broken. Can’t right now.

  2. Carson
    Ditë më parë

    Thanks Hank! I subscribed to SciShow's Patreon just to thank you for advocating not to cut my birthday short by a second every year!

  3. Bangs Cutter
    Bangs Cutter
    Ditë më parë

    We shouldn't underestimate human activity. The more dams we build, the more it concentrates huge masses of water, increasing the moment of inertia of the earth, so it will slow down the earth's rotation too. Though, still on the order of milliseconds per year.

  4. James C
    James C
    2 ditë më parë

    So my takeaway from this was that literally the entire planet wanted 2020 to be over asap.

  5. Alexi Xeno
    Alexi Xeno
    2 ditë më parë

    Honestly, so many clocks are just controlled digitally they could just delete a random second out of a random month and no one would notice

  6. Teddy Sofia
    Teddy Sofia
    3 ditë më parë

    I was once a herpes patient, but now I have finally got rid of it with the help of Ben Uda on youtube channel, with his Herbal medicine which he prepare for me,,.

  7. Euzer
    3 ditë më parë

    how about we call it a "Sleep Second"

  8. Raymond Chan
    Raymond Chan
    3 ditë më parë

    As of today, I'm still baffled by the fact that "Coordinated Universal Time" is not called CUT but UTC instead.

  9. alex lewis
    alex lewis
    3 ditë më parë

    Hey Hank Green how does this relate to your tic tok saying we're are actually speeding up because of the polls melting. Does that not contradic what you just talked about?

  10. Lorine Necro
    Lorine Necro
    3 ditë më parë

    its about time. hehe.

  11. Kyler Chin
    Kyler Chin
    3 ditë më parë

    We can take the Google approach and shorten the time of each second slightly on it's computers

  12. Lucas Scemist
    Lucas Scemist
    3 ditë më parë

    Lyrics in other languages PLEASEEE I want brazilian portuguese first, thanks...

  13. zzubra
    4 ditë më parë

    Why would it be “computer scientists” managing the atomic clocks? That seems highly unlikely.

  14. Larry Scott
    Larry Scott
    4 ditë më parë

    I haven’t found a 2009 anomaly. During 1998-2005 was absent leap seconds, increased rotation. In the 1970s leap seconds were more frequent. But 2009?

  15. Cody'sLab
    4 ditë më parë

    So we are just ignoring the long term trend caused by the moon then?

  16. Luis Aldamiz
    Luis Aldamiz
    4 ditë më parë

    Can't those atoms be messed by the Earth's wiggling in relativistic ways. I mean: time is after all curved, very especially in gravity wells such as planets. Have they tried to do those experiments in zero gravity instead?

  17. Luis Aldamiz
    Luis Aldamiz
    4 ditë më parë

    Why not an imaginary leap second?

  18. Jakey
    4 ditë më parë

    Novartis needs to stop burying ritalin in the ground

  19. Kajice K
    Kajice K
    4 ditë më parë

    I don't get why they would choose the ONE second many people on earth would notice is missing. Take any other second, no one would know. But why that one second where lots of western people will be watching the clock and literally count the seconds.

  20. ZipplyZane
    4 ditë më parë

    Seeing as we keep having to add leap seconds, I think it would make the most sense (due to electronic time keeping) to just not add the next one. Sure, if we stop having to add leap seconds for a while, maybe we get forced to take one away. But, if we do keep adding leap seconds, it seems silly to cause the problems that occur by taking one away, and then having the problems that occur for adding it back later.

  21. What's A Good Username?
    What's A Good Username?
    4 ditë më parë

    Imwe kuri algorithm

  22. Josef Rey
    Josef Rey
    4 ditë më parë

    Hey SciShow, does the speed of rotation of the Earth affect the speed of revolution around the sun?

  23. Colin MacKenzie
    Colin MacKenzie
    4 ditë më parë

    Actually, it was COVID-19. Y'see, all these people died, so their bodies were put underground, closer to the Earth's center. That reduced the Earth's moment of inertia.

  24. Lukan Cravens
    Lukan Cravens
    4 ditë më parë

    We shouldn’t worry about how we measure time but what we do with that time

  25. Leonardo Morellato
    Leonardo Morellato
    4 ditë më parë

    did Oumuamua slow us down?

  26. Jim DeCamp
    Jim DeCamp
    4 ditë më parë

    The explanation of the second definition in terms of the cesium atom is incorrect. It has nothing to do with the period oscillations between states of the cesium atom, and everything to do with the energy level between states. The frequency of the electromagnetic radiation associated with the transition is given by Planck's equation, f = E/h. In practice an oscillator is tuned to f by maximizing the number of cesium atoms measured as undergoing this transition by absorbing a photon of microwave energy. Another misstatement is that UTC has nothing to do with earth's rotation. Leap seconds are inserted in UTC to keep UTC within 0.9 seconds of UT1. UT1 is purely determined by the earth's rotation, although, not with respect to real sun, but with respect to distance stellar objects. It is determined by measured sidereal (star) time. The relationship of sidereal time to solar time is purely convention, but the conventional relationship is designed to keep the true sun passing the Greenwich meridian very close to 12:00 UTC on average.

  27. TMA1
    4 ditë më parë

    One thing these kind of videos never make clear is that they leave the layman with the impression that the day is 1 second longer than the last time a leap second was added. In fact the Earth is slowing down _and_ speeding up all the time on a milli-second timescale for some of the reasons explained in this video. Even if the Earth kept rotating at a constant rate from now on to eternity, we would still need leap seconds. The reason is because of clock drift - 2 clocks ticking at slightly different rates will always drift apart from the accumulated difference. Just 1 ms a day would accumulate ~ 1 sec offset every 3 years.

  28. Internet Gnom
    Internet Gnom
    5 ditë më parë

    Hank is such a blessing to humanity.

  29. Arrgghh
    5 ditë më parë

    And they say the sun rises and sets like clockwork. smh.

  30. NomadUniverse
    5 ditë më parë

    I would say the pandemic had a lot to do with it. Parts of the natural world sprung back to life without us out there vomiting and defecating our vile and poisonous industrial and commercial excretions all over it. This year will be fast, but not as fast as last year and we will see that trend continue as we slowly choke the Earth into submission again.

  31. far1ander
    5 ditë më parë

    Or, maybe we're just falling - ever so slowly - into the Sun? 😉

  32. Frank Page
    Frank Page
    5 ditë më parë

    Just build a few more dams like the three gorges in China. 🤣

  33. Earl Cedric Mediavillo
    Earl Cedric Mediavillo
    5 ditë më parë

    1:18 9 192 631 770 Hz, memorized it

  34. Core E
    Core E
    5 ditë më parë

    Much like the intricacies' of government problems. We won't even notice if they do it because our smartphones will adjust it for us. Not even an email, just another silent update. While we literally destroy a second from existence. hahahahaha

  35. Josh Hobbs
    Josh Hobbs
    5 ditë më parë

    Does the passing by of Comets & Astroids affect the gravitational pulls & push upon Earth or other bodies in Space?

  36. WantedVisuals
    5 ditë më parë

    I am once again blown away by how well the pattern on Hank's shirt is matched. I know that's not the main focus of this video, but I really appreciate that he invests time and money into getting well-made clothes that look good.

  37. SpazzyMcGee1337
    5 ditë më parë

    El Nino resists rotation using leverage. La Nina flicks her protrusion.

  38. Arian
    5 ditë më parë

    You used a really bad image when talking about the "Rocky's Andies and Himalayas"

  39. Håkan Bråkan Kråkan
    Håkan Bråkan Kråkan
    5 ditë më parë

    If everyone just jumps at the same time we’ll fix it. Clearly a leap second.

  40. UGNAvalon
    5 ditë më parë

    “FIVE! FOUR! THREE! TWO! *_Whaa~~??”_*

  41. TigerHawk709
    5 ditë më parë

    Didn't we adjust our time back in 2011 because of the Japan earthquake? I want to say I remember something about the Earth getting slightly smaller from it and speeding up, due to the angular momentum thing.

    1. Allan Olley
      Allan Olley
      5 ditë më parë

      Yeah I remember that. I think I remember similar stories after other major earth quakes. I suspect such tectonic shifts create the largest single sudden shifts, so I was surprised Hank did not talk abou them.

  42. Jake
    5 ditë më parë

    in theory the two methods should disagree with each other by an amount up to one cesium oscillation lol also earthquakes the most accurate and precise way to tell time is still sticking a stick into the ground lol

    1. Allan Olley
      Allan Olley
      5 ditë më parë

      I'm told they use multiple cesium clocks and careful modeling to average the measurement and smooth out irregularities. If you use the sun's position in the sky to calculate time your prediction of solar eclipses timings will be noticeably off soon enough (like by a whole minute or something in a few years), so that is not precise and so less precise then atomic time. If you just define time as solar time it is accurate by definition but you are building in a large imprecision in your way of telling time if you use the Earth's rotation as your definition of time.

  43. Pascal S.
    Pascal S.
    5 ditë më parë

    Not mentioned but very interesting is, computer don't like leap seconds. It's hard to add an extra second to a computer and don't mess up the time critical systems. Don't forget for a computer even microseconds are like years for them.

  44. Liam Becker
    Liam Becker
    5 ditë më parë

    0:36 Hank is such an amazing host

  45. Tommy Lee
    Tommy Lee
    5 ditë më parë

    Is there any subject matter that the term "Climate Change" can't be beat into? I'm sure it's just a matter of time till, we hear the ridiculous continuation of tying everything into "Climate Change", when we'll be told "Climate Change" is going to burn out the Sun.

  46. Simon
    5 ditë më parë

    Hey Hank don't you go crying about missing a 12:59:59 second. Isn't that also the second we get an extra of every time we have a slow year? I feel like you've had plenty extra of your favorite seconds! Give the rest of us who likes different seconds some time in the sun as well! :P

  47. Project DarkWolf
    Project DarkWolf
    5 ditë më parë

    Coordinated Universal Time is UTC? Why? That's so counterintuitive!

  48. Najwa Laylah
    Najwa Laylah
    5 ditë më parë

    "Unprecedented adjustment" except for leap years, the change from Roman to Julian, and from Julian to Gregorian calendars...

    1. Jose Fernandes
      Jose Fernandes
      5 ditë më parë

      But those adjustments were never deleting a second from the clock.

  49. John Johansen
    John Johansen
    6 ditë më parë

    Now, that explains why I was a little dizzy last July.

  50. Diane Wallace
    Diane Wallace
    6 ditë më parë

    Now I know Hank's favorite second is 11:59:59...Moo Ha Ha.

  51. DISTurbedwaffle918
    6 ditë më parë

    No need to adjust. All time should obey the Earth time. Anything else is heresy.

  52. AuthenticDarren
    6 ditë më parë

    Maybe the Great Conjunction had something to do with the Earth speeding up. Yet maybe anything did :/.

  53. raythegardener
    6 ditë më parë


  54. FA Riesz
    FA Riesz
    6 ditë më parë

    that comment about prying it from your cold hands makes it seem like that second was removed from the calendar entirely ^^;

  55. Justin Fuller
    Justin Fuller
    6 ditë më parë

    Check out Suspicious Observers on ALfirst for the answer to these questions

  56. Felipe Carvalho
    Felipe Carvalho
    6 ditë më parë

    Wait wait wait. The wind pushing us wouldn't it be like that situation of a guy in a chair holding a fan and a umbrella? Meaning, conservation of energy says it's not possible? (And it is not possible)

  57. Cha Lao
    Cha Lao
    6 ditë më parë

    can we please bring back bearded hank for just a few episodes? LOL

  58. Ricardo LC
    Ricardo LC
    6 ditë më parë

    It happened in July 19 because I turned 25 that day I'm just built different

  59. WeaselWJ
    6 ditë më parë

    I really liked Hank's presentation for this vid. Cheers!

  60. KOB
    6 ditë më parë

    4:15 Just say it. There is a 500-year record amount of ice in the Antarctic and relatively high amounts in the Arctic with quite a bit more than usual in Greenland -- f'n climate change! It's got nearly everyone talking nonsense!

  61. totalfreedom45
    6 ditë më parë

    Let's stick to International Atomic Time (TAI), which uses atomic clocks, and get rid of leap seconds. 💕 ☮ 🌎 🌌

  62. Kayclau's Shipposts
    Kayclau's Shipposts
    6 ditë më parë

    I'm a second late to everything because I forgot to change the clock.

  63. Jens Nöckel
    Jens Nöckel
    6 ditë më parë

    Computer scientists are saying: go ahead, blame us for leap seconds, positive or negative (as long as you don't notice the years we've stolen from you by inventing Facebook).

    1. TMA1
      4 ditë më parë

      I found it bizarre that he keeps talking about computer scientists when he actually means physicists as if they were in charge of time standards - leap seconds are a pain in the neck for programmers though but that's another issue.

  64. Rob Lucas
    Rob Lucas
    6 ditë më parë

    Flat earthers be like told you so

  65. bcubed72
    6 ditë më parë

    Even the Earth was racing to get 2020 over with.

  66. steve lawrence
    steve lawrence
    6 ditë më parë

    Nice vid sir.

  67. Ken
    6 ditë më parë

    Hank I love when your super literal but you should have continued on with the cold dead hands thing, it would have been super funny to hear you say that with such vigor

  68. srksii
    6 ditë më parë

    And I was timing my NY champagne with atomic clock in vain! Why God, WHY!

  69. GinoKaneki Sasaki
    GinoKaneki Sasaki
    6 ditë më parë

    These people are so upset about milliseconds then there is me who wasted 2 years doing nothing...

  70. Plazmoidial Soup
    Plazmoidial Soup
    6 ditë më parë

    Ask Ben Davidson

  71. Kal Random
    Kal Random
    6 ditë më parë

    There also having to recalculate it constantly, as it keeps getting faster that originally thought. Hmm, kinda weird when you consider all the planets in our solar system, are also doing something scientist have never seen before now.

  72. CJC 3636
    CJC 3636
    6 ditë më parë

    Hank, thanks for a phrase idea: Next time I'm totally baffled on something, I'll just say quietly, "That's not totally intuitive."

  73. Babs likes cartoons
    Babs likes cartoons
    6 ditë më parë

    Imagine the new year's countdown. 5... 4... 3... 2... HAPPY NEW YEAR

    6 ditë më parë

    Explaining the complexity of the Earth’s rotation in 5 minutes

  75. Bradley Evans
    Bradley Evans
    6 ditë më parë

    Did the reduced commuting in 2020 allow the Earth to spin faster?

  76. Bradley Evans
    Bradley Evans
    6 ditë më parë

    Hold up. We may be getting ahead of ourselves.

  77. The Rogue Wolf
    The Rogue Wolf
    6 ditë më parë

    So how will this affect a New York minute?

  78. TRDPaul
    6 ditë më parë

    It bothers me that Coordinated universal time is UTC. Why is it not CUT or Universal time - coordinated

  79. James Bell
    James Bell
    6 ditë më parë

    Ok, "computer scientists" have literally nothing to do with decisions or mathematics concerning leap seconds. Physicists and aerospace engineers do those things.

  80. Joaquin Pirotto
    Joaquin Pirotto
    6 ditë më parë

    Summer in july 19th, huh? That's definitely a jniversal thing that happens in both the north and south hemisphere /s

  81. dorgesh
    6 ditë më parë

    Can we just have 2020 be a negative leap year so the whole thing can just be forgotten about

  82. Dragon Skunk Studio
    Dragon Skunk Studio
    6 ditë më parë

    Every time or day adjustments should occur on the last day of the year, not February. While you're at it, start the first day of the year on the same day of the week regardless of what day it was on the last day of last year. 1 Calender for life.

  83. Volker H
    Volker H
    6 ditë më parë

    Coordinated Universal Time = UTC, which braindead made the short version of that?

  84. Mike
    6 ditë më parë

    10 9 8 7 6 5 4 3 2 Happy new year!

  85. Landon Kryger
    Landon Kryger
    6 ditë më parë

    They don't have to take it from Dec 31, they also could do it Jun 30.

  86. FvckYoutube'sCensorshipAndTheirAdBuyers UseAdblock
    FvckYoutube'sCensorshipAndTheirAdBuyers UseAdblock
    6 ditë më parë

    Dunno why we even need leap anything. Just stick to UTC and be done with it. Why does the clock or calendar need to keep doing what the sun and moon is doing when they are just labels anyway? Assuming Earth survives somehow what are you going to do in 6-7B years when the sun is a white dwarf and it's permanently night and no moon either due to tidal forces flinging it off into space so regular seasons no longer exist? A leap positive or negative year or second, daylight savings time, or redrawing time zones (or abolishing them as they should be) won't fix that.

  87. Jim_shum_179
    6 ditë më parë

    The earth is speedrunning the day

  88. Delbert Newman
    Delbert Newman
    6 ditë më parë

    0:40 Clarification: A solar day of 86,400 seconds is the _average_ time over a year between solar meridians. It changes during the year because the Earth's orbit is elliptical.

  89. PinkKirby11
    6 ditë më parë

    Really surprised that it was computer scientists who defined the second and not physicists.

  90. JinzoDefiler
    6 ditë më parë

    Hey at least it wasn't in 2020 they decided not add or subtract a leap second. Everyone would of had a collective groan. 2020 would of refused to end.

  91. NERO
    6 ditë më parë

    The Julian Calender was good enough for me.

  92. rogue277
    6 ditë më parë

    Wait a sec. Even if earth's speed right now never changed again, wed still need periodic leap seconds, because since the second was defined the earth has slowed down. And this accumulates to one extra second every 18 months. One earth rotation is no longer an integer number of seconds like it was when it was defined.

  93. KarmaIsEternal
    6 ditë më parë


  94. Lennard
    6 ditë më parë

    There's a solution you're missing here: abolish these confusing 1:60 systems and introduce new metric time.

    1. Xiefux
      6 ditë më parë

      " metric time " ew. if you use the devils measurements (metric) you will always come short.

  95. Cristina Pruitt
    Cristina Pruitt
    6 ditë më parë

    Because of the economic crisis and the rate of unemployment ,now is the best time to invest and make money 💯

    1. Russell Fautheree
      Russell Fautheree
      6 ditë më parë

      Ummm… This comment thread has nothing to do with the video it's on. I'm confused. Are ALfirst Comments sections just message boards now?

    2. TheVindicitive
      6 ditë më parë


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      Steve Abreau
      6 ditë më parë

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      Adam Snyder
      6 ditë më parë

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      Mo Mo
      6 ditë më parë

      Really y'all know him? I even thought I'm the only one he has helped walked through the fears and falls of trading

  96. Deldarel
    6 ditë më parë

    We have to insert a leap second often because our second doesn't match up 1/86400th of a day. Can't we just take one of those away? I doubt they'd agree to actually make such a culturally significant second get the axe once the time comes for it.

  97. Stewy
    6 ditë më parë

    So I wasn't just imagining it. Time really was distorted the past year.

  98. colt mc dougall
    colt mc dougall
    6 ditë më parë

    This whole video is contradictory to information that has been given in previous videos. Look into the plasma universe theory

  99. Ryan Lynrah
    Ryan Lynrah
    6 ditë më parë

    This wouldn't matter except for precise science... As for normal life, humn civilization would end before the leap second make any noticible change

  100. Ben Eisen
    Ben Eisen
    6 ditë më parë

    I was hoping for a nod to sidereal days as well, accounting for Earth's revolution around the Sun as well as its rotation. Oh well, maybe next time.