Precession causing perihelion to happen later | Cosmology & Astronomy | Khan Academy

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  • Опубліковано 29 гру 2024

КОМЕНТАРІ • 24

  • @AprilEmber
    @AprilEmber 9 років тому +2

    I finally understand precession! FINALLY

  • @guivyse
    @guivyse 13 років тому

    Really good Clarifying point.
    i got the same wrong idea.
    thanks..
    by the way great work with Khan Academy.

  • @bobertgamz
    @bobertgamz Рік тому

    Which changes quicker- precession or obliquity?

  • @2TaroT
    @2TaroT 5 років тому

    Hi! Can you or someone help me understand how those Gregorian calendar adaptation works? As long as I thought, the leap years exists due to the 1/4 extra spin to complete 1 translation around the sun, which would represent around *6 extra hours per year.*
    But there's 2 things that confuses me:
    1. Wouldn't leap years just make season's days stay at same date forever, not contributing to the precessions adaptations at all?
    2. I also heard precessions causes just *20 min* change in the seasons *per year* , so it's totally different from the 6 extra hours per year, causers of the leap years. _(20 min difference per year would cause 1 day difference each 72 years.. So in mere 2160 years all seasons would begin 1 month earlier)_
    _*also the thing that "out of 400 years 97 are leap years, not 100" just exists because a full translation, instead of containing exact 360+1/4 (or 0,25) of a spin, in reality contains 365+0,2422 of spin._
    Help me!
    (and thank you for the amazing video!)
    =D

  • @0219-n1e
    @0219-n1e 6 років тому +2

    Thank you. I checked perihelion dates and times of coming years ahead and found out that it fluctuates a lot from 3rd Jan to 5th Jan and then to 2nd and 4th. why is it like this. you said it changes 20 minutes a year.

    • @rainyday6430
      @rainyday6430 5 років тому

      This might have something to do with our calendar. We give the year 365 days, but a true solar year is a fraction of a day more than 365. Perhaps leap year influences perihelion dates?

  • @edwardsmith4353
    @edwardsmith4353 4 роки тому

    axial precession occurs over 25,700 approximately

  • @oakwind
    @oakwind 13 років тому

    OK, you've explained what axial precession and obliquity are, but why does it happen?
    I'd also like this to head into our moons dynamics and global warming.

    • @estontin123
      @estontin123 6 років тому

      OakWind it directly relates to global warming. We are entering an interglacial period just like we've done many times before.

    • @rainyday6430
      @rainyday6430 5 років тому

      @@estontin123 We have been in an interglacial period for around 14,000years. Towards the bottom of the page you'll find a list of known interglacial periods en.wikipedia.org/wiki/Timeline_of_glaciation

  • @VangbroYellowboi
    @VangbroYellowboi 13 років тому

    smart guy...

  • @rohithbr4341
    @rohithbr4341 2 роки тому

    If December 22nd moved back by 23deg in those 1800 years then in another 11200 years would December move to the other end of the orbital plane around the Sun? In which case is it still winter in December (in the northern hemisphere) but just that the earth's position w.r.t the Sun is an erstwhile summer position?
    Also, if we consider a Dec 22 - Dec 22 as an year, this movement of Dec 22nd is shrinking each successive year by a few arc minutes, isnt it? Is that the right way to look at it?

    • @chukfunk
      @chukfunk Рік тому

      Someone please answer! Will winter one day be in aphelion?

  • @ManaOkamiMeiun
    @ManaOkamiMeiun 13 років тому

    Doesn't the earth actually orbit in the shape similar to a spirograph (or a flat Bohr's model atom picture)?

  • @Penndennis
    @Penndennis 13 років тому

    Absolutely wonderful! A model of clarity. Thank you so much.
    BTW How can anyone dislike this material?

    • @samsonwill5572
      @samsonwill5572 3 роки тому

      i know im asking randomly but does any of you know a trick to get back into an instagram account..?
      I stupidly forgot the account password. I would love any assistance you can give me.

    • @ianaryan233
      @ianaryan233 3 роки тому

      @Samson Will instablaster ;)

    • @samsonwill5572
      @samsonwill5572 3 роки тому

      @Ian Aryan i really appreciate your reply. I got to the site on google and Im in the hacking process atm.
      Seems to take quite some time so I will get back to you later when my account password hopefully is recovered.

  • @jparks6544
    @jparks6544 8 років тому +4

    Playing with concepts but getting the details all wrong. Dec 22 will NOT be the same in 1800 years - without a change to the calendar. The days do not just disappear. A modification will be needed to keep the calendar solstice days accurate to the visible solstice days. The Gregorian calendar does not automatically adjust to keep them in sync.
    Also, there is no proof of precession - it's all theoretical. In actual fact, the earth's axis exhibits a logarithmic sine curve recovery from an initial value of 26.5 degrees at an event 4330 years ago (as of 2016) which has almost reached stability.

    • @aleksabradic6607
      @aleksabradic6607 8 років тому

      World couldn't care more what ignorant paranoid youtube "scientists" think.

    • @estontin123
      @estontin123 6 років тому

      Calendar makes automatic adjustments to take precession into account..

    • @slappy8941
      @slappy8941 5 років тому

      Axial precession is different from orbital precession. The Earth takes 365.25 days to make a full 360° orbit, so that it's 50' of arc farther behind each year, taking 72 years to get back to the same relative celestial position.

    • @hereIam1965
      @hereIam1965 5 років тому +1

      Something happened 4330 years ago that put the earth into a wobble and it has been recovering ever since ? and virtually recovered ? or stabilised ?

  • @simonhadley8829
    @simonhadley8829 2 роки тому

    I made it about five minutes and gave up. Listening to you stumble and bumble through the explanation making constant mistakes is just too much. Next time write a script and use real graphics.