Milankovitch cycles precession and obliquity | Cosmology & Astronomy | Khan Academy

[@jjamesstewart]

Thank you! I took a college astronomy course and left unable to visualize precession. Now in about twelve minutes you've put my college instructor to shame. Awesome.

[@ahrims221]

Who is Khan? and why does this guy know so much about every subject? Biology, chemistry, math, geology...amazing

[@VietNguyen-dp5pv]

+Juan Antonio he initially started teaching math to his cousin by posting videos on youtube. Many people liked his videos so he left college to start his company now called Khan Academy. He hires people to teach various subjects.

[@CiaraCorroon]

Khan is the most dangerous and calculating enemy the crew of U.S.S Enterprise NCC-1701 encounters in any lifetime. he is a warlord from Earth’s past who was genetically engineered to be part of a superior human race.

[@lukehyndman3998]

Gotteem

[@callumwilson9805]

Milovan Banicevic actually no Milankovic is wrong, proper Serbian or Russian translated Roman script it should be Milanković but as that is not a character in curtain western languages Milancovich is also accepted either way it should end in h or have an acute above the c

[@chrisw1462]

KAAAAAAHHHHHHN!!! (can't believe no one did this yet.. ) Oh, and also, Toowerds.

[@NatsumiBunny]

So glad I came to this vid, i have an exam in an hour's time and I understood it better in less than 13 min, than my lecturer spending an hour explaining it... Thanks! :) The top example really helps!

[@Dorkus89Malorkus]

I'm taking Astronomy now and had a hard time understanding this obliquity vs precession thing but this video just hit the spot. I completely get it. Sal, you're a godsend!

[@vicksoma]

If i understood this correctly, precession changes the time of the seasons over long periods of time, and obliquity changes the strength of the seasons over long periods of time. So in a several thousand years, if we still use the same calendar system, summer and winter will happen in different months and they will be more mild or more harsh.

[@estontin123]

vicksoma yes plus you have to add the orbit's eccentricity into the mix. It also cycles and affects the strength of the seasons

[@custosnocte1528]

Yes, this is the way I understood it. Based on the instruction in the video, there must have been thousands of ice ages over the 4,500 million years life of the planet, meaning sea levels rising and fall. So, if this is correct, the last time the Sea was much higher, none of the coastal cities existed at all. The climate change alarmists are simply trying to cash in with spreading fear about an event which will happen again, regardless of human behavior. So, when an elected member of the US House of Representatives uses her Twitter following to make a highly irresponsible statement such as "We only have 12 years left... Unless we spend trillions now" why is no one holding her accountable for these false claims ? So, perhaps we should ask this Congresswoman, Al Gore, and the girl from Sweden, Who do we write the check to ? Mother Nature ?? Father Time ?? LMAO... The Earth is going to do what the Earth does, regardless. Perhaps the human race is here on borrowed time ? After all, we are talking tens of thousands of years for these cycles to come full circle. Just my two cents. Thanks.

[@Jerundd]

@@custosnocte1528 Not entirely true. Yes, thousands of ice ages have happened before and many warmer period on earth have occured. However, the difference now is the speed at which the temperature on earth is rising, leaving ecosystems and humans that built their society on those ecosystems unable to adapt quickly enough, causing all sorts of trouble. Mother nature won't care much, but as humans we're just getting ourselves in a world of trouble, which is something we can still contain if we act now.

[@GregoryJByrne]

Precession causes the planets glacial/tropical ClimateCycle not the seasons. Tge seasons are caused by the annual rotation of the planet wiyh the tilt causing the north south opposite seasons

[@jaredmccracken5263]

@@Jerundd Just pure alarmism.

[@darcydomanko6396]

This topic is so relevant in 2021 than ever before.

[@mirabilo]

Thanks dude. I finally got my head around this...

[@TylerSimonds]

Helpful! Thanks, Sal. Obliquity and precession are a bit mind-bending at first but you explain it well! Hopefully people understand that in a given year, neither phenomena can be measured--by the average person--but they have a bit impact over thousands of years.

[@tornaparttv3831]

Many thanks for taking time make such an informative video ad this! Helped me alot with my schoolwork. Thanks!

[@dylanbuchman8128]

Thank you! I have been trying hard to figure out exactly what these differences in the earth's movement and orientation about the sun look like--it is super hard to visualize at first, I'm still trying to formulate the ideas in my head, but this is helpful

[@AJ-et3vf]

awesome video! Thank you!

[@bobleclair5665]

do you think the Milankovitch cycles have any effect on the magnetic pole reversal

[@casemace92]

Wish he connected this to our current Milankovitch cycle, and its ties to global warming.

[@erikandersson1647]

He was probably afraid of being labeled a heretic.

[@doffi213]

Todays Climate change is solely due too increased CO2 consentrations and other greenhouse gasses. The Cycles alone won't usher inn a new periode of extreme heating, but they can be the last drop of water that makes the cup overflow. This is what the IPCC concluded with in 2013 and again in the Paris agreement of 2015.

[@adambateson2116]

Concern re climate change is specifically focused on the best 270 years (since the industrial revolution in 1850). Milankovitch cycles occur at a minimum of around 20,000 years, i.e. a more longer timescale. The perturbation on the climate system due to Milankovitch forcing over the period of concern re climate change is going to be very small. Basically Milankovitch forcing is irrelevant to the current climate change observed; the latter is happening way too quickly to be attributable to the former.

[@SkillUpMobileGaming]

There is no "warming".

[@LuminousAnima]

IPCC is pure fraud. Go shill somewhere else surdal. wattsupwiththat.com/

[@haleyhutchinson8152]

the title of the video (Converting fractions to decimals (ex2)) has nothing to do with the actual video.....however this video was what I was looking for and is informative

[@justincase4812]

How is it known that the periodicity of the axial tilt is 41,000 years? And, how are the minimum and maximum degrees of obliquity known?

[@davinderdhanjal5690]

How did Millencowitch work out 41000 year cycle?

[@mardinecampbell2870]

Mathematics but I’m not a mathematician. Heard it in geology classes.

[@phaethonsviews]

does anyone know what kind of software was used to make this video and how I can find it?

[@alexflores7652]

Another factor to add in is gravity. The other planets in this system also effect the ecentricity of Earths orbit around the Sun.

[@aalexanderlopez]

Just to double-check I'm understanding this concept accurately, does this mean that the cycle of when summer and winter occur in the northern and southern hemisphere flips? I.e., if we're in the northern hemisphere, will we eventually begin to experience our hot summers during November, December and January?

[@BrogeKilrain]

how does that wobble effect making CO2 so they can tax us for it ?

[@politykanazw6579]

Does it means that in thousands years a summer may be for example in other months than now?

[@thechosenone5644]

Yeah, pretty much. Roughly estimated it in my head and over a lifetime it would only change by a noticeable part of a day

[@tednugent1351]

Thank you

[@libbyharris1749]

+Khan Academy - so does obliquity affect the intensity and extremity of the seasons, and precession the timing of the seasons?

[@libbyharris1749]

I've just noticed that's literally the subject of the next video so yeah dw

[@BackInTheLab2011]

Does nutation cause obliquity?

[@leslie7872]

so which part of the milankovitch cycle are we in right now?

[@custosnocte1528]

Approximately 23.4° tilt relative to the Earth's vertical orbital plane around the Sun. I believe he said we are heading toward 24.5 and then back down toward 22.1 ? That is a really good question though. I am sure NASA has that all mapped out as to what part of the Milkyway the Solar System is in, which would give a good indication as to where the Earth's axis is currently pointing to. Perhaps that is one way of finding out what part of the cycle Earth is in, and what direction the cycle is headed ? Very interesting subject to say the least.

[@Bayubadu]

Milankovich also along with one serbian math teacher `invented` the most accurate calendar, but it is not accepted so far

[@sagebias2251]

Hire an intern to do editing and add visuals with pictures and animations.

[@DauntlessPT]

Incredible

[@stevenhuffnagel]

@Neueregel: astrology does consider the precession of the equinoxes. The problem is that modern people think that astrology is some kind of fortune-telling. Actually, it has more in common with modern psychology and sociology. Do they "work", or are they just "nonsensical social constructs"? Btw. the Great Year is ~25920 years. It's not an "exact" number as the angle tilts between ~22-24°, but it's used in most calculations.

[@hopelivingood1529]

+Steven Huffnagel Thanks for your comment. Do you happen to know the difference in the 41,000 years and the 26,000 years that was referenced? I got lost.

[@JamesMcCormickIV]

@Hope Livingood 26,000 is the precession cycle. 41,000 is the Axis / tilt cycle. The orbital cycles are on a 100,000 cycle

[@davidkeane7802]

Steven Huffnagel Yes-on account of 2160*12=25920

[@troydixon7]

He's a genius almost. I would also add that his explanations have led me not to believe in the Carbon theory.

[@nibiruresearch]

The Milankovitch theory is a complicated way of explaining a cycle of about 25,000 years. But ancient books as the Indian Mahabharata and the Mayan Popol Vuh, tell us that the Earth is suffering from a cycle of seven natural disasters. The only possible natural cause of this cycle can be a ninth planet in our solar system, orbiting our sun in an eccentric orbit. Those disasters are causing massive floods, earthquakes, hurricanes and a bombardment of fiery meteors every few thousand years. Several animal species become extinct and mankind hardly survives. If you don't know this cycle, history is incomprehensible. To learn much more about the cycle of recurring floods, the recreation of civilizations and its timeline, and ancient high technology, read the eBook: "Planet 9 = Nibiru". You can read it on any computer, tablet or smartphone. Search for: invisible nibiru 9

[@DataLog]

I would argue that axis movement of a degree or so could have potentiated effect due to it's effect on moon. Think about it, 384 400km is a lot and that angle could fuck up a lot too.

[@estontin123]

Trololololol its effect is on the angle the sun hits the earth. It has a tremendous effect.

[@MoCassidy]

Wow, does this mean that when civilization began 10,000 years ago, polaris was almost 45 degrees from the zenith? Almost half way towards the equator?

[@vichkovski]

funny all the dragon myths, like quetzalcoatl, since the pole star changes over time, tracing a circle around the constellation draco, over 26k years. maybe the mayans and egyptians were trying to warn that every time precession completes a circle something big happens to earth. like a severe change in tilt, a new equator, or a change in rotation. guess we'll see

[@Thattramp94]

I love you Robbie.

[@YU-mv3ku]

Milankovich Serb

[@KeithHayon]

One thing has always irritated me about the nature of a teacher expressing knowledge. If that subject is not clearly expressed and a person's desire to feel intelligent stands in the way of that message, the powerful essential ingrediants of the magic you describe is lost.

[@GregoryJByrne]

So when the earths inclination is 27 degrees Arctic tilted towards the sun all of the frozen CO2 trapped will thaw raising the level of co2 due to the earth's 26,000 year cycle of the earths axis being tilted either north or south pole towards the sun. This would also cause the earths 26,000 glacial tropical climate cycles. Or global tidal waves washing over the continents when the tilt of hte earth is at 0 degrees.

[@xGravit8x]

You should use universe sandbox :D

[@Paul__FC]

You'll need to exclude all 90's data as corrupt. Measuring devices were place on black roof tops next to ac units.

[@GregoryJByrne]

The planets ClimateCycle is glacial/tropical due to the MILANKOVITCH cycles not co2. Earth has a 5 billion year old closed co2 loop Cause and EFFECT Temperature rises first causing thawing arctic raising co2 EFFECT

[@andaimhineach4131]

Sorry, but still unclear on how the precession wobble doesn't change the angle of obliquity.

[@izzzzzz6]

Where are we right now? ice age wise.

[@dhaba4708]

gooodddd..........

[@romanmindset-r2j]

Precession is 25920 years 1° = 72 years

[@lokynokey4822]

And Al Gore thinks that seasons are caused by the distance from the Sun.

[@doffi213]

Technically true, when the axis is at it's highest at 24.5 degrees it is further away from the sun in the northern hemisphere and closer at the southern. And this will again affect the seasons.

[@estontin123]

christoffer surdal but it's not what cause the season's.

[@chrisw1462]

@@doffi213 Yeah.. no. To visualize: Take the mean diameter of the earth (for simplicity, 8k miles) and divide it in half. That would approximate the difference in your distance from the sun between noon and sunset/sunrise, which is the MOST the earth's axis could change that distance (reality=nowhere near that). Now divide that by 93 million miles. What you get (4,000 / 93,000,000 = 0.00004301) is a 0.004 percent difference (approx.). If the distance of half the earth's diameter makes that little change in the distance from the sun, the much smaller change due to precession, or even the slightly greater wobble of obliquity, is nothing.

[@nikitaw1982]

So we are headed to an ice age some time in the next 8000years and we should up CO2 output to minimize how cold it goes?

[@ravencole2740]

No, you should just relax, live your life to your own measure, and leave everyone else alone.

[@williamhad]

cool

[@stevenjamesdavis22]

helps me understand more of the Mayan calendar

[@MusicalSawMen]

Why not prepare your graphic before the video !

[@jparks6544]

41000 years? Really. The axis was about 26.5 degrees only 4330 years ago from an initial value of 5.1 degrees. An asteroid can ruin your whole day - and smarty-pants theory.

[@zeph6439]

So the earth is like a spinning top.

[@melodyscamman244]

When you think of it, we're more like a small piece of dirt, circling a drain... The sun is traveling through space, pulling us along,.. more like a stretched out spring than a frisbee... But that is for another class

[@zeph6439]

@@melodyscamman244 An interesting analogy! . What I find fascinating is that many ancient and prehistoric cultures have legends which include the precessional numbers.

[@boomafoo9]

Alright ma niggas, we be learnin bout that Milakovitch cycle and we on its tip for the boys. How many times I gotta tell yall we doin it big. These rotations be makin my dogg roll around on the floor he actually loves it haha. How many times are you gonna roll around lol how manytimes. I asked him twice, he never answered

[@SamWatcham]

GEOLOGY WOO JHawk is my homeboi. Also, we love milankovitch cycles, but not as much as dinosaurs or slaty cleavage. Or granite, if you're Alex. Love, the Uplands Geology Crew (and Alice)

[@AIWASS999]

Had to watch this to understand a leak project show just released.

[@BuddhamSarnamGachchami]

for precession its 23,000yrs

[@MoCassidy]

Err, if you're standing on the north pole, I mean :)

[@GregoryJByrne]

Ive been there feels kinda weird no centrifugal forces. other than the fact the sun never set. Flew for two days nothing buy frozen co2/carbon muskeg. There is also a lazer there that shoots up into the sky to measure what the precession of the axis's tilt is. We are heading towards tge vega star as the new north star.

[@StijnHmrAwesome]

weird top comments are weird

[@ekul3374]

Ok, Sal, I love your videos and they help very much, but you need to stop talking about things that you already cleared up in each and every video, and you take around 2 minutes and 30 seconds to explain it in this video. It could have been like 9-10 mins but you rant about the same things in the beginning of every video.

[@RA-fb2qu]

Nope. Have to diagree. I just want to watch this one video. If he left something out I'd have to watch 2 video's. Besides, these are all educational videos for the beginner and any review helps the subject sink in.

[@Melb321]

This is too complicated

[@buggaman2009]

Beware when it reach 24.5 deg Volcanoes will erupt!!!

[@davidandrewwhite5147]

Why would they? One would expect only the climate (average weather) to change.

[@phorrheel5289]

David Andrew White interesting it could be a good theory. . Increase solar energy angle like a magnifying glass on an Ant.. could heat up core trigger? ? Earthquakes volcanic activitie plate movement etc .. i agree w some statements above on them keeping it a secret and preparing to Ensure continuity of "government" lol mafia/fixed game .. while Saying its for something Else as they say the climate is due to us. Never mind not one of us own a nuclear power plant Monsanto etc. The Real polluters of the earth

[@Thattramp94]

In the pants.

[@DDG2023]

Incorrect. The earth wobbles cos Jesus farted. Kthnxbye

[@vlogafter3054]

This could be the cause of climate change.

[@estontin123]

Lulu Dahliah this is precisely the cause of climate change. Except powers that be don't want you to know that climate change is natural and cyclical. No they want you to have less kids live in micro apartments taking less showers and eating no meat. Meanwhile their carbon footprint in one day is more than yours for your whole lifetime. Its an effing joke.

[@jonatanlarsson8617]

The milankovitch cycles have actually been trending towards another ice age (glacial period) since about 8 000 years ago. Temperatures have been gradually lowering over the long-term with rapid fluctuations in the short-term. These short-term fluctuations are unrelated to the milankovitch cycles which happen very slowly.

[@bvaljalo]

@@estontin123 You are wrong. Per these cycles the earth should be cooling these days, not warming. Also, these cycles are not the ENTIRE cause of HISTORICAL (over 1000's and 10's of 1000's of years) cycle of natural climate change. Changing CO2 levels as a result of these cycles also add as a feedback system, exacerbating the effect on earth's temps that the cycles cause. These models explain long term climate cycles, not the earth's temps raising at a rate that's about 20X faster (atm, likely to accelerate) than any natural cycles like these ... would ever predict. It's human's, dude, and it's not even a debate anymore.

[@misterbulger]

can someone please explain how this works to the global warming man made climate change loonies!? how can "98% of scientists" not take this into account?

[@davidkeane7802]

tubeyourself because they all use the same syllabus

[@tsamuel6224]

Worthless collection of words explaining nothing about anything.