The Coriolis Force
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- เผยแพร่เมื่อ 17 พ.ค. 2024
- The mysterious force changing wind patterns across the globe that is caused simply by the earth rotating. For more information I recommend:
Anders Persson, Back to basics: Coriolis: Part 1 - What is the Coriolis force?, Weather, 55, (2012).
Anders Persson, Back to basics: Coriolis: Part 2 - The Coriolis force according to Coriolis, Weather, 55, 6, (182-188), (2012).
Anders Persson, Back to basics: Coriolis: Part 3 - The Coriolis force on the physical earth, Weather, 55, 7, (234-239), (2012).
rus.ums.rshu.ru/file1626
Special thanks to Jeremy Dittmer and Douglas Merrell for their help with this video. - วิทยาศาสตร์และเทคโนโลยี
This channel is underrated! I can't wrap my head around the fact that a channel THIS good is not THAT popular.
This was awesome. Thank you for your hard work.
A very clear and detailed explanation. Very well done!
i'm glad your channel exists. great concepts explained in a simple way. thank you for your work!
Thanks for your work and effort
Hello, Thanks indeed for the time you allocated on elaborating this physical complicated concept, It was really helpful
Outstanding presentation. Kudos.
Hey @It's Just Astronomical! Excellent adjunct vid to the How Weather Works videos. Great stuff, thank you! I'd love to chat finer points to see if I have Coriolis in applied weather contexts clear in my head if you're up for it sometime (I'm currently teaching understanding weather in a year-long format relevant to our context here in SE Australia). Thanks again! J
Loving centrifugal force explanation
😂❤
Thanks for the video, it's awesome!
Thank you, excellent work ,top bloke
Thank you sooooo much!!!!! I have an geography exam and I was so extremely confused with this topic and now I fiinalyy have an answer that makes sense!!! 😭😭😭❤❤❤
Good stuff!
Superb 👍
wow...well done
Please!! More!!!
I'll have to look at this several more times to not be lost after about 6 or 7 minutes. Too many object, too fast. In the mean time, I think I'll stick with what the math says for acceleration in spherical polar coordinates, which is easy enough (for some) to derive. Still, I appreciate your effort on this video. Great graphics! Suggest also a look at George Gamow's book Earth under "world winds" for some insights on this topic.
Very good explanation of Coriolis forces. Is time a victim of those forces as well? We look up at the night sky and see
the stars as they were in the past. But in reality they are no longer there today. They have all moved either away or closer,
and up or down or left to right. Everything is moving including you the person seeing the light of those stars.
So if I took a faster than light spaceship to a distant star it would no longer be there if I traveled directly to it.
Or did I miss the mark on both?
The stars are extremely far away and even though light is moving super fast, the light takes time to get here. What you said is true, but it is unrelated to the Coriolis Force.
You might have mentioned the relationship between the rotational and inertial frames.
amazing!!1
Hi! I'm pretty weak on understanding everything. But I remember a Wikipedia explanation involving a person alternately sitting on a merry-go-round and being suspended above it. Could you do demos in real life, using just one or two balls? Or maybe simulations, but with the merry-go-round context--and maybe fewer balls at once (or, if all the balls are needed at the same time, then maybe starting with only one ball, and showing how it changes with just one--then adding others). Sorry, I can tell this is a great video, just wondered if there was any chance of a slightly more hands-on approach for denser people like me...
Yeah, I maybe should have mentioned this, but there are some pretty good real-world demonstrations showing the effect. For example:
th-cam.com/video/_36MiCUS1ro/w-d-xo.html
th-cam.com/video/okaxKzoyMK0/w-d-xo.html
I guess the explanation is very good but I have difficulty in understanding it :D
At 8:19 you explain that if an object in a rotating frame of reference is moving along the rotation, the coriolis-force is pointing outwards.
But if it's pointing away from the centre, shouldn't it be considered a centrifugal force? Because now this object would just circle around the axis of rotation with a greater speed, therefore applying a greater centrifugal force.
Or does one have to add the centrifugal- and the coriolis-force when calculating the right amount of 'force' that are applied for this object?
Edit:
At 1:26 there are only 2 fictitous forces present. Isn't the Euler-force missing? The force that is so unsignificant that it is only needed for tidal-locking which is really slow haha
Yes, you have to add the centrifugal and the Coriolis force together. That's right. In the case of 8:19, the Coriolis force is pointing outward so they agree with each other, but in other cases they don't. I didn't include the Euler force because I'm assuming the rotation speed is constant. That's a safe assumption when you're talking about a rotating planet. The rotation does not speed up or down much at all.
man you are a genius👑🛐
Eeshk!! 💆 I'm going to have to pick up my brain from all over the floor and watch this again... Probably a lot of times!! Thanks for the moments of comic relief!! And wtf - so the whole thing doesn't affect plug holes and toilets?! So is it basically just a weather thing? If so I might just accept that they always rotate in those ways and leave it at that! 😅🤪🤯😭
Yeah, this was a tough topic. As I was working on this I almost gave up many times, thinking it's just too difficult. I wanted this explanation for an upcoming video about the weather, but maybe I should have just said "the Coriolis force exists, deal with it" and left it at that. I'm happy to try to answer any questions you have.
Yes, it's mostly a weather thing. It occasionally pops up other places. If you're going to be launching any nuclear missiles, you definitely want to take this into consideration. Long-range snipers also will work this into their calculations, but still it's a small effect.
As a physicist I loved the video. There is no simpler way of explaining this with words. It is very dense but reachable. Congratulations. Still, there's one missing direction to the explanation and it is the normal to the surface of Earth. Objects do not fall exactly straight to their nadir on our planet.
Thanks, this video was made for people like you. I'm afraid I just confused everyone else.
@@ItsJustAstronomical Well, confusion is not always a symptom of bad pedagogy. A simpler explanation of the Coriolis force would have been easier to digest but also would have been wrong. Lets face it, fictitious forces are not the most intuitive of concepts in physics. Sometimes when you go deeper into an argument you break that wall of satisfying simple explanations and discover that the devil is in the details. When that happens you might feel more confused, but in fact you are just realizing that you have been confused all the time and now, at least, you have reasons to acknowledge your confusion. This is a good video, and some of its essence will slip thought the cracks of the viewer's brain. I think you've done a good job =)
@Miki P The "vertical" motion on earth is not the same as the third dimension of the reference frames used for explanation. The coriolis force only acts on the plane of rotation (perpendicular to the rotation axis). "Vertical motion" on earth has always two components (except at the poles): parallel and perpendicular to earth axis of rotation. Therefor "upward" motion is similar affected by coriolis force like motion towards the equator, and vice versa. @It's Just Astronomical! please correct me if I'm wrong.
@@enricometzner I think that's right. The part at the end where I say "North is in" and "South is out", it is a little more complicated than that. But I'm mostly interested in the Coriolis force to explain wind patterns and most of the atmosphere is confined to a relatively thin layer above a large sphere.
@@ItsJustAstronomical Although I study meteorology (PhD candidate), it is a while since I learned such basics. I am curious how the next parts will be.
Thanks for the interesting video. I do, however, have a small bone of contention. @ 1:25 you give an equation for the force on a rotating object, where the Coriolis component is 2MWxV. I understand this to be the velocity in the radial direction (radial component of the velocity), If the radius is not changing, this is 0. To me this is a porblem with the table at 8:22 -
- I agree with object moving out away from axis, there will be a Coriolis acceleration pointing backwards.
- I agree the object moving inwards towards axis, there will be a Coriolis acceleration pointing forward.
- however, if the rotating object moves forward (radius fixed, lets just say) - increase in angular velocity....it will experience an outward acceleration due to Wx(WxR) (this is referred to as the Eotvos effect, observed with movement around the earth, in the same direction of rotation)
- in a similar way if the rotating object slows (radius fixed) angular velocity, the acceleration will be directed inward.
In summary, if the rotating object moves along the tangent line (forward or rearward) the overall acceleration experienced will be a vector sum of the centrifugal and Coriolis acceleration.
Agree? Disagree? Please let me know....
BTW Awesome video !
Well, the table at 8:22 is describing just the Coriolis force. It's not describing the total force (the sum of the centrifugal and Coriolis force). The Coriolis force 2MW x V is not just in the radial direction. It can go both in the radial and tangential directions. Am I answering your question?
@@ItsJustAstronomical I am trying to argue it is caused by a radial velocity (or change in radius): Lets consider if a rotating object has a fixed radius, can it experience the coriolis acceleration? Consider a ball spinning on a string : If the angular velocity increases, will it experience an outward force due to centripetal acceleration , Or will it experience both centripedal and coriolis acceleration? The reference I am using is "Coriolis acceleration
by Frank Owen", it shows a great derivation of the equation. Please get back to me, because I am trying to get to the bottom of it myself!
@@markberardi109 Let's just follow the equations. An object in a rotating coordinate frame always experiences a centrifugal force. The centrifugal force only depends on the radius. It does not depend on the velocity. If the object has some velocity in the rotating coordinate frame this results in a Coriolis force. The ball on the string will experience both centrifugal force and a Coriolis force if the angular velocity of the ball is faster than the angular velocity of the rotating frame. Assuming the ball is still attached to the string, the string will pull harder on the ball and it will continue in its circular motion.
At the end you say that it does not affect small or slow objects in motion for like sports and such?
What do you think about Neil Degrasse Tyson saying a professional football field goal being aided by the Coriolis effect?
Don’t snipers have to deal with Coriolis even though it is an incredibly small object? Why would the speed of the object even matter?
Tyson is technically correct, but the effect is very small. Sniper bullets are moving fast enough that it has a small effect: washingtoncitypaper.com/article/224118/do-snipers-compensate-for-the-earthrsquos-rotation-what-the-coriolis/
As for why speed is important, I don't know how to explain it any better than I did in the video. It is complicated. But in every animation I show it's the speed of the object that determines the effect.
@@ItsJustAstronomical well to clarify I understand that the speed would affect the rate of displacement but I thought you were suggesting a minimum speed for objects to experience Coriolis. That isn’t what your suggesting am I right?
@@NotYourCitizenAnymore You're understanding is correct now. There is no minimum speed at which this has an effect. I was just saying the effect is normally not noticeable unless you're talking about things moving fast or large things like hurricanes.
@@ItsJustAstronomical are you aware of the new long distance shooting record holder stating unequivocally that he and is his team did not take Coriolis into account for their record breaking shot?
Why was this channel hidden from me all these days 😶🌫️
It is about the time which has taken to complete the one cycle,,,,not the speed,,,, I think speed of the rotation is equal at the poles and equator,, only the time may be varied because of the area,,,so how much we can stand on coriolis force,,,becoz for me it has been a matter of mystery
WTF? Can we have the girl with the ball back?
Sorry, it's complicated. I thought about putting a warning in that "if you're happy with the simple wrong explanation, just stop the video now." I almost gave up several times thinking it was impossible to explain at all without a lot of equations.
Not to worry...my husband (a helicopter pilot) has tried to explain it to me several times. He’s now threatening me with a conker on a string.
In 11:03 orange object is wrong for inertial frame. If it is true, orange object in the rotating frame should be outer than the blue object. Because if rotating observer goes lower because of its turn and orange object goes higher, then gap between this two thing will be more than the blue object. So it means if gap is more than the blue then distance is more than the blue too. By the way i am not an native english speaker so if i have some mistakes sorry for that.
Also your videos are a favor for me. Because in my country there is no such videos like that in my language and also there is not a school system for these kind of things. So i am very glad to find you. Thanks!
I'm not following you. I'm pretty sure all of motions are correct. I generated them all using the same computer code. The orange object has the same radius between the two frames. In both cases, it's less than the blue object.
@@ItsJustAstronomical Probably I made a mistake. But I can't really see where I made the mistake. thanks anyway
Couldn't there be a situation where the orange body could go higher and be equal in radius with the other orange in inertial frame? Because if I'm going down while turning, and the object is going up, then the distance between us would be greater than the fixed one and the object that is not going up.
I dont really get it
so air drifts
like eurobeat?
CHECK OUT MY ORIGINAL CHALLENGE ON CORIOLIS AND CENTRIFUGAL FORCES HERE:
th-cam.com/video/Shy_-I5-lgc/w-d-xo.html
Bob is on the 45th parallel so he is half way to the north pole, wouldn't he be going half of 1000mph? So 500mph?
My brain cannot process the audio and the visual inputs simultaneously !
I need a biological processor upgrade to be able to understand this :-(
The farther away you are from the equator the slower you’re moving not faster. Just like on a track. You would have to work harder and run faster if you want to keep pace with the person in the first lane if you’re in the fifth. We can run at the same speed but position would put me behind you still. The middle of the earth is spinning slower than when you move towards the poles
You made mistakes is all I’m saying
@@dom_blvcc No, the equator is moving faster than the poles. You're track analogy is wrong. Imagine you have a circular track. Yes, it would take longer for a person to run if they were in an outside lane, but that's not what we are talking about. We're talking about the earth rotating or in your analogy the track is rotating. Or think of merry-go-round. The farther you go out from the center the faster you are moving. In the center, you're not moving at all. At the poles you're not moving.
You are moving at the poles. You're still spinning. You're traveling a greater distance at the equator. It would take less time to walk around the block that it would to walk Your house even if the block was spinning
I knew all about the Coriolis force once upon (a lot of) time while being a student in mechanics, but now I have forgotten everything, and even the so called mathematical culture tends to get lost. I find the graphics beautiful, but I was not able, alas, to intuitively understand things, which is a pity, but it may be only my own laziness.
It's not intuitive at all. I've spent all month thinking about this and it still doesn't feel intuitive to me.
In support of all but the last 2 statements about flushing a toilet and catch which are process oriented effects. I would rephrase to state the Coriolis effect offers no utility in measuring an effect on spin OR trajectory. The author give rise to this contradiction when an offer in hypothetical situations is posed.
I'm not sure I'm following you. It does affect trajectory. In certain high speed settings you do need to consider that the Earth is rotating.
You lost me!
According to the law of inertia, the spinning earth gives you a free ride, naturally and eventually you have to give it back by rotating backwards.
very hard to follow in my opinion and the reason why it happens wasn't clearly explained to me. thanks for trying though, i'm sure many people will find this explanation helpful
The Coriolis effect is a very complicated idea. I have a feeling nobody really understands it. The educational system requires parroting and not understanding. Many ideas are simply assumed to be correct.
Great videos! One minor thing though, the Coriolis "force" is actually an effect and not a real (physics-wise) force.
💖💖💖💖💖💖
Still a mystery to me. Trying to listen to the explanation and watch two reference frames, still doesn’t give any intuitive explanation. The merry-go-round and throwing the ball us a better visual. Maybe you could key off of that for a more intuitive demonstration.
Problem is that the Coriolis effect IS non-intuitive.
Surely great but i'm french, and it was too technical without translation.
Yeah, sorry, this video was really complicated. But you know Gaspard-Gustave de Coriolis was French, so maybe French people would have some special insight into it.
Dude looking like AVGN
Let me try to explain this in my own words: Assuming the setup of Alice and Bob passing a ball while on a disk that is rotating counterclockwise where Alice is further out on the disk than Bob.
The Coriolis force occurs for two reasons: First is due to the difference in speed between the two people. Alice is moving more quickly than Bob at the time the ball leaves her hand. Even if her throw accounts for centrifugal force, throwing the ball directly at Bob will cause the ball to veer right for the simple reason that the ball had an initial velocity (Alice's due to standing on the rotating disk) that is greater than Bob's.
This works the other way too, where if Bob throws a Ball directly at Alice, it will also veer to his right relative to Alice simply because she is going faster than he anticipated, and she will be to the left of the ball by the time it lands.
But there is another fact best visualized in the case where they are the same distance out on the disk. Let's say that Bob is "east" of Alice, such that he will reach a point (in the inertial frame) and then she will pass it a few seconds later). If she throws the ball directly at Bob, the ball will veer to her right and miss Bob because Bob is constantly curving to her left (as the disk moves counterclockwise). Likewise, if he tosses a ball directly to Alice, she will move to his left as the disk turns, and he will miss.
How does this flat disk example differ from the sphere of the earth? It seems somewhat different. If Alice and Bob stand at the same latitude, and Bob stands east of Alice, it seems to me that he is constantly accelerating downward, not leftward. So, for example, if the ball is thrown at the equator, Bob will accelerate downward, and the ball will have longer to fall, but there will be no veering. By "downward" I mean that Bob has not spun to Alice's left as in the flat disk example, but he has spun lower than Alice as the Earth turns eastward. You might say that the case is different at a different latitude, but I contend that it remains the same. If they stand at the tropic of cancer, and Alice throws the ball, the BALL will indeed fly up north of the tropic of cancer, because its parabolic arc is perpendicular to the earth, while the tropic of cancer is parallel to the equator. So you might think that there's some similarity to the flat disk example, but I don't think there is, because the ball arcs back down to hit Bob at the Tropic of Cancer again. So while the ball's arc may be influenced by the Coriolis force, the ultimate destination is not.
The reason I think this is relevant is because that strange arc the ball follows due to the spinning can only be detected over the long arc. But in considering any moment-to-moment "force" on the ball, I think you would need Bob to be spinning leftward (or rightward), not downward.
The Earth isn't spinning! It's Flat.
No, it is not. Be less gullible.
So coriolis force is drift. Got it.
How did nature figure this shit out man xD
I’m afraid that, in the interest of reaching a larger audience, you’ve oversimplified. For the record, and I think you know this, the centrifugal force doesn’t push out it’s another inertial frame trick. The only force co linear with the center of rotation and the center of mass of the object - is the centrifugal force, and it pushes towards the center. There is no such thing as a “centrifugal force”
Maybe, it wasn't totally clear, but the beginning explains that we're talking about fictitious forces that only occur due to a frame of reference change.
Newton was a Christian and a Creationist , he understood that the cosmos has a Creator .
its very clear and dizzy when i try to imagine it. very hate this
The author is confusing himself. And when he said textbooks have it wrong lol but his channel is correct 😅
I stand by that statement.
I said that some textbooks and nearly all TH-cam video have this wrong. Most textbooks and any of the serious ones would agree with me.
This is really overkill. Coriolis force is NOT real, it has everything to do with the observer *anchored* on a rotating frame. The appearance of object moving direction change could be explained by the introduction of this fictitious force. Of course there are mathematical explanations for all of this but simply put, it’s a reference system difference between rotation and translation.
I explain several times that these are fictitious forces and not real and that this has everything to do with rotating coordinate frames. I wanted to give people some intuition for why the Coriolis force acts the way it does. Admittedly, this is a difficult task. But just saying they're fictitious is a hand-wavy argument. It's not an explanation.
No, this didn’t help at all, I’m still totally confused.
But centrifugal force isn't a force...it's centripetal, the opposite.
It is a fictitious force. It's a product of using a rotating coordinate systems. But this fictitious force is pointing outward, not inward. Centrifugal is correct.
3rd
1st
2nd
Gavin, what did you think? Someone give me some real feedback.
@@ItsJustAstronomical very confusing but towards the end when you brought up the cardinal directions it became more clear and I was wondering about toilets in australia the whole time😂
Yeah right. Well somewhat. So let me check on the toilet? However, your voice has done wonders with my mind. Your voice was smooth in the brain and thus I was totally submerged into your explanation. Thank you for the amazing education.
@@ItsJustAstronomical Your video is great and your efforts are appreciated!
I have to admit I found it hard keeping track of 4/8 moving dots and their underlying meanings (also, the "green" is teal, which kept confusing me 😆).
As a result, I understood the inwards/outwards velocities only on a 2nd or 3rd watch and I'm still trying to understand the forward/backwards velocities.
Everything else was crystal clear!
@@almoni127 Thanks for making the extra effort. I think this video probably does require multiple viewings. And a number of people are confused about the colors. I probably should have explained them better.
Hahaha
Hahhaa... Coriolis effect is named after Gaspard-Gustave de Coriolis a mathematician, mechanical engineer and scientist. He is best known for his explaination for the Coriolis effect as a object in mosion from a rotating referings frame to another referings frame looks apper to reflect, or bending from the observer but it's a illusion because the object in reality is going in a straight line!
Has nothing to do with force or any physicallity.. it is not as a central fugu force like as so many wrongly says, it's just a optical illusion! That's it
PS. There is no Coriolis effect in the sky above the earth because the earth is not moving! ;)
I explain that it is a fictious force. Still it is extremely useful because rotating coordinate systems are extremely useful. If you want to express your position as a latitude and longitude on earth and not a point in space that is constantly moving and extremely difficult to measure, you will find things like this helpful.
You are so good at parroting your charlatans without applying a shred of critical thinking, are you Jon? Laughable.