The Magnus effect: a curved ball explained: from fizzics.org

A spinning curved ball, caused by the Magnus effect is loved and hated by players of all ball games. Top spin makes the ball dip and side spin makes it curve or swing. The video provides examples and an explanation of the cause of the Magnus effect.
Supporting notes are available here: www.fizzics.org/the-magnus-ef...
Notes and many more video lessons available here www.fizzics.org/fizzics-guide/

[@tonywo2735]

I just watched Magnus Carlson playing chess and youtube somehow thinks I need this.

[@djgulston]

Very good explanation! Very easy to understand. I really liked that last experiment with the cylinder. Such a cool effect!

[@vladimirhatter4959]

The last experiment is excellent！

[@johnbarron4265]

Hello, tangent of the angle of the diagonal of a cuboid with respect to the base. For real though, that's a cool profile pic!

[@kevinjoubert7545]

Your improvisation in demonstrating these techniques is quite impressive.

[@fizzicsorg]

Thank you

[@fizzicsorg]

In reply to Prateek. Hi yes, all of what you say is correct. There are many variables here including the nature of the surface of the ball. As you say the force is not perpendicular so a ball so it is likely to be slowed or speeded up depending on the point on the ball where the laminar flow fails, although I think (but I've never tested it) that the change in the translational kinetic energy and hence the speed (as opposed to velocity) only changes a little.

[@enduroaustralia7127]

+Roger Linsell I'm doing a student research project on this topic and I was wondering if you knew how you could control the variables in order to undertake this test. Thanks

[@michaelpiotto4988]

ENDURO AUSTRALIA use water in thing or make a smoke box with a dan

[@Abuydabab]

I've recently had a homework to describe this effect. Most articles on the internet say that it's about Bernoulli's law, but i also found several videos (for instance Yours and on Veritasium youtube channel) saying that this effect is more probable to be connected with 3rd Newton's law. As you wrote below in comments it is hard to measure size of the contribution of each of these effects. Sadly my teacher doesn't know that fact and Bernoulli's law is the answer he wanted to see. Thanks for explanation

[@fizzicsorg]

Suggest that he researches it a little more! And then duck.

[@lozange]

nice and easy to undertsand good!

[@DrTWG]

Great demo !

[@noxusfumes3628]

Great illustration

[@asturiashuelva]

Fantastic explanation👏👏👏

[@sinekonata]

Since there needs to be friction between the fluid and surface, can you augment the Magnus force of a rotor if you put blades on it to augment that friction? If so why haven't I ever seen a "Magnus rotor" with blades?

[@baraskparas9559]

In my estimation the effects of the front and rear of the ball or tube cancel each other out and the lift is caused by the under side pushing air into an oncoming air stream ( higher air pressure and turbulence) whilst the top surface pushes air with the oncoming air stream ( lower air pressure and turbulence ).

[@roderickgustavopivovarski912]

Brilliant explanation! Thank you, ser!!

[@fizzicsorg]

Thank you

[@someblokecalleddave1]

I've been racking my brains trying to get how this works in relation to drift in cricket. I think I have at last. Most of these diagrams relate to the ball spinning and moving along a horizontal plane. Whereas the effect is most prominent in cricket as the ball starts to drop, so this theory also relates to the ball spinning and dropping?

[@prateektathicherla8453]

Would the transitional velocity of the ball affect the lift on the ball? I would imagine the wake would be longer and the resulting force would be larger in magnitude as well. Also it seems that the Magnus force is not perpendicular based on this explanation but only that the force contains a vertical component causing the lift. How does the horizontal component of the Magnus force affect the ball as it would seem that the ball would have to go faster based on the direction of the horizontal force.

[@Bob_Adkins]

I always thought that was a much simpler effect. I thought the tube or ball was "climbing the incoming air" because the leading edge has more friction due to more pressure. The simplest explanation is usually right, so... Experiment: Spin a suspended cardboard tube. Blow on 4 sides with 4 air nozzles simultaneously using the same force. Now increase the force on 1 nozzle by a tiny amount. It will climb at right angles like a tire.

[@markynio]

Nice explanation but the thing i loved the most was your super-great voice accent :D

[@fizzicsorg]

Thank you!

[@R9A9V2]

tnx for that vid it was fun

[@nightwng]

I was searching for techniques in shooting a basketball. Instead, I learned something very useful. Thank you.

[@magna59]

" shooting a basketball " AK 47 would be a good route . Sorry , cheap , east bank of the pond humour !

[@siddhantchaudhari6664]

+magna59 heh heh. nice one. :D :D

[@tommyjenga5976]

Great video. Pleasant British accent, and succinct explanations-- what more can you want from a man?

[@fizzicsorg]

That's a very nice comment, thank you!

[@joelrivera5596]

Nice video 👍

[@marcuschan3906]

why does air cling to the surface becasue speed is slower?

[@pavanpal3504]

What if the spin is parallel to the air flow? How does the air still produce a force?

[@nikhilshukla8828]

Great explanation professor ...

[@fizzicsorg]

Thank you.

[@carlkohweihao9584]

Could this be explained using Bernoulli's principle too?

[@asturiashuelva]

Seeking an explanation for the differences between rotor sails and suction sails

[@soniacastro597]

Hello! I am a big fan of your channel. I lost the link of the experiment in which you make noticeable the motion of a wall by using a laser reflected in a cd. Is it possible to get the link again?

[@fizzicsorg]

Well thanks, but I don't think that's my video

[@StarCrossedGaming]

Mate, I do believe the magnus effect is due to air currents rolling off of the surface and newton's third law creating thrust in the opposite direction/angle of the most substantial air current / surface interaction. The question arises, will a more rough surface create more air friction, and thus more air rolling off of the surface; or will a rough surface nullify the magnus effect by creating more turbulence in vital locations for thrust?

[@fizzicsorg]

Hi good question but I don't know. Experiment with a table tennis ball first smooth and then roughen?

[@StarCrossedGaming]

Sounds like a good plan of attack.

[@gauthamsnair6665]

Hi, I am currently doing my masters thesis on it and turns out it enhances the lift generated in some cases depending on the kind of roughness used! In my studies we found out that when there were ribs along the span of the cylinder, the lift force generated was significantly higher with lesser drag as well!

[@StephenRayner]

Can this effect be used in turbines specifically VAWTs?

[@VigorousVirgo]

This also happens in the NBA

[@stormynite6]

Your diagram says "air speed over the surface is lower" means it should have higher pressure compared to area near lower surface. Means, ball should deflect down but your experiment shows the other way.

[@seenivasankrishnan5786]

Hey roger,, just wanted to know if the ball iin the diagram is undergoing topspin or backspin?

[@fizzicsorg]

Neither since that is a view from above. I guess that is side spin

[@azaruddinshaikh4220]

Thank you very much Sir. Please correct - I feel that the rotation of the ball should have been in the clockwise direction i.e. along the direction of flight, in the diagram. If my concern is right then other indications in the diagram has to be changed accordingly.

[@anganson6177]

yaya true i think the rotation of the ball should be clockwise

[@Maka_Maka]

This confused me as well, did you ever find an answer? Edit: Lift force = - circualation x density x velocity of fluid And circulation is derived as being positive for counter clockwise, so assuming fluid flow of left to right ( ball moving to the left) with a counter clockwise spin, the force should be downward (provided my understanding is correct!)

[@troelsvejenchristensen8850]

So nice! :D

[@VvicsieE78]

Thank you, finally a video with spoken words instead of shite music

[@monishreddy1797]

Sir, I have a doubt here. I understood that there will be an net upward force perpendicular to flow direction, due to pressure difference which is called magnus effect, but will the body experience any drag force in the direction of flow, in other words, will there be pressure difference in the horizontal direction, just due to the eddies formed. Thank you

[@gauthamsnair6665]

It sure does! Whenever there is a lift generated, drag is also generated. But this depends on the rate of spinning of the ball as well. There is a range of rotation rates where the drag is even lesser than a non spinning ball even though it generates a lift which is really interesting because of its potential applications in aeronautical industry!

[@ShanHexis]

here high pressure pushes down. but ball moves up.(Newton 3rd )if ..what about aeroplane wings..( wings moves low pressure side!!)sorry I m confused

[@fizzicsorg]

For an explanation of wings look here kzbin.info/www/bejne/bIKbeaapprx3eqc

[@hamsreal]

If the force down creates equal force up, why don't they cancel out,

[@kmundendy660]

Thank you for the explanations. I would love to know would happen if the experiment is redone either with a more heavier(say metal) tube or done in vacuum.

[@fizzicsorg]

With a heavier tube the effect would be less pronounced. In a vacuum there would be no effect at all.

[@surajsinghbhandari9340]

I think you didn't understand the experiment all is happening because of the air presence ( The air that is present in the surrounding or by externally by the force of like fan or wind also is the perfect example that is blowing only by one direction) Followed by mentioned in bracted column above :- By surrounding means like you are rotating any object in the direction means you have to give the object motion only rotary motion you can give it will not happen in sliding motion and this will happen. Air presence is creating the boundary layer phenomena which causing the object to rotate in opposite direction How: 1. Surrounding case we are rotating the ball in by inclination we given the ball a rotating motion when it is falling the static air is affecting opposite to the motion of rotation which causing this to swing in opposite direction as lighter the weight as much this will affect lastly gravity forces are much stronger then reaction generation forces right? that is why your first and second question gets covered.

[@imumen406]

If we apply Bernoulli equation , is the final answer correct? Or is the magnus effect part ,not being present make the answer wrong?

[@fizzicsorg]

Not sure I understand your question. I don't know what conditions or situation your question refers to.

[@renanuness15]

Nice video. Is there anyway to calculate the moviment caused by this effect?

[@fizzicsorg]

Well there are many variables such as the velocity, the speed of rotation and the texture of the surface so an estimation is possible but close calculation problematic.

[@renanuness15]

Thanks for answer. Which subject can I study to learn how achieve this estimation?

[@fizzicsorg]

It is within the study of aerodynamics. Google Magnus effect calculation

[@magna59]

Great to see the footage . Dining roof flight testing , should have tax advantages !

[@lukekairies9536]

Hi Roger. Just thought i'd let you know that your air flow chart is wrong. First of all the top side would have a faster velocity of airflow over the ball, as the velocity of air flow is dependant on the velocity the object is travelling through the substance and spin velocity. This would create a LOW pressure at the top as the air is travelling at a high velocity and a HIGH pressure at the bottom because the air is travelling at a low velocity, as stated in Bernoulli's principle. This is the factor that causes the swing in a spinning ball, the sudden drop in a top spin and a ball to hold up during back spin during flight. I find it easier to understand if you draw yourself a diagram, label the spin of the ball, label the direction the ball is travelling, and the opposing air direction and how it flows over the ball (like you have). Now, the air travels over the ball at the same time on both sides, what changes is the distance it has to travel. Therefore the velocity of the air (on the top side of your diagram) has to be greater to compensate.. Now think about the stuff i said earlier about the LOW pressure and HIGH pressure and Bernoulli's principle. I hope this helps any students sitting biomechanics tests in the future :) If anyone can correct me and explain why I am wrong please do so!

[@fizzicsorg]

+Luke kairies No, I don't think I am wrong. The deflection does not depend on the Bernoulli Effect but on the rather more well known Newton's Third Law. The air is deflected (downward in my diagram) and there is a resultant reaction on the ball in the opposite direction, this is called The Magnus Effect, as in the title.

[@lukekairies9536]

+Roger Linsell 'When a sphere moves through a fluid and it spins, it increases the speed of fluid on one side, and reduces it on the other. As the speed is inversely related to its pressure (from Bernoulli's equation) there is a pressure difference at right angles to the direction of flow causing a lift force known as the Magnus force.' See: P.Grimshaw, A.Lees, N.Fowler and A.Burden's 'Sports and Exercise Biomechanics', 2006, published by Taylor and Francis group. Pages 238-246 on forces in a fluid. But I would like to see where you are getting your information from? Could you please send me a reference or a link?

[@fizzicsorg]

+Luke kairies Hi Yes I know there is also a pressure difference and there is a difference in opinion of which has the greatest effect, it rather depends upon which pieces of research you read however the difference in air speed is not huge and therefore the difference in pressure operating on a fairly small area is likely to result in a small force. The reaction of the change of velocity of the air flow seems likely to be a greater force and a better explanation but it is hard to measure the relative contribution of each effect.

[@asambhav47]

The fluid that "cling(s) to the ball" is going to be moving in the same direction as the free fluid when at the top, therefore the fluid at the top is faster. That's the "intuitive" way of thinking about it. I'm still uncertain as to why that isn't actually what is happening. I understand what Roger is saying, the velocity at the bottom is faster since that point of the ball is spinning the same direction as the ball itself. Therefore, the fluid "clinging" will just be the same velocity as the ball velocity as an outer point (therefore faster at the bottom). Maybe I'm just confusing myself.

[@tassawariqbal3694]

You can't invoke Bernoulli if the the velocity of the airflow around the ball depends on the velocity of the ball (i.e. there are viscous effects).

[@Nohlannet]

1:42 Isnt the arrow discription on the bottom and top not wrong? The airflow is on the bottom slower, than the airflow on the top of the ball. Because this (and because, the upper airflow rotating with the ball and hits the bottom airflow) , we have a high pressure on the (left-)bottom, and a low pressure on the top of the ball. So the ball is moving to the top.

[@fizzicsorg]

+Nohlan I think they are correct. The lower surface of the ball is travelling faster with respect to the steam of air because it is rotating towards it. There is likely to be a pressure difference but the main effect is the deflection of the air (towards the bottom of the diagram) and the resulting reaction of the ball in the opposite direction.

[@StarCrossedGaming]

The label on the air arrows are incorrect, simply because a faster air speed at the bottom of the ball as well as a slower air speed above the ball will create an area of lower air pressure below the ball- thus making the ball go down. The arrows on the ball demand the ball to have upwards thrust- not downwards thrust (as I have tested) Another flaw with the labeling of the air arrows is that, you say the air below the ball has quicker movement due to a combined speed with the surface of the ball, when the ball's arrow surely notates that the bottom surface is going _against_ the air-flow at the bottom. A vice-versa effect is apparent for the top of the ball, as well. There is certainly something wrong with the labeling and/or the arrows.

[@karandeepblogger8867]

it is correct bcs velocities subtracts when in same direction. and added when in opposite direction. i.e upper part will be slower w.r.t air

[@PlsDontReadThis123]

Roger Linsell when you run simulations stream velocity at the top is higher.

[@nimanthadilz]

Nohlan correct, the diagram is wrong.

[@backYARDbanter13]

Thanks

[@fizzicsorg]

Glad it was useful

[@MrYahya0101]

"The force pushing the ball down results in an equal and opposite force pushing the ball up" (2:13). Newton's third law would state that the force (by the ball) pushing the AIR down results in an equal and opposite force (by the air) pushing the BALL up. Is that what was meant?

[@AV036]

Do artillery gunners correct for long range shell spin in the same way as Magnus effect on the cylinder?

[@fizzicsorg]

No because the direction of movement of the shell is along the axis of the spin rather than perpendicular to it.

[@AV036]

@@fizzicsorg Is cross-wind the [only] long -range correction needed? e.g. same long-range target by interchanging ordnance: [ rifled (spin) vs sabot, smooth bore or fin stabilised ]

[@fizzicsorg]

@@AV036 I'm no expert in gunnery but it may be that different cross wind correction is needed for different ordinance. It seems very likely that speed, therefore time in flight, would make a difference. As I suspect you know, rifled spin is used to avoid the ordnance tumbling but a strong cross wind may effect the flight due to the spin.

[@carmelpule6954]

This is a very interesting "human" communication situation as it looks like Mr Roger Linsell is seeing one scenario and he is correct, while others are not looking at the same scenario and some beg to differ with the author, yet they too are correct noting the direction and states that they are considering . The result is a mix up in a human communication situation depending on the location where we are looking and the states of the air particles. Let me try and explain in a method which I have never done before. 1. We have to assume that the particles of air touching the rotating cylinder , is the same as liquid touching the sides when it flows in pipes, this air/liquid touching surfaces move with the same velocity as that of circumferential speed of the cylinder or zero velocity in a stationary pipe. 2. For the sake of explanation let us assume that on the walls of the circumference of the cylinders there are very small protruding paddles as found on a river paddle wheel. It is the gap between the paddles that causes the air particles to have the same velocity as the circumferential speed of the cylinder. I have no doubt that along the rotating paddles on the circumference of the cylinder there would be some centrifugal action taking place which we shall use later on. 3. When the cylinder rotates but does not translate, keeping the same position, the action of the paddles is uniform around the cylinder, so any phenomena that occurs is equally distributed all around the cylinder and so the cylinder churns it all out in all directions WITH RESPECT TO EARTH, and hence , its centre, does not move in any preferred direction. Since in this state of affair, all air particles in the air are stationary with respect to the ground, then small men standing in between the moving paddles could never shake hands with the ladies swimming in the stationary air particles!! 4 Now when the cylinder moves as shown on Mr Linsell's diagram, and let us assume that the circumferential speed is the same as the motion forward, then with respect to the paddles and gaps between them, the air is moving faster, below the cylinder, twice as much in fact, to the stationary air away from the cylinder and if we still assume that there are small men standing between the paddles, then when they passing the lower part of the cylinder, they could not shake hands with any one standing in the air some distance away from the cylinder as their arms would be torn off by the slipstream. But when when one consider the men on the upper part of the cylinder, well , they would be stationary with respect to the ground for a second and so they could shake hands and do whatever one can do in a split second, with any one occupying a space in the air particles near the cylinder. 5. Now the men in between the paddles are in for a surprise as the centrifugal action throws them out from their comfortable spaces and as they are thrown out well , under the cylinder they would change the momentum of the stationary air, a little distance from the cylinder by making it move in the same direction while the men who are throw out will lose their momentum and their original speed, hence compression. Those on the upper side well , it the circumferential speed was the same as the linear motion forward, when thrown out by centrifugal action, the men would not even bat an eyelid as they would be stationary with respect to the stationary air particles. But if the linear forward motion was not as high as their circumferential speed well, then, when they are thrown out by centrifugal action then they will hit anyone stationary and will move him forward in a differential manner . So basically, the air below the cylinder, a slight distance away has been accelerated forward from stationary and so compressing the men who emerged from between the paddle, while that at the top the men simply stepped out, and not even moved if the circumferential speed was equal to the peripheral speed. If the circumferential speed was higher than the forward velocity, the movement of the air particles in the back direction would not be as much as the movement forward, below the cylinder, This is where the differential pressure come about. Those little men between the paddles below the cylinder will be slammed against the stationary ladies loitering in the air particles, and that will slow the men down, while above the cylinder the men will simply step out and cordially meet the stationary ladies awaiting them. If the circumferential speed is different from the linear translation motion , well the reader can see that the air slightly away from the cylinder and not in between the paddles will be affected differently for those air particles on top compared with the air particles below the cylinder. 6. I feel that all that explains why Mr Linsell showed the arrow with the statement," This side is moving faster because of the combined action of the rotating cylinder and the forward speed." 7. I should complement Mr Linsell on the fact that the two little vortices shows nearest the cylinder are rotating in the right direction, but I am afraid most of the others he could have been a little more careful, as primarily there would have been two larger vortices, one above the other circulating in that gap behind the cylinder. Where they touch the "stationary" air particles above and below that bubble gap behind the cylinder, both vortices will have " stationary or low velocity air, but at a central position in the low pressure bubble they would be moving as fast as the linear motion of the cylinder. If the linear motion of the cylinder increases then Mr Linsell is correct, these two primary vortices will break down into what he showed and the sealed low pressure bubble will create a " hole in it" to introduce higher pressure air from the back . 8. If the circumferential speed is say 20 mph and the linear speed is 100 mph, what was described above will result in a theoretical RELATIVE speed of 120 mph above the cylinder and 80 mph below the cylinder. It is interesting that below the cylinder the distant compression zone as the men where thrown out to move at 80 mph for an instant, will make up for the speed retained by the men who still occupied the spaces between the paddles!!

[@fizzicsorg]

This is a hell of an explanation. I think I agree but I will have to reread it a few times

[@carmelpule6954]

Just to finish this off, the velocity additions are not exactly as stated as they are vector additions and not linear ones so the 120 mph and the 80 mph need reconsidering but when a non rotating cylinder is moved through the air, at 100 mph, with respect to ground , then the most front part or the "stagnant point" is also moving at 100 mph with respect to the ground. But when the cylinder is rotated with a peripheral speed of 20 mph then the air particles will have an upward velocity of 20 mph and a horizontal velocity of 100 mph so theoretically the air particle will move with respect to the ground at the square root of (100^2 + 20^2) and so the stagnant point will move to a lower position , where the relative velocities, will decide where the new stagnant point will now exist. All this is what makes the cylinder to float in the air. Incidentally due to the fact that the low pressure bubble behind the rotating moving cylinder has that particular shape, one can fill it up solidly to produce the more conventional wing airfoil section and the fact that the air below is slower than that emerging from the upper surface, the multitude pairs of helixes or vortices that form behind the trailing will be lower and more controlled, provided that the angle of attack is not increased too much as turbulence will occur which will, form a " virtual pipe" which will bleed higher pressure atmospheric distant air into the low pressure bubble and the wing will stall. When not stalling, the "flight path" of the air particles above the upper surface due to the upwards accelerated air particles by the wedge angle on the upper surface of the leading edge of a wing produces a sealed moving bubble of air above the wing which works in conjunction with the compression zone existing below the wing. The wedge angle of the leading edge of a wing, forces air particles to accelerate upwards to a flight path above the upper surface of the wing as this passes under, this does replace the rotating action of a cylinder shown in this video, and what is more, circulation of air around the wing still exists as in the circulation of a rotating cylinder. What goes on when the low pressure bubble above the wing tries to collapse, due to higher pressure above it and the wing being lifted while the low pressure bubble is continuously being revived by the forces on that wedge on the leading edge........... well that is the miracle of airfoil sections. This was rather long, but then there is so much to explain and this is only a little of it.

[@qaboosmintaka5337]

I don't understand why the stream of air breaks away from the surface of the ball...can someone explain it to me?

[@fizzicsorg]

Remember the ball is flying through the air. The flow of air has to break away from the surface somewhere or all that air clinging on would quickly stop it.

[@Dr_Asma_physio]

Helpful!!

[@fizzicsorg]

Thank you

[@solapowsj25]

Use the standard Boeing wing with FET ion flow to replace the mechanics demonstrated above to get to Mach one and above for passenger flight ✈️. Integration. SJRTC.

[@yonatanshenhav1208]

What i don't understand is this - if the upper side air applies a downwards force on the air coming from below, why is it that the BALL is the one getting the opposite force and not the air? I would expect that the momentum would be conserved by the upper side air coming down at an angle as presented in the video, and then "bounce" back at that angle upwards

[@PlsDontReadThis123]

Yonatan Shenhav he got his vector descriptions wrong when you make it a FBD about it

[@mogusmorbius21]

Roberto Carlos shoot is the perfect example

[@GabrielGreedy]

now, we need a plane with rollers that spin very fast :P

[@THE_MC707]

Does it have something to do with the Bernoulli effect?

[@fizzicsorg]

No, I don't think so.

[@THE_MC707]

@@fizzicsorg ok thank you.

[@shardaalawa4302]

thank-you sir you explain very practically I see a Indian video who tell only about theory and boring formula they don't actually know real science

[@fizzicsorg]

Thank you

[@SL-my4fg]

Excuse me mister...but here even diagram are wrong . Idk what you have toward Indians..but don't just watch one video and come to conclusion bashing the whole nation.. I've seen better explanation on Indian video much elaborated with explanation and experiment...I don't know hwere your inferiority complex is coming from but please you look desperate as well as disgusting

[@virenderbhardwaj3137]

But the air upard on the cylinder gets curved around it because of coanda effect and its caused by entrainment of air, so the upard air (at atm. Pressure) pushes it downward and it gets curved around the cylinder. So cyclinder is not what applying the force on air to get it curved, its the atmosphere, how the hell we can say it the air is moving down so it apllies an upward force on cylinder, equal and opposite forces occurs when the force on object 1 v mes form object 2, here object 3 (the cylinder) is experiencing force out of nowhere

[@augijyotbali2131]

Physics has got beauty baby !

[@ostanin_vadym]

Thank you for content. But I think there is mistake in you diagram. Bottom side moves slow, because directions of cylinder and air are opposite. Top side moves faster, because directions of cylinder and air are same. Bottom side has higher pressure, Top side has lower pressure, and cylinders is pushed upward.

[@fizzicsorg]

I think I have it right, but thank you for watching and taking the time to comment

[@riazhassan6570]

Fizziks Orgamisation, please look at the chart again. What this commentator says seems right. The air is being dragged forward at the bottom. It pushes against the stream and is therefore slower than at the top where the reverse is happening. The would have the effect of compression at the bottom and attenuation at the top, resulting in a pressure differential

[@bluescreen6734]

i just want to finish my homework😭😂

[@douwemonsma5874]

2:01 Shouldn't this be "The force pushing the AIR down results in an equal and opposite force pushing the ball up".

[@kokeskokeskokes]

The stream of the air on that side of the ball ... therefore clings to the surface rather more and because of this it's deflected slightely downwards. This doesn't sound right to me. Is this established fact? Can I learn more about this? The slower the object, the more sticky? Would you consider this? On top side surface of the ball doesn't move so much against the air, ergo there is less air resistance at the top, ergo the ball ends up moving upwards.

[@fizzicsorg]

To move the ball up, as in my diagram, requires an upward force, frictional resistance to forward movement does not provide that. There are a number of information resources of varying quality. Check those out with a good reputation e.g.Institute of Physics (UK). NASA, American Physical Society

[@kokeskokeskokes]

Why NASA? This ain't no rocket science. Imagine simpler situation: You throw a ball in such a way that it barely brushes tops of your bush. Bottom half of the ball will be in path with greater resistance. Now the question is: Will the ball bounce off the tips into a path with less resistance, as I claim, or will it keep going straight regardless of obstacles, because frictional resistance to forward movement does not provide that?

[@fizzicsorg]

Why NASA, because they have good explanations such as www.grc.nasa.gov/www/k-12/airplane/beach.html . I you tried using your brain before your keyboard you might get on faster.

[@kokeskokeskokes]

Thank you for the link. I understand the phenomenon is by large ununderstood. That doesn't mean we have to behave like childern and accuse each other of brainlessness. I value what you do, you could also consider I have explained airfoil in my own way, as well as I have calculated ideal lens, lift turbine and lift propeller, see my channel for details. My questions are: - The spinning ball moves relatively faster on one side and slower on the other, top faster at your drawing. Correct or not? - The greater the relative speed the larger air resistance. Correct or not? - The greater the air resistance, the greater the chace the ball will choose simpler way to fly. Correct? This doesn't mean Magnus effect is explained incorrectly. I personally find it fishy, but I blame noone. I simply gave my questions and await answers.

[@fizzicsorg]

OK, but this is a well researched bit of aerodynamics for which a stream of air around an spinning object is shown in wind tunnels (nice bit of video on Wikapedia which shows a layer clinging to the relatively slower surface) and I was irritated that you simply dismissed the NASA article when aerodynamics of rockets is very much their field. I cannot really see any convincing explanation that does not involve the redirection of the air stream.

[@invalidaccount6147]

Loved it😘

[@fizzicsorg]

Thank you

[@manmohanbisht69]

Speed of air will be less at the bottom, creating high pressure.. Ball should move up...

[@prodjpc34]

I would love the ball to break the window at the beginning 😂

[@fizzicsorg]

I missed that bit out!

[@aw3452]

u spelled physics wrong :(

[@Observ45er]

Because the curved path causes a pressure decrease and the path of the curve is longer on one side, the total force is decreased more on that side. PRESSURE difference. Saying "newton's Third Law is the result, but misses the actual cause.

[@fizzicsorg]

No, I think you have misunderstood. The upper curve, to which the airflow clings, together with the "angle of attack", the inclination of the wing, deflects air downwards which has the effect of pushing the wing up. That is Newton's third Law. There is also a pressure difference between the upper surface and the lower which adds to the lift.

[@Jorasaurus]

Giving me anxiety at the beginning of the video throwing the ball towards the house

[@fizzicsorg]

It survived!

[@Mr_Seppo]

hahaha, he didnt explain it easy, he made it harder to understand

[@basiccreations1876]

ig brought me here

[@user-zh1tw2gc9s]

ты неправ падумай пачему велосипедист непадает-есть еще раскрученый валчек пака крутитса непадает

[@wgb8210]

This video clarified nothing.

[@GhostHawk272]

POV: you’re here because of chess

[@lomasck]

Wrong!!!!!

[@fizzicsorg]

A wonderfully succinct argument. I don't think I am wrong but perhaps you would like to explain.