 This is exactly the reaction of any high school student. As far as the laws of motion is concerned, it must go the straight, right? Now I want you to take a pause here and notice, is there something the ball is doing which we are ignoring here? Don't think that you can notice here my dear friends that the ball while it is moving in the air is spinning. To understand this, we need to first notice few things. First of all, whenever an object moves forward and spins as well, then the relative wind velocity at one location is different compared to the other, okay? So imagine there is a ball that is rotating like this and moving forward. So the relative wind velocity over here is lower compared to over there point. So the pressure over here is a lot higher compared to there and because of that, a force imbalance is created and then a force gets generated in the perpendicular direction of the motion of the object and that my dear friend is creating the curve which you have seen. The Magnific makes the sports very beautiful. For example, sports like football, the lawn tennis, table tennis, everywhere you can see the Magnific effect but can we use Magnific effect to do something which is non-sports like? See there is a very beautiful experiment over here. The fan is switched on to flow the air across a cylinder and then the cylinder is rotated counterclockwise. I can see the vehicle is going on the left hand side and similarly when you keep the cylinder in the same way and rotate in the other direction, the cylinder starts moving forward. Now isn't it awesome? Now looking at this experiment you can surely think of a ship which is sailing in the water and imagine just imagine you have two huge cylinders which are rotating on the ship. Let's say ship is going like this and two cylinders are rotating and let us say wind is breezing like that and because of the rotating cylinder and the wind that cylinder could generate a force in the forward or in the backward direction. Now the trick is whenever the wind is blowing in your direction, you need to rotate the cylinder fast and that will help you save a lot of fuel. Over here there are four rotors. Whenever the wind is flowing across the ship and that is a favorable condition right? So I can rotate the cylinder in one way and that will generate a push to the ship in the forward direction and if I change the sense of rotation then the ship will get a push on the backside direction. Now looking at all of this what else do you think where you can use the Magnus effect for? One thing where people have used it and tried using it but failed was to creating an aircraft where they can have two three cylinders which are rotating like that and moving forward and as the cylinder rotates because of which there is a velocity difference from bottom to top and the lift get generated. But it has not been successfully commercialized. The reason was that even though the rotating cylinders were able to generate the lift but then also there is a lot of drag that was getting created. And having said that people are still trying to break through it and people have tried creating a lot of toys over it. For example you can see here this guy has just made a rotorcraft base out of the AFC buckets. You can see the lift is generated because the rotors are rotating but it has crashed because we don't have that much of technology. So are you the one who can successfully utilize this Magnus effect to create a great aircraft?