Excellent video sir, we hope to see more videos like these on other physics topics in the future. I think this will be GREAT channel in that regard. Thanks very much !!

@@rohinbardhan222 , thank you. I like physics so probably I will make other videos like this in the future, but videos like this take much time to be made, and I don't have much free time, so certainly they will be not many...

Thank you, your words mean a lot to me, coming from a physicist.

You are welcome, glad it inspired you.

Thank you, Mikhail. My terminology is different from that you can find in books essentially because I didn't study physics and I don't know that kind of terminology well. In the video I use the term "nutation" in the physical sense, (torque free wobble), and not in the kinematical sense, (secondary wobble disturbing the main one). I use the term "nutation" for to tell the "torque free precession" too, (for to make evident that the two movements are the same). I have some good intuition for physics, I found the reason that nutation happens in that way, and I really wanted to share it because at my knowledge there aren't any other intuitive explanations about it. I don't use vectors because I find them confusing, I prefer to use the arrows pointing directly in the real direction of the forces and movements, it is more intuitive and it makes the reasoning faster and easier.

Thank you, Jorge !

Thank you. When I started to understand how nutation works, I really wanted to make this video, and share my thoughts, because at my knowledge there were no other intuitive explanations about nutation. I found various intuitive explanations about precession, but no one about nutation, which is more complex. My explanation is not complete; particularly, I could observe that the nutation speed/spin speed ratio decreases at the increasing of the nutation angle, but I don't understand yet why this happens, if not very vaguely.

You are welcome, Gaurang agrawal.

Thank you, Soumyadeep.

You are welcome, Aghiles.

Hi, Rohin. I try to answer. I made a quick drawing for the following explanation, which you can see at the following link: imgur.com/Xb81WDV - Drawing 1: imagine a spinning top made with a cross and four balls attached to their ends, and a tip. Imagine that there is not gravity, and that the top is spinning, clockwise; without gravity, the rotation axis will not tilt by the time, but will stay with a stable and fixed orientation. Let's observe the trajectory of the yellow ball: since the rotation axis is not tilting, as the top spins, at some point the yellow ball will reach the position where now there is the green ball. - Drawing 2: what does it happen if we add gravity ? Gravity will want to make the top to topple down. More precisely, pivoting on the tip, the yellow and the orange balls are pulled in direction of the red arrows. The two directions are not the same, the yellow ball has a component of the force which is directed downwards, the orange ball instead has a component of the force that is directed upwards. I hope this is not confusing, there are forces with two opposite directions. - Drawing 3: This is how gravity modifies the movement of the top: the yellow ball, A, will start to fall, while the top spins. So, the yellow ball cannot go from position A to position B, as if there wasn't gravity, but it will go to a position lower than B. It will go to position C. But, as the top continues to spin, the yellow ball, which now is in position C, will not continue to fall, because, while travelling from position C to position D, will be pushed UPWARDS, not downwards anymore ! So, each ball, as the top spins, is subjected to a rapid sequence of alternate accelerations in two opposite directions, upwards and downwards, which prevent the top from toppling down. This is a very simplified and very poor explanation... and it would be more correct to consider the two red arrows in the drawing 3 parallel to the rotation axis of the top and not to the direction of the force of gravity... so "upwards" and "downwards" are not the most correct terms... (too lazy to make the drawing again, but the concept should be clear enough...) In the drawing 3, because of gravity the position C is lower than the position B. How much lower ? This depends on the spin speed, because, the lower the spin speed, the longer the traveling time from A to C, where the ball is subjected to a force in downwards direction, so the duration of the fall is longer, and the position C will be lower. If the spin speed is very low, the position C can become so low that the top will topple down, with the balls hitting the floor. In the case of the gyroscope, the trajectory can become so much distorted that the gyroscopic effect becomes disrupted. This also depends on the gravitational torque. At parity of the spin speed, the same top, with a greater torque, will increase the speed of the fall. So, a greater torque, like a lower spin speed, has the same effect to increase the distance between the positions B and C. About your question #2: I am not sure what to say: nutation and precession are two completely different kinds of motion, having different causes, and are independent one from the other. A gyroscope can precess without nutation, (pure precession), or nutate without precessing, (pure nutation), or do both the movements at the same time. In the real world, it is difficult to start a gyroscope without having at least a bit of nutation at the start, and if there is an applied torque, it is normal to have both precession and nutation, at the start.

Thanks for your reply; this definitely cleared things a bit.

Thank you for your kind words, Albert. I could make a top for you, but due to the many requests and to my low production the waiting time is very long, maybe three years at present. My tops are largely hand crafted, it takes me 50-150 hours to make just one set, then I make them during my free time, because my real job for earning a living is making moulds of statues, for these reasons my production is low. If you are anyway interested, you can contact me in the ITopSpin forum, the most important forum about spinning tops, (you will have to subscribe to contact me there), or on Instagram, (simonellispinningtops).