The Top That Spins Forever

oh it's still going look at that it's not stopping in the movie Inception one way the main character played by Leonardo DiCaprio knows that he's in a dream is whether his top keeps spinning forever if it falls over then he knows it's real life well if he had this top he would definitely think he's in a dream because it never stops so how does this keep spinning obviously there's something powering it but how could something power to keep spinning when there's no wires or anything touching it this is just a plastic bottom that it's on and the top itself is made of plastic as well so how is there actually power getting sent to the top to keep it spinning and what type of power could keep it turning like that well to figure it out let's open it up and see what's inside so the magic is what's inside of this base here so you can see that it's actually pretty simple inside we literally just have a battery and a coil of wire and then a little part of the you can't see it's just a tiny transistor so just three parts here a battery a coil of wire and a transistor and if you don't know what a transistor is it's just a switch that turns on when you apply a voltage to it so because this is a coil of wire we can assume that this is an electromagnet but notice that I have a neodymium magnet here notice that it's not attracted to it at all so this electromagnet is not on right now so what actually turns it on well notice that in the base of the top there's just a ceramic magnet in here so this ceramic magnet let's see which way it's poles are facing so this is a North Pole of my magnet here you can see that it wants to be on this side if I turn the magnet it wants to repeal it so this side of the magnet is a South Pole and notice on this side it's repelled and it wants to turn the other way okay so let me show you what I mean so I've labeled the two side to the magnet on the top here so the red is one pull and the blue is another pull and then I have a permanent magnet here that I have labeled with its red and blue side here so you can see that the blue side is attracted to the red side so they're the opposite poles attract if I turn it to this side now the red side is attracted so notice how I can get it to spin by changing which way it's facing so what I need is a magnet that turns its field off and on right when the corresponding field of the top here gets it the right spot to be pushed away so that it's always being pushed away and keeps spinning but notice what happens if you wanted to spin fast you needs a field that turns on and off really fast and that's where this special circuit comes in okay so as soon as you start spinning the top the poles of the magnet are alternating really fast and if you have an alternating magnetic field what that does in a coil of wire is it induces a voltage in the wire so basically if it comes near this coil of wire it induces a small voltage and it's enough to turn on this transistor so now this switch closes and it's going it's a complete circuit and now that we have a complete circuit now the current can flow through this and now that there's electric current flowing through it this coil of wire itself becomes a magnet but the thing is it becomes a magnet with the opposite pull of the pole that just turned on the magnet so as soon as it spins past it is now the opposite pull of this red here it becomes blue and pushes it away but now that it's pushed it away the transistor now turns off because there's no longer an applied voltage so it doesn't repel the blue side here so the blue side can just pass freely and then the red side comes around again turned on the switch pushes it away the blue side comes by without being repelled and we can see this happening if only we could see when the transistor was turned on and off and I can do that by putting an LED light in series so basically putting a light in this connection here so that when the circuit is on the light will be on so however many revolutions per second this is doing the lighting up of the LED light should match that so let's look at this in slow motion and see if they actually match now it looks like it's just steadily on but if you look at slow motion video of it you'll notice that the light is actually blinking really fast so the blink rate corresponds to how many revolutions this top is doing the more revolutions the faster it blinks so now that we know this works by the use of an electromagnet I know all your perpetual motion is out there we'll say well why don't we just take out the electromagnet then we don't need a battery put in a permanent magnet and then it will literally last forever and the battery will never run out and we have perpetual motion well let's see if that actually works okay so I have here a permanent magnet I'm going to stick it below here put my top over it now now let's see what happens when I try to spin the top on top of it nope okay so why doesn't this work why doesn't it work with a permanent magnet in there well it doesn't work because the magic of this system isn't that there's a magnet inside of it the magic is that there's a magnet inside of there that turns on and off at just the perfect time so that it pushes one side at the top away from it and pulls the other side towards it so that at just the right time it turns off and on off and on so we need a magnet that's not a permanent magnet with always the same north and south pole facing but we need a magnet that turns on the field and turns it off turn two on turn two off at just the perfect time so that when this magma is passing over it it gets repelled away from it and so it continually pushes it around in a circle and thanks for watching another episode of the action lab I hope you enjoyed it if you did remember to subscribe and we'll see you next time

Channel: The Action Lab

Views: 276,988

Rating: 4.8819008 out of 5

Keywords: top, inception top, forever top, spinning forever, perpetual motion, spinning tops, forever spin, spin top, foreverspin tops, collectible tops, metal spinning tops, angular momentum, longest spin, guinness world records, the action lab, lab, action lab, science, physics, induction, led, Ohms law, forever

Id: rNNZ1B9hTws

Length: 6min 51sec (411 seconds)

Published: Fri Nov 22 2019