[NWA Music Plays]
[ALEX] Hey guys, I'm here, let's get technical.
Check this out, this blew my mind. When I take a fidget spinner and tilt it towards you, just like this...
It does just that ... *mind blown explosion*.
That's actually pretty typical, but check this out.
If I get the fidget spinner going really fast, and then tip it your way quickly ...
... it doesn't actually go your way. What?
It goes kinda tilted, kinda slanted.
As we saw, if it's not spinning, both of the legs of the fidget spinner go down equally.
But when it's spinning really fast it'll actually tilt on a slant.
You can see that here as I push up on my side and as a result down on your side ...
... the fidget spinner becomes slanted, even though you would think it would just tilt down normally.
What's going on here? I swear I'm not pulling any sneaky tricks here.
I'm not pushing it down with my fingers or anything. I'm just tilting it down slightly resulting in its diagonality.
That's a word! Look it up! You can even try this at home if you want.
It works best if you get the spinner going really fast and then tilt it as quickly as possible.
Try not to recognise the slint [meant slant] and then correct it with the muscles in your fingers.
But we'll get to those later. Now let's get to a phenomenon called gyroscopic precession.
Let's break those words down. Gyroscopic; gyro, meaning a Greek delicacy.
Or actually it means relating to motion. And scopic, meaning an instrument ...
... for observing, viewing or examining.
Precession, meaning the slow movement of the axis of a spinning body around another axis due to a torque ...
... (such as the gravitational influence) acting to change the direction of the first axis.
Side note here, I had to Bing that. I legitimately Binged something, and I'll tell you why.
If I type scope into Google it'll only show the definition of the word scope, not the suffix.
And you can't type "-scope" into Google, the dash indicating that it is a suffix, ...
... because when you type a minus into Google, Google reads that as ...
... show me all the results without whatever word you put after the minus.
For example, if you wanted to learn about the new iPhone but you didn't want to see ...
... any of the news about the iPhone 8 you could type in "iPhone -8" and boom.
Now, unsurprisingly, if you type "-scope" into Google nothing comes back because it's ...
... basically the same thing as typing nothing. However, on Bing it doesn't recognise this.
The dash represents the suffix so I can easily Bing away.
Okay, back to fidget spinners. The techincal definition of gyroscopic precession is ...
... when a force applied to rotating thing appears 90 degrees after the point of impact ...
... in the direction the object is rotating. But what does that really mean?
Right now I'm outside with Dumbledore attached to a string. Sorry Dumbledore.
[Dumbledore] It's all for science. [Alex] Yes it is indeed Dumbledore.
It is indeed. Now let's say I'm spinning Dumbledore around like this.
[Dumbledore] Waaaaaah!
[Alex] Dumbledore's path right now is a constant circular path.
It's not going up or down, it is only rotating on 2 axes. But what if I were to, say, push Dumbledore up a bit.
[Dumbledore] Wait, you didn't tell me pushing was involved.
[Alex] When I push Dumbledore up, say 30 centimetres, forcing him onto a third axis ...
... he doesn't just stop everything and move up 30 centimetres and continue on his tilted path.
No, he has to actually take time to move up 30 centimetres.
Dumbledore is going to have to take some time going up 30 centimetres. 90 degrees of rotation to be exact.
So instead of this being his peak, and this being his trough down here ...
... this is his peak and this is his trough. Instead of him spinning around like this, he spins around like that.
It's also good to note here that the direction of rotation does matter.
We were spinning Dumbledore counterclockwise, like such, but if we were to say, spin him clockwise ...
... and push him up at the exact same spot, his peak would be 90 degrees this way, ...
... and thus making this the new peak and his trough would be another 180 degrees that way, ...
... making this the new trough.
So how does Dumbledore flying around on a rope relate to fidget spinners? Well, same rational!
If you push up on my end of a clockwise running fidget spinner the change will register ...
... 90 clockwise degrees away. Creating this sort of tilt shape like this.
Of course, it's reverse if your fidget spinner is running counterclockwise.
And it's not that easy to break this gyroscopic precession cycle either.
If you wanted to, say, actually push this up right here without having it be registered 90 degrees away ...
... you'd have to apply a lot of force from your fingers. So much so that if you do it enough ...
... or at least as many times as I did researching this video ...
... *huh?* your fingers might actually get tired because of all the force you need to exert ...
... to counteract gyroscopic precession.
Now if you've been following along with your fidget spinner at home you'll notice ...
... that there is a bit of a rhythm to your fidget spinner. If you are spinning clockwise ...
... the rhythm kinda goes like this. And, if you're spinning counterclockwise ...
... it kinda goes like that. Wait, this sorta motion seems familiar. Oh, sweet! A Curiosity Box!
Thanks Ex Machina. Let's see what's inside *gasps* A gyrscope!
This one is featured in, of course, these Curiosity Boxes as well as Michael Steven's Vsauce video "Spinning".
I get it now. So check this out. If I get this gyroscope spinning, and then put it on my foot, cause why not? ...
It'll basically stay wherever my foot goes, and you can see Michael's video for an explanation on that.
But after a bit you'll see it circles and starts to spin around like this. Let's look at that a bit closer.
So now I have a stool, a Curiosity Box, a black stand and a gyrscope.
Let's get this gyroscope spinning on the black stand and see what happens.
It's very loud! Notice how it starts falling into that little circular pattern we see in the fidget spinner.
This is because any push to the gyroscope, say from air molecules or dust in the air, ...
... will knock the gyroscope off track. It'll precess into that sort of rhythm we found, and continually ...
... get worse and worse and more bent and more bent until it finally falls over.
And that is gyroscopic precession explained using fidget spinners and maybe a little bit more.
Note some kids play football or chess or video games after school. I play with fidget spinners ...
... and then make a video about the physics behind them.
Please subscribe. [Chase] Hey Alex.
[Alex] Hey chase, what are you doing here? [Chase] I just wanted to say there is a lot more ...
... science to these fidget spinners than just gyroscopic precession. Over on my channel, ScienceC ...
... I talked about how the shape and the design of the fidget spinner allow it to spin so freely, and easily.
[Alex] Awesome! Well, I'll see you guys over there! Oh, and thanks for watching, DFTBA, and explore on.
Let's go!
Shoutout to this awesome person who made fan art. Thank you, it looks amazing.
Uh, in the process of making this video I found fidget spinner apps. What are the point of these?
This one you have to swipe the screen to spin and then this one you don't even have to swipe ...
... you just press a button and it spins it for you. What even? Why?
*sighs* see you guys next time.