*_Matt & Guest_*_ Play with a thing and then do some working out_ should totally be a regular series.

LOL "finally, something named after Euler" "he's nearly forgotten" xD and people say mathematicians have no sense of humor

The sound at the end of the spin is so satisfying.

I really hope this is a long-running series just so I can see that intro again.

Matt is one of my favorite disk jockeys.

8:44 Aw yeah dubstep!

"Should we have a race? 😁😁 I love you Matt.

As to overengineering it, he can still add a stroboscope to it. :D

you know, they say, "As the angle gets less, the wobbling rate gets bigger" so, could we state that when it's laying flat on the table it's wobbling at unseeable and unmeasurable rates? :p

Yay! This series is good, & I am very very happy that it's actually a series now :)

I love it when people talk about things that were named after Leonard Euler :)

Please make a video showing why the best ratio of width to height of an Euler disk is around 6 to 1. I would love to know why this ratio is often considered the best 😀

Super Interesting, but, minus 1point for using white paper

This was adorable to see Matt so candid as he works through a problem

Can we get a series where you two sit on a bench and ramble?

Good channel Matt! So glad it's there to show a little bit to the world that math is fun.

I have no intention to ever replicate anything Matt does. nor do I really have any understanding (all although I nearly bought 72 pencils the other day).... so how is it that I find his videos so entertaining? LOVE IT. thanks Mr maths man.

I love this. Building a contraption just to figure out why a toy does what it does because it interests you. This is the type of stuff a kid would do that for some reason tends to be discouraged when you get older for nothing other than the fact that you are "too old" for that nonsense.

That, right at the end, was an absolutely beautiful sound.

That was an amazing video!!! I love that he had an experiment set up for this.

great episode... looked like lots of fun

Anyone else see the dunking bird in the background to the right? I love those things. Always something interesting to discover in Matt's videos. I wish I could get him to come to a convention I'm an owner of called Farpoint. He'd be a great science/technology/math guest!

Love the Matt and Hugh vids. Great format, great contenr, great fun too

I didn't think it was possible for this one to be funnier than the first on you did. I love engineers. I really do.

That sounds at the end is amazing.

It almost looks like you were learning, looked like a kid for a second!

that noise at the end is very satisfying!

Really enjoyable video - And its nice to see even Matt can end up looking like a schoolboy with a teacher even after years of Stand Up and presentations on mathematics. Makes the rest of us feel a little bit better :) Thanks guys

Wow. That's even more interesting than the regular format!

at 15:50 i love the circular patterns of light reflections on the discs as they spin/wobble.

certainly one of the best videos on youtube

I love to see you both together

These guys are so cute! A really enjoy watching them nerd out with each other.

i did not expect a second video

Math Machine I did some maths. I assumed the disc is of uniform distribution, there's no rolling friction, and there's no air resistance. Under these conditions, I believe the disc should remain at a constant angle from the horizontal. The rate at which the disc spins around the vertical axis is equal to √(6g(2rcos(θ)-hsin(θ))/(sin(θ)((3r²+4h²)cos(θ)+6hrsin(θ)))), where h is the thickness of the disk. Assuming the height is small compared to the radius, this leads to a rotation speed of 2√(g/(rsin(θ))), and assuming θ is small, this gives your approximation of 2√(g/(rθ)). In addition, the rate of rotation of the dot placed on the disc is equal to the rotation speed around the vertical axis, multiplied by cos(θ). A small note, according to the formula I provided, the rate of rotation when θ=π is √(g/r). Technically, the disc could rotate at whatever speed it wants at this angle, as it's technically in equilibrium. However, if the angle were slightly below π, it would need to have a rotational speed of about √(g/R) in order for it to not fall into either the vertical position or towards the ground (depending on how stable the θ=π equilibrium is).

That last bit is so satisfying.

It's a terrific formula. Tremendous.

First time I have seen the Euler discs. I often spin cups and bottles but I never knew that the speed-up effect has a name. KZfaq is better than university.

"the euler disk that I did a video on recently" RECENTLY? have you been taveling in speeds close to the speed of light?

The most exciting footage ever uploaded to KZfaq! :-)

This is so cool - I had my cambridge interview with Hugh Hunt in that very room, a couple of months after getting my calculator signed by Matt at a talk

I seriously was at the edge of my seat with that race

I love this video! BTW, I noticed that here is the difference between maths and Engineering: 9:54 and 11:31 I personally prefer engineering but I realize that they both are beautiful in their own ways.

Incredible!

This is so cool!

Frickin awesome!!!

More this was awesome! Gif more plix!

Excellent ending !

Lovely 4x4 in the background

H: I got a blank disk. The reason I like my blank disk- M: It's got- H: It makes it nice and easy t- M: easy to draw a circle. H: -draw a circle on it. M: yeah. H: And the idea is, that, so this little dot here, when its wobbling like this M: yeah H: you can see that dot- M: Yeah! H: is- M: that that H: tracing out a smaller circle. M: Yes. H: so that smaller circle, is where the edge of the disc is following that. M: yeah H: so the dot has moved from there- M: to there! H: to there. M: okay. H: lets call that angle theta looks like this scene took 10 tries to do, but STFU MATT AND LET HUGH TALK Source: 7:33

INTERVIEW IN PROGRESS PLEASE WAIT TO BE CALLED

DAYUM. This is the coolest thing ever

I wonder how much air resistance affects the slow down. Vacuum chamber experiment maybe??

i am as excited about matt's videos as matt is when meeting hugh

It's a wonder I got interested in math. Every single math teacher I ever had absolutely STUNK. I ended up totally pissing off my algebra teachers by reading books in class because they sucked so bad, but passed because I taught myself using a programmed algebra system.

Matt is awesome!

(1/cos theta)-1 would be a secant graph shifted down by 1 in the y axis. So it would start at (0,0) and curve upwards to infinity at 90 degrees

Matt: This time, I have brought something Hugh: *tries to hold in a smile*

Matt is most well-known for his ground-breaking work on parker squares.

Do us all a favour and put these two guys on prime time tv

This guy is super funny! I would love to have a teacher like him!

Loved it.

Great Ending!

11:33 - Matt reveals his inner Plato

When you said, you were djs I couldn't help but smile.

That is the coolest thing ever!!!

I think you and Brady should introduce Hugh to Cliff Stoll. They'd get on like a house on fire, I feel. Could be the start of a new science KZfaq duo in fact!

The race was oddly exciting!

Love that final sound, like a little engine lol Another interesting thing on that you could see who was going to win, because there was a circle of light reflecting from both disks when the camera was equidistant from them, and Matts circle was larger than Hughs (higher angle) lol. Interesting experiment.

Yup. A good video as always.

For anyone interested, here's the graph of (1/cosθ - 1). prnt.sc/etil7y

Love it!

I have the exact same Euler disk that you guys raced with at the end and I spun mine at the same time as your race. Mine lasted about 27 seconds longer than either of yours.

Two guys spinning their Euler Disks... this is nerdtastic! love it

How about a video on the mathematics involved in cancelling out annoying background noise?

Spinoff was the greatest thing I've seen on KZfaq Lmao great job guys

There is a Guinnes World Record certificate in the background! I would love to see a video on what Hugh got it for

I love the wobble frequency catastrophe, going from high to suddenly zero.

The graph (drawn on the paper) was supposed to go from y=1 at x=0 to y=positive infinity at x=pi/2 if you're considering only 1/cosx where 0

For measuring the angle on his air assisted rig, could it be filmed with a high speed camera and a series of angles marked in the background (similar to a protractor) and then choose the frame from the footage that has the plane of the disc perpendicular to the camera? That way you get a still image with the angle on it, and can get a more exact measurement than using the rubber finger thing and stopping when it looks close enough.

Is that Hugh Hunt or Mark Williams? Anyway, more from the pair of you, please. Most entertaining and educational.

"It's not ridiculous - it's just what we do." LOL

10:28 This is one of the reasons we need formula sheets in exams at uni. Even good mathematicians like these two can't remember everything!

Is there an episode discussing what factors make an Euler Disk spin longer? I've wondered this since I was a little kid spinning coins.

Thank you, Gyro.

I love the drinking bird on the right just chilling there for the whole video (except the experiment and zoom ins)

Can't wait to see this done on the Moon!

It's like watching young Matt & old Matt

Matt is so cute, you can see pure happiness in his eyes throughout the video :)

Ahah ! I love how nerdy this channel can get ! :)

It wouldn’t be a math channel if Euler didn’t show up

I've just discovered this channel, so I've probably missed my chance to ask the burning question: the CG of the disk is moving. If there were zero losses to friction, slippage, or air resistance, what path would the CG follow. Does the path that is actually followed provide a measure of the friction coeficient?

Ha! Disc jockey! That just made my night!

Magnifico..!!!

I'd forgotten about this.

If you substituted a high-polished tungsten circular disc with an elliptical cross-section, your air-blown contraption would make for a brilliant movie prop involving a time travel engine.

Good one

The end of the video made me die of laughter.

I don't really like maths. I didn't understand much of this video. But I watched the whole thing and liked it anyway.

I'd be interested to see how long a disc spins for a given angle. Will doubling the angle double the time of the spin? or is it analagous to how fidget spinners require exponentially more force to double the time they spin?