I love these classic Numberphile videos where James Grime talks about one particular number

@numberphile

6 жыл бұрын

So do we.

@oldcowbb

6 жыл бұрын

make a table of video of every real number like periodic video

@revenevan11

4 жыл бұрын

Can we add the sequence of numbers that numberphile has covered in the order they made the videos to the integer sequence database?

@Taquilou

2 жыл бұрын

@@numberphile I only watch videos where James appear.

@Kirkezz

Жыл бұрын

@@revenevan11 numberphile numbers

Probably my favorite guy on Numberphile.

@conoroneill8067

6 жыл бұрын

He has his own channel as well, where he posts similar stuff (it's called singingbanana, though I don't know why). It's pretty inactive, but you can binge on some of his older videos if you haven't seen them.

@edwardteach841

6 жыл бұрын

i dont think i could ever like anyone more than i like cliff stoll

@superoctave

6 жыл бұрын

James Grime and Matt Parker are my favorites!

@muizzsiddique

6 жыл бұрын

"Singing banana" captures his personality very well.

@christophgrun5636

6 жыл бұрын

I think they are all very likable - and with very different personalities - but there is something very special about James :)

I can feel 7825. When I go somewhere where everyone is having a good time, everything stops when I get there.

@emadgergis6710

4 жыл бұрын

100th like I know you don't care.

@searchwithin1414

3 жыл бұрын

OMG... that is hilarious!!!

@brendawilliams8062

2 жыл бұрын

Especially when the address says 78125 and you are lost

@thorodinson6649

2 жыл бұрын

@@brendawilliams8062 bad take

@brendawilliams8062

2 жыл бұрын

@@thorodinson6649 look Thor grab 1001035 and let’s trash the place

Interesting how 7, 8, 2, and 5 were the digits for 7,825 which also gave you the original issue in a+b=c.

Ramsay theory : The formula to find lamb sauce.

@bcdm999

5 жыл бұрын

Expressed by the notation LS=f*ck

@badhbhchadh

5 жыл бұрын

* Ramsey

@clovermx1472

4 жыл бұрын

Badhbhchadh no. It is ramsay

@prithvip6360

4 жыл бұрын

Its bland.

@lunaros4209

3 жыл бұрын

If you don't understand it, you're a sack of yankee dankee doodle shite.

I have to do some calculus exercises... Me: "Okay, right now I'm absolutely not in the 'math-mood', let's just do other things first." *Numberphile just uploaded a video* Also me: Let's just watch this...

@leonthethird7494

6 жыл бұрын

what is the derivative of an inverse function

@AuroraNora3

6 жыл бұрын

depends

@FlightGearUser

6 жыл бұрын

Maybe use that (f^(-1))' (y) = 1/f'(x) as long as f'(x) =/= 0 and assuming that f is differentiable? :)

@AuroraNora3

6 жыл бұрын

pentix I think you mean f'(x)≠0

@FlightGearUser

6 жыл бұрын

Thanks, obviously it shouldn't have a pole at x=0, therefore f'(x) ≠0 :)

*_lol blue and red makes purple, so 7825 is purple, silly mathematicians_*

@CraftQueenJr

6 жыл бұрын

I know!

@brcoutme

6 жыл бұрын

James Grime said it wrong though, it doesn't need to be red and blue. It needs to be neither red nor blue... so 7825 is obviously yellow, but that leads back to his question at the end of the video of what if their were 3 or more colors would it inevitably still reach a point when it no longer works (assuming a finite number of colors).

@superherothijs12321

6 жыл бұрын

with my experience of mixing multiple colors I bet you 7825 will be brown

@bibasik7

6 жыл бұрын

7825 is purple? I didn't know a number could be comfortable! And don't you wind up about powder. The powder is harmless.

@user-ft4pb5vb3e

6 жыл бұрын

Thijs van Dijk I mean, it's a sort of splitting-the-difference-between-purple-and-brown sort of color.

That blue pen appears rather green

@dvoraj20

6 жыл бұрын

It is an optical illusion caused by rather specific lighting condition. It is the same effect that occasionally makes the light from a row from four lightbulbs occasionally appear to be concentrated in a row of five point sources instead.

@chaosme1ster

6 жыл бұрын

Parker pen

@alexanderf8451

6 жыл бұрын

Oh no its another controversy

@user-rh8hi4ph4b

6 жыл бұрын

Jan Dvořák It's not an optical illusion, i checked with a color picker. Its hue in HSL format is 159 which is pretty much green (a little bit on the turquoise side, but still objectively green).

@fatsquirrel75

6 жыл бұрын

Can't help but picture Picard: "There ... are ... four .... lights !!!"

I always get excited when James grime is on numberphile

Absolutely loves James Grime, always a pleasure to see him featured on Numberphile again.

Fine example of a Parker Grid at 2:31 there James

@soulsilversnorlax1336

6 жыл бұрын

Will Price Ah, yes. The Parker Grid, the ideal space for containing a Parker Square.

@Leyrann

4 жыл бұрын

Except he already knew he was going to fail.

James Grime appears in my subscription box: instant view.

@numberphile

6 жыл бұрын

That’s what we like to hear.

Always enthusiastic, always interesting. So glad James Grime does these.

"imagine all supercomputers in the world checking all the posibilities since the dawn of time you still wont be able to check all the posibilities ... so they used some clever mathematics to reduce the number they had to check, and it took them about 2 days" i snorted when i heard this, but this is actually great!

Whenever there are videos with James in it, I never hesitate to see it at that instant.

I bet I could do this for a^3 + b^3 = c^3

@mathpin

6 жыл бұрын

Clingfilm Productions that would be very interesting to see XD! But will your proof fit in the margin of a book?

@nivolord

6 жыл бұрын

I can do it with one colour.

@blackmagic3286

6 жыл бұрын

that's a joke about Fermat last theorem.

@dlevi67

6 жыл бұрын

Clingfilm Productions Indeed, o man full of wiles. I'll raise you one and bet I can do a^4 + b^4 = c^4 in about the same time as you do the cubes.

@elzian4975

6 жыл бұрын

I might be able to do for both a^3 + b^3 = c^3 and a^4 + b^4 = c^4 at the same time, although you need to give me some time.

...and those two days of supercomputation probably cost more than 100$ :)

@Ridgwaycer

6 жыл бұрын

That's what grant money is for.

@dockmeister8480

6 жыл бұрын

I think the check itself is worth more than 100$, so its even.

@ObjectsInMotion

6 жыл бұрын

The university pays for the electricity.

@tonyennis3008

6 жыл бұрын

WE pay for the electricity.

@djjimmaster8261

6 жыл бұрын

FOR SCIENCE!

"The number 7825 must be both red and blue, which it can't" Superposition: "Bonjour"

@BidenBlessesYou

3 жыл бұрын

well actually, 7825 must be none of red and blue.

@KnakuanaRka

3 жыл бұрын

Actually, it has to be neither or red or blue; if it’s either color, there is a trip,e of one color.

@alexandermcclure6185

Ай бұрын

It is in the superposition |R>|B>|R'>|B'>! (did I get the notation right?)

Ramsey theory has always fascinated me. Thank you so much for this video!

One of the most fascinating videos you've ever uploaded ! Great one !

Cool! I just learned how to come up with pythagorean triples. One of the side affects of watching numberphile: you might accidently learn something.

Great video, love that we're discussing a specific number

Love watching your channel! It’s the never ending pursuit of beauty!

it doesn't look blue because it's on brown paper.

@SashaFierceBadass

6 жыл бұрын

If you draw on it with a yellow marker it would look orange.

@gabydewilde

6 жыл бұрын

but thats a story for a different video

@zetacon4

6 жыл бұрын

I thought the reason was video coloration problems. Having experience with that very thing, that is my first guess. If someone can prove me wrong, that would be interesting also.

@NondescriptMammal

5 жыл бұрын

that makes sense, neutral browns are basically dark shades of yellow

@razzpup7961

4 жыл бұрын

It’s looks green

I have synaesthesia only where numbers are concerned. As a child, I was trying to find a way to make the numbers add up in such a way that their respective colours would blend to give me the correct colour for their total. I quickly ran into the same problem you guys did.

@ciarfah

6 жыл бұрын

Interesting!

@cubethesquid3919

6 жыл бұрын

That's interesting! I wonder if I have synaesthesia, except with feelings. I have certain emotions associated with numbers, and often, based only on how I feel about a given number, I can tell if it is prime. For example, 167. It feels sharp, and makes me feel edgy. One day, I was talking to my mom about my "synaesthesia", and threw out that number because it felt prime. Then, a few minutes later I looked it up, and sure enough! 167 is prime.

@captapraelium1591

6 жыл бұрын

The trick to making this work is to assign numbers to colours in a balanced fashion, rather than linear. As in, red = 1 orange = 2 .....violet = 7, won't work. It would need to be arranged like the Chinese Bagua, where the opposing number was actually opposed on the spectrum. Of course, with synaesthesia, you don't get to choose the assignments so whether it works would depend on your particular individual affliction. Sorry to hear you lucked out :( That would have been really frustrating!

@ianw8479

6 жыл бұрын

Cube the Squid I def have some version of this as well lol

@Tumbolisu

6 жыл бұрын

Colors are a three dimensional thing to our brains. This means you will always need three numbers to represent a color in a unique way. Single numbers just won't cut it.

For the a + b = c case, there are really only 3 options, not 512 - either 1 and 2 are (say) red and 3 blue, or 1 and 2 are different colours and 3 is red or blue. The other colours are derived from there until it becomes impossible.

@grahamrich9956

4 жыл бұрын

almightyhydra Hence why he said that it was easy to convince yourself it was true instead of simply checking every possible combination of red and blue for every space.

@ragnkja

Жыл бұрын

Four options, actually, because if 1 and 2 are the same colour, 4 can be the same colour as either 1 or 3.

@Muhahahahaz

Жыл бұрын

There are exactly 512 ways to assign the colors. Whether those colors actually follow the rules or not is up for you to decide Yes, you can reduce this space through logic. This is the kind of work mathematicians do all the time, but it’s not always so trivial to do so :)

how he is amazed about what he's talking about, it's contagious :)

Where have you been James?! My favorite numberphile guy! Glad to see you back! J

This problem reminded me of a project I did five or six years ago in university, which was also about finding sets of numbers without a certain structure - in our case, we studied Szemerédi's Theorem - and we were using SAT solvers to do this. Turns out that this work is from our supervisor at that time - Marijn Heule was our supervisor. And, indeed he used SAT solvers to create this proof. A little background: SAT this is the satisfiability problem, which asks "given a set of boolean variables (which can be either on or off) and a set of constraints on these variables, is there an assignment of values to these variables that satisfies these constraints?". You can translate the pythagorean triplets problem into SAT in its most basic form by creating a variable for each number from 1 to n, and creating a constraint for each pythagorean triplet stating that of the three variables corresponding to the three numbers at least one must be true (red) and at least one must be false (blue). If there is a solution for this SAT problem, then there is also a solution for the original problem, by colouring the numbers red if the variable is true, and blue if the variable is false. The main advantage of this approach is that SAT is quite a well-known problem, having quite efficient solvers. I can imagine that someone must have created an efficient SAT solver for supercomputers, or at least the Texas supercomputer, as well. This way it would be relatively simple to tap into the huge amount of computing power available in an efficient way (which is really hard if you're doing that from scratch). If I'm making it sound easy: it's not. The basics are quite easy to grasp (and can be coded in 30 lines of C), but in order to get an answer for these huge problems in a useful amount of time, you need to optimize your translation. This requires thorough knowledge of both the solver and the problem, to translate the problem in a way that is most meaningful to the solver. And finally, you need to handle all the data and include it in your proof.

5:30 Actually Ramsays theory allows you to solve for the location of the lamb sauce .

@andrjsjan4231

4 жыл бұрын

Where you referring your joke to the famous chef gordon Ramsay??.

@thinebeatingstick

3 жыл бұрын

@@andrjsjan4231 what does it look like

@andrjsjan4231

3 жыл бұрын

Michael Sowierszenko like your mom opssss by the way I didn’t understand your joke?

He is just fantastic. Loves numbers. Loves math. Is completely consumed by his wonderful passion. And does his very best to spread the thrill and excitement.

This is probably the least click-baity title I've ever seen. That's something I really like about this channel.

Aaaaahh! I've missed seeing James!! 🤗🤗

this problem reminds me of the 17 sudoku clues problem

4:32 omg I tried to find this for such a long time thank you!

I almost never understand this channel, but I love it anyway

I laughed so hard when he so calmly said "so they reduced the number of scenarios they had to check to about 3 Trillion" XDD

I missed you Professor Grime 💕

These videos have no expiration date. Enthusiasm for mathematics is everlasting.

Always happy to see James on numberphile😄

*625² + 7800² = 7825²* *5180² + 5865² = 7825²* WTH, how will we construct a right triangle with this?

@sadkritx6200

3 жыл бұрын

It's possible. The two right triangles are different. Using inverse trig functions the first one has angles 90, 85.42(approx) and 4.58(approx) The second right triangle has angles 90, 48.55(approx) and 41.45(approx) In fact I think this type of triangle seems to be rare in this case since we're using whole numbers. Otherwise we would have infinitely many such right triangles having same hypotenuse. Suppose we have a constant hypotenuse 'x' unit. The other sides are a and b. So, a=root(x^2-b2). Since x constant you can choose infinite values of b to get infinite values of a. Just make sure 0

@adraedin

3 жыл бұрын

I know this is an old post but someone else might stumble here... It's the Pythagorean theorem (using really big numbers). The theorem states that "in a right triangle a² + b² = c². Where side c is the side opposite the right angle." In other words, if there were a right angled triangle with side (a) being 3 units long, side (b) being 4 units and you were looking for side (c)... c² = a² + b² c² = 3² + 4² c² = 9 + 16 c² = 25 c = (sqrt) 25 (*sqrt 25 to remove the exponent from c) c = 5 Using this formula and some trig, so long as you know the length of 2 sides and that the triangle has a 90 degree angle, you can find the length of the remaining side and the other 2 angles. (That's what Sadman did above.) In the case of 7825 being c, there are two ways to form a right angled triangle and either option they choose of the two won't allow them to color the chart correctly to meet the other requirements and it ends their little game.

@princevegeta5907

3 жыл бұрын

@@adraedin Thanks a lot. That's very helpful

@KnakuanaRka

3 жыл бұрын

That’s saying that if you construct a triangle with sides 625-7800-7825 or 5180-5865-7825, one of the angles of the triangle (the one opposite the 7825) is a right angle.

Furthermore, I notice that Mr Heule has been working on Polymath 16 (the Hadwiger-Nelson problem) and just broken his own record for the smallest unit-distance graph with chromatic number 5.This follows the recent breakthrough by Aubrey de Grey, although I imagine this record may not hold for very long, considering the great progress now being made in this area.It's not so difficult to explain .. so maybe a future numberphile video please?

I love Dr. Grime's enthusiasm.

Number: **exists** Numberphile: Do you have a problem?

Can you talk about other patterns showing in the image? I see a lot of vertical lines.

@KaitouKaiju

6 жыл бұрын

That's just a consequence of the size of the grid they used

Shout out to the nail and gear in the background!

@numberphile

6 жыл бұрын

The Mighty Nail and Gear.

@WilcoVerhoef

3 жыл бұрын

@@numberphile I wonder where it is now

I love that James is still a guest on this channel. I think he was in the very first Numberphile video. That was like 5 years ago, wasn't it? Holy mackerel.

This vid popped on my recommendations and I'm first time watching this channel. Mby not the biggest fan of math but I absolutely love how passionate and happy this guy is when explaining all this :D

"It can't be red and blue at the same time" Violet: bonjour

@alexandermcclure6185

Ай бұрын

Did you mean: *Purple*

The time estimate for a brute force approach is a bit off, because you don't have to check all of the possibilities. As soon as you come across a contradiction, you can stop and go on to the next set. Similarly, you only actually have to check 4 of the “512” combinations for the introductory problem to prove it never works (and indeed if you expanded the introductory problem to an arbitrary number of integers, you would never have to check more than those 4).

2:50 He turns into Michael Rosen for a split second when saying "twelve".

James Grimes on Numberphile! Always a great watch when he is the featured mathematician.

If there is always a number you'll reach where these equations break once you count high enough, wouldn't this calculation reflect entropy? With entropy, systems lose organisation over time. With these patterns, the number you reach before being forced into a 3-of-a-kind pattern gets higher as you add more colours. So wouldn't it be possible that this equation could end up having relevance to the concept of entropy if and when we solve it?

@Muhahahahaz

Жыл бұрын

It’s actually kind of the opposite. If more related numbers have the same color, then that represents more structure, which is to say less entropy (The reason they are playing this specific game, avoiding 3 numbers of the same color, is that they want to see how *big* the system has to be before structure is forced to appear) Thus Ramsey Theory says that large mathematical objects often have some inherent structure, or emergent properties, which actually act against entropy! I feel like this connects to the structure of matter and the Universe in some way - Some matter/energy arrangements are just far more stable/favorable! Especially when moving towards larger scales (Yes, over long time scales, eventually all order will disappear as entropy increases. But in the meantime, it’s truly remarkable how organized and structured everything seems to be)

That blue pen didn't look very blue to me

@matejcataric2259

6 жыл бұрын

Agree ahahahah

@H0tdogCat

6 жыл бұрын

probably the yellow-ish paper mixing to make it look green!

@aminulhuda4025

6 жыл бұрын

Nelson Goodman says hi to you

@user-sh6wr7dq6k

6 жыл бұрын

WanderingRandomer perfect amount of blue in the video

@dvoraj20

6 жыл бұрын

It is an optical illusion caused by rather specific lighting condition. It is the same effect that occasionally makes the light from a row from four lightbulbs occasionally appear to be concentrated in a row of five point sources instead.

I don’t know what this man is saying but his excitement sells me every time.

If everyone had a teacher/professor as excited about Math as James then everyone would be a mathematician.

Then proving that, for n colors, there will always be a perfect square which can be written as the sum of n other perfect squares and that those pairs must be the same color will prove the conjecture?

@hammer5064

6 жыл бұрын

That would probably be ridiculous to prove, though

I would've loved to have you as my math teacher.

Man I love this guy. Now I totally wanna study on stampede uni!

If you extend the case of sums of first powers to 3 colours (so we're excluding monochromatic triples (a,b,a+b), where a and b are distinct), then you can go at least as far as 22, using colour classes {1,2,4,8,11,16,22}, {3,5,6,10,12,19,20,21} and {7,9,13,14,15,17,18}.

I found a pattern where a^2+b^2=(b+p)^2 made pythagorean triples if p was a factor of a. (lowest factor being 2 if a is even) I noticed in the video that for 7825; the two triples that make it up one of the two follow this pattern, and the other does not.. Namely 5180^2+5865^2=(5865+1960)^2 .. obviously 1960 is not a factor of 5180 in this case whereas 625^2+7800^2=(7800+25)^2 is. It could be nothing, but.. This was the first time I've come across a case where the a pythagorean triple exists that doesn't fit the above format. (p not being a factor of a). Perhaps this is why?

@dlevi67

6 жыл бұрын

Um, 7, 24, 25?

@yondaime500

6 жыл бұрын

If you expand (b+p)² and cancel out b², you're left with a² = p(2b + p). So p (which is c - b) being a factor of a² is a necessary but not sufficient condition for a Pythagorean triple. I don't know how often it turns out that p is a factor of a, but I see quite a few examples on Wikipedia where this condition is not verified, regardless of which number you pick as a: (20, 21, 29), (33, 56, 65), (48, 55, 73), (65, 72, 97) etc.

@TheEclecticity

2 жыл бұрын

@@yondaime500 more like a commonplace but not necessary condition. Let's move away from the cliché "necessary but not sufficient" which is tired, over-used and has become beyond vague.

Who else is here just because it has James Grime in it?

This was a fun video. I saw immediately that 1 thru 9 was impossible to not duplicate the same color. It happened for me when he showed the number 9 would be red. Bingo! That did it. Then, when he was discussing the 7825 number, I knew it was too large to ever examine every possibility. That somebody narrowed just a subset to 1 trillion was amazing, and then took 2 days to run the sets, was also thrilling to me. This sort of problem is what makes math so wonderful and inviting to me.

Related trivia: Ramsey Theory you mentioned and a vaguely similar problem about graph colouring is where we got the gigantic Graham's Number from.

What, a new Internet Comment Etiquette AND a new Numberphile video at the same time? is it Christmas already??''

@imveryangryitsnotbutter

6 жыл бұрын

But it's not even July!

@styloyt

6 жыл бұрын

Aleatorio can’t wait for the collaboration

@y.h.w.h.

6 жыл бұрын

stylo big money salvia here bouncing on my boy's number?

@MilChamp1

6 жыл бұрын

imagine the venn diagram of the fans of both channels

@faith3174

6 жыл бұрын

Bush did 9/11 (_)(_)::::::::::::::::::D~~~~~~~~~~~@tedcruz~~~~~

whats the name of the generalized version of this problem

@DDvargas123

6 жыл бұрын

Maybe what you are looking for is Ramsey Theory?

These are great videos, enjoy them a lot, I always wonder how things would change if using a different base, instead of base 10. how would the maths change

I really love the new addition to the James Grime space of Numberphile with the Nail and Gear flag

Great video, though I'd mention that the Babylonians were making lists of Pythagorean triples long before the Greeks!

7825 should be either: 1. In a superposition of red and blue 2. Purple or violet

I love this guy. Great enthusiasm and explanations combined :) But also... Is that a CGP Grey Symbol in the background? :D

Is the same limit encountered in octal or hexadecimal or does it only apply to decimal calculations?

Gotta love how briskly and casually he goes through the method of creating a Pythagorean triple. That could be its own whole video!

"I didn't do it. I failed." So this is a Grime Square™?

@boudewijnj.m.kegels5198

3 жыл бұрын

I’d love to live at that squareat nr. 7825.

What an excellent video!

@numberphile

6 жыл бұрын

Thank you.

I appreciate the Nail and Gear logo in the background.

It does strike me as a potentially useful step in understanding why this is the case in that having a brute force example may help mathematicians identify patterns that hadn't been tangible before.

@pierrestober3423

6 жыл бұрын

one color->5 two colors ->7825 Not a very useful pattern (though I understand what you mean to say )

@mnikhk

6 жыл бұрын

We'll that's what they do lot of times

@pierrestober3423

6 жыл бұрын

mnikhk what ?

Me gustaria que hayan subtitulos en español, la verdad me gusta mucho este canal pero no se mucho inglés. Seria una gran ayuda para mi y para una gran cantidad de hispanohablantes seguidores de este canal.

I'd be interested to see a graph theoretic approach; this strikes me as a variation on the many graph coloring problems.

Love the mighty nail and gear in the background

And how can we use these results?

@falnica

6 жыл бұрын

It will definitely be used in the future, but I'm really curious about how!

Even tho I'm a tenth grader, and sometimes I don't decipher completely what numberphile's guests are explaining, but I still love this chanel😍.

Yaaayy Dr. Grime is back 😍😍

Another great video!

7:52 - That's okay, you just have to defragment it and that will make the red go away. Or am I misunderstanding the problem?

Nail&Gear in the background

Everybody knows *42* is the base number system used by the computronium running our reality [actually, it is _Quadragesimal_ (40) plus an independent "C.R.C." on _Binary_ (2)]. -> Knowing that *7825* is part of the equation leading to the "seed" used on this _particular run_ on the multiverse will get us closer to formulate the ultimate question.

I love this channel, guys

@numberphile

6 жыл бұрын

Thank you. We love viewers like you.

8:52 3.6 x 10^2355, for the record.

Hey Brady, please resume making videos on the wordsoftheworld channel! Bring it back to its past glory

Hey Brady, You shown us a lot of discrete value problems that have not been solved. Can you make a video about a discrete number problem that has a proof that comes in less then several terabytes?

great to see dr james again

CGP gray print could not be unnoticed

@alandanielestradamartinez1722

6 жыл бұрын

I had to scroll way too far to find this comment

I wonder if this has something to do with the built-in limitations in DNA.

@newkid9807

4 жыл бұрын

I wonder how you were dropped as a kid SAD!

@angelmendez-rivera351

4 жыл бұрын

New Kid WTF is wrong with you

@valthiriansunstrider2540

4 жыл бұрын

That's a neat idea, maybe there's something to that

Are you guys going to do a video about that new Mersenne Prime?

Are they using some kinda ecological-clear paper? I couldn't find it in local shops...

The symbol in the picture in the background looks like CGP grey’s logo

Wait so is 7825 the first time there is a c in two Pythagorean tripled that have to be of opposite colors

@henryD9363

6 жыл бұрын

Spencer Schmidt -- I'm confused as well. Yes for 7824, no for 7825. But what about lower (and higher?) no's?

@gordslater

6 жыл бұрын

I'm a C shell user so consequently not the best person to ask, but I'm assuming it's more of a C++ thing. I feel old. Again

My aspie ears can’t stand the sound of marker on paper, but I love these videos!

This is insanely fascinating.