I'm confident we can all adopt tau as quickly as the US adopts the metric system.

At 6:28 (tau minutes), the score spells out the first four decimal digits of pi.

TAU makes 100% sense PI makes 50%*2 sense

"If you want a unit to measure things, the unit shouldn't be the whole thing" -- Matt Parker

is this the maths version of a rap battle?

I say we use Pau, which is 1.5 pi or 3/4 tau.

i love how they just switch to the base 12 system at the end because both Steve and Matt were like "Yeah, that's better"

I love that "we used to sacrifice goats" was 2 points for tau.

Imagine, the days before youtube, 780,000 people sitting in this room, to listen to these two men talk about numbers

WHO WON? WHO'S NEXT? YOU DECIDE! EPIC MATH BATTLES OF HISTORY!

1:20 I love how he says shut up so secretively lol

The integration thing was really cool. so many physics formulas are 0.5*something*something else ^2 and its nice to preserve that pattern

Matt got 1 point for saying "wow"

2Pi or not 2Pi... That's the question...

*23 - 27* "There are more advantages if we switch to base 12, than if we switched to tau" *ding* *1E - 23*

This video completely changed my view. I'm team tau now. I never thought of the fact that 1/x of a circle was tau/x radians.

2 points for "historically, we've slaughtered goats" is my favorite

This calls for an epic rap battle.

loved how the scores switched to base 12 too, great detail

It's funny to imagine that neither the Mould Effect nor the Parker Square were known back when this video was made. I mean, those things have become so closely associated with these guys that it feels pretty strange to imagine that there even was a time when they weren't known.

in that case divide it by 360 no one would use that kind of a unit.

This is ridiculous. What would we bake on tau day ? :p

Let's just forget about all this and π=3.2

"Historically, we sacrificed goats" * 2 points* XD

7:53 "In that case divide it by 360" - Steve "Now you've just gone too far, no one would use that kind of a unit!" - Matt I feel like this is underappreciated.

"A unit shouldn't be the whole thing." Somebody forgot what units are.

I remember being continually confused when learning to use radians because of the /2 and having to convert back to degrees to get a picture of how large a given angle was. E.g. 3pi/2 - you can work it out, but I think it would just be simpler to say (3/4)tau

I was never sold on Tau until I watched this video. Thanks Steve.

"Tau gets you nowhere." - 7:27 absolutely loving this!

I love how they got some of their points just for delivering sick burns. XD

I think we should call pi/4 (or tau/8) "pizza." Because: - It is the ratio of crust length slice length on an idealized pizza cut into eight slices - it is the ratio of pizza area to pizza box area, given a perfectly circular pizza that fits snugly into a perfectly square pizza box. - you can't spell 'pizza' without 'pi.' - if people want to complete the pattern we could also then call pi/2 = tau/4 'tauzza.'

The problem with suddenly using tau is that a lot of people (physicists, engineers, etc) already use tau as the symbol for a time constant. They also use it as a dummy integration variable when integrating an equation from, say, zero to t.

I love how the scoring changed to base 12 at the end :p

When the scores changed to be in base 12 was probably the best part.

"Insufficiently right" sounds like the math equivalent of "bless your heart" both in the insulting way and the honest heartwarming way.

Steve: Blah Blah Blah Steve gets 1 point Matt: Wow Matt gets 1 point

when Matt said "the unit shouldn't be the whole thing" his score should've been halved...

I had a really hard time understanding radians and getting an intuition for angles in radians in terms of pi. Once I heard it explained in terms of tau, I understood instantly. Pi totally screwed me learning trig in high school.

Hahaha the moment when you switch the scoreboard to base 12 notation was the most subtly epic thing I've ever seen.

“This tells us something!” - Steve Mould

Actually I think we really ought to stop saying we have a half-dozen items and instead say that we have a double-few items. It promotes positive thinking.

You know you've been watching too much Numberphile when you get excited that both of their scores are primes.

since the circumference is tau x r, we should build a tower on tau day!?

I just use tau when I'm talking about things like sine wave periods and other trig stuff, and pi for the other stuff. But really I just use them both pretty much interchangeably. If I'm talking about pi or half tau, I write pi because you only have to write one thing. If I'm talking about tau or two pi, I write tau because you only have to write one thing. I think schools should teach both and they'll just be equally useful. It's not even something you have to bring in slowly. The only thing you'd have to do would be to say "oh, and by the way, you can just write two pi as tau" and that's it. It's incredibly simple. Circumference? Tau times r. Area? Pi r squared. Period of sin, cos, csc and sec? Tau. Period of tan and cot? Pi. They're constants. So if you can multiply two numbers together and get a single number, do it. Writing two pi or half tau to me seems like leaving 2 cubed as 2 cubed instead of just writing eight. Sometimes that stuff is useful to leave unsimplified; things like three hundred to the power of 256. But when you can write one symbol instead of two, why not do it?

Um, e^i(tau) = 1, which is actually way cooler because it essentially means, "one full turn is one"

Why does τ only have one "leg" and π has two "legs" when τ=2π? Can we please switch the symbols?

the first example matt showed with euler's identity at 2:15 is bad because it also works with tau just as beautifully e^iπ + 1 = 0 e^iτ - 1 = 0

These two became two of my all-time favorite youtube personalities completely independently of each other. It's such a heartwarming trip to see a video over a decade old of them arguing about this. Outstanding.

Solution: Use whichever one is best for whatever you're doing. Argument over.

Love the way the scores switch to Base 12 at the end! I think I wish Tau won the VHS/Betamax wars but we're lumped with PI now.

Cause of WW1: Assassination of Archduke Franz Ferdinand WW2: It is complicated WW3: Pi vs Tau

As great as tau is, pi has become universally known for its constant, and is usually seen as such. Tau, on the other hand is commonly used to indicate torques, shear stresses, and time constants. Feel like there is potential for conflict and confusion when using it.

"Why are we getting so emotional about our irrationals when we should be getting more radial about our base systems." brilliant lol OK now do Base 10 vs Base 12

USE PI WHEN IT WORKS BETTER AND USE TAU WHEN IT WORKS BETTER This was a cute video, though. :-D I like that Matt makes half his points while doing nothing.

I'm amazed at that comeback from 5 - 11 to 11 - 11 and then even going into the lead for a second!

1:20 my man really just got a point just by saying "wow"

I wonder if people who prefer pi over tau think we should measure frequency in "half cycles"...

I'd much rather have a factor of 2 in some equations than a 1/2 in some equations...whole numbers are much nicer to deal with.

I got a phone call in the middle of this video and by chance stopped the video at 6:28. I'm proud of that.

Matt: "the unit shouldn't be the whole thing" Me: Stares in Unit Circle.

"Tau gets you NOWHERE." xDD!

"The unit shouldn't be the whole thing." CONCEPT FAIL. We don't use radians to circles. We use radians to measure revolutions. Seriously, has Matt here gotten past elementary school geometry?

I got points off on a test once for using the 1/2 pi r^2 because I mixed it up with the position equation for acceleration, x=1/2 at^2. And they're derived the same way. The only reason that they're not the same is because we use pi instead of tau.

This is still one of the biggest robberies I've seen on KZfaq. Steve had this in the bag.

Why does one have to be better, this is like arguing "8 is better than 4 because most of the time, instead of writing 2x4, you can just write 8." and the rebuttal is "Well, what if you want to write 2+2=4, then it would be awkward to write 2+2=8/2" yes, yes it would, and that's why we have both.

Isn't fighting between tau and pi, like fighting between kilogram and gram?

The day has come. I was completely enthralled with a video about maths.

I'm in support of pi because using half a circle becomes WAY more useful and intuitive when you first learn trigonometry. Steve talked about how introducing tau to students might make it easier for them, but that is actually not going to work once the subject starts dealing with concept of negative angles where you can go backwards. I also feel like the entirety of trigonometry would suffer if we switched to tau instead of pi.

I love the reaction of Matt when Steve is talking, it's like ''wtf you talkin about''

I like the base twelve switch at the end

I love how they end up giving each other points.

Ah yes, 2/3 if my favorite comedic trio: Steve and Map

Pi is only simpler if you're already accustomed to the arithmetic abstraction of pi. If you are describing anything in physics there is nowhere that half a revolution makes more sense as a unit than a whole revolution.

I'm for pi! And here's why (from a physics rather than Maths point of view). When you talk about interference of waves we use pi radians to describe if it's constructive or destructive interference. For destructive it's π radian out of phase it's destructive if it's 2π it's constructive. Using Tau will create fractions and really detracts from the unit. I agree with Matt, it makes more sense to use π as it allows it to be a better unit. Encompassing something takes something away. Pi is everywhere from Hawking's equations to Coulomb's law (where k is 1/4πe0). It's for this reason that Steve's notion of it not being a just one unit is redundant. If we used Tau we'd get 4τ and 2τ so it doesn't actually "solve" anything.

How did matt get a point just for saying "wow" ?? 😂😂😂

this whole conversation was awesome

So if Tau won would Numberphile have changed their logo?

I think we should use the complete turn as the standard unit of angle size.

Damm! Love the switch of Steve score from base 10 to 12

11 years ago, this video of length 11:11 was posted cool coincidence, time to watch

I was expecting blood and gore by the end of the video

When tau is more used, someone says, "When we use tau, we see τ/2 often. Let's use pi insterd of τ/2. "

I like to think the reason they're sitting in an empty restaurant is that they met up for dinner, started discussing Pi vs Tau and now it's well after closing and all the staff are in the kitchen waiting for these two mathematicians to stop arguing and go home so they can close up shop.

The back and forth at 7:30 had me cracking up, lol.

Tau is twice as large as Pi, but it looks like you cut Pi in half to get Tau.

I agree with steve. The whole deal with a circle being 2pi radians just threw me off when I first learned it. It's much more intuitive to think that a circle is tau radians; that way the fractions of the circle match up with the fractions of the radians. Radians are such a useful way to do calculus and using tau instead of pi would make it much more intuitive.

"Both of them have advantages and disadvantages" -> Matt gets 3 points

So... Tau is a Parker Square?

i would have liked to see the advantages of using base 12, i cant imagine doing anything in base 12, could you let them ramble a bit and show that?

2021: π is now known to τ×10¹³ digits. This took the best part of 4 months to calculate. Such dedication to π vs τ trolling.

Wow...I come from a software development (sans CS degree) background of just a few years and I'm pretty new to math. This video was fascinating; it sounds exactly how I imagine a computer programming language committee deciding whether a feature will be added to the language or not. Or whether a breaking change will be introduced. For example, the former has a chance of bloating the language and making its use complex and not intuitive (I know the meme is to say this of C++, but I have no experience with it so I can't claim those things. I think it says something interesting about a person's temperament as to which side of the discussion they fall on in topics like these.

Its very simple to me Tau makes the meaning of equations at the forefront. Wherever you see tau you see there has been a complete circle or a complete cycle or something of that manner. Any time an equation is simpler with pi its because a meaning has been obscured. Its not just about education, its about making your own results and your own findings clearer, and making a richer understanding of the results of others more immediate.

With pi you get this little nugget: "Pie are squared" (Pi*r^2) "No, they're round" -Hilarity ensures

I think the argument about expressing radians as fractions of a whole circle really clinches superiority of Tau.

Perhaps each of these numbers has merits of its own? Tau could be the "circle constant", because a full circle contains Tau radians, while Pi could be the "triangle constant", as triangles contain Pi radians (in Euclidean geometry, but in other geometries, triangles have either strictly less or strictly more than Pi radians, so either way Pi used as a reference.) Also, why not add in a symbol for a right angle? Historically it was important as being used as the unit of measure for angles in Euclid's Elements. Maybe "Rho" for rect/right angle? And a symbol for the measure of the angle of an equilateral triangle, which is also a sensible choice of angle unit. Perhaps Iota for "Isos" (equality)? There are so many interesting angles that could be given names and symbols. No reason to denounce any in favor of another. Context determines which unit is most appropriate for use.

As someone easily confused by mathematics, I bloody love Tau. It's so much more intuitive and easy to understand how it relates to stuff when it crops up than Pi is. Who cares that occasionally you wind up with equations that are Tau over 2 instead of just Pi when that Tau relates so much better to its subject; radians in a circle? For me, at least, Pi actually is wrong, in that it is wrong to inflict it on people learning maths.

I like how you changed the results into base 12 at the end, that was clever!

Bringin up base 12 at the end giving me the feels man. Some day ... some day

That switch to 1Ɛ - 23 really got me. :D

As a student who always struggled terribly with Maths, I would have appreciated the concept of Tau, seriously. Im not getting into more sophisticated question because I hage no idea, but on a basic, pedagogical levl, Tau seems to work much better.