10 ms·

No, pi is wrong: The Tau Manifesto

128 points by adunk 5y ago

prof-dr-ir 5y ago
That was a surprisingly entertaining and well-researched manifesto. In the same spirit, I think it is time to rethink the verb 'to be': the only consistent conjugation is obviously 'I/you are; he ares; we/you/they are'. And similarly the past tense should be 'ared' instead of 'was/were'. Generations of children have been getting themselves needlessly confused because of this terrible convention! Would it be possible to correct this wrong? Or do you think the time for doing so has passed and, by now, it are what it are.
- wruza 5y ago
  But why “are” and not “be” (past. bed)? Also, pi was not strictly pi by Euler, who used pi for both 3.14... and 6.28... in different papers. Edit: did you know you can do without “be” at all? It purely synthetic.
  - someguyorother 5y ago
    >Edit: did you know you can do without “be” at all? It purely synthetic. Wouldn't it become rather difficult to do identity statements without "is"? E.g. "The Tor network is an anonymous relay network overlaid on the internet". You could perhaps say "The Tor network works on top of the internet and performs anonymous routing", but that's not quite the same thing as saying the anonymous routing is Tor's reason for existence (as opposed to just something it happens to be doing). The E-Prime guys want the is-of-identity to be hard (if not impossible). But it's not obvious that everybody would agree with their sentiment.
    - nathell 5y ago
      > Wouldn't it become rather difficult to do identity statements without "is"? Not really, depending on the language. https://en.wikipedia.org/wiki/Zero_copula https://en.wikipedia.org/wiki/Zero_copula
    - guerrilla 5y ago
      > "The Tor network is an anonymous relay network overlaid on the internet". Nitpick: This isn't an identity statement by the way: You can't replace "is" with "equals" here because it's being used to classify. It denotes subset, not equality or equivalence.
- azornathogron 5y ago
  I don't like "are" for that purpose. "Is" is phonetically clearer and less awkward. I is, you is, he/she/it is, they is. I'll admit the past tense "ised" (pronounced izz-d) is still not very nice. Perhaps it should be "be"... I be, you be, yesterday they beed.
- rich_sasha 5y ago
  > Generations of children have been getting themselves needlessly confused because of this terrible convention! Childs perhaps then?
  - carlob 5y ago
    Generations of childs have ared geting themselfs
  - galkk 5y ago
    Childs and mouses are very common words for non native speakers
  - prof-dr-ir 5y ago
    On the contrary! The manifesto suggests one specific improvement to mathematical notation whilst ignoring all the other issues, for example that Euler's Gamma(n) equals (n-1)! instead of n! or that df/dx is not a fraction. So in that spirit I think it might be better to only propose fixing the verb 'to be' and to leave the poor children out of this discussion.
- bsder 5y ago
  The problem with "to be" is that we have multiple conflated meanings. "Thingy is blue". (nominative connection) "Thingy is presenting". (helper verb) "Thingy is." (existence) Other languages separate them and so can have more logical agreement.
- dTal 5y ago
  I think there's a bit of a difference between a woolly grammar you pick up organically at age 1-2, and a precisely specified system of abstract reasoning, specifically constructed as a tool of mind, that has to be hammered into you over the course of a decade.
ksec 5y ago
I only found out Tau where there was a slightly heated discussion about adding it to Ruby Core[1], still unsure if this is needed or required. And somehow at the same time The Tau Manifesto is written by Michael Hartl, who also wrote the Ruby on Rails Tutorial . [1] https://bugs.ruby-lang.org/issues/17496 https://bugs.ruby-lang.org/issues/17496
- Aardwolf 5y ago
  POSIX defines M_PI, M_PI_2 and M_2_PI None of these is 2 * pi (M_PI_2 is pi / 2, and M_2_PI is 2 / pi) That is a shame because 2 * pi is commonly needed and having it in 2 * M_PI form can cause mistakes such as order of operations if it's a divisor. Since names M_2_PI and M_PI_2 are already taken, M_TAU would be very sensible.
gilmore606 5y ago
Isn't this just a refactor? He should submit a PR, maybe with a few tests.
slver 5y ago
Bikeshedding
DoomHotel 5y ago
Figure 2 in that article, illustrating a constant-width figure with three sides (a Reuleaux triangle), reminded me of a science fiction story from long ago. I finally found the title: it's "The Three-Cornered Wheel" by Poul Anderson. A spaceship crew on an alien planet needs to transport something heavy but the natives worship circles and won't let them use cylindrical rollers. They eventually find a solution that satisfies everyone.
- jonsen 5y ago
  It reminded me of an earthly vehicle usage: https://en.m.wikipedia.org/wiki/Wankel_engine https://en.m.wikipedia.org/wiki/Wankel_engine
Zhyl 5y ago
I like the idea of Tau but "pi is wrong" is wrong. Pi is correct. The pitch for Tau is as a replacement for Pi. That it is more logical than Pi. Tau has an important lesson to tell: intuition is important and in many cases shifting things around so they're easier to create an intuitive understanding is often very trivial and boils down to aesthetic/representation choices. Claiming that "pi is wrong" is picking a fight that doesn't need to be fought with a crowd that will not be convinced. Instead, if I were a more full Tau advocate I would do more along the lines of Khalid from Betterexplained and seek to find other interesting intuitive takes on dry topics that are often taught by wrote.
- bsder 5y ago
  While the article goes for tongue-in-cheek, it brings up an important point. Pedagogy is important. And pedagogy can get stuck. "Electromagnetism" is a good example. We still learn the Heaviside-Hertz formalisms which are based around an "ether". Why?--Because they work and you can calculate a lot of simple systems by hand. This helps A) develop intuition and B) generate calculations which approximate more complex systems. However, once you start trying to do motors and capacitors and stuff--things get weird (starting with "displacement current"). At that point, the fields formulations tend to work much better (See: "Collective Electrodynamics" by Carver Mead). However, your calculations take a jump in complexity that you didn't have to deal with before--your linear algebra and vector analysis better be pretty solid. However, dealing with motors and coupled fields and stuff gets much easier.
  - noir_lord 5y ago
    Not unusual, we still mostly use Newtonian physics even though we know it's only an approximate solution because the math comes out close enough until you get in the realm where you are talking decent fractions of C. I mean Newtonian methods put is on the moon so they are good enough for a lot of cases. Something as 'simple' as inertia looks very different once you step from Newtonian/special to general relativity.
- hilbert42 5y ago
  "pi is wrong" It's just hyperbole to get everyone's attention. From that perspective it's pretty good I reckon.
m4r35n357 5y ago
Pick a better symbol; tau is already overloaded. Or stop wasting peoples' time over trivia!
saagarjha 5y ago
The problem here is that pi shows up in a lot of places that have nothing to do with circles, and in those places tau does not do better (it frequently does worse). It's just not worth the hassle to make it the default, and I say this as someone who celebrates tau day every year (but I call it "my birthday" instead :P)
- tankenmate 5y ago
  But as explained in the manifesto, quite often when you see π on its own generally it is a case of 2 * 1/2 π. And by removing the 2 * 1/2 π terminology you're missing the significance of why the 2 * term is there! The best example of this in the article is the λ (nee τ) version of the volume of a n-sphere; the symbolic algebra form makes far more sense.
  - saagarjha 5y ago
    Eh, the example I had in mind when I was writing that comment was of the evaluations of the Riemann zeta function, where the actual "factor on the pi" is not all that important because there's other things being mixed in anyways.
    - friend-monoid 5y ago
      So in what way does tau do worse?
      - antonvs 5y ago
        It kinda ruins Euler's identity.
        caylus 5y ago
        Arguably it makes it more clear what's really going on. With tau, the identity can be formulated either: - e^(iτ) = 1, meaning that taking a full revolution around the complex plane brings you back to 1, where you started - e^(iτ/2) = -1, meaning that taking a half revolution takes you to the opposite of where you started, -1. If you insist on the "contains the additive identity" formulation (which IMO is gratuitous because e^(ix) is all about the complex plane, not regular addition and multiplication), you can do either e^(iτ) + 0 = 1, or e^(iτ) - 1 = 0.
hilbert42 5y ago
Over the years I've seen a number of similar articles on pi and tau but I reckon this one is by far the most comprehensive. All have the same thread and it's a shame that tau and pi weren't reversed in meaning from the outset as clearly this would have simplified many things. For example (as the article mentions) the number of times I've see this ℏ=h/2π explained or alternatively its explanation omitted when it should have been explained is numerous. With tau, all that could have been omitted. Moreover, it seems to me that starting with tau is more logical in that a circle results from the rotation of the radius, still nothing will change as pi is so absolutely entrenched.
mids_hn 5y ago
While we're trying to change the status quo in mathematics around the world, let's also all switch to the World Calendar and start using Base 12.
- p1mrx 5y ago
  You could start by calling it base twelve (because 10 would be too confusing.)
  - lebuffon 5y ago
    Or to really obfuscate called it base 10 (in base 12) :))
- Hizonner 5y ago
  60 is a better base than 12. Even 30 would be better. And we should drop the stupid Earth-centric metric system and go to some kind of Planck units.
  - dvfjsdhgfv 5y ago
    > 60 is a better base than 12. And it proved itself useful on this Earth for probably longer than the decimal system.
  - p1mrx 5y ago
    Base sixty would be much worse for humans. There are too many digits to memorize, and the multiplication table is enormous. It does give you a factor of 5, but 5 is only so common because we use base ten. Base twelve is better than thirty because you can represent 1/4 (0.3) and 3/4 (0.9) with a single digit.
  - dTal 5y ago
    We do, for physics. Very often c is treated as 1. The "meter" is really just a conveniently human-scaled unit, equivalent to the "degree" in trigonometry.
deleted 5y ago
[deleted]
DoomHotel 5y ago
Is this title trying to riff on "No, it is the children who are wrong"?
tragomaskhalos 5y ago
There's a bad science fiction story in here = humans broadcast pi to the stars in many different formats, but nearby aliens sail right past oblivious, mistaking the signal for random noise because their maths uses tau.
- willis936 5y ago
  Was it absurd tongue-in-cheek sci-fi comedy similar to Douglas Adams? I can't imagine a technologically advanced civilization missing a perfectly correlated signal.
- Viliam1234 5y ago
  The aliens might conclude that we have some taboo against giving correct values and instead write halves of everything. So they would come expecting us to have two heads, four arms, and four legs.
Hizonner 5y ago
Yes, we should be using a circle constant that has a value twice that of "pi". We should not be calling it "tau". That's already used for too many things, and anyway the constant is important enough to deserve its own symbol. Instead of cutting it down from two verticals to one, we should add a symbol that has three verticals. Which has the additional advantage of giving a real visual cue to what's going on.
- antonvs 5y ago
  Logically, it should have twice the verticals of pi, i.e. four. We could arrange them in a square shape.
- hassancf 5y ago
  And maybe we could call it: 2 pi ? Just saying
alfiedotwtf 5y ago
Every year, I look forward to the comments here of that page. Tauday, like the SR-71 ground check story, I’ll happily read the comments every time it’s posted.
boublepop 5y ago
Why do people even measure rotations in radians? It’s a stupid unit that’s never ever written out but always expressed as either “pi radians” or “tau radians”, and just like with degrees, or the measure which has 200 to a circle you end up spending time teaching students how to convert to the sensible unit we all default to, which is just plain rotations. Everyone understands intuitively half a rotation. A full rotation or a quarter rotation. And when you tell a student 30 degrees, they all spend a bit of mental effort thinking before they go “Ah yes, 1/12 of a full rotation” and if you tell them 0.52 radians they’ll just look at you blankly stating they need a calculator before they know what are you are on about.
- bronzeage 5y ago
  because sin and cos have simple Taylor series, but only when measuring angles in radians. sin(x)/x at zero is one only in radians. Just multiplying by the angle is a good approximation of sin for low angles, again only in radians. I bet even an alien mathematician will describe angles in radians.
  - deleted 5y ago
    [deleted]
  - boublepop 5y ago
    The equivalent if sin taking revolutions (let’s say sinr) is just sinr(x)=sin(x2pi) there is no fundamental mathematical relation broken by this, that would indicate math was broken at the core. And the Taylor expansion isn’t any less simple, you simply state the pi’s in the expansion rather than having them implied in your input variable. It’s amazing people assume math will break somehow if you use a different unit for angles, when most should at least be familiar with using both 360 and ~6.283 and some using 200 as the scale for one rotation. And when trying to reason about it every single person always translates this into ratios of rotations or percentages of rotations.
- jonsen 5y ago
  Hz, rpm, no radius nor pi involved.
- 5y ago
derryrover 5y ago
Convinced me that PI is in fact wrong. I had thought myself sometimes why there was always 2PI everywhere and how PI was half a circle (instead of a whole). I was always eventually convinced by the PIr^2 = area function that PI must be correct. Also a lot of people thought about it for a long time right? The example that many other surface area functions have 1/2 in them convinces me that the function should be 1/2 TAU * r^2. Good luck convincing the rest of us degenerates.
rvr_ 5y ago
I am sold. Tau is the law.

128 points by adunk 5y ago

That was a surprisingly entertaining and well-researched manifesto. In the same spirit, I think it is time to rethink the verb 'to be': the only consistent conjugation is obviously 'I/you are; he ares; we/you/they are'. And similarly the past tense should be 'ared' instead of 'was/were'. Generations of children have been getting themselves needlessly confused because of this terrible convention! Would it be possible to correct this wrong? Or do you think the time for doing so has passed and, by now, it are what it are.

wruza 5y ago
But why “are” and not “be” (past. bed)? Also, pi was not strictly pi by Euler, who used pi for both 3.14... and 6.28... in different papers. Edit: did you know you can do without “be” at all? It purely synthetic.
- someguyorother 5y ago
  >Edit: did you know you can do without “be” at all? It purely synthetic. Wouldn't it become rather difficult to do identity statements without "is"? E.g. "The Tor network is an anonymous relay network overlaid on the internet". You could perhaps say "The Tor network works on top of the internet and performs anonymous routing", but that's not quite the same thing as saying the anonymous routing is Tor's reason for existence (as opposed to just something it happens to be doing). The E-Prime guys want the is-of-identity to be hard (if not impossible). But it's not obvious that everybody would agree with their sentiment.
  - nathell 5y ago
    > Wouldn't it become rather difficult to do identity statements without "is"? Not really, depending on the language. https://en.wikipedia.org/wiki/Zero_copula https://en.wikipedia.org/wiki/Zero_copula
  - guerrilla 5y ago
    > "The Tor network is an anonymous relay network overlaid on the internet". Nitpick: This isn't an identity statement by the way: You can't replace "is" with "equals" here because it's being used to classify. It denotes subset, not equality or equivalence.
azornathogron 5y ago
I don't like "are" for that purpose. "Is" is phonetically clearer and less awkward. I is, you is, he/she/it is, they is. I'll admit the past tense "ised" (pronounced izz-d) is still not very nice. Perhaps it should be "be"... I be, you be, yesterday they beed.
rich_sasha 5y ago
> Generations of children have been getting themselves needlessly confused because of this terrible convention! Childs perhaps then?
- carlob 5y ago
  Generations of childs have ared geting themselfs
- galkk 5y ago
  Childs and mouses are very common words for non native speakers
- prof-dr-ir 5y ago
  On the contrary! The manifesto suggests one specific improvement to mathematical notation whilst ignoring all the other issues, for example that Euler's Gamma(n) equals (n-1)! instead of n! or that df/dx is not a fraction. So in that spirit I think it might be better to only propose fixing the verb 'to be' and to leave the poor children out of this discussion.
bsder 5y ago
The problem with "to be" is that we have multiple conflated meanings. "Thingy is blue". (nominative connection) "Thingy is presenting". (helper verb) "Thingy is." (existence) Other languages separate them and so can have more logical agreement.
dTal 5y ago
I think there's a bit of a difference between a woolly grammar you pick up organically at age 1-2, and a precisely specified system of abstract reasoning, specifically constructed as a tool of mind, that has to be hammered into you over the course of a decade.

ksec 5y ago

I only found out Tau where there was a slightly heated discussion about adding it to Ruby Core[1], still unsure if this is needed or required. And somehow at the same time The Tau Manifesto is written by Michael Hartl, who also wrote the Ruby on Rails Tutorial . [1] https://bugs.ruby-lang.org/issues/17496 https://bugs.ruby-lang.org/issues/17496

Aardwolf 5y ago
POSIX defines M_PI, M_PI_2 and M_2_PI None of these is 2 * pi (M_PI_2 is pi / 2, and M_2_PI is 2 / pi) That is a shame because 2 * pi is commonly needed and having it in 2 * M_PI form can cause mistakes such as order of operations if it's a divisor. Since names M_2_PI and M_PI_2 are already taken, M_TAU would be very sensible.

gilmore606 5y ago

Isn't this just a refactor? He should submit a PR, maybe with a few tests.

slver 5y ago

Bikeshedding

DoomHotel 5y ago

Figure 2 in that article, illustrating a constant-width figure with three sides (a Reuleaux triangle), reminded me of a science fiction story from long ago. I finally found the title: it's "The Three-Cornered Wheel" by Poul Anderson. A spaceship crew on an alien planet needs to transport something heavy but the natives worship circles and won't let them use cylindrical rollers. They eventually find a solution that satisfies everyone.

jonsen 5y ago
It reminded me of an earthly vehicle usage: https://en.m.wikipedia.org/wiki/Wankel_engine https://en.m.wikipedia.org/wiki/Wankel_engine

Zhyl 5y ago

I like the idea of Tau but "pi is wrong" is wrong. Pi is correct. The pitch for Tau is as a replacement for Pi. That it is more logical than Pi. Tau has an important lesson to tell: intuition is important and in many cases shifting things around so they're easier to create an intuitive understanding is often very trivial and boils down to aesthetic/representation choices. Claiming that "pi is wrong" is picking a fight that doesn't need to be fought with a crowd that will not be convinced. Instead, if I were a more full Tau advocate I would do more along the lines of Khalid from Betterexplained and seek to find other interesting intuitive takes on dry topics that are often taught by wrote.

bsder 5y ago
While the article goes for tongue-in-cheek, it brings up an important point. Pedagogy is important. And pedagogy can get stuck. "Electromagnetism" is a good example. We still learn the Heaviside-Hertz formalisms which are based around an "ether". Why?--Because they work and you can calculate a lot of simple systems by hand. This helps A) develop intuition and B) generate calculations which approximate more complex systems. However, once you start trying to do motors and capacitors and stuff--things get weird (starting with "displacement current"). At that point, the fields formulations tend to work much better (See: "Collective Electrodynamics" by Carver Mead). However, your calculations take a jump in complexity that you didn't have to deal with before--your linear algebra and vector analysis better be pretty solid. However, dealing with motors and coupled fields and stuff gets much easier.
- noir_lord 5y ago
  Not unusual, we still mostly use Newtonian physics even though we know it's only an approximate solution because the math comes out close enough until you get in the realm where you are talking decent fractions of C. I mean Newtonian methods put is on the moon so they are good enough for a lot of cases. Something as 'simple' as inertia looks very different once you step from Newtonian/special to general relativity.
hilbert42 5y ago
"pi is wrong" It's just hyperbole to get everyone's attention. From that perspective it's pretty good I reckon.

m4r35n357 5y ago

Pick a better symbol; tau is already overloaded. Or stop wasting peoples' time over trivia!

saagarjha 5y ago

The problem here is that pi shows up in a lot of places that have nothing to do with circles, and in those places tau does not do better (it frequently does worse). It's just not worth the hassle to make it the default, and I say this as someone who celebrates tau day every year (but I call it "my birthday" instead :P)

tankenmate 5y ago
But as explained in the manifesto, quite often when you see π on its own generally it is a case of 2 * 1/2 π. And by removing the 2 * 1/2 π terminology you're missing the significance of why the 2 * term is there! The best example of this in the article is the λ (nee τ) version of the volume of a n-sphere; the symbolic algebra form makes far more sense.
- saagarjha 5y ago
  Eh, the example I had in mind when I was writing that comment was of the evaluations of the Riemann zeta function, where the actual "factor on the pi" is not all that important because there's other things being mixed in anyways.
  - friend-monoid 5y ago
    So in what way does tau do worse?
    - antonvs 5y ago
      It kinda ruins Euler's identity.
      - caylus 5y ago
        Arguably it makes it more clear what's really going on. With tau, the identity can be formulated either: - e^(iτ) = 1, meaning that taking a full revolution around the complex plane brings you back to 1, where you started - e^(iτ/2) = -1, meaning that taking a half revolution takes you to the opposite of where you started, -1. If you insist on the "contains the additive identity" formulation (which IMO is gratuitous because e^(ix) is all about the complex plane, not regular addition and multiplication), you can do either e^(iτ) + 0 = 1, or e^(iτ) - 1 = 0.

hilbert42 5y ago

Over the years I've seen a number of similar articles on pi and tau but I reckon this one is by far the most comprehensive. All have the same thread and it's a shame that tau and pi weren't reversed in meaning from the outset as clearly this would have simplified many things. For example (as the article mentions) the number of times I've see this ℏ=h/2π explained or alternatively its explanation omitted when it should have been explained is numerous. With tau, all that could have been omitted. Moreover, it seems to me that starting with tau is more logical in that a circle results from the rotation of the radius, still nothing will change as pi is so absolutely entrenched.

mids_hn 5y ago

While we're trying to change the status quo in mathematics around the world, let's also all switch to the World Calendar and start using Base 12.

p1mrx 5y ago
You could start by calling it base twelve (because 10 would be too confusing.)
- lebuffon 5y ago
  Or to really obfuscate called it base 10 (in base 12) :))
Hizonner 5y ago
60 is a better base than 12. Even 30 would be better. And we should drop the stupid Earth-centric metric system and go to some kind of Planck units.
- dvfjsdhgfv 5y ago
  > 60 is a better base than 12. And it proved itself useful on this Earth for probably longer than the decimal system.
- p1mrx 5y ago
  Base sixty would be much worse for humans. There are too many digits to memorize, and the multiplication table is enormous. It does give you a factor of 5, but 5 is only so common because we use base ten. Base twelve is better than thirty because you can represent 1/4 (0.3) and 3/4 (0.9) with a single digit.
- dTal 5y ago
  We do, for physics. Very often c is treated as 1. The "meter" is really just a conveniently human-scaled unit, equivalent to the "degree" in trigonometry.

deleted 5y ago

[deleted]

DoomHotel 5y ago

Is this title trying to riff on "No, it is the children who are wrong"?

tragomaskhalos 5y ago

There's a bad science fiction story in here = humans broadcast pi to the stars in many different formats, but nearby aliens sail right past oblivious, mistaking the signal for random noise because their maths uses tau.

willis936 5y ago
Was it absurd tongue-in-cheek sci-fi comedy similar to Douglas Adams? I can't imagine a technologically advanced civilization missing a perfectly correlated signal.
Viliam1234 5y ago
The aliens might conclude that we have some taboo against giving correct values and instead write halves of everything. So they would come expecting us to have two heads, four arms, and four legs.

Hizonner 5y ago

Yes, we should be using a circle constant that has a value twice that of "pi". We should not be calling it "tau". That's already used for too many things, and anyway the constant is important enough to deserve its own symbol. Instead of cutting it down from two verticals to one, we should add a symbol that has three verticals. Which has the additional advantage of giving a real visual cue to what's going on.

antonvs 5y ago
Logically, it should have twice the verticals of pi, i.e. four. We could arrange them in a square shape.
hassancf 5y ago
And maybe we could call it: 2 pi ? Just saying

alfiedotwtf 5y ago

Every year, I look forward to the comments here of that page. Tauday, like the SR-71 ground check story, I’ll happily read the comments every time it’s posted.

boublepop 5y ago

Why do people even measure rotations in radians? It’s a stupid unit that’s never ever written out but always expressed as either “pi radians” or “tau radians”, and just like with degrees, or the measure which has 200 to a circle you end up spending time teaching students how to convert to the sensible unit we all default to, which is just plain rotations. Everyone understands intuitively half a rotation. A full rotation or a quarter rotation. And when you tell a student 30 degrees, they all spend a bit of mental effort thinking before they go “Ah yes, 1/12 of a full rotation” and if you tell them 0.52 radians they’ll just look at you blankly stating they need a calculator before they know what are you are on about.

bronzeage 5y ago
because sin and cos have simple Taylor series, but only when measuring angles in radians. sin(x)/x at zero is one only in radians. Just multiplying by the angle is a good approximation of sin for low angles, again only in radians. I bet even an alien mathematician will describe angles in radians.
- deleted 5y ago
  [deleted]
- boublepop 5y ago
  The equivalent if sin taking revolutions (let’s say sinr) is just sinr(x)=sin(x2pi) there is no fundamental mathematical relation broken by this, that would indicate math was broken at the core. And the Taylor expansion isn’t any less simple, you simply state the pi’s in the expansion rather than having them implied in your input variable. It’s amazing people assume math will break somehow if you use a different unit for angles, when most should at least be familiar with using both 360 and ~6.283 and some using 200 as the scale for one rotation. And when trying to reason about it every single person always translates this into ratios of rotations or percentages of rotations.
jonsen 5y ago
Hz, rpm, no radius nor pi involved.
5y ago

derryrover 5y ago

Convinced me that PI is in fact wrong. I had thought myself sometimes why there was always 2PI everywhere and how PI was half a circle (instead of a whole). I was always eventually convinced by the PIr^2 = area function that PI must be correct. Also a lot of people thought about it for a long time right? The example that many other surface area functions have 1/2 in them convinces me that the function should be 1/2 TAU * r^2. Good luck convincing the rest of us degenerates.

rvr_ 5y ago

I am sold. Tau is the law.