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Pi Day Is Coming — But Tau Day Is Better
PerlJedi writes "A few months ago, a Tweet from Randal Schwartz pointed me to a YouTube video about 'Triangle Parties' made by Vi Hart. My nerdiness and my love of math made it my new favorite thing on YouTube. Now, with Pi Day coming up later this week, I thought it would be an appropriate time to point people to another of her YouTube videos: Pi is Wrong. The website she mentions at the end, Tauday, has a full explanation of the benefits of using Tau rather than Pi. Quoting: 'The Tau Manifesto is dedicated to one of the most important numbers in mathematics, perhaps the most important: the circle constant relating the circumference of a circle to its linear dimension. For millennia, the circle has been considered the most perfect of shapes, and the circle constant captures the geometry of the circle in a single number. Of course, the traditional choice for the circle constant is pi — but, as mathematician Bob Palais notes in his delightful article "Pi Is Wrong!", pi is wrong. It's time to set things right.'"
What, pi is 14.3? When did that happen?
Thing is, we like pie. Being able to eat a Pi sized slice of Pi at 1:59 on 3.14 is a geeky excuse to consume treats.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
There are 14 months in a year now?
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Tau day is better because I have an excuse to get 2 pies instead of just one. I still celebrate pie day as well as groundhog day, mmmmm ground hog).
Time to offend someone
I do think tau is the 'better' constant, and both exploring the possibilities of what tau can do, and just 'playing around' with the math involved, has been enjoyable. However, to evaluate it properly and determine just how strong it is, a strong counterpoint is needed - and it is supplied in The Pi Manifesto.
Both its author and I recommend reading The Tau Manifesto (and Bob Palais's original work; both are linked in the article above) before reading The Pi Manifesto, to make proper sense of it.
In the end, I think tau is a much stronger choice than pi for some aspects of math; others, deserve further investigation. It may all be academic discussion, given how firmly pi is entrenched in our mathematics, but perhaps there's a solid place for both - with pi reserved for certain advanced concepts, and tau used through introductory geometry, trig and calculus.
Wait, what about four-thirds pi, the constant that relates the volume of a sphere to the radius???
Using 2pi as the so-called "constant" is two-dimensional chauvinism!
http://www.geoffreylandis.com
Who cares about pi or tau? e shows a much more in depth understanding of mathematics.
Tau is twice the constant Pi ever was!
Comment removed based on user account deletion
I'm not a mathematician, but that Tau "article" seems to steal a few bases.
It whines about A=(pi)r2 while C=(pi)D and how that shows that diameter is fundamental. But that's not the way I learned it anyway - the formula was always C=2(pi)r. Radius was fundamental, not diameter.
Which is even more obvious when you go into spheres, where everything is based off radius (A=4(pi)r2, V=4/3(pi)r3).
If we use diameter, you have to remember additional divisors (4 for the areas, 8 for the volumes). I can't speak on whether the whole "one turn" argument would help understanding other concepts, but aside from people who are working to become mathematicians, I suspect that the fact that the radius-based "magic formulas" are simpler will keep them around...
p.s. What magic brew do you have to use to get Slashdot to accept HTML codes like pi? Or Unicode? Every attempt ended up getting stripped, so I went with (pi).
I managed to get bib # tau for a marathon last year. Gave the timekeeper fits.
Both are irrational.
Oh and obligatory:
Taumorrow, Taumorrow, I love you, Taumorrow, you're only a day away......
"That's the way to do it" - Punch
It is? Like what? There's a lot of greek symbols that are used for different things, so you have to look at what domain you're in before you make any assumptions about their values. This also applies to latin symbols.
Quick: what is i? Well, that depends. If you're a mathematician, it's the square root of -1. However, if you're an electrical engineer, the answer is the AC current. In EE, j is the square root of -1. Omega, theta, tons of symbols like these are reused in different domains for different things.
Offhand, I don't remember tau being used for anything else in mathematics (specifically geometry), so it seems as good a symbol as any. According to Wikipedia, there's a handful of mathematical uses for tau already, but they seem pretty esoteric (or obsolete, in the case of the golden ratio, which more commonly uses phi). It is used for a bunch of things in physics and biology, but those are different domains, so that's pretty irrelevant. You don't use pi (the circle constant) much in biology either, I imagine.
However, there are some greek letters that are barely used, so maybe one of those would be better. Upsilon, for instance, only has one use listed in Wikipedia's list of greek letters used in math, science, and engineering, to represent an elementary particle. Only physicists would ever see that (I don't think I ever saw that in college, as I was a EE major), so maybe that'd be a better choice than tau.
And, I think it's perhaps a little wrongheaded anyway. The area of a circle is pi*r^2. That'd become tau*r^2/2... You took the 2 out of one place and put it in another. And it does nothing for spheres: Volume = (4*pi*r^3)/3 = (2*tau*r^3)/3; Surface area = (4*pi*r^2) = (2*tau*r^2).
And besides, tau's already claimed as the "time constant" variable, so n'yah!
Program Intellivision!
I know that some people will point out that e^(tau * i) = 1, which they'll claim is nicer than e^(pi * i) = -1
But the most beautiful equation in mathematics is e ^ (pi * i) + 1 = 0. The five most fundamental constants, being combined with the three most fundamental operators (addition, multiplication, exponentiation -- sorry, tetration), all equaling out, with absolutely nothing extra. There's no way to make it work as elegantly with tau.
(measuring d then halving doesn't count)
This is where I stopped reading your post.
Sure there is: e^(tau * i) + 0 = 1.
Hey, it's really not any more ridiculous than "... + 1 = 0".
i is always sqrt(-1). EEs just can't spell. Well known fact.
Socialism: a lie told by totalitarians and believed by fools.
Let me see if I get this straight... Tau = 2*Pi and Tau is right. But Pi is wrong. So, by this rational, two wrongs make a right?
But, my point is, it depends on the equation. Some might look simpler, some might not.
IMO, TFA is cherry picking. I'm sure there's a whole list of equations that would suddenly introduce new factors of 1/2 or 0.5, which most would consider more annoying than a 2.
For instance, the area of a circle would be (1/2)tau*r^2 - which seems a bit awkward to me. Since tau = C/r, You could simplify it to (C*r)/2, but again - fractions are awkward to write, especially with a keyboard, and mistakes get easy to make. I like PI*r^2, myself.
There may exist equations in which inserting your 13's and 59s simplify the math, in which case a good old "let banana = 13/59 * pi" might make your paper more readable.
To call any number "right" or "wrong", is a bit stupid.
e^(tau*i) + 0 = 1
Who ordered that?
How in your mind is "x+1=0" ridiculous in the sense that "x+0=1" is? The former is a perfectly valid equation. Setting things equal to zero is extremely common, as anyone with even a middle school level education ought to know. Do you complain that x^2+2x+1=0 is a ridiculous equation too?
Not even this. The angle is in radians. It won't change a bit.
Now, sin(pi*x) is not the same as sin(tau*x), but sin(x) doesn't care whether you prefer using pi or tau.
Pi will always be around because it relates to the diameter, which is easily measurable by actual humans in actual circumstances.
If there's a big circle on the floor, you can measure the diameter with a tape measure and one other person: stand on opposite sides of the circle, one end of the tape stays in one spot, and the other end gets moved back and forth until its length is as long as possible. The widest part of the circle == the diameter.
You can determine "the widest part of the circle" with simple physical measurements. Measuring the radius only requires a way to accurately determine where the center is, which is a non-trivial exercise. (Compared to the above.) Or you could measure the diameter and then divide by 2, but "measure the diameter" will always be one less step than "determine the radius."
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
With Tau, you can have two pies.
Actually, if you are a particle physicist you can have a lot more - one tau can decay into 5 pis (although 3 is more common).
That apple pie has rounded corners, it's probably in violation of one or more design parents from a certian computer company whose name I can't seem to remember at this time.
Any insufficiently advanced magic is indistinguishable from technology.
No it isn't. It completely misses the point of e^(pi * i) = -1, which is that the left side gives you a bloody negative number.
The tau version is rather obvious, since you are squaring (-1). Put it another way, if e^(pi * i) had happened to equal 1, the tau version would be exactly the same. The tau version doesn't really tell you what is special about Euler's identity.
Umm, no!
e^(pi*i) = -1 implies e^(tau*i) = 1
e^(tau*i) = 1 does not imply e^(pi*i) = -1
The tau version follows from the pi version. The pi version does not necessarily follow from the tau version, because the tau version would still be true if e^(pi*i) = 1.
So the tau version is missing some very important information.