Talk:Tau (2π)

Old discussion

For future reference, here are a few links to discussions about this topic prior to the creation of this article:

• Pi is wrong at the Mathematics Reference Desk (August 2007)
• Talk:Tau (several threads, the oldest from October 2010)
• At least 3 threads at Talk:Pi:
  • 2pi? (November 2005)
  • π vs 2π and the unit circle (August 2006)
  • 2 pi (April 2007)

--Waldir ^talk 12:59, 23 July 2011 (UTC)

Multiple issues

This article's got some problems. A lot of this stuff is paraphrased off of the Tau Manifesto, which is self-published, and PCWorld's article is also a blog. We might want to get verifiable sources in here for this. Also, some of the info on this is recentist given Tau Day happened a few days ago, mostly focusing on Hartl's Tau idea and only mentioning Palais's idea in one line. This also reads more like a personal opinion essay than an article. The last two sentences fall under POV but I tagged the article with the individual issues for clarity. If someone could find some good sources and fix the POV problems that'd be great. --RAN1 (talk) 20:28, 2 July 2011 (UTC)

Ive got some issues with some of the issues above.

• selfpublished. Many of the same points appear in "π Is Wrong!" by R. Palais (and Hartl credits him for them). PCWorld, AFAIK, is a respectable monthly publication, not a blog and does not serve as a source for the article. Palais might be mentioned more, since the idea is basically his, but the symbol in question was proposed by Hartl.
• Recentism Although Tau-day was celebrated a short while ago, the concept has been around since R. Palais' publication in The mathematical intelligencer in 2001. Tau-day, although it was largely ignored first time around, was celebrated for the first time in 2010.
• Verifyable The one publication mentioned above is not the main sourc for this article. In fact, the main source for this article and the tau manifesto was "π Is Wrong!", published in The Mathematical Intelligencer, which is a reliable source if ever i saw one.
• POV I removed the offending remarks.

Kleuske (talk) 08:44, 3 July 2011 (UTC)

Addendum. The essay look-and-feel was introduced by an anon (apparantly knowledgable about WP templates), just prior to the remarks above being made. I cannot help suspecting some pointy activity concerning these actions. First wreck the article by rewriting it as an essay, then starting to complain about it. WP:AGF being what it is, i'll try not to accuse anyone, but the suspicion is there. Kleuske (talk) 09:01, 3 July 2011 (UTC)

Seems a bit hasty to start throwing around hinting at accusations; this is a high-interest topic to many tech- and math-savvy people, the kind who would say to themselves "You know what, I'm going to improve this Wikipedia article" even if they've never contributed before.-RunningOnBrains^(talk) 18:27, 4 July 2011 (UTC)

You're right, and thanks for saying so. The above was unwarrented. Kleuske (talk) 15:01, 5 July 2011 (UTC)

It's nice to see some of the POV issues corrected. I tried correcting the citations issue myself, but it seems like there are still issues with the article. I'm looking for info we can use for citations in one of the recent articles that was copied over to Yahoo, but until then I think we should keep the multiple issues there. Recentism is still a problem, or at least if we can differentiate between Palais's and Martl's idea that would be good. As for the anon issue, I don't know what he did, but the article still seems somewhat essayish; it still looks like something made to promote tau rather than an article with NPOV, but I have no idea how to make it seem less POVish. Any ideas? --RAN1 (talk) 18:11, 3 July 2011 (UTC)

As wa pointed out on the deletion page several times, the tau manifesto was published over a year ago and the turn was proposed in 2001. On pi-day a spoof was run under the name half tau-day and in 2010 there was a tau-day, too. So the recentism is ludicrous. The article being essayish is strictly in the eye of the beholder, i merely see a (short) summation of the arguments given in the manifesto. Hence i beg to differ. Regards, Kleuske (talk) 18:28, 3 July 2011 (UTC)

Ok, let me rephrase that. It's difficult to distinguish what is Hartl's work and what is Palais's work. Making it all look like Hartl's work is wrong and recentist. The Manifesto is also self-published work and the opinion of Michael Hartl, which violates POV and makes it seem essayish. On another note, I cleared the citation issue a bit by finding that source for Tau. --RAN1 (talk) 18:36, 3 July 2011 (UTC)

Ok. I see where you stand, but i do not think that the work of one, who is came up with the concept and explaining why it's a good idea, is somehow invalidated by someone else who writes a manifesto and creates a big fuss over the idea. It is not as if the first isn't abundantly credited by the second.

But do explain what you mean by recentism. I hate it when -ism's float around and my understanding of the actual content is hazy at best. English is my third language, and my knowledge of the local patois is limited. 15:15, 5 July 2011 (UTC)

Alright, I'll try to explain my points more clearly. A lot of this article is based on text from proponents of tau, which doesn't make the article NPOV and to me made it seem more like an essay. I cited reliable sources because of that. Also, I thought this out a bit more, and I think recentism doesn't apply here. I tried looking for news focusing on Bob Palais' work, thinking that this might have been covered before in more depth, but it seems like there's been no news regarding that, so that's out of the way. My main problem is that it's slanted to pro-tau people, but seeing as there's been no anti-tau articles I'm not sure if that holds. In any case, I still think that the article needs more reliable sources (neutral, not self-published, third-party, etc.) cited. I'm not editing on Wikipedia often, so sorry if what I said before didn't make sense. --RAN1 (talk) —Preceding undated comment added 19:43, 5 July 2011 (UTC).

Sum of angles

I added the sum of exterior angles again to "possible advantages" after it has been deleted. The reason is that the formula for internal angles appears in the list of "possible disadvantages". Either both should stay or both should be deleted. --Entropeter (talk) 21:40, 25 August 2011 (UTC)

Both are irrelevant (numerology), and should be deleted.--ZealousGnome (talk) 17:19, 26 August 2011 (UTC)

Numerology? Nobody is purporting any "divine, mystical or other special relationship" between the sum of n-gon angles and life. The sum of exterior angles of an n-gon or interior angles of a triangle are geometric identities, useful in geometric proofs, and should both be included. Not sure how this discussion ("both should stay or both should be deleted") led to just the exterior angles point being deleted. Timbojones (talk) 19:52, 14 March 2012 (UTC)

But it's irrelevant because the pro/con format is gone now. Timbojones (talk) 19:56, 14 March 2012 (UTC)

Reference "Lindenberg"

(Number 8 in the present article.)

It was added by the author of the reference. We need to find others who use that term, or it should be excised except, potentially, as an example of usage. — Arthur Rubin (talk) 23:22, 23 September 2011 (UTC)

What term do you mean? (Number 8 is referenced four different places.) Joseph Lindenberg (talk) 23:58, 23 September 2011 (UTC)

Sorry; by "term" I meant "statement", although at least one term also doesn't seem to have an association with π/τ other than in [8]. — Arthur Rubin (talk) 02:02, 24 September 2011 (UTC)

If you mean other tau-related sources that reference [8], then [3] does. Joseph Lindenberg (talk) 16:57, 25 September 2011 (UTC)

scriptstyle

There is a general agreement that, in mathematical articles, < math > \scriptstyle should not be used. Also, many of the inline equations should be either moved to display equations, or set in standard HTML. I noticed a few which wouldn't even need HTML characters, other than that for ⁠1/2⁠ (which can be done as indicated: {{frac2|1|2}}). Even if this article should be kept, the simple equations need to be cleaned up. — Arthur Rubin (talk) 23:26, 23 September 2011 (UTC)

Sorry about that, Arthur. My skills in that area are kind of weak. I'll try to improve them. Joseph Lindenberg (talk) 02:42, 24 September 2011 (UTC)

I don't know if {{frac2}} has been discussed on WT:MATH, but {{frac}} and scriptstyle have been. — Arthur Rubin (talk) 02:47, 24 September 2011 (UTC)

Sounds like a good place for me to start. I'll look through it this weekend. Thanks for the suggestion. Joseph Lindenberg (talk) 03:12, 24 September 2011 (UTC)

OK, Arthur. I have eliminated all occurrences of \scriptstyle usage in the article. If you see it again, it won't be from me. (I was just following how other formulas in the article were written.) Joseph Lindenberg (talk) 14:47, 25 September 2011 (UTC)

Alternative image

τ

I've made an alternate version of a radian image, as seen to the right, which includes tau. Would this be a good replacement for the current image? — MK (^t/_c) 13:04, 29 September 2011 (UTC)

That looks great! And since it's svg, it could be printed out on a full sheet of paper and still look sharp. My initial reaction is that we should add it to the article as a printable tau protractor. I do think that we should have just a very simple drawing at the top of the article, because most people reading it will just be starting to learn about tau. Better not to overwhelm them with something as intricate as your drawing before they get introduced to the basics. But this should definitely be added to the article. I need to think a little more about the where/how details. Joseph Lindenberg (talk) 18:54, 30 September 2011 (UTC)

THAT'S NOT THE UNIT CIRCLE!

Here's my idea of the image that, properly modified, would be perfect for the top of the tau page. Mainly because it's gotten so much praise. But every time I see it, I want to yell, "THAT'S NOT THE UNIT CIRCLE! If it were the unit circle, it would roll out to tau!" I picture two wheels, this one and the true unit circle, rolling in unison. This one only rolls out to pi, while the true unit circle keeps on rolling out to tau. Even have something like "THE REAL UNIT CIRCLE" written on the rim. Unfortunately, though, I think I recall reading somewhere that they don't like the top picture on Wikipedia pages to be animated. Joseph Lindenberg (talk) 02:55, 1 October 2011 (UTC)

Wow, that is a fairly deceptive image. At least the π article properly specifics that it is the diameter as 1, and not the radius. Anyway, feel free to use my image in the article, and if you have any suggestions I can edit it. I pondered adding a 12-sided star polygon in the center to make the 12ths look more clear but my friends suggested against it, and I guess understanding fractions is outside the scope of the image's intent.

My main issue right now is that Wikipedia's SVG→PNG image renderer is not converting my image correctly. Compare the SVG to any PNG version and you can see that the τ in the rightmost sentence, the 2π line, is aligned to the far right. I will bring it up on the commons; I think it is either a library error (it appears that way in an image preview software I have as well) or some error in my image I overlooked. — MK (^t/_c) 06:38, 1 October 2011 (UTC)

Cyrillic Te

Russian Cyrillic letter Pe: П п

Russian Cyrillic letter Te: Т т

2π indeed

Print, Standard Italic, and Serbian italic; be, pe, ge, de, te, sha

Just so this doesn't get lost in the article history, I found it interesting how 99.146.122.70 detected a similarity between Palais' 3-legged pi and the handwritten Cyrillic letter Te, which coincidently, was derived from the Greek letter Tau. Of course, since Palais himself never mentioned this, it is OR and we can't mention it in the article; Still, it's a curious coincidence. --Waldir ^talk 06:18, 3 October 2011 (UTC)

Really, both uppercase and lowercase in Russian Cyrillic handwriting show it. It's just... 2п. I figure I'd add it incase for some reason the symbol tau becomes an obstacle due to prior use, but I guess it does fall under WP:SYNTH :( 99.146.122.70 (talk) 07:55, 3 October 2011 (UTC)

...And funnily enough, the Serbian variant lowercase te vaguely resembles the variant Greek pi ϖ. 99.146.122.70 (talk) 11:27, 3 October 2011 (UTC)

The problem of Russian Cyrillic handwritten T is the same as the problem with the three legged pi that Robert Palais introduced in his 2001 article: It is not part of any of the standard font sets and it does not even have a code in the Unicode system. This should obviously not prevent people from using it on the black board as some already do. Entropeter (talk) 15:55, 3 October 2011 (UTC)

Suggested improvements

I don't have enough mathematical background to perform anything more than basic copyediting on this article but I believe the following changes would be benefitial:

1. The expression "power rule for integrals" should link to Calculus with polynomials#Power rule, but before, that section needs to be adapted to be more relatable to ${\tfrac {1}{2}}\tau r^{2}$, for example as presented here. It would also be useful to mention why the power sule should apply — i.e, why calculating the area of a circle is akin to calculating $\int \!\tau r\,dr$. According to this video, it seems like that could be merged with the paragraph about skinny triangles.
2. The formulas should be compared using a table; that would make the article more extensible without reducing its readability, and would make visual assessment of the benefits much easier, as well as making it easier to write many examples without having to come up with non-repetitive ways to present them in text form. For example:

Formula	Tau	Pi	Notes
circumference of a circle	$\tau r$	$2\pi r$
Arc length of a circle sector	$\theta r$	$\theta r$	A whole circle is just a circle sector with $\theta =\tau$, so students could memorize just one formula for circular arc length instead of two.
circle area	${\tfrac {1}{2}}\tau r^{2}$	$\pi r^{2}$	Note that the formula for the area of a circle falls in line with the power rule for integrals (e.g. kinetic energy $K={\tfrac {1}{2}}mv^{2}$).
Area of a circle sector	${\tfrac {1}{2}}\theta r^{2}$	${\tfrac {1}{2}}\theta r^{2}$	A whole circle is just a circle sector with $\theta =\tau$, so students could memorize just one formula for circular sector area instead of two.
nth roots of unity	$\left\{e^{i\tau k/n}\right\}$	$\left\{e^{i2\pi k/n}\right\}$
Euler's Identity	$\textstyle e^{i\tau }=1$	$\textstyle e^{i\pi }=-1$
Normal distribution	${\frac {1}{\sqrt {\tau \sigma ^{2}}}}e^{-{\frac {(x-\mu )^{2}}{2\sigma ^{2}}}}$	${\frac {1}{\sqrt {2\pi \sigma ^{2}}}}e^{-{\frac {(x-\mu )^{2}}{2\sigma ^{2}}}}$
Fourier transform	$\int _{-\infty }^{\infty }f(x)\ e^{-\tau ix\xi }\,dx$	$\int _{-\infty }^{\infty }f(x)\ e^{-2\pi ix\xi }\,dx$
Angular frequency	$\textstyle \omega =\tau f$	$\textstyle \omega =2\pi f$
Reduced Planck constant	$\hbar =h/\tau$	$\hbar =h/2\pi$
Wavenumber	$\textstyle k=\tau /\lambda$	$\textstyle k=2\pi /\lambda$
reactance of an inductor	$\tau fL$	$2\pi fL$
susceptance of a capacitor	$\tau fC$	$2\pi fC$

...and so on (many more examples can be added from [1] and [2].

So what do you guys think? --Waldir ^talk 01:28, 11 October 2011 (UTC)

I'll address the quick issue (#1) now. The whole power rule for integrals part is really just an explanatory side note. The key point is there are a lot of well-known formulas of the form ${\tfrac {1}{2}}\tau r^{2}$ like ${\tfrac {1}{2}}mv^{2},{\tfrac {1}{2}}I{\omega }^{2},{\tfrac {1}{2}}kx^{2},{\tfrac {1}{2}}at^{2},{\tfrac {1}{2}}\varepsilon E^{2},{\tfrac {1}{2}}CV^{2},{\tfrac {1}{2}}LI^{2}$. We're just saying, oh by the way, the reason you see this form so much is that it's the integral of $\tau r,\ mv,\ I\omega ,\ kx,\ at,\ \varepsilon E,\ CV,\ LI$. But that's not what demonstrates that ${\tfrac {1}{2}}\tau r^{2}$ is a more standard, appropriate form than ^{$\ \pi r^{2}$}. I think the better way to improve this is to list/name/wikilink as many of those formulas as we can to show that that's the common form. I see no need to use the term "power rule for integrals" at all. If there are no counterarguments, I can take care of this rewrite. Are there any other well-known examples of this form that I'm forgetting? Joseph Lindenberg (talk) 06:45, 11 October 2011 (UTC)
If when you opened up a physics textbook, the formulas you saw were $\ mv^{2},I{\omega }^{2},kx^{2},at^{2},\varepsilon E^{2},CV^{2},LI^{2}$ then this argument would instead be in pi's favor. Joseph Lindenberg (talk) 07:09, 11 October 2011 (UTC)
...and we would be talking about how it falls in line with the "power rule for derivatives". (The power rule for integrals says the integral of $x^{n}$ is ${\tfrac {1}{n+1}}x^{n+1}$. The power rule for derivatives says the derivative of $x^{n}$ is $nx^{n-1}$. Notice how the first set looks more like $\tau r$ and ${\tfrac {1}{2}}\tau r^{2}$ while the second set looks more like $\pi r^{2}$ and $2\pi r$? Yet both are valid power rules. That shows why the argument for tau here isn't about the power rule.) Joseph Lindenberg (talk) 10:17, 11 October 2011 (UTC)

Then we should probably present both arguments. I think it's worth mentioning because some of the sources use that as a justification for tau, and not every layman will have the knowledge to evaluate the validity of that claim. And in any case, I still think that pointing out that ${\tfrac {1}{2}}\tau r^{2}$ comes from an integral provides a good intuition about the calculation of the area of a circle, as shown in the video I linked above. (side note: I added line breaks to your three messages above, to make them easier to read with the signatures in the middle. But maybe you could combine them into a single coherent message; that would make it easier to read both for the current discussion and for future reference). --Waldir ^talk 10:41, 11 October 2011 (UTC)

While we're discussing how to do what you're asking, I'm going to go ahead and put the other examples into the article just to have them in place. Maybe I'm missing some deeper point about that power rule thing. Something I may not correctly understand is why Michael Hartl spent so much time/space in the Tau Manifesto showing step-by-step how you integrate gt to get ${\tfrac {1}{2}}gt^{2}$, then showing how you integrate kx to get ${\tfrac {1}{2}}kx^{2}$, then showing how you integrate mv to get ${\tfrac {1}{2}}mv^{2}$, then finally showing how you integrate τr to get ${\tfrac {1}{2}}\tau r^{2}$. The approach I took in my own paper was basically like what I wrote above - to point out that that form shows up in a lot of formulas and name a few examples to jog the reader's memory, who I probably assumed had taken physics and would say, Oh yeah, there were a lot of formulas like that. I have assumed Michael Hartl was just being more hand-holding, but I'll ask him if there was another point to the way he did it. Joseph Lindenberg (talk) 02:14, 12 October 2011 (UTC)

I looked at Pi is Wrong and The Tau Manifesto again. I don't see where either of them ever used the term "power rule". I'm thinking that if you really want to address the integral issue more, the way to do it is with a graph of the line y = mx. Only show the first quadrant (both x and y positive). If you want the area under that line, it's the area of a triangle. ${\tfrac {1}{2}}$base*height where the base is the x coordinate and the height is the y coordinate. Since y = mx, ${\tfrac {1}{2}}$base*height = ${\tfrac {1}{2}}$x * mx = ${\tfrac {1}{2}}mx^{2}$.

Circumference and radius are related to each other just like x and y are. Only instead of multiplying by m, you multiply by tau. I guess the point is that when you have a simple linear relationship like y = mx or C = τr or momentum = mass * velocity or spring force = kx or velocity = acceleration * time. (two variables related by a constant multiplier) you'll integrate and end up with the form ${\tfrac {1}{2}}mx^{2}$. I'm gonna have to chew on this topic some more. Anybody reading this, please chime in if you've got another way of looking at this. Joseph Lindenberg (talk) 08:41, 12 October 2011 (UTC)

Just letting you know that I'm still working on this. I've got something that's almost ready for other people to take a look at, though it will probably still need more refinement. But I've got other things I have to do right now, so I thought I should post just to make clear I haven't abandoned this issue. Joseph Lindenberg (talk) 05:33, 16 October 2011 (UTC)

OK, Waldir. I think I finally understand this. Are you still monitoring this thread? Joseph Lindenberg (talk) 10:22, 17 October 2011 (UTC)

I didn't get around to emailing Michael Hartl about this before I realized a very good reason why he might have laboriously gone through first integrating gt to get ${\tfrac {1}{2}}gt^{2}$, then integrating kx to get ${\tfrac {1}{2}}kx^{2}$, then integrating mv to get ${\tfrac {1}{2}}mv^{2}$, then finally integrating τr to get ${\tfrac {1}{2}}\tau r^{2}$. Whether what I write here was his reason or not, I think it makes a good argument for τ, so I decided I'd go ahead and lay it out here. I'll still ask him about it in case he has a second good reason for doing what he did.

It's all about making sure we can extend the analogy. I said my approach to this issue was just to say, "Remember, this form showed up in a lot of physics formulas. And oh, by the way, if you're curious where all those 1/2's came from, it was from integration." But plenty of people have questioned whether it's valid to draw a comparison between all those physics formulas and the formula for the area of a circle. I didn't really care, because I was convinced about tau by all the other reasons. But I have been wondering how soon some clever $\pi r^{2}$ advocate would point out there's at least one famous physics formula like theirs. The most famous. $E=mc^{2}$ doesn't have a one-half in it and has the same form as $\pi r^{2}$. Doesn't that counter our argument?

No, because you can quickly see the similarity is very shallow. $\pi r^{2}$ is a constant times a variable squared. $mc^{2}$ is a variable times a constant squared. That alone shows it's not a valid analogy. But let's look further. If we differentiate $\pi r^{2}$, we get 2πr, a second very important circle formula. If we differentiate $mc^{2}$ we get just $c^{2}$. That's not an important relativity formula. Even if we did get 2mc, that's not an important relativity formula either.

The bottom line is, the more additional similarities you can show between ${\tfrac {1}{2}}\tau r^{2}$ and ${\tfrac {1}{2}}mv^{2}$, ${\tfrac {1}{2}}kx^{2}$, etc., the more convincing the analogy and the better the argument is for τ. But it doesn't actually "prove" the tau/pi debate should be decided based on these physics formulas. (That's not true of the sector and skinny triangle formulas. They can be directly linked to the circle formulas.) I now presume that Michael Hartl was just trying to show how similar/identical their derivations through integration were. It wasn't anything about integration or the power rule itself.

Take a look at my website (sites.google.com/site/taubeforeitwascool). As a result of our discussion, I've added the 9 physics formulas there in a way that highlights their similarities to the circle/sector/triangle formulas. But I'm keeping them in a separate group, because I consider them more like cousins to the three primary siblings who actually live in the same house (that house being geometry?).

So are we done with issue #1, or as I called it, the "quick issue"? If so, I'd like to call issue #2 the "postponed issue". The orderliness does look appealing, but I think just one big table might be too restricting. Maybe a table for each section. I'd have to play around in the sandbox and look around for ideas on other wikipedia pages before I'd be comfortable with a complete redesign. And I can't commit very much time now. I've been trying to get a few last things squared away here so I can mostly ignore it for a few months. It won't get much traffic until March 14 (Pi Day) anyhow. That's 5 months away. Joseph Lindenberg (talk) 07:27, 19 October 2011 (UTC)

Waldir was right that the article could benefit from the use of tables. It made the physics formulas a lot neater. I'll see if I can find some other sections in the article where they would help. Joseph Lindenberg (talk) 01:58, 24 October 2011 (UTC)

Thanks, Scott!

Somebody Please Animate Me!

Scott Robertson recently brought the animated gif posted on the right here to my attention. Just as it is, you'll notice how perfectly the triangle in the final frame has an area of ${\tfrac {1}{2}}base*height={\tfrac {1}{2}}\tau r*r={\tfrac {1}{2}}\tau r^{2}$

(Justifying that extra 1/2 in the circle area formula is always the number one issue in arguing for tau because, despite all the formulas made simpler by tau, it's just bad luck that one of the few made less simple is the most famous, ^{$\,\pi r^{2}$}. And the best way to justify it is to point out that the 1/2 comes from another formula that everybody also remembers, 1/2 base * height. So with a minor labeling change, this animation would make the case for tau quite nicely.)

But if we're willing to swap base and height by rotating the whole image 90 degrees counterclockwise, the final frame provides what Waldir asked for earlier, a clear demonstration of how the circle area formula comes from integration. That final frame is the graph of circumference versus radius. That's what we integrate to get the area formula. We know that taking an integral is the same as calculating the area under the curve. Here, that's just a triangle! The formula is 1/2 base*height. And we actually saw the "area" physically move from making up the circle to making up the triangle under the circumference plot. Does that fit what you had in mind, Waldir?

I created this color image of the first and last frames to show what I have in mind. But I have no animation experience, and will have very little spare time in the coming months. I will work on it eventually when I find time if nobody else does. But I thought I should lay the idea out here for anyone who's looking for something to do and is good with graphics. (Everyone else, feel free to post comments and suggestions.) Joseph Lindenberg (talk) 03:05, 10 November 2011 (UTC)

We might make this easier for people to understand if the animation only peeled one color strip off the circle at a time. Rather than them moving all together at the same time. But that would make the animation longer. Let's keep both possibilities on the table for now. Also, I think the shiny 3-D effect helps because it makes the strips look like colorful modeling clay, which people can visualize being flexible enough to do this with in real life. But I realize those kind of effects are harder to implement, and require more colors than just flat uniform-color strips do, which can be a problem in gif files. Joseph Lindenberg (talk) 00:25, 16 November 2011 (UTC)

Animation of Circle Area Derivation

The original wmv file looks much sharper and takes fewer bytes. It's at the top of my website (sites.google.com/site/taubeforeitwascool) if anyone wants to try converting it some other way. Joseph Lindenberg (talk) 16:11, 26 February 2012 (UTC)

I guess this animation really shouldn't be done on Wikipedia as a video clip. *Sigh* Joseph Lindenberg (talk) 17:07, 26 February 2012 (UTC)

Requested move (1)

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: Page moved. Since the original move was done without any consultation of other editors involved in the article, I've reverted it, per WP:BRD. Any eventual move should be first discussed and agreed upon here. --Waldir ^talk 04:07, 14 March 2012 (UTC)

---

Tau against pi debate → Tau (2π) – To revert the recent undiscussed move. The new title is ungrammatical (should be "versus" not "against", or recast entirely) and reframes the article. Significantly altering an article's topic requires consensus. Cybercobra (talk) 21:20, 13 March 2012 (UTC)

Rather interesting timing, the day before Pi Day, to move the article. That combined with his addition of,

"... a debate has followed, in which none of the international scientific organizations has been involved and which has not been echoed in any major scientific publication."

makes me wonder about the motivations involved. Perhaps some people should read MIT's recent announcement that they're going to honor Pi and Tau equally by announcing new student admissions on Pi Day at "Tau Time" (6:28 pm). Even if you don't value MIT's opinion on whether tau is a legitimate constant, perhaps we could all learn something from the conciliatory tone of the article. Joseph Lindenberg (talk) 22:54, 13 March 2012 (UTC)

I'm willing to have this discussion if Lazard wants, but his timing was a clear provocation. The page should go back to the title it has had ever since it was created. This was a cheap stunt! Joseph Lindenberg (talk) 00:15, 14 March 2012 (UTC)

• Question. Why spell out "tau", but not pi? "2π" is not a category or a subject, so this is not a properly formed disambiguator according to WP:DAB. I suggest Tau (number). Kauffner (talk) 00:49, 14 March 2012 (UTC)
  • Not quite unambiguous enough. Apparently tau can also refer to the golden ratio. --Cybercobra (talk) 02:01, 14 March 2012 (UTC)

• Support reverting move - The current name is ungrammatical, the move seems a bit POINTy, and it very much changes the consensus achieved at the deletion discussion (i.e. I think under the current name the deletion would have succeeded). Mark Hurd (talk) 01:14, 14 March 2012 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Proposition to move to "Tau versus pi debate"

I open here the discussion on the move that I did previously per WP:BRD. The title of the article suggests ambiguously that the object of the article is the mathematical description of mathematical constant. However the mathematical content of the article is almost empty and may be summarized to "here is a list or well known formulas involving π, some become simpler, some not, when π is replaced by τ/2". To be acceptable for the WP:WikiProject Mathematics, such a trivial article about a mathematical constant needs that the constant is well established and appears as such in reliable sources such as notable textbooks or peer reviewed articles. This is not the case here. This is why the article has been previously asked for deletion.

However, when reading the article, it appears clearly that the subject of the article is not the constant τ, but a polemic about the replacement of π by τ. It is clear from the lead where the words "proponents" and "opponents" appear, from the sections which are all devoted to compare π and τ and from the titles of the main sources which are clearly polemical: "Pi is wrong", "The Pi manifesto", ... This polemic is notable, as it has been relayed by several news. IMO this is the main reason for which the AfD has been rejected.

Thus the present title is misleading about the content of the article and this is the rationale of my proposition to move it to Tau versus pi debate

D.Lazard (talk) 11:54, 14 March 2012 (UTC)

I'm not really even sure how notable the argument is. Most of the news items are about "tau day", and don't really document the supposed "debate" in any serious way. I think a better target for a proposed move would be tau day. Also, almost none of the sources currently referenced in the article are reliable, so the article will need to be rewritten. Sławomir Biały (talk) 12:04, 14 March 2012 (UTC)

Multiplying a famous constant by 2 and then treating the new number as equally important is ridiculous. Anyone presenting this constant as new and equally important is manufacturing a big-end/little-end squabble, which is a waste of time. Rschwieb (talk) 12:38, 14 March 2012 (UTC)

I agree with you. This is because WP:NPOV that I have done this edit [[3]], which has been reverted. D.Lazard (talk) 12:54, 14 March 2012 (UTC)

Requested move (2)

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was} not moved. - UtherSRG (talk) 03:17, 22 March 2012 (UTC)

Tau (2π) → Tau (mathematics) – It's strongly recommended that we avoid article titles with advanced characters. Georgia guy (talk) 14:52, 14 March 2012 (UTC)

This is a dreadful idea. There are other much more established uses of the symbol τ on mathematics. Moving this article there would be assigning undue weight to a thoroughly marginal use of the term. Sławomir Biały (talk) 14:59, 14 March 2012 (UTC)

But what about Tau (mathematical constant)?? Georgia guy (talk) 15:00, 14 March 2012 (UTC)

The bigger issue is that tau isn't actually used in mathematics instead of 2pi. This is just an invented controversy that happen to garner media attention on pi day. Sławomir Biały (talk),

As you can see from the link Tau (mathematics) there are other uses including one constant, the golden ratio, which is a far more common usage for Tau. So Tau (mathematics) and Tau (mathematical constant) both don't work.--JohnBlackburne^words_deeds 15:05, 14 March 2012 (UTC)

The idea that 2pi is actually a bit better than pi has popped up several times under various guises carrying different symbols. I first heard of it from a maths teacher in highschool. It is useful to have a page to describe the idea. The current name is as good as any. I can't help thinking this debate is more about the pi-vs-tau thng than it is about the article or the encyclopedia. Kleuske (talk) 15:44, 14 March 2012 (UTC)

• Support. "2π" is another name for tau, so it is not a proper disambiguator according to WP:DAB. It is inconsistent to spell out one Greek letter, but not the other. The current title is like a formula, a crib note to help you calculate for an exam: Energy (mc²), Force (ma), or Compound interest (Pe^rt). Kauffner (talk) 16:49, 14 March 2012 (UTC)
• Oppose Apparently ambiguous with the golden ratio. Perhaps Tau (circle constant)? --Cybercobra (talk) 18:22, 14 March 2012 (UTC)
  • Comment. The golden ratio is phi, according to all times I checked. Georgia guy (talk) 18:32, 14 March 2012 (UTC)
    • Tau (mathematics)#Mathematics --Cybercobra (talk) 22:31, 14 March 2012 (UTC)
    • And Mathworld: "It is denoted φ, or sometimes τ."--JohnBlackburne^words_deeds 23:54, 14 March 2012 (UTC)
  • Support for Tau (circle constant). Isheden (talk) 08:23, 19 March 2012 (UTC)
• Oppose. Even if 2π is not a good disambiguator, there are many uses of "tau" in mathematics, some much more common. "Mathematical constant" might be accurate, but if even an obscure mathematical usage commonly occured, it would be more common than this in mathematics, and we'd need to move it again. Perhaps "circle constant", although I'm not sure there aren't other uses of "tau" as a circle constant. — Arthur Rubin (talk) 18:39, 14 March 2012 (UTC)
• oppose - per my above inline reply (as we're now !voting).--JohnBlackburne^words_deeds 19:05, 14 March 2012 (UTC)
• oppose. Comments above. Sławomir Biały (talk) 19:31, 14 March 2012 (UTC)
• Oppose - If it is "strongly recommended that we avoid article titles with advanced characters", I'll consider supporting a move to a valid page title, but this isn't it. Mark Hurd (talk) 09:57, 15 March 2012 (UTC)
• Oppose - For having a valid page title, it suffices to move it to tau (2pi) which is already a redirect to this page. D.Lazard (talk) 12:03, 15 March 2012 (UTC)
• Comment - This might as well be closed seeing as the page has now been moved to Twice pi. Even though the consensus for the move to Tau (mathematics) is clearly no, as I have been part of this "survey" I will not close it myself. Mark Hurd (talk) 01:02, 19 March 2012 (UTC)
  • That move should be reverted shortly. --Cybercobra (talk) 01:19, 19 March 2012 (UTC)
    • Wasn't the move a violation of Wikipedia rules, given that we're supposed to be working on reaching agreement on a new name? While at least this time it wasn't right before Pi Day, it seems really obnoxious to me to preempt everyone, change it unannounced, and then say, "Put it back if you don't like it." If Slawomir Bialy thought "Twice Pi" would make a good title, why couldn't he just post the suggestion here? Joseph Lindenberg (talk) 02:02, 19 March 2012 (UTC)
      • And that's why the admins reverted it! --Cybercobra (talk) 06:03, 19 March 2012 (UTC)
• Move to something else: maybe "Movement to use tau instead of two pi" of something like that. Tau in the sense of two pi is not a widely accepted in mathematics; so it should not be used as a title. And Tau (mathematics) is even worse. —teb728 t c 02:19, 19 March 2012 (UTC)
  • Tau should definitely be in the title though. That's how it's known to everyone. I've suggested "The Tau Movement" below. Joseph Lindenberg (talk) 02:24, 19 March 2012 (UTC) I do agree that Tau (mathematics) would not be appropriate at this time. Joseph Lindenberg (talk) 02:26, 19 March 2012 (UTC)
    • It's not known as Tau to everyone: the only academic source in the article doesn't use Tau, for one. I've updated the article to reflect this.--JohnBlackburne^words_deeds 02:44, 19 March 2012 (UTC)
      • That's because that one article you left us with is 11 years old. Its author does indeed now know it as tau. Here's a link to his website. Furthermore, there are plenty of articles online from legitimate sources attesting to the fact that Michael Hartl proposed and supports using tau. Quite frankly, I would think something like that would qualify as "common knowledge", at least in this field, and wouldn't even need a reference. I haven't started rebuilding the article using sources that you'll find more acceptable yet, because I want to wait til the dust settles on the page title issue. A simple "citation needed" would seem more appropriate for the fact that Michael Hartl proposes using tau. Joseph Lindenberg (talk) 03:10, 19 March 2012 (UTC)
• Comment - It does a disservice to Wikipedia's readers to not use tau in the title. They hear or read about tau and then come to Wikipedia for information. It doesn't matter whether tau is currently used in professional math journals. Professional math journals are not the whole universe. Outside of their pages, many people are CLEARLY using tau to refer to a proposed alternative way of writing 2π. And actually, many of them don't even use it like it's only proposed. Even most people who absolutely hate the idea of using tau, still use the word and symbol exactly like they use the word pi and the symbol π. To refer to a particular number. If you hate that fact, then you should really want them to easily find a page here on Wikipedia that, among other things, will make clear that, at present, tau is NOT used that way in math journals, etc. If they can't easily find tau described here, they'll just go to Google and find descriptions out on the internet that often don't make that clear. It's just like teaching your kids about sex. If they don't learn about it at home, they'll learn about it on the streets. Joseph Lindenberg (talk) 06:18, 19 March 2012 (UTC)
• Oppose, but I would like to propose Tau (circle constant). Circle constant already redirects to this page. And a circle constant is what it is. Isheden (talk) 08:19, 19 March 2012 (UTC)

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

history duplication

Much of the history section belongs in pi rather than here and should be deleted, pending an AfD at any rate. Tkuvho (talk) 15:32, 14 March 2012 (UTC)

Youtube videos

Does the article really need four of these? Per EL:YES external links should normally be to official sites, the content being discussed and neutral and accurate sites related to the topic. More generally YouTube is a poor source for external links, requiring special plugins and using especially objectionable advertising (the sort that pops up over content), and except for the official channels of some news media being under no editorial control. I.e. per WP:ELNO 2, 5, 11, these should be removed, or limited to one representative link.--JohnBlackburne^words_deeds 14:27, 15 March 2012 (UTC)

I agree. I would delete them all. This kind of page is an invitation for popular entertainment of this sort. The best course would be to AfD this. Tkuvho (talk) 14:35, 15 March 2012 (UTC)

It was Kept at AfD (see talkpage header template). --Cybercobra (talk) 16:40, 15 March 2012 (UTC)

The "keep" summary of the AfD discussion was an error. As you can see for yourself, there were numerous "deletes" in the discussion, which did not lead to a consensus. At best this was an "undecided". The next AfD may be more definite in the direction of "delete". Tkuvho (talk) 17:20, 15 March 2012 (UTC)

We got sidetracked a bit. So remove them (the YouTube links) all?--JohnBlackburne^words_deeds 19:22, 18 March 2012 (UTC)

They're all by notable commentators, except the Houston one. So, no. --Cybercobra (talk) 19:45, 18 March 2012 (UTC)

I've not actually watched the videos, but just based on a preliminary gestalt, I think the Khan and Hart videos should be ok, but the Houston and Dixon less so. Sławomir Biały (talk) 21:14, 18 March 2012 (UTC)

Proposition to move to "The Tau Movement"

I'm making this proposition as follow-up to my post here that, "I'm willing to have this discussion if Lazard wants, but his timing was a clear provocation." D. Lazard has since claimed justification for what he did as WP:BRD. I have two problems with that. First of all, the evening before Pi Day, when there would obviously be a big spike in Wikipedia readers (not contributors) visiting the page, seems like a very poor choice of time to do this. IF the timing wasn't malicious, then it was certainly poor judgment. Furthermore, I don't see how the situation he found here at the tau page fits any of the situations where WP:BRD is deemed appropriate. A lot of distrust could have been avoided if he had simply posted his proposition, along with the concerns that motivated it, on the Talk page first.

Anyhow, about my proposition. A google search for "The Tau Movement" shows that the phrase is used for this topic, with no other competing uses that I can find. One big advantage over the current title that I do indeed like is its elimination of parentheses, which often confound people's attempts to link to the article. Finally, it should address concerns that readers are being misled into thinking tau is already standard notation. The title helps make clear that the article is about the call by some to use the symbol tau to supplement or supplant using the symbol pi. Joseph Lindenberg (talk) 05:42, 18 March 2012 (UTC)

Let's at least wait until the Tau (mathematics) move request above gets closed. --Cybercobra (talk) 06:08, 18 March 2012 (UTC)

Requested move (3)

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: not moved. -- Waldir ^talk 13:50, 27 March 2012 (UTC)

---

Tau (2π) → The Tau Movement – as per the discussion above and the closure of the previous move request.

• Comment. Umm... what movement? Where is this so-called "movement" documented? Sławomir Biały (talk) 11:16, 22 March 2012 (UTC)
  • I'm trying to work with you guys and address your concerns about the title. But you can use google as easily as I can. There are plenty of articles out there attesting to its existence. Joseph Lindenberg (talk) 20:58, 22 March 2012 (UTC)
• Oppose I think the current title is appropriate. See my second comment here. --Waldir ^talk 14:55, 22 March 2012 (UTC)
• oppose - what movement? There's nothing on it in the article.--JohnBlackburne^words_deeds 15:02, 22 March 2012 (UTC)
• Oppose – not only is there no movement in evidence, but the proposed title violates all normal style about "the" and caps. Dicklyon (talk) 05:48, 23 March 2012 (UTC)
• strong oppose what the hell? did you read the article? the advocacy section is only half the article. 70.24.244.198 (talk) 03:46, 27 March 2012 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Title

If the article is to be about the mathematical constant, then by far the vast majority of reliable sources use 2π. In fact, no reliable mathematical sources use the symbol τ. If, on the other hand, the article is to be about "tau day" (which is what the news items mostly talk about), then it should be moved to that title and completely stubbed. To write an article that is ostensibly about the mathematical constant but whose purpose is actually to push a marginal usage is the very definition of WP:COATRACK. It has to be one thing or the other. Sławomir Biały (talk) 10:56, 19 March 2012 (UTC)

This is exactly the point which motivated my reverted move to Tau against pi debate: The article was not really about a constant but about a polemic supported by a few individuals. It is yet the case, although the percentage of place devoted to the "tau day" is now much larger D.Lazard (talk) 14:11, 19 March 2012 (UTC)

The most notable item about tau seems to be the fact that MIT announced its admissions on tau time. I would suggest redirecting this to a subsection of MIT entitled MIT tau time. Tkuvho (talk) 16:46, 19 March 2012 (UTC)

If the page is otherwise to remain as its current muted, no supposedly OR version, I'm tempted to agree it should go, but as it was only a couple of days ago, it definitely described τ and its possible uses. Mark Hurd (talk) 00:41, 20 March 2012 (UTC)

But this version was based entirely on original research and self-published sources. So while indeed it did build a case for τ, that isn't exactly our goal as an encyclopedia any more than it is to build a case for orgone generators based on sources of similar pedigree. Sławomir Biały (talk) 01:07, 20 March 2012 (UTC)

Really? You're comparing the proposal to use tau with orgone generators? Don't look now, but your bias is showing. Joseph Lindenberg (talk) 01:55, 20 March 2012 (UTC)

Actually, as far as Wikipedia is concerned, tau is probably less sourced than orgone generators. We're not supposed to consider whether the sources are correct, only whether they are reliable, and there are many more reliable sources about orgone generators than about this use of tau. — Arthur Rubin (talk) 19:09, 20 March 2012 (UTC)

Mark, I'm waiting for the dust to settle on the page title issue before I start spending (wasting?) time trying to rebuild the page in an environment so hostile to it. But extending the comment I made above in the "Requested move 2012" section, maybe this is one unfortunate case where the kids will truly get better information out on the streets than at home. Joseph Lindenberg (talk) 01:42, 20 March 2012 (UTC)

Tkuvho, THAT'S EXACTLY MY POINT! The most notable item about 21-month-old tau JUST HAPPENED! That's a sign of something that's on the rise. If the page didn't already exist, it would be fine to say, let's see where tau goes over the coming months before creating it. But isn't it silly and disruptive to delete the page when you'll just have to create a new one in the near future? Leave the tau page alone for now. If you're right that it's all downhill for tau after March 7, 2012, time will prove it soon enough. Joseph Lindenberg (talk) 09:24, 20 March 2012 (UTC)

I believe some points need to be made clear in this discussion because it seems to me that we're starting to go around in circles:

1. The concept of using 2π as the circle constant is not a modern fringe theory. It has been used throughout the years by many respected mathematicians.
2. There are plenty of reliable third-party sources for the proposals regarding 2π/tau: trustworthy news organizations have provided extensive coverage of the original proposals (the fact that they did so close to the relevant "tau day", in order to garner interest from the non-mathematical audience should not in itself imply that the proponents of tau are joined in a "movement". Hartl did propose the Tau day, and many people have joined him, but that is merely accessory to the mathematical arguments presented for tau, just like Pi day is accessory to Pi)
3. Several of the main sources used for the article were indeed self-published, but self-published sources are NOT banned from Wikipedia. From WP:SPS: Self-published expert sources may be considered reliable when produced by an established expert on the topic of the article whose work in the relevant field has previously been published by reliable third-party publications (which is the case here: most sources were from established, reliable mathematicians — actual experts in the field) and if the information in question is really worth reporting, someone else will probably have done so (again, this is the case with tau/2π). In any case, some of the recent documents were NOT self-published.
4. The concept of a Tau Day or Tau movement is merely accessory to the main topic: the use of 2π as the circle constant and its mathematical implications. The mere fact that a consensus has emerged among the proposers that Tau is a good shorthand notation for the 2π constant surely needs to be included in the article; however, it doesn't make it about the movement.

I'd like to stop seeing these points being challenged in recent discussions. Unless, of course, I am mistaken about them, in which case I'd appreciate a point-by-point rebuttal. We need to establish some common ground of understanding about the subject before we decide what to do with the article. --Waldir ^talk 15:43, 22 March 2012 (UTC)

I believe you are mistaken on some of them. There are certainly some respected mathematicians involved in this discussion. However, which respected mathematicians have actually used this abbreviation in their work in a notable way, in addition to talking about it on youtube? Tkuvho (talk) 15:47, 22 March 2012 (UTC)

If, as you say, the concept of 2π is not a "modern fringe theory" and "as been used throughout the years by many respected mathematicians" (I would agree with this), then why don't we reference them? Let's make a pile of references to those respected mathematicians. We'll count number of them out of the total that use the symbol "tau", and let that decide what the article should look like. If none, or very few of them, use "tau" to denote this constant, then probably the article title should be something other than it is now. Is that acceptable to you?

It seems to me that #3 is a misinterpretation of the SPS policy, and that the kind of sources being used here are one of the kinds of things that our policy was specifically meant to exclude. First of all, self-published sources are only considered reliable as factual sources on matters of fact that their authors are established experts on. But these sources aren't being used to establish matters of fact. Indeed, they were written and self-published precisely because the ideas that they espouse are contrary to the mathematical orthodoxy. Self-published sources are never acceptable in such a situation (consider orgone, for example).

Also, I don't see how "tau day" is an accessory to the main topic. The media articles seem to focus primarily on tau day (or in the MIT case, tau time). These suggest that the whole tau business is more of a nerdy college prank than a serious encyclopedia-worthy article. The lack of actual scientific sources lends further credence to this viewpoint. How are we to comply with NPOV? Sławomir Biały (talk) 22:50, 22 March 2012 (UTC)

In any year, most media articles about pi focus on, and are written for, Pi Day, so that's really not an argument. Tkuvho says the most notable item about tau has been the MIT announcement, and that's not on Tau Day. So even if tau is destined to become some perpetual nerdy joke, the Esperanto of mathematics, it doesn't make sense to move the main article to "Tau Day". And don't get any ideas about moving it to Tau (Perpetual_mathematics_joke) just yet. Joseph Lindenberg (talk) 16:09, 23 March 2012 (UTC)

Indeed, I definitely agree that viral "human interest" news stories should not be used as sources about mathematical constants. I tried to make this very point at Wikipedia:Articles for deletion/Tau (mathematics). Certainly, for most mathematical concepts, we demand a much higher standard of scholarly sources. However, for whatever reason the consensus at that debate seemed to be there that this "tau" business was notable because of these news articles. Since these news articles are all about "tau day", the encyclopedia article should also be about tau day. Either that, or we have an article about 2π, named accordingly to what scholarly sources use (i.e., 2π), and include a paragraph about renaming the constant. Sławomir Biały (talk) 01:26, 24 March 2012 (UTC)

The references to 2π from past mathematicians were in the article: Al-Kashi and Laurent being the most prominent (but not necessarily only) examples. From the contemporary ones, we have the main proponents Palais, Hartl and Harremoes all presenting their ideas independently at first, one of them publishing them in a respected mathematical journal (Palais). Lindenberg might not be as well known but to his credit he also presented the idea independently in an academic paper and also chose Tau (independently!) as a shorthand notation. All of these agreed in the use of Tau for the constant, after Hartl's proposal. So did dozens of supporters, including well known web personalities and/or respected academics/mathematicians such as Salman Khan, Vi Hart, Spiked Math, Kevin Houston, Stanley Max, the MIT, among many others. I don't think there's any supporter of 6.28... that has rejected Tau, so from all supporters that are alive to have an opinion, 100% agree on Tau. I see no reason to separate this from the concept of 6.28... as I se no reason to separate Pi from 3.14... The Tau notation is as established as it can be.

We might have differing interpretations of WP:SPS, but still Palais' article isn't self-published, so the article wouldn't be entirely based in self-published sources. Moreover, I believe it is important to have the reputation of the main authors of the SPS the article was based on (whom I listed in the above paragraph), as that is specifically addressed by the policy, as I quoted above. Contrariwise, I can't see where the policy states, as you say, that "self-published sources are only considered reliable as factual sources on matters of fact". Would you mind copying the relevant passage from the policy page here?

Regarding Tau day, I maintain my stance. The news articles can certainly prove that the concept is notable, but I insist that their focus on Tau day is merely a product of the nature of their business: they have to appeal to people and make news that are actually... news, rather than just having an article about a mathematical proposal out of the blue because they felt like... Physics articles are also mostly reported when there's some sort of announcement or discovery, etc. --Waldir ^talk 05:00, 25 March 2012 (UTC)

Self-published sources are not generally considered reliable, especially if there is some reason to think that those sources may be inaccurate or biased. Note the wording in WP:SPS that self-published sources may be considered reliable if they are written by an established expert. There is no guarantee that they are reliable. In this case, the sources are expressly outside the mathematical orthodoxy, in much the same way that (say) self-published sources about cold fusion are often outside the physics orthodoxy. Such sources are no more acceptable here than they are there. They are primary sources. On to the sources in particular: Palais suggested using 2π as the fundamental constant, but did not use τ. Moreover, this was an oped in the Intelligencer. Maybe this counts as a primary source for Palais' opinion, but it is not a secondary source as demanded by WP:NOR policy. As for Harremoes, Hartl, Houston, Max, Lindenberg: I see no evidence that these people are experts in any relevant capacity. But in any event, these are also primary sources, and entirely self-published. Neither Hart nor Khan is an academic or mathematician (Khan holds an MBA and an MS in engineering, Hart has a Bachelor's degree in music!) They are web personalities, it is true, but still just primary sources for the opinions of their proponents. Sławomir Biały (talk) 11:14, 25 March 2012 (UTC)

I just want to insert a point here: as far as Sławomir Biały arguments are concerned this tau idea is clearly stuff and nonsense and should be deleted. I believe we need to ignore the possibly discreditable sources and find more. That is the only way this argument is going away, irrespective of how much we feel the sources are reliable, as long as some feel they are unreliable, they will at some stage succeed in a RfD. Mark Hurd (talk) 08:56, 27 March 2012 (UTC)

(1) Exactly: they may be considered reliable (it's up to the editors to exercise their good judgment on this), and in this case I offer that they should. I offered the links above, to point out that they do have credentials to provide evidence that they are experts in the subject. (2) The fact that Palais didn't include Tau in his article was merely because he hadn't heard about it: after both Hartl and Harremöes contacted him with that proposal, he promptly adopted the notation, as can be seen in his site. (Note that I did mention this in my previous message.) (3) The sources may be biased when they say that Tau is preferable to Pi, but certainly are neutral when they describe the mathematical properties of Tau. It can barely be called original research, in fact, since so many people reached the same conclusion independently; they were just observing the basic properties of a mathematical constant, not concocting a new theory out of the blue. (4) When I mean that those people are well-known mathematicians, I didn't mean to imply that they have an academic degree in mathematics. However, I wouldn't expect anyone to put in cause their obvious knowledge of mathematics, which is evidenced by the wealth of math-related content they produced (either in web content or in academic publications) and the extensive following they have achieved, many among a mathematical audience. What I'm saying is that we need to be reasonable here, rather than simply attempting to stick blindly to the rules. --Waldir ^talk 13:54, 25 March 2012 (UTC)

Well, I think we can say that they are not reliable sources, for reasons I have stated. They are primary sources advancing a position well outside the mainstream written by people who largely lack any relevant credentials, This, to me, seems to be exactly the sort of thing that our SPS policy is written to discourage. It's astonishing that anyone would argue otherwise. Sławomir Biały (talk) 13:57, 25 March 2012 (UTC)

You don't need a PhD in mathematics to knowledgeably discuss basic trigonometry. However, Palais and Houston are indeed university math professors with PhD's in mathematics. Hartl has a PhD in physics, which tends to require a little bit of math. Not sure what Harremoës' degree is in, but a look at http://www.harremoes.dk/Peter/ shows he's clearly up to handling trig. Stanley Max teaches mathematics at Towson University. Khan has an MS in engineering and isn't qualified to discuss basic trig? The origin of Khan Academy was his math instruction. Slawomir, since you've apparently got a PhD in mathematics, are you available for tutoring work? I had planned on teaching my niece her multiplication tables, but I now realize that I'm not qualified. Joseph Lindenberg (talk) 16:36, 25 March 2012 (UTC)

The criterion in SPS under discussion is whether that have relevant publications in the peer reviewed scientific literature. Obviously not everyone who understands basic trigonometry is qualified to be an authority on the subject. In short: find peer reviewed sources. Otherwise no article. Geddit? Sławomir Biały (talk)

But they do have relevant publications in the peer reviewed scientific literature! I again point out that I linked above to the webpages for most of these people, where they list their publications. (A side note: Joseph, I kindly ask you to please stop making sarcastic and ad hominem remarks, that definitely isn't productive for this discussion). --Waldir ^talk 19:08, 25 March 2012 (UTC)

Sorry, who has publications in the peer-reviewed literature establishing them as an authority on trigonometry? Sławomir Biały (talk) 19:21, 25 March 2012 (UTC)

Argument against "2π" or "Two pi" or "Twice pi" as an article title. Using a "multiplied noun" as the actual title of a Wikipedia page is not normal. I can't find any similar cases. It's not even normal for redirects. Consider where the following "multiplied nouns" take you if you treat them as article titles:

• 100 Years -> Song with that name
• 10 Years -> Music group with that name
• 365 Days -> Episode of the TV show The West Wing
• 9 Months -> Hugh Grant movie, not an article on pregnancy
• 14 Days -> Music album
• 7 Days -> Disambiguation page. No page titles listed there beginning with "7 Days" or "Seven Days" are about the time unit.
• 24 Hours -> Disambiguation page. No page titles listed there beginning with "24 Hours" are about the time unit.
• 60 Minutes -> The TV news program
• 60 Seconds -> A BBC news program
• 2 Pints or Two Pints -> BBC sitcom
• 4 Quarts or Four Quarts -> Nothing
• 3 Feet or Three Feet -> Nothing
• 12 Months -> Nothing
• 5280 Feet -> Nothing
• 16 Ounces -> Nothing
• 1000 Grams -> Nothing
• 2 Weeks -> Nothing, not even redirected to Fortnight, a term which is never used in scientific journals yet has a Wikipedia page.

Joseph Lindenberg (talk) 22:39, 24 March 2012 (UTC)

NB Some of the above should really use lower case words, but the point was still true for those I checked. Mark Hurd (talk) 08:56, 27 March 2012 (UTC)

You are making silly arguments. In a scientific setting, reliable sources are considered to be textbooks supported by references to the scientific literature. If you can find no such sources that use the term "tau", then this is a WP:NEOLOGISM. It's really that simple. Sławomir Biały (talk) 00:43, 25 March 2012 (UTC)

NOT OFFICIALLY RELEVANT, but this is funny so I'll share it: Students picketing for tau and against pi on Pi Day in a college math building. (And no, Slawomir, I don't know these kids, nor did I have anything to do with this. I simply found the video on YouTube.) Joseph Lindenberg (talk) 18:58, 25 March 2012 (UTC)

Merge_with_turn_(geometry)

The two pages are on an identical subject (see turn (geometry)) and should be merged as per User:Sławomir Biały's suggestion. Tkuvho (talk) 15:07, 22 March 2012 (UTC)

This specific proposal is already being discussed at Wikipedia talk:WikiProject Mathematics#Merge proposal. Any comments should be made there so as to not disperse the discussion. --Waldir ^talk 15:45, 22 March 2012 (UTC)

Request for comment

I would like to gauge consensus on what the configuration of this article should be. Some items to consider are:

• The only reliable sources we have about "tau" actually concern "tau day", and are news stories of the human interest variety. Not only are such sources poor for scientific topics, but they are notorious for conveying a false sense of notability to a topic. "Viral" human interest stories are a phenomenon not unknown to the Wikipedia community (see, for instance, Wikipedia:Articles for deletion/Jacob Barnett). In the spirit of WP:ONEEVENT, it is essential that we actually gauge those sources for whether the subject is of lasting (scientific) importance.
• The remaining sources that specifically address "tau" are all self-published sources, and none of them is by someone who seems to be a recognized authority on geometry or trigonometry as would be evidenced (for instance) by widely cited publications on closely-related topics in the peer reviewed scientific or educational literature (WP:SPS). These sources also are all primary sources (WP:PSTS). There isn't a single reliable scientific secondary source that discusses the use of the term "tau" in a mathematical setting.
• The closest thing we have is the Palais opinion piece in the Mathematical Intelligencer. The purpose of this editorial is to advocate that 2π is more fundamental than π, but nowhere does it advocate the symbol τ. It is, moreover, a primary source (as an opinion piece).
• This article was previously at AfD. Although I argued (I felt very convincingly) that for mathematical topics, we need mathematical sources—and that means properly peer reviewed sources—the fact that "tau day" showed up in some human interest stories was taken as evidence enough for the closing admin to consider the topic sufficiently notable for an encyclopedia article. To his credit, the admin left a great deal of latitude in the final form that the article should take. But it may be necessary to reassess even that decision.

So, in light of the failed merge proposal, as I see it there are exactly three options that are consistent with our policies (WP:SPS, WP:NOR, WP:PSTS, and WP:NEOLOGISM). These are:

• Move the article to tau day, and make it about the day. (Although the day is of dubious notability, this seems to be most consistent with the sources introduced at the AfD.)
• Move the article to twice pi, and make it about the mathematical constant 2π. Sources of high scientific credibility can be found about 2π, but if that's the case then we shouldn't be engaging in advocacy of the protologism of "tau".
• Delete the article entirely.

Please make your !vote below. Sławomir Biały (talk) 18:54, 25 March 2012 (UTC)

• Delete the article. Advocacy of the constant 2π can easily be covered in a paragraph of the main pi article, but it is insufficiently notable to deserve its own article. Sławomir Biały (talk) 18:54, 25 March 2012 (UTC)
• I would redirect this to a section in the article pi, I don't see anything in the article that warrants having a separate article. — Carl (CBM · talk) 18:59, 25 March 2012 (UTC)
  • That's because Slawomir recently gutted it, and we haven't rebuilt it yet. Here's what it looked like before. Slawomir also deleted all mention of this topic from the Pi article. Joseph Lindenberg (talk) 19:24, 25 March 2012 (UTC)
    • Thanks. I looked through that, but I don't agree that we need a page of formulas stated in terms of τ. For example I have never seen τ used in any calculus book I have taught from, nor in graduate books, they always just use 2π. The page seems to be claiming there is some sort of controversy with proponents and opponents of τ, which I find a little silly, any "controversy" is a joke at best. — Carl (CBM · talk) 19:35, 25 March 2012 (UTC)
      • Comment Carl, "redirect" votes aren't too helpful as they don't express the intention of the voter. Obviously this can be redirected even if the article itself is deleted. If your intention is that the article should be deleted you should state so. Tkuvho (talk) 12:14, 26 March 2012 (UTC)
        • If no redirect is created after deletion, then obviously the redirect votes weren't taken into account, so a redirect opinion should be lodged to indicate post deletion disposition of the name. 70.24.244.198 (talk) 09:47, 27 March 2012 (UTC)
        • I don't see any reason to hit the "delete" button, just redirect this page to pi and put any appropriate information there. There's no need to lose the page history to achieve that. And this isn't a vote, it's not even a deletion discussion, it's an RFC. — Carl (CBM · talk) 21:16, 28 March 2012 (UTC)

• Maintain in its present state [4] as a short article describing the advocacy and without any mathematical detail. We can maybe add a sentence in the π article pointing back here, but I don't want to clutter that article with more of this cruft, and on the other hand the human interest side of this does seem to (barely) be enough for a non-mathematical article. An acceptable alternative would be, as Sławomir and Carl advocate above, deleting this article and just leaving the sentence or two (nothing longer!) in the π article. Rebuilding it to Joseph Lindenberg's preferred version (essentially a content fork of π) is not acceptable. —David Eppstein (talk) 19:26, 25 March 2012 (UTC)
  • Keeping the Pi article "clean" - Good point. If you eliminate the tau article, future contributors will target the Pi page. MIT just created a bunch of these potential contributors and will create a bunch more every year. There's a kid math prodigy and "mathemagician" named Ethan Brown who's spreading word about tau in Connecticut at his shows. Vi Hart just joined Khan Academy and will continue her advocacy. This isn't going away, even if I do. Joseph Lindenberg (talk) 20:15, 25 March 2012 (UTC)
• delete. The improperly sourced old version is irrelevant: it's what can be reliably sourced that matters. tau day has the same sourcing issues while twice pi is an unnecessary fork of pi and turn (geometry). No need for a separate article when those cover it as fully as it can be reliably sourced.--JohnBlackburne^words_deeds 19:28, 25 March 2012 (UTC)

• delete or KIWF. Anybody sane who does calculus or dynamics will support pi as more fundamental. leave it here for the loons to play with. I suppose tau day on the the 6th of february would be ok, but it's a bit unremarkable really. Oh i forgot wikipedia is only about the USA. Greglocock (talk) 23:19, 25 March 2012 (UTC)
• Delete and have a blurb section in the pi article, as per Slawomir's suggestion. There is simply no "meat" to the topic, a paragraph should be plenty. Rschwieb (talk) 00:05, 26 March 2012 (UTC)
• Keep with current title - Tau is very popular, and is recognized by many. Using another title will confuse people who are already familiar with the term and go searching for it. Rothschilde (talk) 01:48, 26 March 2012 (UTC)
  • Tau is not "very popular": Most of the millions of engineers, searchers and teachers who use daily pi in there professional activities have never heard of tau. Most of the few ones who know of it consider it as a subject of in-jokes, like, apparently, the MIT's admission dean. D.Lazard (talk) 09:06, 26 March 2012 (UTC)
    • Agreed. If there is any calculus book that works in terms of τ instead of π, I have never seen it. — Carl (CBM · talk) 10:14, 26 March 2012 (UTC)
    • Do some web searching, and you'll find there are already an awful lot of people out there who support tau. SO IF YOU'RE RIGHT THAT "most of the millions of engineers, searchers and teachers ... have never heard of tau", then a whole lot more supporters will be appearing as they hear about. For a simple estimate, assume that the same percentage of people who find out about tau in coming months/years, as people who found out about it in the last 21 months, decide that tau is better. That translates into many additional eager contributors posting about tau over in the Pi article if you delete the Tau article. Joseph Lindenberg (talk) 17:31, 26 March 2012 (UTC)
      • Your claims would be more credible if backed up by actual evidence. Tkuvho (talk) 17:49, 26 March 2012 (UTC)
        • You just have to use the right search terms, because tau and pi show up a lot in the names of fraternities and societies like Tau Beta Pi. I usually add a third search term like circle, math, mathematics, or number to weed out those pages. Another of my favorite examples is that when you type just the two words "pi is" into Google or Bing, the top autocomplete choice is "pi is wrong". How do you think it got that way? Aren't there a lot of other phrases containing "pi is"? Also, look at how many new comments get posted every single day on Vi Hart's YouTube video about tau. I'm too busy now doing my taxes and other things to compile a long list for you. Try what I described with using a third search term. Then maybe you'll see what I'm talking about. Joseph Lindenberg (talk) 19:29, 26 March 2012 (UTC)
    • Can't believe I have to explain the joke in that MIT cartoon to you, but here goes. They weren't making fun of tau. They were making fun of the belligerence in the tau/pi debate. Did they depict the pi supporters as any less caveman-like than the tau supporters? No. Go take a look. I'll wait. ...OK, now do you get the joke? They're saying we can have both numbers. At MIT. And at Wikipedia. I've never tried to delete or rename the Pi article. How about returning the favor? As further evidence MIT wasn't making fun of tau, see the follow-up to their announcement, where Associate Director of Admissions Matt McGann shows Vi Hart's video and asks MIT applicants, "What do you think? Are you sold on Tau? Or are you a Pi loyalist?" Joseph Lindenberg (talk) 20:28, 26 March 2012 (UTC)
      • Can I be the first to point out that you are citing a cartoon. Sławomir Biały (talk) 00:56, 28 March 2012 (UTC)
• No changes for now - Slawomir already deleted ALL mention of tau from the Pi article. There were only five sentences. If we are to believe that he's not simply pursuing a scorched earth policy here, why not put something about tau back in the Pi article first? Before trying to delete this article as well? Joseph Lindenberg (talk) 06:10, 26 March 2012 (UTC)

• Keep with current title Wikipedia is not a scientific publication, the idea of 2pi has been floating around for a long time and has generated some discussion. It does not compete with the article for Pi and the WP:POINTyness of this page is getting boring. If you're not in favor of ou, fine, but take that sentiment elsewhere. 07:49, 26 March 2012 (UTC) — Preceding unsigned comment added by Kleuske (talk • contribs)
  • If "the idea of 2pi has been floating around for a long time" as you say, then surely the correct course of action is to move the article to something like 2π rather than using the neologism tau. This was one of the options I had presented. (Also, calling my actions WP:POINTy while in the same breath describing my sentiment as anti-tau shows a complete lack of understanding of what WP:POINT is even about.) Sławomir Biały (talk) 08:42, 26 March 2012 (UTC)
    • See my earlier comment about the use of a "multiplied noun" as an article title on Wikipedia. That's never done. (The comment is near the end of the section of this page called "Title".) Joseph Lindenberg (talk) 09:37, 26 March 2012 (UTC)
      • The relevance of that post was questionable. There are articles (in that post!) that are "multiplied nouns". Even if 2π or twice pi were not acceptable article titles, that does not mean that we should use a neologism that is not accepted by the scientific community. (In fact WP:NEOLOGISM is policy.) Rather your argument against "twice pi" or "2π" seems to support redirecting this to pi and adding a paragraph there about 2π. Sławomir Biały (talk) 10:00, 26 March 2012 (UTC)
        • Which article in that post do you claim is actually about a "multiplied noun"? None of them are. The article 100 Years is not about a length of time. 2 Pints is not about a volume. Joseph Lindenberg (talk) 14:08, 26 March 2012 (UTC)
          • Ok, I see your point. However, there is no policy-based reason that we can't have 2π or twice pi as the title of an article (if indeed the constant 2π is notable independently of its relationship to π, which is what some people seem to be claiming here)—see WP:OTHERSTUFFEXISTS. In fact, we have many articles whose titles are in this spirit: for instance, 1 + 1 + 1 + 1 + … instead of ζ(1) or −1/2. There is also the article −1. We usually go by whatever the commonest form of something is (in this case, 2π is the clear winner since no sources use τ). However, even if we wished to have an article title that was not a "multiplied noun", we would still be forbidden by policy to use a symbol that is not used in the sciences (WP:NEOLOGISM). Sławomir Biały (talk) 14:39, 26 March 2012 (UTC)
• Delete and replace it by a few sentences in section In popular culture of Pi (see my comment above about "very popular"). D.Lazard (talk) 09:16, 26 March 2012 (UTC)
• Keep because tau is a fact, Wikipedia is supposed to keep information open, and tau makes more sense in most applications than pi. Just because YOU don't use it doesn't mean nobody does. — Preceding unsigned comment added by 71.206.24.106 (talk) 11:22, 26 March 2012 (UTC)
  • Actually, no one does use it. I've never seen tau used in any textbook or scientific article for this purpose. In the entire history of this article, and the many debates that have surrounded it, not a single reliable scientific source has been presented where the symbol τ is used for this purpose. As for the argument that "[it] makes more sense in most applications", Wikipedia is not a soapbox. Sławomir Biały (talk) 12:41, 26 March 2012 (UTC)
  • Comment "Tau is a fact"/"Tau makes more sense"/(paraphrased):"even if you don't use it somebody does" None of these statements even border on being a supporting reason in any sense. Two are just mere assertions of opinion. The last is a non-reason because it apparently suggests that any belief, no matter how exceedingly rare, shouldn't be excluded from WP. This use of tau does not rise to any reasonable threshold of notability. Rschwieb (talk) 13:24, 26 March 2012 (UTC)
• Keep like this. Something should be said about it, and I rather have it here (without the undue/original research stuff there was before) than in a section over at pi; a simple "See also" link in the pi article is just fine. I certainly support moving the article to 2π or similar while retaining the current title as a redirect, since different names and symbols for the constant have been proposed in the past, and this would make the title more consistent with the article content. Nageh (talk) 20:53, 26 March 2012 (UTC)
• Merge to Turn (geometry). Tau is just a proposed alias of the extant Turn concept. --Cybercobra (talk) 00:44, 27 March 2012 (UTC)
  • That proposal was already discussed here. It appears to have been rejected because tau (like pi) is simply a number, while turn is an angle or an angular unit (like degrees and radians). Joseph Lindenberg (talk) 00:55, 27 March 2012 (UTC)
    • Ok, if we're being pedantic: the concepts are closely related and IMO it's the best viable merge target. Since Keep seems unlikely, Merge so as to WP:PRESERVE. --Cybercobra (talk) 01:55, 27 March 2012 (UTC)
  • 2π is a dimensionless constant, a turn is an angle (which we defined(!) to be equal to 2π radians). Merging it there would be a "type error". —Ruud 17:57, 27 March 2012 (UTC)
    • Radian measures are dimensionless "pure" numbers anyway; so no units/type error. --Cybercobra (talk) 00:19, 28 March 2012 (UTC)
      • Because radians are such a "natural" unit for angle they are often considered dimensionless by convention. That does not mean a turn and 2π radians are not still angles, while 2π does not necessarily have to be so. By your logic we might as well redirect 360 to turn. —Ruud 11:47, 28 March 2012 (UTC)
• Merge to Pi. The current article is problematic because both the title and introductory paragraph will leave an unsuspecting reader with impression that "tau" is an accepted name for the mathematical constant equal to 2π. This is not the case. Both the fact that 2π is such an ubiquitous mathematical constant and any notable information about "the tau movement" can be discussed in a short paragraph in the article on Pi. Moving the article to 2π and moving any mention of "tau" from the introduction would also be an acceptable alternative. —Ruud 10:18, 27 March 2012 (UTC)
  • I beg to differ. As I already pointed above, all major (alive) proponents of 2π have agreed on using Tau. Is is not a "neologism", for it's not a new word — sure, it's a recent coinage, but AFAIK it is not challenged as a shorthand for 2π. Quite the contrary: rather than tacit acceptance or neutral stances, there is explicit endorsement from all major proponents and most supporters. Are you aware of any (current) prominent opinion opposing τ as a notation for 2π, instead of (or in addition to) opposing the notion of 2π being the proper circle constant? --Waldir ^talk 14:09, 27 March 2012 (UTC)
    • Bollocks. Please try to provide some of the sources Mark Hurd suggested below. The name "tau" is completely fringe terminology for 2π. 99% of mathematicians wouldn't have a clue what you would be referring to. —Ruud 17:48, 27 March 2012 (UTC)
    • Is is not a "neologism", for it's not a new word : So if I propose to move this article to "Fred", that would be ok, since "Fred" isn't a new word? That's a beyond-ridiculous interpretation of the WP:NEOLOGISM policy. Please read it again. Especially the part that reads: "Some neologisms can be in frequent use, and it may be possible to pull together many facts about a particular term and show evidence of its usage on the Internet or in larger society. To support an article about a particular term or concept we must cite what reliable secondary sources, such as books and papers, say about the term or concept, not books and papers that use the term. An editor's personal observations and research (e.g. finding blogs, books, and articles that use the term rather than are about the term) are insufficient to support articles on neologisms because this may require analysis and synthesis of primary source material to advance a position, which is explicitly prohibited by the original research policy." Sławomir Biały (talk) 00:23, 28 March 2012 (UTC)
      • That was not my point, it was just a passing observation, and I stand behind it. Nevertheless, I agree that WP:NEOLOGISM applies, precisely because I am willing to interpret the project rules liberally rather than blindly adhering to their explicit wording. (I suggest you do the same regarding for instance WP:SPS). Still, while I agree that the quote above is relevant, you will surely agree that (1) the 2π concept is not new, and is notable, and (2) nobody currently refers to the 2π constant as 2π. Even those who originally proposed a different letter (Palais, Harremöes) today endorse τ. All secondary sources do so too. All supporters as well. What I offer is that it would simply be a disservice to readers to remove tau from the title of this article, because that's the term people will search when looking for this concept. Two excerpts from WP:TITLE: "the ideal article title will resemble titles for similar articles" and "be recognizable to readers", which represent the WP:CRITERIA of consistency (see also Lindenberg's "multiplied nouns" argument above) and recognizability. There's also this relevant passage from WP:COMMONNAME: "Wikipedia does not necessarily use the subject's "official" name as an article title; it prefers to use the name that is most frequently used to refer to the subject in English-language reliable sources. This includes usage in the sources used as references for the article. If the name of a person, group, object, or other article topic changes then more weight should be given to the name used in reliable sources published after the name change than in those before the change." In summary, I am just defending that we must attempt to cater to the spirit of the rules and the mission of the project, rather than interpreting the policies and guidelines literally and discarding whatever doesn't fit perfectly to the wording provided. --Waldir ^talk 10:12, 28 March 2012 (UTC)
        • Agreed. This is precisely the reason why this should be redirected to pi rather than 2π. Tkuvho (talk) 10:15, 28 March 2012 (UTC)
        • Well, we definitely disagree on a number of things. Most glaringly "nobody currently refers to the 2π constant as 2π". You mean except for all mathematicians currently in existence? Also, I assure you that I am not blindly adhering to the explicit wording of WP:SPS. As someone with experience in applying this to fringe topics like this, I can assure you that my interpretation is fully consistent with its intent. Sławomir Biały (talk) 11:17, 28 March 2012 (UTC)
        • I strongly oppose to the assertion "nobody currently refers to the 2π constant as 2π". It is the opposite which is true: in every mathematical text I have ever seen, the constant 2π is referred to as 2π, even when it appears many times in a few lines, like in Root of unity or Quintic function (Palais article is an opinion, not a mathematical text). D.Lazard (talk) 12:02, 28 March 2012 (UTC)
          • I was referring to its use as a single symbol, of course (such as Laurent's usage). Note that I said "2π constant", not merely "2π", which obviously occurs pretty often in math: after all, that's precisely one of the reasons mentioned in favor of τ. --Waldir ^talk 17:47, 28 March 2012 (UTC)
            • 2π being a constant, any distinction between "2π constant" and "2π" is a mathematical non sense. More, you use improperly "symbol" in the meaning of "name". The fact to have, for a naming something, either a single character, an ideogram, a chain of characters or a formula is only a question of choice. The name 2π is very short and this is certainly the reason for which mathematicians do not need any alternative name for this constant. Moreover it is well known by everybody who has taught mathematics or written mathematical papers that unnecessary notation is confusing. That is a fact which is not in favor of tau. D.Lazard (talk) 18:31, 28 March 2012 (UTC)
            • (@Waldir) I think you have adequately staked out your position. You believe that the article should be about attempts to rebrand the mathematical constant 2π as something else (possibly τ). However, to write such an article requires reliable secondary sources such as published literature reviews on this subject, peer-reviewed papers in the history of mathematics, or reliably published textbooks in the history of mathematics. In short, some historian needs to have written, in a properly peer-reviewed source, something like: "Many mathematicians over the ages have tried to redefine the mathematical constant of π..." (or whatever). To call it τ, that person would then need to go on to say "...and such-and-so has suggested the symbol τ." We are an encyclopedia, and explicitly demand such sources (WP:PSTS).
              
              Nothing I've seen even comes close to that. We cannot accept sources that are written as it were in the moment, especially written by the proponents of a new idea. We don't accept cartoons or proclamations of MIT admissions deans (as has seriously been put forth as a reliable source here). This runs against the very core of our founding principles. We must apply those principles here with the same vigilance as in articles like intelligent design, orgone, or the Flying spaghetti monster. There is no double standard for topics that one feels are "clearly" not fringe just because they don't involve UFOs or mysterious energies or works of God. We have no scope for such distinctions (WP:NPOV).
              
              The only meaningful datum we have to go on are the sources: are there reliable secondary sources to substantiate and provide context for the subject of an article? In this article we see sources that are advocacy pieces and (almost) entirely self-published—the authors of which appear to have published no reliable secondary sources on the history and cultural context of mathematics, to say nothing of the subject of 2π versus τ—YouTube videos, and human interest stories (which I firmly believe are never to be considered reliable sources in a scientific setting, and will defend this at WP:RS/N if you would like to start a thread there as to why you believe there is an exception in this case).
              
              That said, of course we should welcome an article written from what we normally consider to be reliable sources. However, it seems that in order to do that, we need to divorce ourselves from the idea that random Google/YouTube searches for "tau" and "circle" are magically going to give reliable sources that provide meaningful historical and reliable mathematical context for an encyclopedia article. Rather, we should be looking at books and journal articles (dead tree if necessary). An article written from such sources could be worthwhile. If there are no such sources, then clearly there can be no article. This is the very essence of our guiding principles: WP:V, WP:NPOV, WP:NOR. Sławomir Biały (talk) 02:08, 29 March 2012 (UTC)

              Thanks, Sławomir, for your clear exposition and good arguments. I can perfectly understand what you mean and I do agree to a certain degree. My only objection is that for a concept that is so recent (the naming of the constant, not the proposition of the constant itself) it is not reasonable to expect such scholarly sources to exist, such as cultural/historical perspectives on the issue -- not the least because, admittedly, while this issue has huge pedagogical consequences, it is not especially groundbreaking, mathematically speaking. The flow of knowledge consolidation takes its time, especially regarding dead tree publications, and in a subject whose consequences lie mostly in a basic level of science acquisition, it is perfectly understandable that this could take even more time in the tau case than for the average new theory or fact.

              Note, however, that while Wikipedia is WP:NOT#NEWS, it has been deemed perfectly appropriate to cover recent events whose notability is confirmed by reliable news coverage. I know that mathematical sources would be preferable for this article, but specifically in the issue of naming the constant Tau, the subject is undeniably a "human interest" one, and therefore human interest news stories should be considered as valid sources (as well as the self-published mathematical texts, videos, images, etc).

              Secondly, to clarify: I do not believe the article should be about the proposal to name 2π as τ. I believe it should be about the 2π constant, which has been proposed by several people, and whose characteristics can be neutrally described (per WP:CALC), but I don't believe the naming of this constant as tau should be purged off. I already mentioned below that I am willing to accept a compromise where the article is moved to 2π or some similar name — as long as the tau concept is not removed from it, for that would be confusing to readers. In any case, even if I accepted that the current sources are not valid for providing evidence of the notability of the tau subtopic, and the appropriateness of its coverage in a Wikipedia article (which I don't), we would still be left with the proposals for using a constant that is twice the value of π, regardless of what name it is given — and note that there aren't even competing naming proposals: there were individual initial suggestions that differed, but they have unequivocally converged.

              Summing up: my stance is that the article should remain in place, about the 2π constant, and the consensus among its proponents to name it tau should be included, preferably in the title, but most definitely in the article text. Also, please note my proposal below to cool off this discussion for a bit. --Waldir ^talk 09:23, 29 March 2012 (UTC)

• • Due to WP:UNDUE, I feel much of the content wouldn't be preserved, whereas this would be less of an issue with some other merge targets. --Cybercobra (talk) 00:19, 28 March 2012 (UTC)
    • While "the tau movement" may be very cute, it remains completely fringe. No serious mathematical publication has been brought forward using this terminology/notation. If there is any material worth preserving at all it can be done so inside another article. Devoting a whole article to this would be giving it undue weight. —Ruud 11:47, 28 March 2012 (UTC)
      • I don't really understand your response. You suggested merge to Pi and I countered with merge to somewhere else, yet here you're talking about separate articles and "the tau movement" out of nowhere... --Cybercobra (talk) 23:41, 29 March 2012 (UTC)
        • That could be my fault. I didn't understand the comment either, but I recently had to refactor the discussion when it started to become unclear who was replying to whom. Sławomir Biały (talk) 00:23, 30 March 2012 (UTC)
• Keep or move to 2π. I already expressed my opinion on why I think Tau should be in the title (2nd comment here and 1st paragraph added on this edit). But if it is moved to 2π and this title is kept as a redirect, I wouldn't object, even though it's not my preferred option. Deletion or merging to Pi, however, are not desirable outcomes, since the concept definitely begets coverage, so deletion would actually harm the project, and merging would probably create quite some controversy in the Pi article, which would only waste everyone's time and would end up in a watered-down text that would not serve the readers properly. --Waldir ^talk 12:36, 27 March 2012 (UTC)

• Keep and also create article about mathematical constant also. Thepoodlechef (talk) 01:40, 13 April 2012 (UTC)

Discussion

I just want to know how far τ would have to go as being used for it to be worthy of a Wikipedia article in the terms of those who don't think it does now:

• Never
• Many text books using τ instead of 2π
• Many peer reviewed articles using τ instead of 2π
• One text book to only use τ and never 2π
• One peer reviewed article to only use τ and never 2π
• One text book to mention τ but use 2π
• One peer reviewed article to mention τ but use 2π
• Many people suggesting τ may make more sense than 2π, but it is probably too late to change now
• One reliable source suggesting τ may make more sense than 2π, but it is probably too late to change now
• Some other minimum.

In my opinion this is similar to the controversy about a page reflecting the currrent reliable sources that were wrong when someone actually fact-checked the historic records, except the (correct) conclusion here is no where near as clear cut. Mark Hurd (talk) 09:45, 27 March 2012 (UTC)

What you are proposing is a hypothetical discussion and not many people are going to be interested in one of those. I suggest you cite ONE textbook using tau (two pi), and we will take it from there. Tkuvho (talk) 09:52, 27 March 2012 (UTC)

Stuff like the following just keeps cropping up all over the place. Tau on a lab exam in a C programming course at Grand Valley State University: http://www.cis.gvsu.edu/~mcguire/teaching/261/2012_1winter/tests/lab_xm1/Section_02/ Joseph Lindenberg (talk) 23:05, 27 March 2012 (UTC)

Great non-example. Sławomir Biały (talk) 00:58, 28 March 2012 (UTC)

Agreed. Even if it occurred on 100 similar assignments, such usage isn't proper support. Rschwieb (talk) 16:01, 28 March 2012 (UTC)

My posting wasn't a direct response to Mark Hurd's posting. I wasn't trying to say this was one of the things he listed. It's about what I've been saying about seeing more and more people supporting tau. This computer science professor clearly was doing that in his exam. Joseph Lindenberg (talk) 17:24, 28 March 2012 (UTC)

There are more and more people at WPM who are increasingly sceptical about your unsupported claims. Tkuvho (talk) 17:29, 28 March 2012 (UTC)

I explained above how to do a google search with the terms tau, pi, and a third term like circle, math, or number. Since writing that, I've noticed that two or double or twice may also work as a good third search term. I know these aren't the kind of footnotable usage in math journals you're insisting on. I'm not claiming that. I'm saying I see many people out on the internet agreeing with the arguments put forward about tau. Now maybe it's just that Bob Palais has an enormous amount of time on his hands, and he has gone all over and posted using aliases on all the forums, ghost-written the newspaper articles, and even offered to help this computer science professor write his exam so that he could sneak something in about tau. But I promised Waldir I'd quit being so sarcastic, so that's probably not the explanation. What I'm saying is that, even now, it's not just a few people, and it's growing fast. Why not agree to delay this decision for 3 months until the day after Tau Day? If tau is really a dud, the newspapers will ignore it this time, we'll all know I was wrong, and I won't fight deletion/renaming/merging. If the opposite happens, Wikipedia won't have to change the page title back to tau, or deal with new tau pages being created that day. Punt this decision forward three months to June 29? The right decision should be a lot clearer then. Joseph Lindenberg (talk) 20:23, 28 March 2012 (UTC)

Is there a single calculus textbook that mentions τ? The lab assignments above just look like instructors with a sense of humor following current events - not any sort of "support for τ". — Carl (CBM · talk) 21:14, 28 March 2012 (UTC)

Sure looks like he's evangelizing to his students. Why would he reprint all that stuff from the Tau Manifesto AND provide a link to the Tau Manifesto website if he were just making a joke? Joseph Lindenberg (talk) 02:28, 29 March 2012 (UTC)

I think you must never have written a lab assignment. This type of thing is very common - it's just a way of making an otherwise boring assignment a little more interesting. It is not "evangelizing". — Carl (CBM · talk) 11:01, 29 March 2012 (UTC)

Is this exam a peer-reviewed source with a reputation for fact-checking and accuracy in the history and cultural context of mathematical developments? Has its author published articles in such? If not, then this is totally irrelevant to the discussion. No number of primary sources are adequate to justify the existence of an article. Google all day, if you like. Sławomir Biały (talk) 02:57, 29 March 2012 (UTC)

www.cadaeic.net/centaurs.htm

www.fanfiction.net/s/6877684/1/The_Argument_For_Tau

hackage.haskell.org/packages/archive/tau/6.283/doc/html/Math-Tau.html

Joseph Lindenberg (talk) 10:52, 29 March 2012 (UTC)

What exactly are more irrelevant links supposed to show? Sławomir Biały (talk) 11:22, 29 March 2012 (UTC)

I probably should have indented those under Tkuvho's last post. This is really more follow-up to the issue of how much use of the name tau is out there. I am getting more familiar with the formal requirements for sources here at Wikipedia, so I see your concern about secondary sources. The two are related though, in that if many people have indeed started to use the name tau, secondary sources will inevitably follow. Joseph Lindenberg (talk) 23:29, 29 March 2012 (UTC)

Per Lindenberg's suggestion above, I propose that this discussion is left cooling off for a few weeks and restarted after tau day (28 June). The events, reports and publications released around that time should provide us with a clear insight regarding the current status of this topic, and allow us to take a more informed decision. What do you guys think? --Waldir ^talk 09:23, 29 March 2012 (UTC)

I don't see any reason to wait. Everyone in the discussion agrees that τ has been mentioned, the question is just how we should cover it on Wikipedia. Π day, and by extension τ day, are mostly novelty days enjoyed by a few college students, they aren't particularly important holidays in the broader sense. — Carl (CBM · talk) 11:01, 29 March 2012 (UTC)

I agree. I don't see why we should attach any significance to these arbitrary dates. (Also, I once again question the assertion that "news reports" are somehow relevant in ascertaining notability of scientific matters. This has repeatedly been shown not to be the case.) Sławomir Biały (talk) 00:34, 30 March 2012 (UTC)

The idea is not to give importance to those dates, but in practice, it is likely that many activities or works related to tau will be released/reported on that day, whether they happened then or have been in the works for a while. Since it's just a few weeks away, I see no downside in both cooling off this already long debate, and having the chance to include the extra information in the discussion. --Waldir ^talk 09:48, 30 March 2012 (UTC)

There is nothing wrong with waiting for tau day, or omega day, or any other day, to see if tau can gain notability that would make an article appropriate. In the meantime, we should redirect this to pi. Tkuvho (talk) 13:08, 1 April 2012 (UTC)

• Merge and redirect into Pi. I defend Slawomir's removal of the blatant advocacy previously in the article and I don't feel that there's enough left to justify a stand-alone article. This can be revisited in a couple of months. Reyk _YO! 21:37, 2 April 2012 (UTC)

How do people feel about requesting an admin close? the arguments and discussion appears to have dried up. IRWolfie- (talk) 17:04, 12 April 2012 (UTC)

I'd not object to someone uninvolved gauging the consensus here. Sławomir Biały (talk) 17:53, 12 April 2012 (UTC)

life of pi over

An additional reference has just been added to the article with the sensationalist headline "life of pi is over?", brought to you by the helpful Times of India. Tkuvho (talk) 10:13, 27 March 2012 (UTC)

Has anyone actually read these references? To read them, you would think that the mathematical world has been turned upside down by an organized revolution. In reality, it's just some wacky dudes with Youtube videos and personal webpages. It really reaffirms the conclusion of debates like this: items appearing in the local press are not at all reliable for assessing the notability of scientific developments. Sławomir Biały (talk) 22:50, 27 March 2012 (UTC)

It's a silly title, and fails to distinguish between "mathematicians" and "a few mathematicians", but it's no worse (or better) than the other "further reading" links aleady on the page. Jowa fan (talk) 05:18, 28 March 2012 (UTC)

Another reason why this should be redirected to pi. It will be much easier to delete these references there. Tkuvho (talk) 10:17, 28 March 2012 (UTC)

Based on this citation, obviously we should take pi to AfD. The relevant bits can be kept here! Sławomir Biały (talk) 00:37, 30 March 2012 (UTC) Ok, don't really do that.

is tau parasitic on pi?

I can't help comparing the tau affair with non-Newtonian calculus. After several years of debate, this was found to be non-notable, and deleted after having wasted many hours of editor time. The framework for such affairs is all too familiar: take a famous scientific notion, string together an argument challenging it, and look for a greedy publisher. Tkuvho (talk) 10:17, 27 March 2012 (UTC)

Tau does not seem remotely notable to me. However, whether it is worth the effort of arguing to have the article deleted is another matter. JamesBWatson (talk) 11:29, 27 March 2012 (UTC)

Lindenberg commented above as follows: "I've never tried to delete or rename the Pi article. How about returning the favor?" Returning favors is fine, but the idea that there is some kind of symmetry between pi and tau that clamors in favor of reciprocity is precisely an instance of parasitism on the part of tau advocates. Tkuvho (talk) 13:42, 27 March 2012 (UTC)

Parasitism? Could you further explain your use of that term? Your comment above about "look for a greedy publisher" sounds like you're accusing me or other people involved with tau of somehow having a book we're trying to sell. Where do you get any such notion? My comment about "returning the favor" was in the context of discussing the MIT cartoon, which encourages live-and-let-live between pi supporters and tau supporters. Joseph Lindenberg (talk) 14:34, 27 March 2012 (UTC)

"Live and let live" again is guilty of an odd attempt to imply a symmetry which is only there in the imagination of Palais and his followers. It should be noted that this is not the famous Palais (as in Palais-Smale) but someone with about 3 or 4 publications (perhaps a relative). Tkuvho (talk) 14:50, 27 March 2012 (UTC)

He's his son. And you know the three-legged pi Palais originally proposed as a symbol? His dad was the one who designed it. That was mentioned on Bob Palais' website and in his paper. Joseph Lindenberg (talk) 15:41, 27 March 2012 (UTC)

"Designed"? It took me exactly half a minute to reproduce it: $\pi\hskip-5pt\pi$. Tkuvho (talk) 09:53, 28 March 2012 (UTC)

Tell you what: get the father to endorse the "tau movement". I assure you WPM will take the idea more seriously. Tkuvho (talk) 15:42, 27 March 2012 (UTC)

I assume Bob wants to be his own man on this. Joseph Lindenberg (talk) 15:58, 27 March 2012 (UTC)

Folks at WPM feel the same way. Do try to channel your energies at wiki more constructively, i.e., toward other pages. Tkuvho (talk) 08:13, 28 March 2012 (UTC)

Tkuvho, can you understand why, after I put a lot of work into this page, and then saw all my work wiped out in a single day, that invitation doesn't have a lot of appeal to me right now? Joseph Lindenberg (talk) 17:40, 28 March 2012 (UTC)

In your nine months of participating in the project, you have almost exclusively dedicated yourself to advocacy of the τ notion, and promotion of your own work. Neither of these activities are in any way compatible with what we do here. While I'm sure you are capable of doing constructive work here in accordance with our pillars, I see little evidence that you have any inclination of doing so. Prove me wrong if you like, but it's no skin off anyone's teeth if you stay or go. There's really no sense in playing the victim card. Sławomir Biały (talk) 23:07, 28 March 2012 (UTC)

Joseph, I sympathize with your predicament. Something similar happened in the case of Non-Newtonian calculus. I can only suggest that you redirect your energies in a more productive direction, i.e., another article. Tkuvho (talk) 13:09, 1 April 2012 (UTC)

Here's a telling edit summary from Lindenberg: Tau may impact Pi's future enormously. It's a replacement for Pi, not an alternative. Tkuvho (talk) 13:54, 1 April 2012 (UTC)

Tkuvho, I do genuinely appreciate your suggestion. For the last couple weeks, Wikipedia has been very aggravating to me, but obviously I'll get over it. Yes, I very much favor the tau idea and am optimistic about its chances. (But I NEVER wrote anything like the edit summary you quoted into the article itself. That was a reply to the preceding editor, explaining why I thought there should be more about tau in the article on pi.) Do understand, I haven't been trying to do anything underhanded here at Wikipedia. If that were my intent, would I have used my real name as my user ID? As a new contributor, I haven't been aware of how stringent Wikipedia's requirements about notability and footnotes apparently are. I still find it incredible that The Tau Manifesto can't be footnoted in an article about tau. And that tau is "not notable", no matter how many people are discussing supporting it, until it appears in official math journals. Joseph Lindenberg (talk) 20:31, 1 April 2012 (UTC)

I made a related proposal here. Tkuvho (talk) 14:54, 2 April 2012 (UTC)

Tau is not notable from a scientific perspective; however, it is notable in that it received significant news coverage once. And for that notability we mention it in this article (though I am of the opinion that the article's title should be changed to something neutral). I do not see any issue with using the Tau manifesto for additional sourcing to Hartl's reference of the constant as tau; it is also a courtesy to the reader who quickly wants to find out what Hartl is up to, without requiring us to go into any of this. Get rid of some of the redundant news sources, instead. Nageh (talk) 22:49, 1 April 2012 (UTC)

I've responded in the next Talk page section. Joseph Lindenberg (talk) 23:28, 1 April 2012 (UTC)

Too many references

Whether they are in Further reading or References it is excessive to have twelve references, almost all in support of just two facts. Many if not most do not introduce new information, they re-report what was originally in The Times newspaper, in some cases using identical wording. When the sources are essentially the same there is no point listing so many of them.--JohnBlackburne^words_deeds 22:37, 1 April 2012 (UTC)

Given the doubts some have expressed about notability, it seemed necessary. But give me a few days – I'm busy right now – and I'll sort through them, move some to footnote other text, and delete some. I'll also take Nageh's advice about using the Tau Manifesto as a reference for Hartl. Can I likewise use Bob Palais' website as a reference for the fact that he now supports using tau? Joseph Lindenberg (talk) 23:16, 1 April 2012 (UTC)

All of these additional references are sensationalist and stem from dubious publications, and therefore don't belong in a scientific page. Tkuvho (talk) 12:24, 2 April 2012 (UTC)

Tau's claim to fame is arguably more (pop) cultural than mathematical. Sensationalism is in the eye of the beholder. --Cybercobra (talk) 12:48, 2 April 2012 (UTC)

Articles with titles like "Life of pi over" are clearly either sensationalistic or incredibly bad journalism. You can take your pick. Sławomir Biały (talk) 13:04, 2 April 2012 (UTC)

I have to agree with Sławomir here. There are enough reliable sources reporting on the Tau/2π issue; we don't need to resort to prove notability through sheer number of references. About three per claim suffice, as Nageh suggests below. We should pick the more respectable/neutral/informative ones and stick to them, IMO. --Waldir ^talk 04:16, 3 April 2012 (UTC)

Well, is it primarily a scientific page? I wouldn't say so – after all tau isn't notable for its scientific merit. And what concerns the Tau manifesto, it is mentioned in the article just as in the media that reported on Tau, so either we explain it or we link to it. Nageh (talk) 12:52, 2 April 2012 (UTC)

Back on topic: this is far too many references to support a single fact. I think there is little question that the requirements of verifiability are met regarding the statement "Some individuals, such as Robert Palais and Tau Manifesto author Michael Hartl, have proposed giving this number its own symbol and using that instead of π in mathematics notation." Indeed, a single reference would suffice. Sławomir Biały (talk) 13:02, 2 April 2012 (UTC)

Generally, when you want to make a point – show that something is indeed covered by multiple sources – you include about three references. Ten references is excessive, and really should be trimmed down. I certainly agree on that. Nageh (talk) 13:08, 2 April 2012 (UTC)

OK, just in case doubts about tau's notability arise in the future, I've listed 22 of these sort of news references in my sandbox. You'll notice that all of them are at sites that are substantial enough to have a Wikipedia page about them. Feel free to swap some of them in if you like them better than what we're currently using. I can start deleting some references, but at this point, I don't feel too strongly about which ones. Certainly though I agree with Waldir about the basis on which to select them. Joseph Lindenberg (talk) 09:50, 3 April 2012 (UTC)

I like the Deseret News article, in part because it would appear they did actually interview Palais, not to mention getting a picture of him wearing a Tau shirt. The Toronto Star article seems good too; says they interviewed Hartl by phone; Wikipedia says it's Canada's highest-circulation newspaper. How about this. Which references bother you guys the most? Let's start by cutting those. Joseph Lindenberg (talk) 10:31, 3 April 2012 (UTC)

Some of the "largest circulation" outfits are tabloids. As such they may merit wiki coverage, but may not be suitable for notability discussions of a scientific page. Most editors seem unexcited about pop culture articles masquerading as scientific ones. Tkuvho (talk) 11:59, 3 April 2012 (UTC)

I agree it can be difficult to tell which are respectable newspapers outside your own country, but I see no indication The Toronto Star is what we in the US would call a tabloid. Any Canadians here? Joseph Lindenberg (talk) 20:00, 3 April 2012 (UTC)

So nobody has any references they dislike more than the rest? Or like more than the rest? Last call before I go eenie meenie miney moe. Joseph Lindenberg (talk) 10:20, 4 April 2012 (UTC)

Hartl: no publication record

The fact that Hartl has no publication record in math is significant and should be mentioned in the lede and not just a footnote. Tkuvho (talk) 17:58, 3 April 2012 (UTC)

I agree that it is significant for quantifying the level of its notability. But this is not the subject of the article and thus is misplaced in the article itself. D.Lazard (talk) 18:04, 3 April 2012 (UTC)

If Hatrl is to be mentioned in the lead, then so should his (lack of) credentials. — Arthur Rubin (talk) 19:46, 12 April 2012 (UTC)