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No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

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31–40 of 159 posts

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#32
post #10

Tau is an awful symbol in my opinion. If the people who support double pi as the true symbol they should be writing papers with a definition of double pi and truly proving to the mathematical community that pi is the wrong definition. I personally think pi*D is a perfectly sane way to describe pi and that thinking in 180 degrees is just as easy as in 360 degrees. Once the math community is convinced good luck with en…

Tau is an awful symbol in my opinion. Agreed, mainly because it's already used so widely in so many very standardized ways (including many constants). Of course, most of the Greek alphabet has been used by convention for one thing or another, and people would find it all but impossible to change those habits. If the people who support double pi as the true symbol they should be writing papers with a definition of dou…

Agreed, mainly because it's already used so widely in so many very standardized ways (including many constants).

In particular, note that it's used for torque. The formula for torque from force and radius involves a cross-product, so you're very likely to need both the constant conversion factor for radians/cycle and the variable for torque.

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#33
post #7

Is this a parody or for real?

I should have anticipated this confusion, which resulted from my infelicitous use of the phrase "A modest proposal". The Tau Manifesto is meant to be fun, but it's definitely not a parody. For clarity, I've changed the name of the section in question.

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#34
post #2

Perfect; to my lisp startup file was just added: (defconstant tau #.(* 2 pi)) Regarding adoption, I think it's worth pointing out that these sorts of conventions can and do shift within a generation. I recall quite clearly while growing up the convention for indicating years = the year one [1] was B.C. and A.D. It seems like over the past few years we've definitively decided on B.C.E. and C.E. instead [2]. All it rea…

> It seems like over the past few years we've definitively decided on B.C.E. and C.E. instead.

I don't think that is the case. Amongst recently published works of history that I have read (1st ed. books), from some very reputable publishers (Cambridge, Oxford, UC, etc), I have only seen BC/AD in use.

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#36
post #23
post #7

Is this a parody or for real?

Like Jonathan Swift's proposal for ending poverty and hunger in Ireland, I am sure this "modest proposal" is entirely serious.

Though it shares some elements of propagandistic tone, the Tau Manifesto is unlike Swift's proposal in the most important sense, in that it's perfectly serious. Using the phrase "a modest proposal" in this context was a dubious choice (to say the least). I've changed the section name for clarity.

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#37
post #2

Perfect; to my lisp startup file was just added: (defconstant tau #.(* 2 pi)) Regarding adoption, I think it's worth pointing out that these sorts of conventions can and do shift within a generation. I recall quite clearly while growing up the convention for indicating years = the year one [1] was B.C. and A.D. It seems like over the past few years we've definitively decided on B.C.E. and C.E. instead [2]. All it rea…

Only there is no year zero, by (that) definition. http://en.wikipedia.org/wiki/0_(year)

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#38
post #2

Perfect; to my lisp startup file was just added: (defconstant tau #.(* 2 pi)) Regarding adoption, I think it's worth pointing out that these sorts of conventions can and do shift within a generation. I recall quite clearly while growing up the convention for indicating years = the year one [1] was B.C. and A.D. It seems like over the past few years we've definitively decided on B.C.E. and C.E. instead [2]. All it rea…

I have no problem with people trying to do this in principle. I really don't care enough, but other people can.

The symbol "tau", however, is an especially poor choice for a trigonometric symbol, because it's also used for torque. You won't get many physics teachers to change over if every time you try to calculate a torque from a force and radius, you run into a symbol conflict.

Re: No, really, pi is wrong: The Tau Manifesto (Tau Day, 2010)

#40
post #13

Earlier quoted context omitted.

To be fair, even though I disagree with them, they did try to show through their examples why they believed pi to be wrong.

Pi is defined as C/D, the only way to prove it wrong would be to show that C/D isn't a constant in euclidean geometry, which you can't. What they show examples of is that using pi is ill advised.

You're operating under the wrong definition of "wrong". Axioms and definitions simply exist, but we are not therefore obligated to suspend all judgment on which ones are better for some purpose.

I can reformulate all of physics to accept the Earth as a constant reference frame. It will be isomorphic to current physics based on being set in inertial reference frames, and therefore every bit as "correct" as conventional physics. There will be no place where conventional and Earth-centric physics will disagree about the result of an experiment. However, Earth-centric physics is wrong. It produces terrifically complicated equations for even simplified versions of predicting the orbit of a planet around a distant star. The speed of light is anisotropic. If you really get down to specifying things precisely it has to include rather a lot of kludgy compensations for variations in the Earth's rotation that are nevertheless perfectly definable. It isn't a useful way to approach physics. It is "wrong".

The previous paragraph isn't metaphorical. I am not saying "it is theoretically possible to reformulate all of physics to be Earth centric". I'm saying that one can in fact mechanically translate all physics equations into such a framework, and similar transforms occur all the time (although with better cause). I'm not just being rhetorical, though of course I am, it is also literally true. There is a set of equations that corresponds to the reference frame I am describing.

We select our representations of equations for two major reasons that I can see: One, to minimize the number of symbols necessary to express the concept. "distance = velocity x time" encodes a number of assumptions into it to shorten it, including a wrong idea about reference frames, but we still teach it because it's simpler than the relativistic version (and a hell of a lot simpler than the Earth-centric version!). Second, to enhance the human understanding of the situation being represented by the equation. That's not entirely separate, obviously, but they're not quite the same.

And I would argue tau wins on both fronts, and I for one plan on adopting it in my code. It's better.

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