13 ms·

This joke is starting to get pretty annoying.. There are lots of things we do for conventional reasons, such as having electrons exhibit negative charge. If y

• anonymoushn 16y ago
  Electrons exhibiting negative charge is something that would be difficult to fix because the fix would result in a lot of confusion. Using tau as the circle constant doesn't cause nearly as many problems. I don't see it as a joke; we should do it.
  • amalcon 16y ago
    It strikes me as more analogous to using j = sqrt(-1) so that it doesn't conflict with current: it works fine, but you're never going to get everyone to do it because people want the papers to stay consistent. Actually, in this case, there's a particular discipline that's especially inconvenienced (physicists, due to the torque conflict). Contrast with j: there's a particular discipline that benefits, and they use j=sqrt(-1) all the time.
    • foob 16y ago
      As a side note, to a physicist j = sqrt(-1) is also a conflict because we're used to i, j, and k being quaternions.
      • drbaskin 16y ago
        I'm confused by your statement -- in the quaternions, i, j, and k are all square roots of -1.
• rudiger 16y ago
  Perhaps you're right about people doing "actual" complicated maths simply not caring about a multiplicative constant. However, a lot of people do most or all of the complicated maths they're ever going to do in their lives when they're in university. During this period, the correct symbol makes every formula and equation simpler and easier to learn. Crucially, it's also during this period that people's understanding of complicated maths is most important, as they are judged by letter grades upon which many of life's opportunities depend.
  • amalcon 16y ago
    How often do people actually make this error? I make all sorts of errors of that class when doing math by hand, but I've never once been off by a factor of two because the formula calls for 2pi.
    • aplusbi 16y ago
      It's not about errors but understanding. A lot of math involving trig is abstract enough to be confusing to most people. Tau makes is [slightly] less so. For example, understanding that sin represents the y value of a point on a unit circle is easier when 1 tau is a full circle rather than 2 pi.
      • amalcon 16y ago
        That's only a problem when you need to use radians, which is only necessary for calculus. You can do all the explanations with "cycles" (1 cycle = 2*pi radians), and it's actually simpler.
        • aplusbi 16y ago
          It's not simpler, it's identical. 1 "cycle" = 1 tau = 2 pi. And in any case, I think using degrees to teach trig is a terrible idea and only causes more confusion later. sin90 = 1 makes no sense, and the fact that that's my first thought when thinking about sin only causes me problems. If I had instead been taught radians first, a lot of stuff would be significantly easier.
• gte910h 16y ago
  I'm not so sure it is a joke. The author clearly states it's more for neophytes. And the convention can be explained of using 2π after showing what it all means by explaining Tau If nothing else, we should at least get a non-separated printing character that looks like 2π connected up, similar to latin dipthongs.
• tybris 16y ago
  No need to look so far. The area of a circle is πr^2. π without 2 is used everywhere.
  • natep 16y ago
    But in analogous equations (energy of motion .5mv^2, energy of spring, .5kx^2), there is a 1/2. Basically, anytime you integrate a linear equation, you get a factor of 1/2. Using pi as the circle constant hides this fact. http://tauday.com/#sec:circular_area http://tauday.com/#sec:circular_area
    • tybris 16y ago
      I like that it hides the fraction. I'm a computer scientist. I don't like fractions. Instead of celebrating tau, we should be celebrating integers. Robust, fast, compact, reliable, easy to understand. With pi I can use more integers. Thank you pi!
      • natep 16y ago
        Well, as a computer scientist, I'd hope you use pi * r * r, because there's no reason to compute tau/2 every time, and pow() is needlessly inefficient for integer powers (on all languages I know. ~6 times slower in python). I'd expect you to make the same optimizations with the analogous equations, but that shouldn't have any bearing on which constant is better for learning, etc.
      • iuygtfhnjmn 16y ago
        You don't think celebrating integer day every day would get a bit repetitive?
        • tybris 16y ago
          Only the first 5 million years, then something interesting happens.
      • billswift 16y ago
• natep 16y ago
  If you're doing complicated math or physics, the last thing you want is to be off by a multiple of 2 when you're done. It's happened to me enough times, I almost wish I were still doing physics so I could use tau instead of pi. For electron charge, I have, at times for intermediate calculations, used 'e' in place of the negative sign from electrons, and then substituted -1 at the end. Being off by a multiple of -1 is just as annoying as a multiple of 2.
  • billswift 16y ago
    Even more annoying since it is even easier. Losing a negative sign is the most common mistake I make working through a complicated problem. Your idea of using something less likely to be overlooked when transcribing intermediate steps in solving a problem strikes me as a really good idea. Thanks.
• amalcon 16y ago
  Not to mention that they seem to have chosen one of the worst possible symbols: the one that happens to represent torque. Further, it looks a lot like t, which is often used to represent turns (== cycles == 2pi radians). There are alphabets out there other than the Latin and Greek ones, with plenty of untapped symbols.
  • loup-vaillant 16y ago
    > it looks a lot like t, which is often used to represent turns I see that as an asset. It makes the correspondence between 2Pi and one cycle even more obvious.
    • amalcon 16y ago
      This is something I can't quite wrap my head around. Why would I want the symbol for a unit to be similar to a constant that I will very often use in the same calculations? That has a good chance of ruining my dimensional analysis if I finish up a calculation later. A bathroom break could convert 2 * pi radians into 1 cycle * radian, or 1 cycle into a unitless 2 * pi.
      • loup-vaillant 16y ago
        And these conversions would be correct, wouldn't they? Radians are length ratios, and as such dimensionless anyway.
        • amalcon 16y ago
          While not technically required, it's pretty convenient to treat radians as their own "angle" dimension. This lets you distinguish an angular velocity from a simple periodic repetition. The latter happen to rarely (never?) occur naturally, but I run into artificial ones often enough.
• maxbRuns 16y ago
  I don't see it as a joke. Why not strive for the conceptually cleanest possible conventions? It's pretty plain to me that tau is more deserving of the status of 'conceptual entity' than pi is. It's the number of radians in a cycle. Practically every time it occurs in physics, pi represents 'half the number of radians in a cycle'. Kind of crufty if you ask me.
• abecedarius 16y ago
  When you're programming something complicated, arbitrary ugliness in the APIs you're using brings you more trouble than when you're programming something simple. Right? So what's different about complicated math or physics? That's how I realized pi was wrong, back before the manifesto came out -- from looking at math the same way I'd learned to look at programs.
• techiferous 16y ago
  This is not a joke any more than the dvorak keyboard layout is a joke or the metric system is a joke. It's an objectively better approach whose only drawback is the overwhelming force of tradition.
  • ek 16y ago
    You cannot compare use of the metric system to use of Dvorak or tau=2pi. While Dvorak and tau may be objectively better, the real world gains to be had by switching to either are slim in reality. I already type upwards of 90 words a minute on Qwerty and I doubt that switching to Dvorak would yield much of a gain to my typing. The problem behind pi is that it is never explained correctly, and this can be worked around by fixing pedagogy without having to introduce yet another physical constant. If the United States switched to the metric system, however, doing business with foreign economies would immediately become easier and we would no longer have to memorize long tables of arbitrary conversion factors. It makes much more sense objectively AND pragmatically to use units that are derived from physical quantities, rather than legends about kings' feet and so forth. With the other two examples, the pragmatic improvement isn't there -- the improvements in quality of life/quality of thought that we would experience simply aren't worth the trouble of switching.