Tau versus Pi

Happy Pi day everybody!

Should Pi be replaced by Tau? Or, do you prefer to have your Pi and eat it to?

On Pi Day, is 'pi' under attack?

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When you think of dividing a circle, you probably know that a quarter-turn is 90 degrees and a half-turn is 180 degrees. But trigonometry uses a unit called "radians," where a quarter-turn of a circle is pi/2 and a half-turn of a circle is pi, and so on -- which is confusing for new learners. Tau makes this more intuitive, says Hartl: A quarter turn of a circle is tau/4, and a half turn is tau/2.

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Sounds like Tau makes more sense. Never even heard of it. Probably would have made high school geometry marginally better.

Doubt it, if we had to convert from tau to degrees to radians and such and forth. Chemistry never got easier when we added Kelvin, and that was a simple "+273" addition problem.

My math teacher raged today when she heard about this article.

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Originally Posted by Dreadnaught

Sounds like Tau makes more sense. Never even heard of it. Probably would have made high school geometry marginally better.

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And it would add powers of two absolutely everywhere, esp. with Euler's equation it'd be a pain in the ass. Hell, h-bar is defined as h divided by two-pi! No no no. You leave pi alone, you teaper twits.

Silly idea. If you can't understand /2 Or *2 by the time you're studying trig, you have bigger problems.

I do. :(

Also, kelvin does make a lot of things easier.

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Originally Posted by Nessus

And it would add powers of two absolutely everywhere, esp. with Euler's equation it'd be a pain in the ass. Hell, h-bar is defined as h divided by two-pi! No no no. You leave pi alone, you teaper twits.

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What's the problem with h divided by Tau? And Euler's equation? The number of radians in a circle doesn't change. How would there be a problem?

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Originally Posted by RandBlade

Silly idea. If you can't understand /2 Or *2 by the time you're studying trig, you have bigger problems.

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So you are happy with there being 2Pi in every pie?

Being: differential equations would become different, which would be a bit annoying to say the least.

I'm doing a lecture on very basic social science stats today (which is a repeat of last week's lecture). The degree of math knowledge in this country is appalling. Not only do a large number of people not understand the most basic of stats methods, but they complain about needing to do long division (2-digit numbers divided by 6-digit numbers).

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Originally Posted by Loki

I'm doing a lecture on very basic social science stats today (which is a repeat of last week's lecture). The degree of math knowledge in this country is appalling. Not only do a large number of people not understand the most basic of stats methods, but they complain about needing to do long division (2-digit numbers divided by 6-digit numbers).

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Without a calculator? ;)

Being: I'd be more concerned about only having one pie ;)

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Originally Posted by Loki

I'm doing a lecture on very basic social science stats today (which is a repeat of last week's lecture). The degree of math knowledge in this country is appalling. Not only do a large number of people not understand the most basic of stats methods, but they complain about needing to do long division (2-digit numbers divided by 6-digit numbers).

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What counts as most basic stats methods? I'm wondering whether I do know some and can't connect them to the term, or if I've managed to get to where I am while remaining as ignorant as your students :noob:

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Originally Posted by RandBlade

Without a calculator? ;)

Being: I'd be more concerned about only having one pie ;)

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And it was worse than I thought. Numerous people were whining about needing to divide a three-digit number by another three-digit number. The people who ventured a guess as to the answer were several orders of magnitude wrong. Unbelievable.

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Originally Posted by Nessus

What counts as most basic stats methods? I'm wondering whether I do know some and can't connect them to the term, or if I've managed to get to where I am while remaining as ignorant as your students :noob:

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How to find the base probability of an event, how to find the conditional probability of an event, and the expected number of times that event occurs if the probabilities were the same across all conditions (also did Z-scores and p-values, but we don't require them to calculate those). Coincidentally, I know that several of the people who wouldn't do the simple multiplication and division are engineering-majors.

Without being silly, what engineer nowadays needs to divide one number by another three digit number without a calculator/computer/calc app in phone?

I have not done a three digit long-division in my entire adult life. More advanced maths than long division is useful to know, but long division is dead as a useful tool. I wouldn't be seen dead at work nowadays without my phone in my pocket and its not just iPhones that have calculator apps, my first Nokia more than a decade ago did.

In stat classes, you have to calculate correlations and very complicated probabilities by hand. If they can't do long division by hand, I don't understand why they're in college. This isn't calculus. It's not trigonometry. It's not even algebra. It's freaking arithmetic.

Seriously, what is the point? You should understand how to calculate correlations and complicated probabilities. You should also understand how to use a calculator.

By the time I reached University you were allowed a calculator in all exams, throughout High School even I was! Junior School I can understand saying no you need to learn this, but adults can and do use calculators. Why hold back a college student teaching them less than you otherwise could as you're wasting their time on basic arithmetic? Arithmetic is why they shouldn't need to learn it.

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Originally Posted by RB

Without being silly, what engineer nowadays needs to divide one number by another three digit number without a calculator/computer/calc app in phone?

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RB, that's not entirely true. I never do long division, true, since it's faster and easier to use a calculator. But I frequently do back-of-the-envelope calculations to figure out an answer to within an order of magnitude (this is useful for quickly determining whether an effect is important in an analysis).

I think actually being able to do four function math by hand is definitely 'dead', yes (I don't need to figure out square roots or whatever by hand, either, even though slide rules make it pretty quick). But being able to have a feel for how big something is? That's invaluable. For a classic example, I've worked some on microfluidic designs of various bioreactors and the like (the details aren't important). When you get down to microscale or smaller phenomena, classical equations to describe behavior (such as fluid flow, electrodynamics, etc.) may need revision as other physical effects start to dominate. Having a feel for whether effect X is bigger than effect Y is pretty important.

That being said, I do agree that having to perform arithmetic by hand in a class is largely silly.

I agree you can get a feel for something, but if I need some long division etc then I can have an answer on my screen from a phone that was locked and in my trouser pockets within 20 seconds. Pen-and-paper calculations are dead, doing numbers in your head should never be. Loki isn't talking about numbers-in-head scenarios though.

I frequently do maths in my head. As you agreed though, don't do long division or square roots etc on paper anymore. Who besides someone interested in them for history's sake even owns a slide-rule anymore? There are no logical or efficient reasons for an adult to do long division on paper.

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Originally Posted by Flixy

Also, kelvin does make a lot of things easier.

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Never did when I took Chemistry or Physics. :(

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Originally Posted by RandBlade

Being: I'd be more concerned about only having one pie ;)

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But one pie forces two Pi upon you. :p

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Originally Posted by coinich

Never did when I took Chemistry or Physics. :(

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Celsius is Kelvin, only with a shifted zero point. And I don't quite believe you did any serious calculations in Fahrenheit.

Sorry, I only work in Rankine.

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Originally Posted by RandBlade

Seriously, what is the point? You should understand how to calculate correlations and complicated probabilities. You should also understand how to use a calculator.

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I also like to use the calculator better. Still I think it added some understanding to do all my algebra and calculus exams for my master without calculator. It helps you when you have to solve problems like partial fraction decomposition. But I have to admit I always need pen and paper to do even simple calculations.

About Tau, it's an interesting idea, it could be used together with Pi, the same way as gas constant (R = N[a] * k[B]).
The gas constant is not really a "new" constant, it's just handier in some cases.

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Originally Posted by wiggin

Sorry, I only work in Rankine.

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Real guys measure their cocks in fermis

Wait what

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Originally Posted by Khendraja'aro

Celsius is Kelvin, only with a shifted zero point. And I don't quite believe you did any serious calculations in Fahrenheit.

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Yes and no. I did much of my homework in F and C and K in high-school, but that was mostly as an instructive thing. I honestly don't recall my physics and chem labs two years ago; since it was entry level phys/chem we may have not even touched the subject. I do think I would've remembered it if most of my calculations were in C though.

Math is not my strong point, so my dreams of engineering went away after that D in Physics II and my 2nd failure in Calculus. :(

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Originally Posted by Khendraja'aro

Celsius is Kelvin, only with a shifted zero point. And I don't quite believe you did any serious calculations in Fahrenheit.

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Word, everything was in Celsius or Kelvin for me--granted it was only Honors Chemistry--and that system makes a hell of a lot more than Fahrenheit, which didn't even accomplish what it set out to do (100 degrees was meant to be body temp., right?).

I think it's a bit ludicrous to suggest that pi be substituted for tau, seeing as how so much of geometry, and then higher applications in other maths, use pi at such a fundamental level. There's nothing special about tau, whereas pi is ridiculously useful in the understanding of..well, shitloads. I don't know why I'm so emotional about this, but it's such an insulting idea to me as an intelligent person that we replace pi because it's too "confusing for new learners."

Welcome to ivory tower academic elitism, otherwise knowing as having the ability to tell apart the nearest metro station and your own asshole without a map