# Thread: Pi is out! Tau is in!

1. I still do not see how much more convenient Tau is. As several people have stated, 2pi = Tau is a quite simple equation and at some point kids will have to learn about pi in math when they're calculating the volume of some structures. Besides if pi isn't taught and we move to Tau, how will teachers then tell kids if they're not given new books?
"Hey children, do you see that Pi sign in the book? Yea, cross that over and put in Tau instead"

I won't mind using Tau along with pi and as a person who just started on engineering this summer it won't affect me at all. I'll just define tau as 2pi in the beginning of my MathCad document and forget all about it.
I'm sorry but I still can't see how tau makes it easier to teach math to children.

Edit: is it really a problem for children today to understand the fundamentals of pi? Seems like an odd solution to a problem that doesn't even exist

2. Originally Posted by Didactic
Farenheit is a scale of convenience? At least Celsius' 0 and 100 degrees mark common phenomena. Furthermore, Celsius is interchangeable with Kelvin because 1 degree Celsius = 1 degree Kelvin.
Yeah, Fahrenheit's quite intuitive for people that have always used it. It's fairly German centric in nature, and I grew up in an area that has similar weather to the chilly parts of Germany. For me, zero has always meant really fucking cold and 100 has always meant really fucking hot. It works well for looking temperatures outside, and it has more granularity than Celsius does.

Celsius is an obviously better system for anything that's not describing weather though.

---------- Post added 2012-11-10 at 01:38 PM ----------

Originally Posted by belfpala
I'm probably in the minority of Americans who think in SI units. 1 tsp = 5 ml, 1 Tsp = 15 ml, 1 cup = 240 ml, 1 quart = 960 ml, and so on.
I go back and forth pretty easily. Stupid lab work.

3. Originally Posted by Spectral
Yeah, Fahrenheit's quite intuitive for people that have always used it. It's fairly German centric in nature, and I grew up in an area that has similar weather to the chilly parts of Germany. For me, zero has always meant really fucking cold and 100 has always meant really fucking hot. It works well for looking temperatures outside, and it has more granularity than Celsius does.

Celsius is an obviously better system for anything that's not describing weather though.

---------- Post added 2012-11-10 at 01:38 PM ----------

I go back and forth pretty easily. Stupid lab work.
Doesn't seem that different from -40 is really fucking cold and +30 is really fucking hot in celsius.

4. This seems like a whole lot of nothing. There are many formulas and relationships where pi is by itself and not multiplied by two (area of a circle). Using tau means that while the circle constant is now simpler, those equations become more complex because you would now have to multiply or divide by 2.

Tau is not a magical solution and serious mathematicians will go about their business using pi, because serious mathematicians are not afraid of multiplying by 2.

http://en.wikipedia.org/wiki/List_of...volving_%CF%80

Take a look at how many equations have 2pi. Circumference, surface area and volume of a sphere would be simplified by replacing Pi with Tau. Now look at all the rest. There is no simplification in those. For many integrals, it would make much more sense to simply use Pi instead of Tau/2.

5. Originally Posted by Methanar
Doesn't seem that different from -40 is really fucking cold and +30 is really fucking hot in celsius.
It's not. I'm not declaring Fahrenheit objectively better than Celsius (I think it's objectively inferior), I'm just saying that Fahrenheit is a system of convenience rather than usefulness. For weather, Fahrenheit works really well.

You've got to admit, 0 and 100 are a bit more round and intuitive than -40 and 30. Anyone that's dealt with either scale for more than about two days will be totally comfortable with either though.

6. I might have changed professional orientation if i had knew this back in elementary school!

7. True story: One time I bought a key-lime pie, and offered my roommate "half a pie", and she said sure, and I gave her a quarter of the pie.

Tau would ruin that joke. I would be forced to retreat to low-brow fart jokes.

8. Originally Posted by Gheld
True story: One time I bought a key-lime pie, and offered my roommate "half a pie", and she said sure, and I gave her a quarter of the pie.

Tau would ruin that joke. I would be forced to retreat to low-brow fart jokes.
That is brilliant.

9. Originally Posted by Garnier Fructis
That is brilliant.
That's what life is like in my crew of aged chess-club nerds. Like one time my ex's phone was acting up, and she mentioned at dinner that she wasn't sure if it was still on or not, so I told her "It is as long as you don't check it"

But back on topic, pi makes more sense when dealing with classical mechanics, because radius is more often used. Tau would clearly make more sense when dealing with waves, such as in modern physics.

So both Pi and Tau have their moment. Yes, pun intended.

10. Lets count:
0
pie
tau

Interesting that I've never seen a problem using 2pie or learning it... while tau makes sense when teaching I'm not sure it'll really help that much in the long run.

Either you'll have to get used to pie or just replace every pie with ½tau.

And then confuse them later on. Remember how in early math classes they called those funky negative-under-a-square-root values from the quadratic formula imaginary numbers? A good lot of students get confused as hell for a while when they find out that not only are those values not "imaginary", but they pop up everywhere and have very tangible uses.

Once formulas make use of pi (and not 2*pi) later on, it's going to have to be defined as (tau/2), which is just going to end up confusing students.
Exactly

11. Originally Posted by belfpala
But then again, in terms of fundamental numbers, I don't see any difference between:

pi = C/D

or

tau = C/R
R isn't a fundamental property of a circle - that is the difference. To get R you either need Pi (or Tau) or D first.

pi = C/D

tau = C/(D/2)

12. I'm not a mathmatician (I'm bad at it) not a physicist but the guy in the video is very clear O.o wish it was my math/physics teacher in high school.

13. Originally Posted by Brazorf
I'm not a mathmatician (I'm bad at it) not a physicist but the guy in the video is very clear O.o wish it was my math/physics teacher in high school.
Yeah me too, I had some gnarled 70 year old man who had half of his body paralyzed from a stroke or something and was impossible to understand. And since half his good hand was paralyzed his writing was impossible to read too...

14. mines simply lacked charisma and ability to keep the classes in check or to have them motivated in learning the subject. ;(

15. Originally Posted by schwarzkopf
R isn't a fundamental property of a circle - that is the difference. To get R you either need Pi (or Tau) or D first.

pi = C/D

tau = C/(D/2)

Well, it's all convention. R is usually what's used rather than D when describing geometries in my experience. You need 1 parameter to describe a circle, and that parameter is going to be fundamental, but what you pick is up to taste.

I'd say that having two constants that are reserved for the same physical constant is pointless. The hard science community wouldn't accept a change in convention that purely benefits grade school children, so basically you are teaching children something that is technically wrong.

I think the problem is only that "pi" sounds like "pie" which has a definite connotation when it comes to circles.

16. Originally Posted by Auloria
Well, it's all convention. R is usually what's used rather than D when describing geometries in my experience. You need 1 parameter to describe a circle, and that parameter is going to be fundamental, but what you pick is up to taste.
Actually - that is incorrect. D is fundamental by nature, R is the derived quantity.

Try it out yourself - draw a circle and try and find the radius without first finding the diameter.

17. Originally Posted by ag666
He's right it would be easier to teach tau instead of 2pi - but apart from that it is irrelevant. And teaching was never about easy.
Tau is artificial construct, while pi is real. That's more important than easier teaching. I don't want kids to know nothing about pi.
Well... i isn't real either

18. Just realized something

3.14 written backwards is 41.3 which looks remarkably like PI.E

19. Originally Posted by Angry Bob
Just realized something

3.14 written backwards is 41.3 which looks remarkably like PI.E
:O Mind = Blown.

Aliens? IT'S A CONSPIRACY! ... hehe. Cons-Pi-racy. Get it?

Ok nvm...

20. Originally Posted by Angry Bob
Just realized something

3.14 written backwards is 41.3 which looks remarkably like PI.E
Holy shit you're right

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