# Thread: Pi is out! Tau is in!

1. I liked my TI-85 and then TI-89 better.

---------- Post added 2012-11-10 at 11:14 AM ----------

Originally Posted by Spectral
If I recall correctly, typing "tau" did it. That might be wrong though, it's been a long while.
Yes, it did.

I migrated to Mathematica for University, though. Long live playing Tetris during high school math classes.

2. Originally Posted by Spectral
Indeed, Celsius (and Fahrenheit to an even greater extent) are scales of convenience for commonly dealt with everyday temperatures. They're quite useless if we're trying to deal down to "real" heat.
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.

3. 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.
Hey, it only makes sense that water freezes at 32 degrees and boils at 212 degrees at sea level. Duh. Next you'll probably say it doesn't make sense that a mile is 5280 feet. /facepalm.

Now my question: Why can't those Metric people get their acts together? 2.54 centimeters to an Inch? really? Can't you use round numbers?

(SARCASM).

4. I don't get it. I took (and passed) a physics class in high school, but I don't remember ever using 2pi. It seems like a lot of talk over nothing, but if you want to add it to calculators, go for it.

5. 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.
A few things ... Farenheit is more a scale of convenience than Celcius as it used 0 and 100 to correspond to the normal extremes of human involvement. It was a common sense approach at the time.

Also - and think about this, whilst 1 Celcius degree = 1 Kelvin degree, 1 degree Celcius is NOT equal to 1 degree Kelvin.

6. Originally Posted by belfpala
Hey, it only makes sense that water freezes at 32 degrees and boils at 212 degrees at sea level. Duh. Next you'll probably say it doesn't make sense that a mile is 5280 feet. /facepalm.

(SARCASM).
-backhands- Go apologise to the SI gods.

---------- Post added 2012-11-10 at 08:38 AM ----------

Originally Posted by schwarzkopf
A few things ... Farenheit is more a scale of convenience than Celcius as it used 0 and 100 to correspond to the normal extremes of human involvement. It was a common sense approach at the time.

Also - and think about this, whilst 1 Celcius degree = 1 Kelvin degree, 1 degree Celcius is NOT equal to 1 degree Kelvin.
Yes yes, semantics. I meant in terms of increments. 1 degree Kelvin would be just above absolute zero.

7. Originally Posted by belfpala
Hey, it only makes sense that water freezes at 32 degrees and boils at 212 degrees at sea level. Duh. Next you'll probably say it doesn't make sense that a mile is 5280 feet. /facepalm.

(SARCASM).
According to wikipedia he based it on three basic measurements:

the temperature of a 1:1:1 mixture of Water, ice and ammonium chloride is 0F.
the temperature of a 1:1 mixture of water and ice is 32F
the temperature of the human body is 96F

The difference between the freezing point of water and its boiling point is 180 degrees

The celcius scale is based around the triple point of water - the temperature at which pure water exists in all three physical states (solid, liquid and gas) at standard air pressure and Absolute Zero (-273.15°C, or 0K).

8. Originally Posted by Didactic
-backhands- Go apologise to the SI gods.[COLOR="red"]
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.

9. Originally Posted by Butler Log
According to wikipedia he based it on three basic measurements:

the temperature of a 1:1:1 mixture of Water, ice and ammonium chloride is 0F.
the temperature of a 1:1 mixture of water and ice is 32F
the temperature of the human body is 96F

The difference between the freezing point of water and its boiling point is 180 degrees

The celcius scale is based around the triple point of water - the temperature at which pure water exists in all three physical states (solid, liquid and gas) at standard air pressure and Absolute Zero (-273.15°C, or 0K).
I think the French have it right as regards temperature. Just saying.

10. Originally Posted by Butler Log
According to wikipedia he based it on three basic measurements:
I understand the science, thank you. If I were to pick a scale based on scientific rational, I would pick the Celsius unit but the Kelvin zero point. So... the Kelvin scale.

11. Originally Posted by belfpala
I understand the science, thank you. If I were to pick a scale based on scientific rational, I would pick the Celsius unit but the Kelvin zero point. So... the Kelvin scale.
Hence why serious scientists use Kelvin. The Celsius/Kelvin dynamic is pretty much perfect, if you ask me.

12. Wouldn't this confuse the shit out of everyone when they make the transfer from tau to pi, in terms of the guy saying its very unlikely the real world will stop using pi.

Especially if they've never been taught how to use anything but tau.

Not really sure why he thinks using pi is all that hard either. I never had a problem learning geometry/trig/pre calc 30

13. Originally Posted by Methanar
Wouldn't this confuse the shit out of everyone when they make the transfer from tau to pi, in terms of the guy saying its very unlikely the real world will stop using pi.

Especially if they've never been taught how to use anything but tau.

Not really sure why he thinks using pi is all that hard either. I never had a problem learning geometry/trig/pre calc 30
This isn't from a pure mathematical perspective, this is from a (hur hur) didactic perspective. It's easier to teach kids Tau versus 2 Pi.

14. Originally Posted by Methanar
Not really sure why he thinks using pi is all that hard either. I never had a problem learning geometry/trig/pre calc 30
It isn't, some people just get off on changing stuff that doesn't need changing.

---------- Post added 2012-11-10 at 05:54 PM ----------

Originally Posted by Didactic
This isn't from a pure mathematical perspective, this is from a (hur hur) didactic perspective. It's easier to teach kids Tau versus 2 Pi.
And how is that different to teaching kids pi as opposed to tau/2?

c = 2πr
a = πr²

as opposed to

c = tr
a = (t/2)r²

It is the same damn thing.

15. Originally Posted by Didactic
Hence why serious scientists use Kelvin. The Celsius/Kelvin dynamic is pretty much perfect, if you ask me.
I'm familiar. I did experiments with liquid helium in undergrad.

16. Originally Posted by Butler Log
And how is that different to teaching kids pi as opposed to tau/2?

c = 2πr
a = πr²

as opposed to

c = tr
a = (t/2)r²

It is the same damn thing.
Did you watch the video or not?

17. Originally Posted by Didactic
This isn't from a pure mathematical perspective, this is from a (hur hur) didactic perspective. It's easier to teach kids Tau versus 2 Pi.
What I mean was teach the kids tau, but when they get a real job or go to university they are still going to be using pi.

So they won't be fully/properly prepared for the world if this transition happens.

18. Originally Posted by Methanar
What I mean was teach the kids tau, but when they get a real job or go to university they are still going to be using pi.

So they won't be fully/properly prepared for the world if this transition happens.
/facepalm

The idea is that the entire academic sphere would make the transition. And nobody in the "real job" world gives a shit about formulae, they only care about results.

19. Originally Posted by Methanar
What I mean was teach the kids tau, but when they get a real job or go to university they are still going to be using pi.

So they won't be fully/properly prepared for the world if this transition happens.
The only reason to teach Tau seems to be for trig functions. As I said above, we put coefficients in front of almost everything. Kids should get used to it. As I noted above, even with tau, you have coefficients for the surface area or volume of a sphere, for example.

But then again, in terms of fundamental numbers, I don't see any difference between:

pi = C/D

or

tau = C/R

20. Originally Posted by Didactic
This isn't from a pure mathematical perspective, this is from a (hur hur) didactic perspective. It's easier to teach kids Tau versus 2 Pi.
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.

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