
The pi is a lie… Happy Half Tau Day! - mhartl
http://halftauday.com/?
======
GavinB
If we don't fix this, everyone at the galactic congress is going to laugh at
us.

~~~
archangel_one
If the only thing the others at the galactic congress laugh at us about is our
usage of pi instead of tau, I reckon we'd be doing pretty well :)

~~~
zyfo
They'll also laught at the west for seeing chess as the ultimate intellectual
game instead of Go.

 _While the Baroque rules of Chess could only have been created by humans, the
rules of Go are so elegant, organic, and rigorously logical that if
intelligent life forms exist elsewhere in the universe, they almost certainly
play Go._ \- Edward Lasker

~~~
nazgulnarsil
in the rules for first contact (they do exist) should be "Show them Go and
Bach ASAP so we at least have a chance of not looking like idiots."

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sp332
This tau video was posted already, but it's off the front page and... you
really need to see it! <http://news.ycombinator.com/item?id=2321796>

~~~
mhartl
I love this video. Vi Hart says, "No! You're making excuses for pi." With this
beautifully succinct exclamation, Vi cuts through the pi smokescreen and puts
her finger squarely on the problem. This phrase will, I think, become a
rallying cry for tauists everywhere. As the author of _The Tau Manifesto_ , I
am proud to have Vi on Team Tau!

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snissn
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 you're doing any actual complicated math or physics, the last thing you
care about is having a different constant floating around in your terms.

What it is, however, is a great learning tool - This thing called pi, maybe we
could get away with, or even be better off calling it 2pi. - Can get lots of
people thinking about math and possibly learn something cool like trig. But
when used in a psuedo intellectual way, it 'really grinds my gears'.

~~~
rudiger
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
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
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.

~~~
dunstad
>>>"...understanding that sin represents the y value of a point on a unit
circle..."

Wow, I'm enrolled in a college trig class right now and your comment just made
me realize that. Thanks for the heightened understanding :)

~~~
swolchok
For the sake of completeness, cos is the x value, because of the identity
sin(x)^2 + cos(x)^2 = 1. You should find a good unit circle trigonometry
picture if your class isn't giving it to you.

Wikipedia's picture is frightening
(<http://en.wikipedia.org/wiki/Unit_circle>), but perhaps
<http://www.themathpage.com/atrig/unit-circle.htm> or
[http://www.snow.edu/jonathanb/Courses/Math1060/unit_circ_tri...](http://www.snow.edu/jonathanb/Courses/Math1060/unit_circ_trig.html)
will help.

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3pt14159
I'm having a bit of crisis. Ever since I found out about Tau, I just can't
look at my username the same. Maybe I can get it changed to 6pt283185?

In either case: Happy me day!

~~~
camiller
Hmmmm....

You are half the man you should be.

;)

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wallflower
Good luck to those who hope and dream to attend MIT, for today is admissions
decision day! 3/14 9:26pm (not 1:59pm this year because of Class of '15)

~~~
cjtenny
I sent this link to the admissions staff. 6/28 decisions next year, perhaps?

~~~
nickbarnwell
I think that might be a bit cruel to those who get deferred in December, not
to mention slightly impractical ;)

Only 7 hours and 15 minutes to go....

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ilovecomputers
I'm sorry, but on pi day, I eat a whole pie. I am not settling for half a pie.

~~~
camiller
No no, tau is 2pi. So eat 2 pies.

~~~
kissickas
On June 28th. Today you can eat half a tau...

~~~
ilovecomputers
How does one eat a tau?

~~~
camiller
convert into pi equivalent units.

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dskhatri
Tell that to my 12-year old nephew who memorized π to 128 decimal places in
celebration of today! He'll be heart-broken to find out he memorized an
inconsequential number.

~~~
jonsen
He should have memorized π in binary then.

~~~
graywh
only the last bit is different (if you can find it)

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randomibis
Every objection here is answered succinctly and powerfully at
<http://tauday.org/>

I suggest you read it if you haven't done so.

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bugsy
This whole thing is ridiculous because it ruins the whole justification for
baking pies on 3/14.

Those of you that want to study the Dao De Jing on 6/28 are free to do so but
please leave those of use that eat pies on 3/14 alone.

~~~
rtaycher
At my HS they gave everyone a piece of pie on pi day.

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graywh
It's funny when the dup makes the front page and the original doesn't. Guess
it's all a matter of timing.

<http://news.ycombinator.com/item?id=2322355>

~~~
mhartl
I saw the first submission, but I wanted to use a different headline, so I
appended a question mark to the URL and submitted a new link. It's always a
good sign when people submit your stuff before you do, but in this case I had
a clear idea of what I wanted the headline to be. If I recall correctly,
essentially the same thing happened on Tau Day itself, with the same result.

~~~
graywh
And I didn't realize _you_ were the duper until later.

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Fice
Just think of 2π as a single symbol — the circle constant. Why do we need
another name for 2π?

~~~
tspiteri
Is 22π equal to 2 times 2π or is it equal to 11 times 2π? That is, is 22π
equal to 2(2π) or (22)π? If 2π is a single symbol, then 22π would be equal to
2(2π), which would be really confusing.

~~~
Fice
What I was trying to say is that there is no need to introduce another symbol
τ as we can simply refer to "the circle constant" as 2π. I am not suggesting
to treat 2π as a single symbol in formulas.

~~~
jerf
The _hard_ part is getting people to agree that 2pi is the true "circle
constant" and that pi was a historical accident; once you've gotten over that
hurdle agreeing that it should have its own symbol is a no-brainer.

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redcap
While we're at it, can we please:

\- change electric theory so that it's a flow of negative charge and not
positive. \- get the US to use SI units instead of Imperial or whatever they
think they're using.

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tokol
I already bought a pie for the office. Where can I find a half Tau?

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DennisP
Kinda messes up Euler's Identity.

<http://en.wikipedia.org/wiki/Euler%27s_identity>

~~~
DennisP
Ok, so I read down further and I'm wrong.

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itsnotvalid
Just missing a stroke under the horizontal line.

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gsivil
Maybe we should wait for June the 28th for that discussion. Just to show some
respect for pi that was with for quite some time

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tybris
bah e^(0.5τi)+1=0

~~~
tspiteri
> bah e^(0.5τi)+1=0

nah e^(τi)=1

~~~
pixcavator
It's not as good! You can get it from the original formula easily, but not
vice versa.

~~~
waterhouse
You can get _both_ formulas from this one:

    
    
      e^(0.25τ) = i
    

but that doesn't make it a better formula. Or if it did, then the following
formula would be infinitely superior to all of the above (and it doesn't
directly mention either π or τ):

    
    
      e^(ix) = cos x + i*sin x

~~~
pixcavator
Yes and yes. A formula is better if it reveals more of the math behind it, in
a compact form.

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VladRussian
well, Gamma(1/2) = sqrt(pi), putting tau there wouldn't make things better.

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sliverstorm
I dunno, I'm rather fond of people forcing pie into my hands on Pi Day...

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vjwaks
You think you've got issues : my sci fi series TAU4 is getting all your
emails, as Google alerts! I am learning a great deal! check me out at
vjwaks.com or on Amazon books. VJ WAKS TAU4 HAMMERSPACE Los Angeles, CA

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lmkg
Tau is only convenient in geometry. In calculus, Pi rules the day because the
natural unit is radians. Since I like calculus more than geometry, I won't be
accepting Tau anytime soon.

~~~
ddlatham
If your natural unit is radians, then you're arguing for tau rather than
against it.

How many radians in the circle? Tau

How many in half a circle? Tau / 2

How many in a quarter turn? Tau / 4

Much better than mentally switching from a quarter circle to half a pi.

And if you're using it in calculus, it's more natural to integrate from 0 to
Tau than from 0 to 2 Pi.

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justatdotin
that's 14.3, not 3.14

