# Happy PI Day 2010

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## Main Question or Discussion Point

I went to Google this morning and found out that today is http://www.cnn.com/2010/TECH/03/12/pi.day.math/" [Broken].

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## Answers and Replies

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Danger
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It's pi day because it's 3-14.

I believe that means it's not pi day in foreign countries because they put the day of the month first.

And, since there's no month 14, there will never be a pi day in foreign countries.

Or is that just circular reasoning?

Gokul43201
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Danger
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Or is that just circular reasoning?
Arrrggghhhh...

You mean $\pi r_0^2$ ?
Exactly. Cakes are square; pie are round.

Gokul43201
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It's pi day because it's 3-14.

I believe that means it's not pi day in foreign countries because they put the day of the month first.

And, since there's no month 14, there will never be a pi day in foreign countries.

Or is that just circular reasoning?
To be intentionally obtuse, that's not circular, but incomplete. Completeness, within this particular argument, would also require you to note that April never has 31 days.

Of course, Jan 3rd is really not so terrible, but just doesn't have enough zing in it.

Science Advisor
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It's pi day because it's 3-14.

I believe that means it's not pi day in foreign countries because they put the day of the month first.

And, since there's no month 14, there will never be a pi day in foreign countries.

Or is that just circular reasoning?
Hmm. 3-14-15 will be PI year.

And, since there's no month 14, there will never be a pi day in foreign countries.
Sure there will. We just do it on 22/7 (22nd of July) which is actually closer to pi than 3.14. Alternatively people have been known to do it on the 314th day of the year, but I can never remember when that is and I don't reckon it's that popular except for people who want an extra chance to celebrate pi day.

happy Pi-nstein day!

I have a problem with pi. Pi was arbitrarily chosen to be the ratio of circumference over diameter thousands of years ago. But as most problems in math and physics are solved in term of radius than diameter, there is more elegance for pi to be circumference over radius (6.28318). It represents a full 360 degree revolution, and not 180.

Moonbear
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Happy pi day! I found the perfect square pie to celebrate.

To be intentionally obtuse, that's not circular, but incomplete. Completeness, within this particular argument, would also require you to note that April never has 31 days.

Of course, Jan 3rd is really not so terrible, but just doesn't have enough zing in it.
And it's too close to New Years.

Happy pi day! I found the perfect square pie to celebrate.

That's not pie, it's...

Just think how hard they partied on 3/14/1592

Shouldn't pi day be tomorrow? It rounds up to 3.15

Moonbear
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Shouldn't pi day be tomorrow? It rounds up to 3.15
How? 3.141...rounds down.

Matterwave
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Some of the calculations are done by infinite series approximations. There are proofs that some infinite series converge to the value pi. One can then calculate these infinite series to many many terms and get a good approximation of pi (the faster the series converges the better).

Another method would be to make more and more sided polygons and measuring the perimeter vs "radius" of these polygons. If you get a polygon with 1 billion sides, you get a pretty good approximation of pi as well.

How? 3.141...rounds down.
Oh never mind(well, atleast I know pi is 3-ish).