PDA

View Full Version : Happy Pi Day Everyone



Mike Henderson
03-14-2018, 10:13 AM
Anyone know why it's called Pi? I know the Greeks did some of the early work, but it could have been called "Alpha" or "Beta" or...

Mike

[Today is 3/14 and the first digits of Pi are 3.14]

[Perhaps it was called Pi because Pi deals with the relationships of a circle and a pie is round. So they picked the Greek letter that sounded like pie:)]

George Bokros
03-14-2018, 10:31 AM
I think you hit on it Mike. Everybody knows pi are round. The surface area of pie contradicts that because it says pi r sq.

Jerome Stanek
03-14-2018, 10:48 AM
Isn't it ironic that Steven hawking died on Pi day

Perry Hilbert Jr
03-14-2018, 10:59 AM
ironic or very freaky?

Bill Orbine
03-14-2018, 11:46 AM
Isn't it ironic that Steven hawking died on Pi day

And Hawking was born 300 years to the day Galileo Galilei died!

Jim Koepke
03-14-2018, 1:03 PM
Hope this tee shirt with pi depicted on it doesn't raise too many hackles:

381393

It is kind of a left coast sort of thing. Especially on April 20th.

jtk

John K Jordan
03-14-2018, 3:14 PM
Anyone know why it's called Pi? I know the Greeks did some of the early work, but it could have been called "Alpha" or "Beta" or...


From this, it's a shorthand for "perimeter":
"The symbol “π” and the term “pi” come from the Greek alphabet, where “π” is merely the old school version of “p”; these titles were slapped onto the 3.14 mathematical constant in the early 18th century by mathematician William Jones, who merely used “pi” as an abbreviated form of “perimeter” (because of the number’s connection to circles and circumference and all)."
https://www.primermagazine.com/2009/field-manual/know-it-all-the-origins-of-pi

For those who don't know, some quick approximations for pi:
22/7 (common but pretty poor, 3.1429, but usually good enough for the wood shop)

My favorite:
355/113 (extremely good)
This one is easy to remember. Take the first three odd digits 1, 3, and 5, use each twice for 113355, split the string into two and divide the first half into the second: 355/113. This gives pi to better than six significant digits:

3.14159292 vs
3.14159265 for pi

JKJ

Rod Sheridan
03-14-2018, 3:20 PM
We had Pi day at work as usual.

$3.15 for a slice of pie, we had apple and strawberry/rhubarb.

the money goes to a local charity............Rod.

Lee Schierer
03-14-2018, 3:35 PM
We went to Blaze Pizza where a pizza "pie" was $3.14.

Jay Nossen
03-14-2018, 4:08 PM
I only celebrate Tau Day (June 28). Take a look: https://tauday.com/

It's a nice "manifesto" explaining why Tau=2Pi is a better number to use.

Mike Henderson
03-14-2018, 6:15 PM
We went to Blaze Pizza where a pizza "pie" was $3.14.

I tried to go to Blaze today for the Pi Day special ($3.14 for a pizza) but the line was too long. I gave up and went somewhere else.

Mike

Mike Henderson
03-14-2018, 6:28 PM
I only celebrate Tau Day (June 28). Take a look: https://tauday.com/

It's a nice "manifesto" explaining why Tau=2Pi is a better number to use.

The only advantage I see to Tau is that you don't have to write the 2 in 2Pi. And that's a small advantage.

The area of a circle is given by Pi*r^2. If you go to Tau, it turns into 1/2 Tau*r^2

The argument for Tau is just not compelling so the world will continue to use Pi.

Mike

Lee Schierer
03-14-2018, 7:42 PM
I tried to go to Blaze today for the Pi Day special ($3.14 for a pizza) but the line was too long. I gave up and went somewhere else.

Mike

The line where we were was also long, but it moved quickly.

Lee Schierer
03-14-2018, 7:42 PM
I only celebrate Tau Day (June 28). Take a look: https://tauday.com/

It's a nice "manifesto" explaining why Tau=2Pi is a better number to use.

Two pies are always better than one.

John K Jordan
03-14-2018, 10:09 PM
Two pies are always better than one.

Unless perhaps they are cow pies. Unless perhaps those are fertilizer for the rhubarb.

Jason Roehl
03-15-2018, 6:16 AM
I had shepherd's pi and derby pi for dinner.

Jerome Stanek
03-15-2018, 6:37 AM
I just got a half priced pizza