Happy Pi Day! - Page 2 — Parallax Forums

# Happy Pi Day!

• Posts: 21,233
Very compelling arguments there Phil, but, but... you are giving me headache...

Let me try the following argument:

1) Let's work in binary. Because we are supposed to be computer nerds and it's as good as any base.

2) I suggest that as one wonders down the binary digits of PI one might find, somewhere along the way, that the digits start to look exactly like Tau. In fact they might continue to look like the digits of Tau forever and actually be the infinite digits of Tau. Does that thought break any rules? We still have random looking, "normal", gunk going on forever. We have not suddenly broken out into a rational number.

3) But as you point out, in binary the digits of Tau contain the digits of PI, by a simple shift.

Ergo, Pi can contain Tau, and you say Tau contains Pi. Which will again contain Pi, ad infinitum.

There seems to be some paradox going on here...

• Posts: 22,976
heater wrote:
Does that thought break any rules?
No, but it's not guaranteed by pi's presumed normalcy. The only guarantee applies to finite strings of digits.

In fact, pi contains an infinite number of infinite strings. You just pick which digit to start from. But, according to the rules of normalcy, the probability of finding a particular infinite string, picked at random, is zero, since it occurs with zero frequency.

-Phil
• Posts: 21,233

Thanks to Cantor we have have the idea that there are infinitely more real numbers along the number line than there is integers. If you were selecting numbers off the number line at random the probability of hitting an integer would be zero. But, we know already that there are integers in there!

Similarly, I don't yet buy the idea that "probability of finding a particular infinite string, picked at random, is zero, since it occurs with zero frequency".

The probability of finding it may be zero, but like the integers among the infinity of reals, it is still in there.

• Posts: 22,976
The probability of finding it may be zero, but like the integers among the infinity of reals, it is still in there.
Maybe. But it's not a requirement of normalcy.

-Phil
• Posts: 22,976
Here's another thought: does the decimal expansion of pi contain itself? No, it can't, because then it would be a repeating decimal, IOW rational. But pi is irrational.

-Phil
• Posts: 22,976
Here's another rebuttal: the number of infinite subsequences in any expansion of pi (or any other number) is countable, since the number of digits in that expansion is countable, and you have to start from one of those digits. The number of real numbers, all of which can be expressed as infinite expansions, is uncountable. Therefore, there are an uncountably infinite number of infinite sequences that cannot be found as a subsequence of any particular infinite expansion, normal or otherwise.

-Phil
• Posts: 21,233
I'm getting confused as to which "grade" of infinity you are using when, there.

But you seem to be suggesting that there is an uncountably infinite number of countably infinitely long sequences than cannot be found in the digits of PI.

PI itself being one. (Apart from the sequence starting at the beginning of course)

Sounds reasonable.

I'm going to take another beer and think about it...

• Posts: 19,925
edited 2018-03-19 02:51
I can't imagine PhiPi switching without a fight. Is there an irrational fellow anywhere who can go tau to tau with PhiPi on his best day?
• Posts: 21,233
erco,
I can't imagine PhiPi switching without a fight. Is there an irrational fellow anywhere who can go tau to tau with PhiPi on his best day?
Perhaps we can get all the Phillip Tau's in the world to argue the case. For example: https://hypebloomington.wordpress.com/2015/02/02/featured-yp-of-the-month-phillip-tau/

• Posts: 1,116
it's been about a year since I got an external hard drive for my Raspberry PI. Purchased from Western Digital... 314 GB, introduced on March 14th for the price of \$31.42.

@
• Posts: 356
edited 2018-03-20 01:28
The Argentinian author Jorge Luis Borges wrote a short story on this theme, "The Library of Babel," which is included in his anthology, Labyrinths. The library is of indefinite size, and its books contain every possible sequence of 25 lexical symbols. Borges riffs on this theme in exquisite detail, making it a very fun read.

-Phil

I always think of a 640 by 480 VGA screen with 256 colors. You could easily create a program to go through every sequence in order from all black to all white. You would be able to view every image ever produced and anything that ever could be produced. Not sure but I think there would be 256^(640*480) combinations. Might take a while, especially if you had to press the space bar to step through the series!

Sandy

• Posts: 19,925
edited 2018-03-20 18:24
Heater. wrote: »
Perhaps we can get all the Phillip Tau's in the world to argue the case.

Touché! We just gotta get these kids together.

Have to get back to you later, I'm watching a movie now.

pi.jpg 31.4K
• Posts: 11,903
edited 2019-03-14 13:37
• Posts: 19,925
Jim, you beat me to it! As far as I'm concerned, Boston Market and other restaurants have forever settled the whole "which is better, Pi or Tau" debate. See also https://www.thrillist.com/news/nation/pi-day-2019-deals-food-cheap-pizza

This says 7-11 pizzas cost 3.14 today, although the in-store ad I saw said 2 for \$7. Still cheaper better than gnawing on some nasty Tau all day IMHO.
• Posts: 19,925
Got 22 trillion decimal places? It was calculated using an Arduino.

JK...

https://www.pi2e.ch/

Says NASA only uses 15 decimal places for rockets, and you'd only need 40 DPs for an atom-precise measurement of the universe. Now I almost feel silly for memorizing 50 DPs back in Jr. High, "except that chicks dig Pi", said no one ever.
• Posts: 232
My access PIN is the last 4 digits of Pi, can you tell me what they are?
• Posts: 19,925
My access PIN is the last 4 digits of Pi, can you tell me what they are?

6666.

The Devil's in the details.
• Posts: 232
erco wrote: »
My access PIN is the last 4 digits of Pi, can you tell me what they are?

6666.

The Devil's in the details.

Are you sure it isn't 9999, for those folks down-under...
• Posts: 11,903
Happy Pi Day.
Another year has come and gone.
• Posts: 19,925
Jim beat me to it! Happy Pi Day and everyone please stay safe. If you don't go out for Pie then stay in and spend your day running the Pi algorithm of your choice on the Parallax processor of your choice. The devil's in the details!

https://en.wikipedia.org/wiki/Category:Pi_algorithms
• Posts: 8,690
Happy Pi Day all, and in view of the posting time here (EST) happy Pi Minute.
• Posts: 11,903
erco wrote: »
Jim beat me to it! Happy Pi Day and everyone please stay safe. If you don't go out for Pie then stay in and spend your day running the Pi algorithm of your choice on the Parallax processor of your choice. The devil's in the details!

https://en.wikipedia.org/wiki/Category:Pi_algorithms

Wondering if you were awake.
• Posts: 19,925
Yup, working hard all weekend on a well-paying freelance robot project for a client. Watch out, Scribblers, coming atcha!
• Posts: 19,925

Don't make me say it...

We're celebrating Pi Day tomorrow with an extra hour of daylight! That's over 19*Pi minutes.

Sorta. Kinda. Ish. Though Tau lovers will probably say we're losing an hour...

• Posts: 1,075

I think the record for Pi is 31 trillion digits, depends on how much you want to split a hair. Goes on indefinitely.

• Posts: 772

## Hapπ π-day 2021!

### Stand-up Maths — Calculating π with Avogadro's Number

Ok... mayhaps the molecules aren't really square... but the result still is impressive for such slopπ assumptions!

• Posts: 169

My late wife (Wendy) made this pie for me back in March of 2012 in celebration of Pi Day.

I made this pizza pie...same night.

Wendy's counter-point to the phrase, "Pi R Round" was, "Cobbler R Square"

• Posts: 19,925

NICE Pie! And speaking of irrational constants...

I'm late to Netflix's "Stranger Things" party but daughter Amy loves it. It's set in the 1980's and suddenly she's interested in lots of my retro things, cassette tapes, Heathkit ham radios, my Nike leather Cortez, etc. Lots of nerdy references too. Planck's constant literally saves the day in the final episode of season 3. Turns out, the value is the combination to a safe which...

• Posts: 8,690

Yay, Pi day. we've got a nice chicken pot pie for dinner and a strawberry rhubarb pie for dessert.

• Posts: 19,925