Easy as Pi? (1 Viewer)

[MichaelBA]

So, it's not a pointless exercise?

 

[Holadem]

*Gulp*

I only know the first 6 digits, and I am an engineer.

For those who are curious, from Wiki:


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[Christ Reynolds]

with enough time spent, people can memorize anything. it's impressive i guess, but if i had a kid, asking him to memorize digits of pi would be one of the most useless ways of "learning" i could think of.

CJ

 

[Jay H]

Is he memorizing it or computing pi in his head?

Jay

 

[Paul Padilla]

I saw a show a couple of weeks ago on TLC about a guy named Daniel Tammet who set the European/British record for 22,500 places. He's a savant, but he's one of the only ones known to be completely functional. At the end of the show he learned to speak Icelandic in 7 days. That was meant to show that it was more than just memorization.

As crazy as 22,500 is, the world record is 42,195 and the unofficial world record is 83,431.

Pi World Ranking List

 

[Haggai]

He might be doing some sort of computations relating to tricks for remembering all those digits, but I'm all but positive that he's not actually computing each digit as he goes along, in terms of using any of the possible methods for calculating digits of pi. I don't think any human being, even the most talented human calculators, could do all the calculations necessary in their head to get that many digits of pi.

 

[andrew markworthy]

There are numerous examples of people with freakishly good memories. BUT in nearly all cases the good memory is only for memorising without interpretation. In other words, it's not necessarily indicative of intelligence. However, some of these cases are fascinating for psychologists, because they provide insight into the workings of the mind.

For mere mortals, remembering that Pi is near as damnit the same as 22/7 is all you need to know for most calculations.

 

[Haggai]

I find pretty silly for someone who becomes obsessed with the number pi to spend that much time memorizing its digits. Being a mathematician-by-training, if I had a 15-year old son or daughter who, for whatever reason, suddenly wanted to memorize as many thousands of digits of pi as they could, I'd stop them right there and just send them to the Wikipedia page instead, and start them off by trying to learn why some of these different formulas for approximating pi actually work. It'd be a great way of learning about some really fascinating and important areas of math, as opposed to spending tons of time on a parlor trick like memorizing digits. He or she would be a much better math student for it!

 

[MarkHastings]

Did it say how long it took him to recite all of those 8,784 digits?

 

[Steve Kuester]

Anyone else think that the idea of Pi is as neat as I do? (Neat being the only word I can think of right now) It's just neverending... I've always found that rather intriguing.

 

[Chu Gai]

Can he do it backwards?

 

[Christ Reynolds]

if i needed to get x digits of pi, i find a computer with mathematica and enter N[Pi, x] and that will give me many more digits than any human can recite. this can produce as many digits of pi as your computer's memory will allow. the great thing is, nobody will ever need this many digits of pi.

CJ

 

[Holadem]

Well yeah... why do you think people are going around memorizing part of the thing?

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[Jeff Gatie]

Not as unique as you think. Matter of fact, the set of non-terminating, non-repeating decimals is huge, in fact it is infinite.

For instance, take Pi+1, Pi+2, Pi+3 ... Pi+n

or

Pi+0.111..., Pi+0.222..., Pi+0.nnn...

Not to mention all the other non-terminating, non-repeating numbers not based on Pi. The (semi)-unique thing about Pi is you can actually use it for something.

 

[MichaelBA]

I was wondering that too, but I haven't seen any article detailing that.

If you figured two digits vocalized per second, then it would take (I think) about an hour and, oh, thirteen minutes. Something like that.

Hmmph. This kid must have some social life....

 

[Holadem]

Pi is fairly unique in the sense that it's a "naturally occuring" number, for lack of a better term. Can't say the same for Pi+1.

Haggai math wiz, (or anyone else):

I wonder how one can prove that a number like Pi is in fact irrational.

How do we know it's not the ratio of some humongous integers that we cannot yet express?

EDIT: Err... nevermind, I found some relatively simple proofs online, I feel almost embarassed by the question now :b.

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[Christ Reynolds]

as far as cool irrational numbers go, you can't beat e. *dreaming of e-day on february 71st*

CJ

 

[Haggai]

Heh, glad you found some guidance, Holadem...

Here's a proof that the number e is irrational, another very useful/"natural" number.

And here's a proof that the square root of 2 is irrational, probably the most common introductory result of this sort in college math classes that deal with this type of thing (algebra, number theory).

Another important class of numbers is the transcendental numbers; all transcendental real numbers are irrational, though not all irrational numbers are transcendental. Both pi and e are transcendental, but square root of 2 is not. The proof of the fact that pi is transcendental, first demonstrated in the 19th century, was the crucial part of the solution to the ancient problem of "squaring the circle".

 

[Christ Reynolds]

care to share where you found it? i'm curious to know why it's irrational, even though i vaguely remember why.

CJ

 

[Holadem]

Actually, I thought the relatively simple proof of the irrationality of sqrt(2) could be applied to Pi but I was wrong. The proof for Pi is definitely not trivial (for me anyway).

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