Incredulous!
A Japanese man, Mr. Haraguchi, sounded off pi 100,000 decimal places from memory.
Is this humanly possible, or trickery?
http://www.foxnews.com/story/0,2933,217765,00.html
The source is faux-news.
It’s certainly possible. People use all kinds of tricks to memorize large amounts of data, and digits of pi has been a favorite target for setting a record. I don’t mean “tricks” as in “they’re not really memorizing it” but as in “they are using mnemonic devices rather than brute force.” One memory expert described a way to assign a particular image to each of the three-digit numbers up to 999, and to memorize long strings of numbers he would create a story stringing these images together. Now, memorizing 1,000 images associated with numbers is a bit of a feat in itself, but this gives you some idea of what can be done. The book “Mind Hacks” gives a lot of these strategies.
In the case specific to the OP I do not know this gentleman’s approach.
So, it is possible that the gentleman DID memorize 100,000 numbers in their correct order?
And recite them back in a reasonable (very quickly) time period?
(Son-of-a-gun…sounds absurdly impossible.)
(my highlight)
Was it really necessary? It can’t be that bad if you yourself quote it.
Dude, 100000 of anything is astonishing.
I remember when I cracked 100 digits and I felt like a supercomputer.
Throughout history, people have memorized holy works like the Bible and the Koran. The Iliad and the rest of the Greek classics were memorized and handed down from generation to generation. The highest degree of Masonry required the memorization of an hour-long speech, which until this year had never been written down but taught from member to member through memorization sessions.
It’s true that stories and speeches have built-in mnemonic tricks because of continuity and that random strings are harder. That’s why memory experts take as much of the randomness out as possible.
The capacity of the human mind to keep and absorb huge amounts of information in a given order is astonishing and seemingly far beyond that of any animal. It’s an aspect of intelligence that I feel gets far too little attention when the subject is talked about.
Ají de Gallina
Assuming it was a while back that you were able to pi-out 100 digits, now after ‘x’ amount of time,
how many places-digits can you recite now? Your being out of practice, I am trying to figure the time factor in memory.
I know, small sample survey, but…
Thanks.
Related question: what real-world application uses the most digits of pi? Does the space shuttle or a suspension bridge or something need 10 (or whatever) digits of accuracy?
John, there’s no reason whatsoever for that many digits. I don’t recall the precise number, but estimating the circumfrence of the known universe with a degree of error the size of a hydrogen atom requires something like 20 digits. 100,000 serves no purpose. But it’s awesome.
I’m glad I read this today, I remember reading a while back that he had surpassed 100,000 but I could never find the story. I must have misremembered reading about his training instead.
Article says about 16 hours. Via my poor math skills (i.e., I could be terribly wrong) that’s averaging about 1.7 numbers a second. No idea about bathroom, eating, or drinking breaks.
Amazingly quick, huh? 100,000 times!
How do they calculate it out to that many digits in order to check his work? I assume they use a computer somehow, but isn’t floating point math on a computer somewhat imprecise?
First, note that “his work” was memorizing, not calculating, the digits. Presumably they could check his memory against the same sources he used. Pi is currently known to way more than 100,000 digits, as long as by “known” you don’t mean that some human being actually has them all in his memory.
As for how pi is calculated to that many digits, you’re right that ordinary floating-point arithmetic is imprecise: it isn’t accurate enough to produce tens, let alone thousands, of digits of accuracy. But there are ways to get a computer to use greater precision in its calculations. You can find information online about how pi is actually calculated. Here are a couple of sites:
http://www.codeproject.com/KB/recipes/CRHpi.aspx
http://www.cs.uwaterloo.ca/~alopez-o/math-faq/mathtext/node12.html
Hour 11
Adjudicator: Humph, what? Oops, sorry, I drifted away there for a second … I think I lost my place. Where were you? Was that last bit 8546932146698** or 8546932146689?
Note that having keys to 3-digit groups of numbers would reduce the memorization down to 33,333 of these, not 1,000.
On the flip side. I was once working with an engineer on some back of the envelope calculations. We were barely doing better than pulling numbers out of our ass. If we were within a factor of 4 of the right answer I’d be surprised. He got really bent outa shape that I just used the number 3 for pi in one of the calculations.
This is a bit off. First off the diameter of the universe (whatever that means exactly) isn’t known that precisely by orders of magnitude. But suppose we take it as a very conservative 20 billion light years and assume that is known with absolute precision. Then the circumference of the universe is 210^10pi light years an error of 1 in the 20th decimal place would give an error of 2X10^(-10) light years. There are about 10^16 meters in a light year so the error is about 2 million (2 x 10^6) meters. The size of a hydrogen atom in its ground state is about 10^(-10) meters. so you’re off by 16 orders of magnitude. You’d need something like 36 digits of pi for the accuracy you want.
Of course, that’s still a lot less than what this guy knows.
I suspect that the real-world calculation that uses the most digits of pi is GPS. I know that relativity must be taken into consideration there, and I’m sure they must use trigonometry which at least implicitly uses pi.
When I want my circle’s area calculated, I’m going to that guy.
What I meant that to use that method, you first have to establish your baseline system of images for numbers from 000-999, or 1,000 images. That in itself is a feat.
Well, there’s the old method of doing this in small increments; like training to become a champion weightlifter by adding 1 pound to your barbell every day. If you could lift n pounds yesterday, surely you can lift n+1 pounds today, right?
So if you started today just learning 3, then tomorrow 3.1, every day adding one more digit to learn to the ones you already have memorized, then you could learn pi to 100K digits in only … 273 years, 11 months, and 21 days.
Um … never mind!
Yeah, but if you learned two digits a day, you could cut that time in half. 