Page 2 of 6

Re: Forum Statistic - What's the odds?

Posted: Fri Apr 15, 2011 3:47 am
by owlice
Some numbers are beautiful. I'm not ascribing magical powers to them; I'm just appreciating the beauty of them. 50101, for example. This is a prime number that appeals to me, much like I find some images particularly appealing.

Re: Forum Statistic - What's the odds?

Posted: Fri Apr 22, 2011 12:56 pm
by owlice
Rob, I had added to my previous post appreciation of the deliciousness of your post, but see now the edit didn't take! Dang. Cracked me up, though.

Today: Total posts 73523 • Total topics 6740 • Total members 5431

Two primes. :D

The second number will be going down, however, when a couple o' new spam members are deleted.

Re: Forum Statistic - What's the odds?

Posted: Sat Apr 23, 2011 12:18 am
by rstevenson
I was sure you'd appreciated it, but just didn't want to prime the pump any further.

By the way, is zero a prime? I suppose not, since there's a law against dividing by it. Kind of sub-prime, I suppose.

Rob

Re: Forum Statistic - What's the odds?

Posted: Sat Apr 23, 2011 3:12 am
by neufer
rstevenson wrote:
By the way, is zero a prime? I suppose not, since there's a law against dividing by it. Kind of sub-prime, I suppose.
One is also 'sub-prime' but it didn't used to be:
http://en.wikipedia.org/wiki/Prime_number wrote:
<<Until the 19th century, most mathematicians considered the number 1 a prime. Then, the definition was that a prime is divisible only by 1 and itself. For example, Derrick Norman Lehmer's list of primes up to 10,006,721, reprinted as late as 1956, started with 1 as its first prime. Henri Lebesgue is said to be the last professional mathematician to call 1 prime. A large body of mathematical work is also valid when calling 1 a prime, but the fundamental theorem of arithmetic does no longer hold as stated. For example, the number 15 can be factored as 3 · 5 or 1 · 1 · 3 · 5. If 1 were admitted as a prime, these two presentations would be considered different factorizations of 15 into prime numbers, so the statement of that theorem would have to be modified. Furthermore, the prime numbers have several properties that the number 1 lacks, such as the relationship of the number to its corresponding value of Euler's totient function or the sum of divisors function.>>

Re: Forum Statistic - What's the odds?

Posted: Sat May 14, 2011 8:23 pm
by owlice
Total topics 6869

6869 is in a sequence of prime numbers: 5857, 6869, 7879 and 8887, each formed by 2 consecutive numbers, and their differences are 1012, 1010 and 1008. 6869 is also a twin prime, a prime number that differs from another prime number by two; 6871 is its twin.

Re: Forum Statistic - What's the odds?

Posted: Sat May 14, 2011 11:58 pm
by Beyond
So, if you could add up all the prime numbers, would you end up with a prime number??

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 2:04 am
by bystander
Beyond wrote:So, if you could add up all the prime numbers, would you end up with a prime number??
The odds are, no, but I'm not going to try to find out. :wink:

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 2:23 am
by rstevenson
Beyond wrote:So, if you could add up all the prime numbers, would you end up with a prime number??
Define all.

Rob

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 12:56 pm
by owlice
Total posts 74747

That's a smoothly undulating palindromic prime. You don't get one of those every day, you know!

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 1:38 pm
by neufer
bystander wrote:
Beyond wrote:
So, if you could add up all the prime numbers, would you end up with a prime number??
The odds are, no, but I'm not going to try to find out. :wink:
It would be an infinitely large number with an infinitely small probability of being prime.

2, 5, 10, 17, 28, 41, 58, 77, 100, 129, 160, 197, 238, 281, 328, 381, 440, 501, 568, 639, 712, 791, 874, 963, 1060, 1161, 1264, 1371, 1480, 1593, 1720, 1851, 1988, 2127, 2276, 2427, 2584, 2747, 2914, 3087, 3266, 3447, 3638, 3831, 4028, 4227, 4438, 4661, 4888, ....

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 3:27 pm
by Beyond
But at least no matter how you look at it, it would at least be infinite, or would it?
Another question. What's the biggest number currently in use? And would it hapen to be a prime number?

Re: Forum Statistic - What's the odds?

Posted: Sun May 15, 2011 9:57 pm
by neufer
Beyond wrote:
What's the biggest number currently in use? And would it happen to be a prime number?
Probably the biggest interesting number currently in use (that would be understood by Euclid, at least)
is a composite number: the biggest perfect number = 243,112,608×(243,112,609 − 1)

This number contains 25,956,377 digits.

A standard word processor layout (50 lines per page, 75 digits per line) would require 6,922 pages to display it.

If one were to print it out using standard printer paper, single-sided, it would require approximately 14 reams of paper.

Re: Forum Statistic - What's the odds?

Posted: Mon May 16, 2011 4:44 am
by Beyond
GADS!! Dats a lot of digits!!

Re: Forum Statistic - What's the odds?

Posted: Mon May 16, 2011 5:25 pm
by Ann
There is a book by Oliver Sacks, The Man Who Mistook His Wife for a Hat, where he tells the true story about a pair of identical, autistic twins. The twins, who were in their fifties or maybe sixties, knew one wonderful pleasure in life - they told each other prime numbers. They kept going higher and higher. Oliver Sacks, who was their psychiatrist (or something like that) bought a table of prime numbers. He could follow the twins as they climbed higher and higher on the prime number ladder. Oliver Sacks' table came to an end, but the twins kept soaring higher and higher in their mathematical heaven.

Then, if I remember correctly, some bureaucrat or other decided that the twins needed to learn how to tie their own shoelaces and boil their own eggs and do other useful things, and he (or she) decided that they were best able to do this if they were separated. So the bureaucrat separated the twins, who were thus brutally torn out of their prime number heaven, and brought down to Earth, where they spent their time making their beds and cleaning out their toilet bowls and doing other similar necessities.

I'm not saying it's not a good idea to clean up your toiled bowl after using it, but seriously - I think this story about the autistic, prime number-loving identical twins who were separated in order to learn household chores is one of the cruellest I have heard about.

Ann

Re: Forum Statistic - What's the odds?

Posted: Fri Jul 22, 2011 9:40 am
by owlice
Total posts 77377

A wing prime (or near-repdigit palindromic prime), and in another one hundred posts, we'll have another. :mrgreen:

Re: Forum Statistic - What's the odds?

Posted: Fri Jul 22, 2011 2:07 pm
by neufer
Proof that there are no uninteresting numbers:
  • 1) Define the set of uninteresting numbers.

    2) Note that the smallest number of this set is clearly interesting.

    3) Remove that number from the set.

    4) Go back to step #1 .

Re: Forum Statistic - What's the odds?

Posted: Tue Jul 26, 2011 12:29 pm
by owlice
One of today's interesting numbers (to me, at least) is our current total members number: 5737

Re: Forum Statistic - What's the odds?

Posted: Tue Jul 26, 2011 3:41 pm
by neufer
owlice wrote:
One of today's interesting numbers (to me, at least) is our current total members number: 5737
Only 1677 of which have posted two or more times.

Re: Forum Statistic - What's the odds?

Posted: Tue Jul 26, 2011 3:45 pm
by bystander
owlice wrote:One of today's interesting numbers (to me, at least) is our current total members number: 5737
neufer wrote:Only 1677 of which have posted two or more times.
Only 319 of which have posted 10 or more times.

Re: Forum Statistic - What's the odds?

Posted: Thu Jul 28, 2011 5:55 am
by alter-ego
APOD Numbers.JPG
OK, you got me going on this, so here is a plot of Member Count (normalized) v Post Count with annotations quantifying essentially where Art and Bystander were heading.

Edit: Added Total Posting counts

Re: Forum Statistic - What's the odds?

Posted: Thu Jul 28, 2011 11:51 am
by owlice
hahahahaha!! alter-ego, that chart would work for 99% of all message boards! Oh, that's great; thanks for sharing it!

Re: Forum Statistic - What's the odds?

Posted: Thu Jul 28, 2011 12:12 pm
by neufer
alter-ego wrote:
OK, you got me going on this, so here is a plot of Member Count (normalized) v Post Count
http://en.wikipedia.org/wiki/Poisson_distribution wrote:
The Poisson distribution P = exp (- αx)/α arises in connection with Poisson processes.
The following examples are well-modeled by the Poisson process:
  • The number of goals in a soccer match

    The arrival of customers in a queue.

    The number of raindrops falling within a specified area.

    The number of telephone calls arriving at a switchboard.

    The number of particles emitted via radioactive decay by an unstable substance. In this case the Poisson process is non-homogeneous in a predictable manner - the emission rate declines as particles are emitted.

    The number of yeast cells used when brewing Guinness beer. This example was made famous by William Sealy Gosset (1876–1937).

    The number of soldiers killed by horse-kicks each year in each corps in the Prussian cavalry. This example was made famous by a book of Ladislaus Josephovich Bortkiewicz (1868–1931).
alter-ego wrote:
with annotations quantifying essentially where Art and Bystander were heading.
We are the double dwarfs at the far right.

Re: Forum Statistic - What's the odds?

Posted: Thu Jul 28, 2011 12:23 pm
by owlice
neufer wrote: We are the double dwarfs at the far right.
Oh, there's a joke in there somewhere... I just know it!!

Re: Forum Statistic - What's the odds?

Posted: Thu Jul 28, 2011 1:57 pm
by neufer
owlice wrote:
neufer wrote:
We are the double dwarfs at the far right.
Oh, there's a joke in there somewhere... I just know it!!
  • I'll punt on that one.
Image

Re: Forum Statistic - What's the odds?

Posted: Fri Jul 29, 2011 3:32 am
by alter-ego
neufer wrote:
alter-ego wrote:
OK, you got me going on this, so here is a plot of Member Count (normalized) v Post Count
http://en.wikipedia.org/wiki/Poisson_distribution wrote:
The Poisson distribution P = exp (- αx)/α arises in connection with Poisson processes.
The following examples are well-modeled by the Poisson process:
  • The number of goals in a soccer match

    The arrival of customers in a queue.

    The number of raindrops falling within a specified area.

    The number of telephone calls arriving at a switchboard.

    The number of particles emitted via radioactive decay by an unstable substance. In this case the Poisson process is non-homogeneous in a predictable manner - the emission rate declines as particles are emitted.

    The number of yeast cells used when brewing Guinness beer. This example was made famous by William Sealy Gosset (1876–1937).

    The number of soldiers killed by horse-kicks each year in each corps in the Prussian cavalry. This example was made famous by a book of Ladislaus Josephovich Bortkiewicz (1868–1931).
alter-ego wrote:
with annotations quantifying essentially where Art and Bystander were heading.
We are the double dwarfs at the far right.
APOD Numbers - Poisson Fit.JPG
Ahhhh, the world is copacetic :)