```

wu :: forums
(http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)

general >> truth >> Has anyone seen this before?
(Message started by: BenVitale on May 7th, 2009, 5:30pm)

```

Title: Has anyone seen this before?
Post by BenVitale on May 7th, 2009, 5:30pm
I came across quite accidentally this forum where it discusses

http://eqworld.ipmnet.ru/forum/viewtopic.php?f=3&t=128

I'm not familiar with "structural geometry"

Then, on the same site, I found at

http://eqworld.ipmnet.ru/forum/viewtopic.php?f=3&t=143

y = x2 + 16

y' at x=3

the author finds y'= 10 ... it's quite extraordinary!
Okay, this result is bogus. But what about the so-called "structural geometry" at the first link ?

Title: Re: Has anyone seen this before?
Post by towr on May 8th, 2009, 12:12am
There's probably a reason why all replies in that thread are spam.
It's not clear what he's trying to do, nor are his equations even correct in many cases.

Title: Re: Has anyone seen this before?
Post by Noke Lieu on May 8th, 2009, 1:03am
It's awesome- it's like a ghost town or something. ) registered users, 1 guest, when I looked.

Title: Re: Has anyone seen this before?
Post by BenVitale on Jun 29th, 2009, 12:15pm
We start with 2
The second digit is twice the first, the third is twice the second, etc., with "carries" added in as we go along ...
and then we stop when we find a number starting with 10.

................................2
..............................42
............................842
........................16842
......................136842
......................736842
..................14736842
..................94736842
..............1894736842
............17894736842
..........157894736842
........1157894736842
........3157894736842
......63157894736842
...1263157894736842
...5263157894736842
105263157894736842

Moving the last 2 to the front gives 210526315789473684, manifestly twice 105263157894736842.

This blog (http://tierneylab.blogs.nytimes.com/2009/04/10/puzzle-answers-from-freeman-dyson-and-a-fourth-grader/) also contains Dr. Mutalik's explanation of the phenomenon in terms of arithmetic mod 19.

Title: Re: Has anyone seen this before?
Post by towr on Jun 29th, 2009, 12:34pm
http://en.wikipedia.org/wiki/Parasitic_number

Title: Re: Has anyone seen this before?
Post by BenVitale on Jun 29th, 2009, 1:23pm

on 06/29/09 at 12:34:50, towr wrote:
 http://en.wikipedia.org/wiki/Parasitic_number

Thanks for the link. These numbers are intriguing.

Title: Re: Has anyone seen this before?
Post by BenVitale on Jul 14th, 2009, 12:08pm
Has anyone done this experiment:

http://www.youtube.com/watch?v=UB1vd8614gg

Title: Re: Has anyone seen this before?
Post by TenaliRaman on Jul 14th, 2009, 1:25pm
http://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction#Data_storage

-- AI

Title: Re: Has anyone seen this before?
Post by BenVitale on Sep 18th, 2009, 2:57pm
Binary Clock (http://joerg.pretz.de/)

It has a detail PDF document (http://joerg.pretz.de/uhr_art_eng.pdf)

Title: Re: Has anyone seen this before?
Post by BenVitale on Sep 28th, 2009, 2:09pm
Have you seen this book : A = B (http://www.math.upenn.edu/~wilf/AeqB.pdf)?

Title: Re: Has anyone seen this before?
Post by BenVitale on Oct 13th, 2009, 1:55pm
The Book of Odds (http://www.bookofodds.com/) is an online statistical encyclopedia.

The Book of Odds is a searchable online database of “odds statements,” the probabilities of everyday life.

Title: Re: Has anyone seen this before?
Post by BenVitale on May 12th, 2010, 7:14pm
I've just read the following: The sum of digits of prime numbers is evenly distributed (http://www.physorg.com/news192907929.html)

Title: Re: Has anyone seen this before?
Post by BenVitale on Sep 8th, 2010, 10:44pm
Furstenberg's Proof of the Infinitude of Primes

Quote:
 Perhaps the strangest is the following topological proof by Fürstenberg

http://primes.utm.edu/notes/proofs/infinite/topproof.html

What makes this proof so strange?

Title: Re: Has anyone seen this before?
Post by rmsgrey on Sep 9th, 2010, 7:25am

on 09/08/10 at 22:44:40, BenVitale wrote:
 Furstenberg's Proof of the Infinitude of Primes http://primes.utm.edu/notes/proofs/infinite/topproof.htmlWhat makes this proof so strange?

If you look at the other proofs listed on that site, they are all couched in the language of arithmetic. They talk about taking a list of distinct primes (or a list of numbers that represent distinct primes), performing arithmetic operations on them, and producing a number that represents a new prime.

The topological proof is, unsurprisingly, couched in the language of topology, so, while it's actually saying pretty much the same thing as the other proofs - that no finite set of primes can cover the integers with their multiples - there will always be some numbers that aren't divisible by any of the primes in the set, it's saying it in an unusual way.

Also, it's a non-constructive existence proof - it doesn't tell you anything about how to find these non-multiples, just that they must exist - the other proofs all tell you where to look for your new prime.

Title: Re: Has anyone seen this before?
Post by BenVitale on Nov 30th, 2011, 2:42pm
A regular expression to check for prime numbers

http://www.noulakaz.net/weblog/2007/03/18/a-regular-expression-to-check-for-prime-numbers/

Title: Re: Has anyone seen this before?
Post by towr on Nov 30th, 2011, 10:11pm
It actually checks for non-primes :P
And it's a bit irregular for a regular expression, since you can't translate it to a finite state machine.

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board