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        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.html

What 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.


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