## possible mistake in wiki

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wintersolstice
Posts: 21
Joined: August 25th, 2010, 3:42 pm

### possible mistake in wiki

this statement from the "wiki" doesn't seem to make sense:

"that oscillators are known that oscillate at all periods other than 19, 23, 34, 38, 41, 43 and 53"

does it mean:

oscillators can oscillate at all periods other than 19, 23, 34, 38, 41, 43 and 53"
(as in these are the only periods that are impossible)

all known oscillators, oscillate at periods between 1 (still life) and some "unknown number" (the largest known period) apart from 19, 23, 34, 38, 41, 43 and 53 (and this "unknown number" has not been stated

or (very far fetched) infinitly many oscillators are known (infinite sets) and 19, 23, 34, 38, 41, 43 and 53 are the only periods that don't exist yet

the sentence also seems to have a bit of bad grammer

Macbi
Posts: 765
Joined: March 29th, 2009, 4:58 am

### Re: possible mistake in wiki

infinitly many oscillators are known (infinite sets) and 19, 23, 34, 38, 41, 43 and 53 are the only periods that don't exist yet
This one.
Last edited by Macbi on January 26th, 2011, 3:29 pm, edited 1 time in total.

calcyman
Posts: 2317
Joined: June 1st, 2009, 4:32 pm

### Re: possible mistake in wiki

Oscillators are known for all periods, except for 19, 23, 34, 38, 41, 43, and 53.

(There are explicit examples for each period < 62, and a constructive proof for all periods >= 62.)
What do you do with ill crystallographers? Take them to the mono-clinic!

Sokwe
Moderator
Posts: 1677
Joined: July 9th, 2009, 2:44 pm

### Re: possible mistake in wiki

To elaborate further, the first method of constructing oscillators of all arbitrarily-high periods, Herschel loops, was developed by David Buckingham in 1996 (see this article). Herschel loops based on stable technology have facilitated oscillator of all periods greater than or equal to 58, and herschel loops with periodic support have achieved periods as low as 54 (note: herschel loops also allow the construction of all gun periods greater than or equal to 62). Although we have not found explicit examples of oscillators of periods below 54, the possibility of their existence has by no means been disproved (I think it is generally believed that oscillators of these periods do exist). Dean Hickerson has made some attempts at finding these oscillator periods using his drifter search program in an attempt to find signals that can travel quickly around a stable track (a method that is essentially the same as building herschel loops), but no track-turning components have yet been found that allow the construction of complete loops.
-Matthias Merzenich

calcyman
Posts: 2317
Joined: June 1st, 2009, 4:32 pm

### Re: possible mistake in wiki

Anyway, did no-one read my recent article?

http://pentadecathlon.com/lifeNews/2011 ... iodic.html

That was the seventh article published this year, in an attempt to restore LifeNews to its original publication rate. Dave and I have 13 more articles to write between us, at which point most of the interesting recent discoveries would be out there.
What do you do with ill crystallographers? Take them to the mono-clinic!