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Life Lexicon update -- now Release 29, 2 July 2018

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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby wildmyron » June 29th, 2018, 5:40 am

Noticed this in a quote on the forum -

[b]:sparse Life[/b] ... but it is not at all clear that there is any mechanism for these to deal with _the all_ junk produced by switch engines.
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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby Apple Bottom » June 29th, 2018, 9:14 am

wildmyron wrote:Noticed this in a quote on the forum -

[b]:sparse Life[/b] ... but it is not at all clear that there is any mechanism for these to deal with _the all_ junk produced by switch engines.


Thanks --- fixed. (And also updated the "reverse caber tosser" entry to reflect the fact that the best lower bound is now 58, rather than 59.)
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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby wildmyron » July 2nd, 2018, 1:46 am

A review of 'J':
  • :Jaws: contains a partial list of smaller breeders which should either be updated or instead reference a single list as I proposed in discussion of :mosquito5: above. The growth rate is not mentioned. Perhaps: "A {breeder} constructed by Nick Gotts in February 1997 which exhibits quadratic growth. The same comment applies to the mosquito entries.

A review of 'I':
  • :inductor: does not refer to :gutter:. Not sure that it needs to, because the current wording is probably better than something like "Any oscillator with a {gutter} down the middle ..."
  • :infinite growth: states "Nick Gotts and Paul Callahan have also shown that there is no infinite growth pattern with fewer than 10 cells, so that _the_ question has now been answered." Remove "the". Also, is there a date for this proof?

A review of 'H':
  • :Herschel: contains a reference to end of 2017 (already fixed?)
  • :Herschel loop: needs to be updated to reflect the recently discovered p52 loop.
  • :Herschel track: Is this the same as :Herschel circuit:?

Other:
  • As for :Herschel loop:, :emu: should also include p52 in list of flightless herschel loop periods.
  • Are :circuit: and :track: synonymous? If they aren't I can't discern the difference aside from the alternate meaning discussed for track.
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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby dvgrn » July 2nd, 2018, 2:55 pm

wildmyron wrote:
  • :Herschel loop: needs to be updated to reflect the recently discovered p52 loop.
  • As for :Herschel loop:, :emu: should also include p52 in list of flightless herschel loop periods.

Here's an attempt at an update. I included period 52 in the list of emu periods, but I'm not entirely sure it really belongs there: does a signal loop count as a "Herschel loop" as long as there's a Herschel in the loop somewhere -- even if the signal turns into a triplet of gliders at several points?

-- Or is a loop made out of four Snarks also an emu, since it shares the same annoying problem of being "flightless"? It would certainly be nice to be able to extract over-unity gliders right down to p43. So maybe the "emu" definition should be expanded to "signal loops" instead of just "Herschel loops". (?)

Revised draft definition for "Herschel loop":

:Herschel loop: A cyclic {Herschel track}. Although no loop of length less than 120 generations has been constructed it is possible to make {oscillator}s of smaller periods by putting more than one Herschel in a higher-period track. In this way oscillators, and in most cases {gun}s, of all periods from 54 onwards can now be constructed (although the p55 case is a bit strange, shooting itself with gliders in order to stabilize itself). A mechanism for a period-52 loop was found in April 2018, but it includes stages where the signal is carried by triplets of {glider}s so it may not be considered to be a pure Herschel loop. The missing period, 53, is a difficult case simply because 53 is prime and so no small sparkers or reflectors are available.
See {Simkin glider gun} and {p256 gun} for the smallest known Herschel loops. See also {emu} and {omniperiodic}.
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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby Sokwe » July 2nd, 2018, 8:04 pm

under :Herschel loop you write
The missing period, 53, is a difficult case simply because 53 is prime and so no small sparkers or reflectors are available.

I think the snark would count as a small p53 reflector. I would rewrite that sentence as follows:
The missing period, 53, is a difficult case, because 53 is prime and no small sparkers are available.
-Matthias Merzenich
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Re: Life Lexicon update -- now Release 29, 2 June 2018

Postby wildmyron » July 3rd, 2018, 12:04 am

dvgrn wrote:
wildmyron wrote:
  • :Herschel loop: needs to be updated to reflect the recently discovered p52 loop.
  • As for :Herschel loop:, :emu: should also include p52 in list of flightless herschel loop periods.

Here's an attempt at an update. I included period 52 in the list of emu periods, but I'm not entirely sure it really belongs there: does a signal loop count as a "Herschel loop" as long as there's a Herschel in the loop somewhere -- even if the signal turns into a triplet of gliders at several points?

Please feel free to ignore my suggestions when they don't make sense! I remembered the p52 loop being posted when I read the entry and to be honest I didn't even run the pattern or consider whether it qualified as a Herschel loop or an emu. However, I think your draft makes sense - the signals in the p52 loop are predominantly Herschels, though you do then have a hazy definition for what qualifies as a Herschel loop.

I looked through 'G' and didn't find any issues of note aside from a few references to 2017. Perhaps someone else can review the :glider synthesis: entry as that's such an active and large topic. It may be worthwhile adding some more content about the current state of glider synthesis technology - particularly for spaceships.

Also, can someone verify the truthiness of this statement in :glider duplicator: "Glider duplicators and turners are known for backward gliders using p2 c/2 spaceships, and for forward gliders using p3 c/3 spaceships." I'd be surprised if there are no c/3 glider duplicators or turners for backward gliders, but I have no idea whether or not they exist.

----

I guess we're getting down to the wire for including further corrections to v29 in Golly. Is there a date for checkin of final v29 version?
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Re: Life Lexicon update -- now Release 29, 2 July 2018

Postby dvgrn » July 3rd, 2018, 10:07 am

wildmyron wrote:I looked through 'G' and didn't find any issues of note aside from a few references to 2017. Perhaps someone else can review the :glider synthesis: entry as that's such an active and large topic. It may be worthwhile adding some more content about the current state of glider synthesis technology - particularly for spaceships.

Yeah, the history of spaceship synthesis is good as far as it goes, but it stops in 2003... For Release 30 it would probably be worth mentioning in each relevant spaceship article the discoverer and date of all the recent glider syntheses.

wildmyron wrote:I guess we're getting down to the wire for including further corrections to v29 in Golly. Is there a date for checkin of final v29 version?

Yes! It was early this morning -- at least as long as no one finds awful horrible problems before Andrew gets around to a Golly 3.2 release build.

There's an associated checkin to the GitHub repository, so the single-page preview should have all the latest changes for review.

... Except I noticed this morning that my manual post-processing notes weren't updated with Sokwe's correction to the single-page :spaceship: table, so it still links to 25P3H1V0.2 instead of 25P3H1V0.1. (Not a problem for the Golly multi-page HTML.) So I'll have to do a little quick patching and rebuilding ZIP files in the next few days, and do another checkin before moving things over to conwaylife.com/ref/lexicon.

Anybody see anything else I broke? Other little stuff can get rolled into the same patch.
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Re: Life Lexicon update -- now Release 29, 2 July 2018

Postby dvgrn » July 4th, 2018, 5:11 pm

dvgrn wrote:...noticed this morning that my manual post-processing notes weren't updated with Sokwe's correction to the single-page :spaceship: table, so it still links to 25P3H1V0.2 instead of 25P3H1V0.1. (Not a problem for the Golly multi-page HTML.) So I'll have to do a little quick patching and rebuilding ZIP files in the next few days, and do another checkin before moving things over to conwaylife.com/ref/lexicon.

Anybody see anything else I broke? Other little stuff can get rolled into the same patch.

The patch to the single-page :spaceship: table is done, so the single-page preview should be correct now, and should exactly match what's in Golly.

That's probably a wrap for Life Lexicon Release 29, 2018 July 2, at least unless some really annoying little typo shows up that it's worth patching directly in the various HTML files, rather than waiting for the next full build. Otherwise I'll probably plan on getting a review of A through G done by the end of 2018. Will try to keep up with editing in new details that need updating between now and then... and that will become Release 30.

Please keep the reviews and suggestions coming!
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Re: Life Lexicon update -- now Release 29, 2 July 2018

Postby wildmyron » July 5th, 2018, 11:04 pm

dvgrn wrote:The patch to the single-page :spaceship: table is done, so the single-page preview should be correct now, and should exactly match what's in Golly.

The table of elementary spaceships in the entry for :spaceship: has an error:
(2,1)c/7 oblique    Sir Robin         Adam P. Goucher    Mar 2018

which obviously should read (2,1)c/6.

Also, what came of Dean Hickerson's comments on the Golly list about the first c/3 ship discovered in early August 1989?
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Re: Life Lexicon update -- now Release 29, 2 July 2018

Postby Apple Bottom » July 6th, 2018, 3:09 am

wildmyron wrote:The table of elementary spaceships in the entry for :spaceship: has an error:
(2,1)c/7 oblique    Sir Robin         Adam P. Goucher    Mar 2018

which obviously should read (2,1)c/6.


Already corrected (but I can't build/push updated lexicons, so it's not showing up anywhere yet).
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