ConwayLife.com - A community for Conway's Game of Life and related cellular automata
Home  •  LifeWiki  •  Forums  •  Download Golly

Reflectorless Rotating Oscillator Discussion Thread in Life

For discussion of specific patterns or specific families of patterns, both newly-discovered and well-known.

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby BlinkerSpawn » January 27th, 2018, 11:49 am

I'm certain we have more than sufficient technology to make a self-constructing/destroying loop.
LifeWiki: Like Wikipedia but with more spaceships. [citation needed]

Image
User avatar
BlinkerSpawn
 
Posts: 1753
Joined: November 8th, 2014, 8:48 pm
Location: Getting a snacker from R-Bee's

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby Macbi » January 27th, 2018, 11:55 am

The problem is that any kind of Geminoid construction won't work, because the two pieces would move by different amounts.
User avatar
Macbi
 
Posts: 481
Joined: March 29th, 2009, 4:58 am

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby BlinkerSpawn » January 27th, 2018, 12:53 pm

Macbi wrote:The problem is that any kind of Geminoid construction won't work, because the two pieces would move by different amounts.

I was thinking more along the lines of a loop a la the newest spiral-growth except I don't know how to put new elbows at the opposing corners since you can't just leave them there.
LifeWiki: Like Wikipedia but with more spaceships. [citation needed]

Image
User avatar
BlinkerSpawn
 
Posts: 1753
Joined: November 8th, 2014, 8:48 pm
Location: Getting a snacker from R-Bee's

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby dvgrn » January 28th, 2018, 1:32 am

BlinkerSpawn wrote:
Macbi wrote:The problem is that any kind of Geminoid construction won't work, because the two pieces would move by different amounts.

I was thinking more along the lines of a loop a la the newest spiral-growth except I don't know how to put new elbows at the opposing corners since you can't just leave them there.

This stuff is slightly tricky but all definitely known technology, a mix of mechanisms previously seen in the 10hd and 0hd Demonoids and in the linear propagator. Latest progress on a potential RRO design is posted in the Self-Synthesizing Spaceship thread.

It may not be terribly obvious, except maybe with hindsight, that a self-synthesizing spaceship can be configured to travel in three different ways, with pretty much the same amount of design work:

  • diagonally (optionally with a slight oblique shift for extra exotic flavor)
  • orthogonally, by mirror-reflecting after each cycle and thus traveling in a zigzag
  • in a loop, either four steps of 90 degrees or two steps with a 180-degree turn, making a reflectorless rotating oscillator.

EDIT: Now that you mention it, though, it's not necessarily true that "any kind of Geminoid construction" wouldn't work! There's a possible RRO design that's also a mix of a Demonoid and the linear propagator, that would probably be somewhat simpler than a self-synthesizing spaceship memory loop design -- it wouldn't require two copies of the construction data.

Let's see if it still looks good after I run through a summary:

  • start with a Demonoid, but replace let's say the SW end with a constructor arm attached to a 90-degree reflector, not the usual 180-degree one. This end of the RROnoid will pretty much rotate in place.
  • All construction is done from this 90-degree construction-arm end -- the 180-degree end will be just a simple reflector
  • First the constructor builds and launches a Cordership seed. The Cordership heads back in the direction that the recipe gliders are coming from.
  • Next the constructor sends a Cordership-stopping recipe either in the opposite direction, or in the 90 degrees counterclockwise direction, to catch a Cordership that was launched one or two cycles ago. (Which of these allows the timing, or rather the spacing, to work out correctly? It's too late at night for me to sort it out, but I think one of them is right.)
  • The Cordership-stopping recipe builds a new 180-degree reflector end in the correct location.
  • The recipe builds a new 90-degree construction arm.
  • The recipe sends gliders to shoot down the previous 90-degree construction arm _and_ the previous 180-degree reflector, using either long-distance sniping or, more likely, an elbow block left near the old 180-degree reflector for this purpose.
  • The recipe gliders reflected by the 90-degree construction arm bounce off an existing 180-degree reflector (constructed in a previous cycle) and return to feed into the newly constructed 90-degree construction arm.
  • Done! The cycle repeats.
  • To make cleanup easier, the 90-degree and 180-degree circuits could be easily wired to self-destruct after use, with a single trigger glider coming in from somewhere -- lots of options there.
User avatar
dvgrn
Moderator
 
Posts: 4785
Joined: May 17th, 2009, 11:00 pm
Location: Madison, WI

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby 77topaz » January 28th, 2018, 3:46 am

dvgrn wrote:in a loop, either four steps of 90 degrees or two steps with a 180-degree turn, making a reflectorless rotating oscillator.


Would a loop of two steps with a 180-degree leave enough room for a second copy of the oscillator to cycle at the same time, though? Because, to have a proper RRO (of period p), it needs to be possible to have n copies loop the same circuit to create a single oscillator of period p/n, for some n greater than one. This should be possible with a four-step loop, but I'm not sure if there would be enough space in a two-step loop without the copies interfering with each other.
User avatar
77topaz
 
Posts: 789
Joined: January 12th, 2018, 9:19 pm

Re: Reflectorless Rotating Oscillator Discussion Thread in Life

Postby dvgrn » January 28th, 2018, 8:42 am

77topaz wrote:
dvgrn wrote:in a loop, either four steps of 90 degrees or two steps with a 180-degree turn, making a reflectorless rotating oscillator.


Would a loop of two steps with a 180-degree leave enough room for a second copy of the oscillator to cycle at the same time, though?

Maybe not, you're right. Was thinking about the multiplicity problem after posting -- I don't think any of the pieces get in each other's way for the 90-degree case, but would have to do a detailed layout to make sure.

We could patch up the 180-degree case by building two 180-degree reflectors next to each other at the Cordership shoot-down point, and a 180-degree reflector plus a 0-degree constructor arm in the center. Send the recipe back and forth twice. That would create enough space, I believe, though current versions of HashLife would be even less happy with it.
User avatar
dvgrn
Moderator
 
Posts: 4785
Joined: May 17th, 2009, 11:00 pm
Location: Madison, WI


Return to Patterns

Who is online

Users browsing this forum: No registered users and 7 guests