ConwayLife.com

Posted: **March 9th, 2022, 6:10 pm**

A new crab stretcher technology based spaceship with an adjustable slope may be possible.

I already have a design for the adjustable slope mechanism:

Posted: **March 9th, 2022, 11:03 pm**

AlbertArmStain wrote: March 9th, 2022, 6:10 pm A new crab stretcher technology based spaceship with an adjustable slope may be possible.

I already have a design for the adjustable slope mechanism...

Interestingly, this topic just came up on another thread this afternoon, and I was just thinking about making a new thread for what Pavgran calls an "omniship" -- seems like a good name! I hope it's okay to commandeer this thread for that purpose; if it's not, just let me know and I'll move this post.

The shortcoming of the design currently shown in the first-post image is that it will have a speed limit in orthogonal-ish directions that's much lower than the asymptotic limit. Two near-c/4 diagonal stages can't add up to a near-c/2 orthogonal velocity. As Pavgran's post mentions, what we haven't done yet is sort out a 1G seed for a standard blinker puffer that can burn orthogonally at a speed greater than c/2, and then cleanly stop the puffer without releasing any gliders.

After that we'll need to build a universal-construction database for slow salvos of *WSSes, I think, so that the blinker puffer can be followed by a cleanup and construction salvo that builds the next universal constructor.

I guess my next question is, is it necessary to have a combination of orthogonal and diagonal directions of travel to make an asymptotically maximum-speed omniship? Or would two orthogonal c/2 stages of different lengths work just as well?

Posted: **March 10th, 2022, 4:20 am**

dvgrn wrote: March 9th, 2022, 11:03 pm As Pavgran's post mentions, what we haven't done yet is sort out a 1G seed for a standard blinker puffer that can burn orthogonally at a speed greater than c/2, and then cleanly stop the puffer without releasing any gliders.

Well, part of the solution is already present in your own post.

dvgrn wrote: March 9th, 2022, 11:03 pm I guess my next question is, is it necessary to have a combination of orthogonal and diagonal directions of travel to make an asymptotically maximum-speed omniship? Or would two orthogonal c/2 stages of different lengths work just as well?

Two orthogonal stages would work as well.

dvgrn wrote: March 9th, 2022, 11:03 pm After that we'll need to build a universal-construction database for slow salvos of *WSSes, I think, so that the blinker puffer can be followed by a cleanup and construction salvo that builds the next universal constructor.

I think the bare minimum would be to find a *WSS salvo that transforms blinker fuse debris into MWSS-to-G (probably 135-degree one as it's the simplest solution) and everything after that can be done with known glider technology.

Posted: **March 10th, 2022, 10:08 am**

Pavgran wrote: March 10th, 2022, 4:20 amWell, part of the solution is already present in your own post.

Yikes, and that was only a year and a half ago -- it had pretty much slipped my mind that Kazyan had completed that seed. I've added it to the list of one-glider seeds now, so I won't forget about it again.

Pavgran wrote: March 10th, 2022, 4:20 am
dvgrn wrote: March 9th, 2022, 11:03 pm After that we'll need to build a universal-construction database for slow salvos of *WSSes, I think, so that the blinker puffer can be followed by a cleanup and construction salvo that builds the next universal constructor.
I think the bare minimum would be to find a *WSS salvo that transforms blinker fuse debris into MWSS-to-G (probably 135-degree one as it's the simplest solution) and everything after that can be done with known glider technology.

Right -- though I'm still not sure that it's worthwhile to focus on the MWSS-to-G construction, since using that will result in an extremely inefficient recipe compared to a *WSS slow salvo recipe for the full construction. Once we've learned enough to build an MWSS-to-G successfully, it seems like it might only be a short step to a complete workable database for slow *WSS salvos. Wasn't somebody starting to work on a database like that at one point?

There are some interesting ideas in this dedicated thread from 2020, but that's mostly about single-channel MWSS streams, not slow-salvo *WSSes. And there was this thread for orthogonal up-to-c/2 Geminoids.

Posted: **March 10th, 2022, 7:38 pm**

AlbertArmStain wrote: March 9th, 2022, 6:10 pm A new crab stretcher technology based spaceship with an adjustable slope may be possible.

I already have a design for the adjustable slope mechanism:

Scrap that old design, Iv'e made a better and more efficient step-by-step design for the omniship:

1. A single channel glider stream constructs a crab stretcher

2. In the same channel, a snark recipe immediately follows the crab stretcher. So when the stretcher dies due to the fuse burner, the crab turns into a snark and block

3. The fuse the stretcher makes is lit and the crab turns into a snark and block

4. Another stretcher recipe of the same channel reflects off the snark, hits the block, and makes a crab stretcher

5. The stretcher is immediately followed by a memory loop recipe that was reflected off the same snark

Here's the updated diagram:

: Better version of the omniship design; Adjustable slope design.jpg (53 KiB) Viewed 8020 times

Edit:

Pavgran wrote: March 10th, 2022, 4:20 amWell, part of the solution is already present in your own post.

Whatever is easier for the design

.
Edit2:I'd love to see both designs used.

Posted: **March 10th, 2022, 8:05 pm**

AlbertArmStain wrote: March 10th, 2022, 7:38 pm Scrap that old design, Iv'e made a better and more efficient step-by-step design for the omniship...

This seems to have the same limitation as the previous design, that it can't travel more than c/2 orthogonally (EDIT: sorry, not more than c/4 orthogonally)... which makes it not an omniship. It could still be a Spaceship with an Adjustable Slope, though, if you want to reserve this thread for developing that design. An up-to-c/2o omniship might draw in a few more collaborators, is all.

Posted: **March 10th, 2022, 8:16 pm**

dvgrn wrote: March 10th, 2022, 8:05 pm
AlbertArmStain wrote: March 10th, 2022, 7:38 pm Scrap that old design, Iv'e made a better and more efficient step-by-step design for the omniship...
This seems to have the same limitation as the previous design, that it can't travel more than c/2 orthogonally... which makes it not an omniship. It could still be a Spaceship with an Adjustable Slope, though, if you want to reserve this thread for developing that design. An up-to-c/2o omniship might draw in a few more collaborators, is all.

How about we see what the c/2 orthogonal would look like?
You’re going to need c/2 orthogonal design for the omniship.

Posted: **March 10th, 2022, 10:57 pm**

AlbertArmStain wrote: March 10th, 2022, 8:16 pm How about we see what the c/2 orthogonal would look like?
You’re going to need c/2 orthogonal design for the omniship.

That does seem like a reasonable step along the way.

As Pavgran says, the absolute minimum would be to find a slow-salvo *WSS recipe that produces a 135-degree MWSS-to-G, oriented to accept MWSSes from the same direction that the slow *WSS salvo is coming from -- plus an elbow block positioned in standard pi-exploding block (SPEBOE) position to catch the output of the MWSS-to-G, at a safe distance.

Just Need A Minimal Universal Block-Move and Block-Splitting Library
This is actually something that it doesn't take an expert or a programmer to work on, necessarily. Something that would work would be to find a series of slow collisions of *WSSes with a block, that produce two well-separated blocks, preferably edgy ones (showing up near the edge of the reaction envelope). That plus a few block-moving recipes, forward, backward and sideways, could be patched together into any constellation of well-separated blocks that we might want -- and we could definitely build a Blockic 1G seed for a 135-degree MWSS-to-G if we wanted to!

Or anyway at least one block should be edgy, in at least one block-splitting or block-moving recipe. Details are negotiable.

With that part figured out, and some more experimentation to clean up the blinker puffer's debris with some set of (preferably but not necessarily slow) *WSSes without any of those *WSSes being on lanes that conflict with the blinker puffer ... then the rest of the recipe can be built with a standard slsparse compilation.

The Perfect Is The Enemy Of The Goodenough
I'm not saying that the above is the right way to do it -- the right way is probably to build a multi-gigabyte database of all possible patterns reachable with N slow *WSSes, and stop when we find the 14-bit piece of the MWSS-to-G (or thereabouts).

Patching the MWSS-to-G together by hand would be terribly old-fashioned, but might be more fun (and therefore might actually get done, whereas that multi-gigabyte database shows no sign of ever being anything but vaporware at this rate.)

Posted: **March 11th, 2022, 11:42 am**

dvgrn wrote: March 10th, 2022, 10:57 pmJust Need A Minimal Universal Block-Move and Block-Splitting Library
This is actually something that it doesn't take an expert or a programmer to work on, necessarily. Something that would work would be to find a series of slow collisions of *WSSes with a block, that produce two well-separated blocks, preferably edgy ones (showing up near the edge of the reaction envelope). That plus a few block-moving recipes, forward, backward and sideways, could be patched together into any constellation of well-separated blocks that we might want -- and we could definitely build a Blockic 1G seed for a 135-degree MWSS-to-G if we wanted to!

I made an ugly and slow brute force script to look for *WSS block-interacting recipes and I was able to find quite a lot of block-movers and splitters. I think this collection allows for universal blockic construction (excluding bi-blocks), though many of the recipes aren't very edgy:

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