Errors of glider synthesis

[BobShemyakin]

Errors of glider synthesis

Attention: in this post all examples of glider synthesis are resulted with errors. The purpose of this post is their exposure.
Examples of errors of glider synthesis:

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x = 249, y = 80, rule = B3/S23
182bo$181bo$181b3o2$68bo101bo72bo$66bobo102bo69b2o$25bo41b2o100b3o70b
2o$21bo2b2o209b2o$19bobo2bobo46bo160bobobo$2o18b2o28b2o20b2o30bo21bo
33b2o8bobo43b2o18bobobo5b2o$obo47bo21bobo27b3o17bo3bobo32bo9b2o37b2o4b
o21b2o6bo$bobo48bo48bo19bo4b2o32bo10bo38bo2b2obo26b2obo$2bobo18b2o26b
2o47bo2b2o16b3o36b2o50b2obo27bobo$3bo19bo48b2o26b2obo58bo76bo$4b3o17b
3o44b2o30bo58bo77b2o$6bo19bo46bo29bobo13b3o2b2o34b2o77b2o$6bob2o16bob
2o74b2o15bo2bobo33bo10bo$7bo2bo16bo2bo89bo3bo36bo9b2o$8b2o18b2o130b2o
8bobo65b2o$237bobo$239bo$169b3o$171bo$170bo2$181b3o$181bo$182bo19$10bo
$8bobo$9b2o173bo$183bo64bo$164bo2bo2bo2bo9b3o60b2o$247b2o$66bo101bo$
64bobo97bo4bo3bo69bo$65b2o53bo2bo2bo2bo2bo34b3o73bobo$227bo2bo2bo2bo2b
o3b2o$164bo8bo$120bo7bo3bo35bobo$70bo2bo2bo2bo44bo3bobo38b2o56bo6bo4bo
$2o48b2o52bo18bo4b2o30b2o2bo4bo3bo42b2o17b2o9b2o$obo47bo24bo26b3o15bo
2b3o6bo28bo48b2o4bo17b2o10bo$bobo48bo17bo3b2o3bo21bo58bo49bo2b2obo10bo
11bo3b2obo$2bobo18b2o26b2o21bobo23bo2b2o55b2o4bo5bo39b2obo14b2o11bobo$
3bo19bo8bo2bo2bo2bo58b2obo16bo2bo2bo2bo2bo29bo66bobo$4b3o17b3o43bo8bo
23bo58bo64bo3bo7bo$6bo19bo47b2o27bobo54b2o5bo2bo$6bob2o16bob2o2bo8bo
31b2o29b2o54bo$7bo2bo16bo2bo5bo33bo4bo3bo37b3o6b2o33bo65bo2bo2bo2bo2bo
$8b2o18b2o5b2o82bo6bobo31b2o2bo4bo3bo$32bo2bobo3bo76bo7bo42b2o$70bo2bo
2bo2bo88bobo$164bo8bo$32bo2bo2bo2bo$167b3o63b2o$164bo4bo3bo58bobo$168b
o65bo2$164bo2bo2bo2bo9b3o$183bo$184bo!

The top row contains the found errors of glider synthesis. In the bottom row they are exposed: pay attention to behaviour of the allocated gliders.

In the first example the configuration cannot be received due to the bottom glider. The bottom glider interacts with object earlier, than will reach collision with other glider. It is visible in the bottom part where gliders should be in position for 44 generations up to the top part.
It is the general method of revealing of errors of glider synthesis. Gliders should not interact with what before useful collision.

In examples 2-4 there is an interaction of parallel flying gliders. In these examples, the bottom of the upper configuration played for 8 moves backward.

Still objects do not interact among themselves if the distance between their any part is not less 2. For gliders it not absolutely so. In flight this distance can change up to 1 and destroy their joint flight.

On the following diagram collapsing configurations of gliders with distance between them 2 and more are resulted:

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x = 143, y = 61, rule = B3/S23
140bo$31bo34bo34bo3bo30bo3bobo$30bo34bo4bo29bo4bobo27bo4b2o$30b3o2bo
29b3o2bobo27b3o2b2o28b3o$35bobo32b2o$35b2o20$140bobo$32bo34bo34bo2bobo
29bo2b2o$30b2o33b2o3bobo27b2o3b2o28b2o4bo$31b2o2bobo28b2o2b2o29b2o3bo
29b2o$35b2o34bo$36bo24$140bo$105bo34bobo$2bo29bo34bo2bo31bo2bobo29bo2b
2o$2o28b2o3bo29b2o3bobo27b2o3b2o28b2o$b2o2bo25b2o2bobo28b2o2b2o29b2o
33b2o$5bobo27b2o$5b2o!

However there are also good news. Below not collapsing configurations of gliders about distance between them less than 2 are resulted:

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x = 112, y = 6, rule = B3/S23
111bo$76bo32b2o$o34bo5bo28bo3b2o29bo4b2o$obo3bo28bobob2o29bobo2b2o28bo
bo$2o2b2o29b2o3b2o28b2o33b2o$5b2o!

Last example with crossed gliders. It is taken from the synthesis 12.82 noted M.Niemiec 10G. It is because of this, I open this topic.The distance between them in flight all time changes. To define an opportunity of their collision it is possible on aim distance, that is distance in a direction perpendicular for rapproachement.
Bad news: this aim distance also can change up to 1 and gliders will interact earlier, than it is necessary:

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x = 133, y = 58, rule = B3/S23
bo25bo23b2o24b2o22bo25bo$b2o24b2o21bobo23bobo22b2o24b2o$obo23bobo23bo
25bo21bobo23bobo3$3b3o22b3o22b3o22b3o23b2o23b2o$3bo24bo24bo24bo24b2o
23b2o$4bo24bo24bo24bo25bo24bo18$3bo25bo23b2o24b2o22bo25bo$3b2o24b2o21b
obo23bobo22b2o24b2o$2bobo23bobo23bo25bo21bobo23bobo3$3b3o22b3o22b3o22b
3o23b2o23b2o$3bo24bo24bo24bo24b2o23b2o$4bo24bo24bo24bo25bo24bo18$5bo
25bo23b2o24b2o22bo25bo$5b2o24b2o21bobo23bobo22b2o24b2o$4bobo23bobo23bo
25bo21bobo23bobo3$3b3o22b3o22b3o22b3o23b2o23b2o$3bo24bo24bo24bo24b2o
23b2o$4bo24bo24bo24bo25bo24bo!

Each pair gliders has this aim distance equal 2. The top row of the diagram is quite correct and can be received from a similar line on 4 generations earlier. The second (third) row should turn out from first (second) for 4 courses. The second, the third and the subsequent (if to continue) are already incorrect as 2-nd row does not turn out any more from the first.
But there is also a good news. Following pairs gliders with aim distance equal 1 do not interact:

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x = 33, y = 7, rule = B3/S23
3o22b3o$2bo24bo$bo24bo2$5bo25bo$4b2o24b2o$4bobo23bobo!

Bob Shemyakin

[Freywa]

Shemyakin: OK, if this affects Niemiec's syntheses, what are we to do now? Should we place a separate compendium of syntheses somewhere else?

[BobShemyakin]

Check the production of synthesis. To do this, pull apart the gliders in the direction opposite to the movement.
Well, everyone makes mistakes.

Bob Shemyakin

[mniemiec]

Usually, when I create a conversion tool, I pull the gliders back a fair distance (e.g. 10 spaces), then run them forward until 1 generation before they interact, which usually avoids this kind of mistake. In my automatic synthesis tool, each recipe has the gliders moved back 25 spaces (i.e. 100 generations) before the point of impact, for the same reason.

If any of the collisions in my synthesis collection suffer from this problem, please let me know, so I can correct them. (I haven't cross-referenced the ones above against my list yet). I am very close to having a massive update to my old site ready, which should also correct several errors discovered along the way.

Dave Buckingham used to call collisions of two gliders on parallel streams (or some too close to cross) "impossible collisions", and found a few that were actually useful. In such cases, he would synthesize the collision by synthesizing the frontmost of the offending gliders directly in front of the rearmost one.