Stable reflector: Difference between revisions
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There are several distinct categories of stable reflector: | There are several distinct categories of stable reflector: | ||
* ' | * 'Create-then-remove' reflector - A reflector that temporarily creates an unwanted still-life and later destroys it. | ||
* ' | * 'Destroy-then-rebuild' reflector - A reflector that temporarily destroys a necessary still-life and later reconstructs it. | ||
* Direct reflector - A reflector that does not contain a Herschel track. | * Direct reflector - A reflector that does not contain a Herschel track. | ||
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==Staged-recovery systems== | ==Staged-recovery systems== | ||
The staged-recovery system was invented by Dave Greene, when he incorporated it into his [[highway robber]] and stable [[Heisenburp]] patterns. In 2009, Adam P. Goucher built two ' | The staged-recovery system was invented by Dave Greene, when he incorporated it into his [[highway robber]] and stable [[Heisenburp]] patterns. In 2009, Adam P. Goucher built two 'Create-then-remove' reflectors using a staged-recovery system. | ||
==External links== | |||
* A detailed summary of stable technology, 1996-2009. [http://www.calcyman.co.uk/life/stable.htm] | |||
* A complete list of notable stable reflectors. [http://www.calcyman.co.uk/life/reflectors.htm] | |||
Revision as of 15:39, 1 June 2009
A stable reflector is a reflector composed entirely of still lifes. The first stable reflectors were found by Paul Callahan in 1996.
Types of stable reflectors
There are several distinct categories of stable reflector:
- 'Create-then-remove' reflector - A reflector that temporarily creates an unwanted still-life and later destroys it.
- 'Destroy-then-rebuild' reflector - A reflector that temporarily destroys a necessary still-life and later reconstructs it.
- Direct reflector - A reflector that does not contain a Herschel track.
Records
Ideally, stable reflectors should be as small and fast as possible. :
- Smallest 90° reflector: [1]
- Fastest 90° reflector: [2]
- Smallest 180° reflector: rectifier
- Fastest 180° reflector: rectifier
The third record is debatable, since the boojum reflector has a smaller bounding box across all phases; the rectifier has the smallest quiescent configuration. The terms 'active' and 'passive' bounding box should be used to avoid confusion.
Prizes
Dave Greene has offered two $50 prizes for stable reflectors:
- Find a stable glider reflector that fits inside a 50×50 bounding box.
- Find a stable glider reflector that fits inside a 35×35 bounding box.
Staged-recovery systems
The staged-recovery system was invented by Dave Greene, when he incorporated it into his highway robber and stable Heisenburp patterns. In 2009, Adam P. Goucher built two 'Create-then-remove' reflectors using a staged-recovery system.