Difference between revisions of "Boat-bit"

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(New page: {{Glossary}} A '''boat-bit''' is a binary digit represented by the presence or absence of a boat next to a snake (or other suitable object, such as an aircraft carrier). The bi...)
 
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{{Glossary}}
 
{{Glossary}}
A '''boat-bit''' is a binary digit represented by the presence or absence of a [[boat]] next to a [[snake]] (or other suitable object, such as an [[aircraft carrier]]). The bit can be toggled by a [[glider]] travelling along a certain path. A correctly timed glider on a crossing path can detect whether the transition was from 1 to 0 (in which case the crossing glider is deleted) or from 0 to 1 (in which case it passes unharmed). Three gliders therefore suffice for a non-destructive read.
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A '''boat-bit''' is a binary digit represented by the presence or absence of a [[boat]] next to a [[snake]] (or other suitable object, such as an [[aircraft carrier]]). The bit can be toggled by a [[glider]] travelling along a certain path. Such an object is sometimes called a '''snake-bit''', although that name is less sensible because the snake can easily be replaced by other objects.<ref>{{cite web|url=http://www.argentum.freeserve.co.uk/lex_s.htm#snakebit |title=Snake-bit |work=The Life Lexicon |publisher=Stephen Silver |accessdate=June 3, 2009}}</ref> A correctly timed glider on a crossing path can detect whether the transition was from 1 to 0 (in which case the crossing glider is deleted) or from 0 to 1 (in which case it passes unharmed). Three gliders therefore suffice for a non-destructive read.
  
 
The mechanisms involved in reading and writing a boat-bit are shown in the diagram below. The bit as shown in is the 0 state, with no boat present. It is about to be set to 1 by the incoming green glider, and then switched back to 0 again by the red glider. The first crossing glider will survive, but the second will be destroyed.
 
The mechanisms involved in reading and writing a boat-bit are shown in the diagram below. The bit as shown in is the 0 state, with no boat present. It is about to be set to 1 by the incoming green glider, and then switched back to 0 again by the red glider. The first crossing glider will survive, but the second will be destroyed.
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[[David Bell]] found a method of reading the bit while setting it to 0 in January [[:Category:Patterns found in 1997|1997]]. It works by firing a [[middleweight spaceship]] at the boat-bit. If it is already 0 then the middleweight spaceship passes unharmed, but if it is 1 then the boat and the middleweight spaceship are destroyed and, with the help of an [[eater 1]], converted into a glider that travels back along exactly the same path that is used by the gliders that toggle the boat-bit.
 
[[David Bell]] found a method of reading the bit while setting it to 0 in January [[:Category:Patterns found in 1997|1997]]. It works by firing a [[middleweight spaceship]] at the boat-bit. If it is already 0 then the middleweight spaceship passes unharmed, but if it is 1 then the boat and the middleweight spaceship are destroyed and, with the help of an [[eater 1]], converted into a glider that travels back along exactly the same path that is used by the gliders that toggle the boat-bit.
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==References==
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<references />
  
 
==External links==
 
==External links==
 
{{LinkWeisstein|Boat-Bit.html}}
 
{{LinkWeisstein|Boat-Bit.html}}
 
{{LinkLexicon|lex_b.htm#boatbit}}
 
{{LinkLexicon|lex_b.htm#boatbit}}

Revision as of 18:21, 3 June 2009

A boat-bit is a binary digit represented by the presence or absence of a boat next to a snake (or other suitable object, such as an aircraft carrier). The bit can be toggled by a glider travelling along a certain path. Such an object is sometimes called a snake-bit, although that name is less sensible because the snake can easily be replaced by other objects.[1] A correctly timed glider on a crossing path can detect whether the transition was from 1 to 0 (in which case the crossing glider is deleted) or from 0 to 1 (in which case it passes unharmed). Three gliders therefore suffice for a non-destructive read.

The mechanisms involved in reading and writing a boat-bit are shown in the diagram below. The bit as shown in is the 0 state, with no boat present. It is about to be set to 1 by the incoming green glider, and then switched back to 0 again by the red glider. The first crossing glider will survive, but the second will be destroyed.

The glider-based read and write mechanisms of a boat-bit
Download RLE: click here

David Bell found a method of reading the bit while setting it to 0 in January 1997. It works by firing a middleweight spaceship at the boat-bit. If it is already 0 then the middleweight spaceship passes unharmed, but if it is 1 then the boat and the middleweight spaceship are destroyed and, with the help of an eater 1, converted into a glider that travels back along exactly the same path that is used by the gliders that toggle the boat-bit.

References

  1. "Snake-bit". The Life Lexicon. Stephen Silver. Retrieved on June 3, 2009.

External links