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First Self-Replicating Creature Spawned In Conway's Game of Life
Calopteryx writes "New Scientist has a story on a self-replicating entity which inhabits the mathematical universe known as the Game of Life. 'Dubbed Gemini, [Andrew Wade's] creature is made of two sets of identical structures, which sit at either end of the instruction tape. Each is a fraction of the size of the tape's length but, made up of two constructor arms and one "destructor," play a key role. Gemini's initial state contains three of these structures, plus a fourth that is incomplete. As the simulation progresses the incomplete structure begins to grow, while the structure at the start of the tape is demolished. The original Gemini continues to disassemble as the new one emerges, until after nearly 34 million generations, new life is born.'"
From the article:
In fact, this is arguably the single most impressive and important pattern ever devised.
Really? Not the universal Turing machine pattern, or the pattern that emulates the game of life itself? Those both seem more impressive to me.
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some alien 43 dimensional child's entry in the local science fair
"look: i've created self-replicating life based on a few simple rules!"
and the judge says: "but it's only 4 dimensions, and one of the dimensions is only one way. shoddy, very simplistic, not a good middle school level effort"
to which the alien's mom says: "don't worry honey, next year we'll put baking soda and vinegar in a paper mache cone and simulate a volcano!"
and the alien child says: "that's ok mom, i don't like science anymore, i want to be a ranch hand. bye bye, little universe critters, i always thought you were cute"
and then he pulls the plug on his simulation, and trillions of animal, plant, and human lives on earth and septillions of lives on the other inhabited planets cease to exist in a puff
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
My favorite CA is WireWorld. The designs in the CA look and behave like circuit boards. People have designed some very complex "computers" in it.
WireWorld on Wikipedia
This flash-based wireworld app is listing prime numbers.
"His name was James Damore."
If every time one human was born, an identical human died, it would be like that.
If I understand correctly, it creates two copies while self-destructing in the process. So it is, indeed, replicating.
That's a superb joke, but if you're bored and want to read some extensions of the idea you should find a copy of Venus Equilateral by George Smith some time. In one of the stories, engineers make (by mistake, basically) a device that can replicate other devices, and then realize it can replicate itself, so they build a few mostly for fun. Since they're on an isolated space station they transmit information about what they've done back to earth and then find out that earth's economy is collapsing because everyone's either duplicating money or duplicating duplication machines and there's no reason to buy anything. Smith explores how that affects the economy for a while (one character's snooty wife has to stop being a socialite and get a job as a nurse, because Smith was basically a 1930's misogynist) and then has his engineers cook up a physical item that contains energy, which the matter duplicator can't duplicate (since it only deals with matter) to act as a new basis for currency. He wrote all this in the 1940's, so, y'know, prior art and all that.
Nostalgia's not what it used to be.
Detrimental traits such as lactose-intolerance can be preserved if there is no or weak evolutionary pressure for this trait. But over time and changing enviroments it's the beneficial traits that are more likely to preserve the genotype.
A better wording is perhaps that the enviromental viability of a geno and phenotype is what is the driving force behind evolution.
If I understand correctly, it creates two copies while self-destructing in the process. So it is, indeed, replicating.
Now that's interesting.
When i first read the headline I was befuddled. The whole point of the game is that its structures replicate themselves and create other things all over the map.
But I don't recall ever seeing one that made multiple copies of itself, and then died.
This is a tricky point. The people who say that this new pattern is not ultimately different from a glider are correct, in a sense -- the Gemini spaceship is technically a spaceship, not a replicator.
It _does_ make two copies -- but the copies are of the two replicator units at the ends of the glider channels, not of the entire spaceship.
But replicator units replicating themselves, even with the help of an outside stream of instructions (which is then reflected on to the next newly-created copy of a replicator unit) are still something that hasn't been seen before in the Life universe. So this is a much more impressive technical accomplishment than, say, finding a new variety of spaceship using a search utility.
Gliders and spaceships "replicate" themselves in somewhat the same way that salt crystals or wildfires do -- that's just the way the universe works, you might say. But the Gemini pattern keeps itself going by continuously reconstructing itself, in *spite* of the way the universe normally works.
The replicator units are like robots that include all the tools needed to make more robots exactly like themselves -- but they're radio-controlled and have no internal memory, so you have to pipe the actual construction recipe in from somewhere else. That means they're not self-contained self-replicators, true -- but they're a darn sight closer than a salt crystal or a glider!
Eventually someone will build a pattern with an internal memory that can hold a complete self-construction recipe -- but the Gemini is an important milestone along the way to that goal, and the first true Life replicator will probably contain ideas taken from the Gemini, just as the Gemini contains ideas and mechanisms from preceding patterns.