Tag Archives: busy beaver

The numberphile microbe and the busy beaver

This is another weirdly named, but contentful post after this one, During an attempt to launch myself into video explanations, I made a post on the numberphile microbe.

The numberphile microbe is the chemlambda version of a multiplication of two Church numbers, in this case 5X5=25. I called the creature evolving in the video a “numberphile microbe” because it really consumes copies of the number 5, metabolizes them and produces eventually 25. In a very careful way, though, which inspired me the following description (but you have to see the video from that post):

“The numberphile microbe loves Church numbers. His strategy is this: never one without the other. When he finds one Church number he looks around for the second one. Then he chains the first to the second and only after that he starts to slowly munch the head of the first. Meanwhile the second Church number watches the hapless first Church number entering, atom by atom, in the numberphile mouth.

Only the last Church number survives, in the form of the numberphile’s tail.”

The  mol file used is times_only.mol.  Yes, allright, is the mol version of the AST of a lambda term.

You can see the numberphile also in this animation, together with a busy beaver Turing machine (the chemlambda version explained here):



In the first half of the animation you see the “numberphile” at the left and the busy beaver as a reddish loop at the right.

What happens is that the lambda term like 5X5 reduces to 25 while in the same time the busy beaver machine works too. In the same time, the Church number 25 in the making already makes the small loop to replicate and to grow bigger and bigger, eventually 25 times bigger.

So that explains the title.

The mol file used is times_only_bb.mol. Open it and see how is it different than the first.

You can see a simulation (js) of Church number applied to a busy beaver here.

And the most important is: during the making of this short movie, no human director was present to stage the act.

Busy beaver’s random church

The demo linked here would surely look impossible.

One computer, WHILE IT WORKS, is multiplied into 3 computers which  continue to work, each of them. This feat is done without any higher control and there are never conflicts which appear. All computers work asynchronously (mimicked here by randomness). Moreover, eventually they arrive to read and write on the same tape.

There are no calls, nothing you have seen before.Everything is local, no matter how you slice it into separated parts.