The Bunny theorem

Mathematics are terrifyiing becasue they are the language of absolute, inescapable truth. In mathematical language falsehoods can be stated, but when it expresses certainties, those certainties are beyond question. Mathematics tells us that, since the universe is finite, as we know it to be, the end will come, inexorably.

Suppose we have a fenced alfalfa plot. It can sustain a few bunnies feeding on the alfalfa. The bunnies reproduce, and as their numbers grow, the alfalfa starts having trouble growing back. The small alfalfa plants, mere sprouts, are devoured the moment they put out a leaf. Each plant loses the ability to feed bunnies, and slowly but surely, the sprouts themselves are eaten before they can grow leaves at all. The starving bunnies dig up the ground and eat the roots, the seeds, everything. If the plot were enclosed, if the entire existing universe were limited to it — a universe of alfalfa and bunnies — then once the last seed had been devoured, the bunnies would begin to die, all of them, inexorably.

Unless, of course, they could actually escape and find other plots. In that case the bunnies would become adventurers and explore outer space in search of alfalfa, in search of other food, and they would find it. If the alfalfa plots multiplied without limit, the bunny population would multiply exponentially to match. But the universe is finite. The amount of matter and energy in the universe is limited, and the number of bunnies tends to grow exponentially, so a day will come when they will all die, inexorably.

Unless, of course, the bunnies are intelligent. They realize the situation and limit their population to the number that, in a bad year, can survive without the alfalfa plants shrinking, without total production being irreversibly reduced. That means, for example, that the minimum surplus of seed is enough to replant the whole plot. Our intelligent bunnies would live happily, eat just enough, reproduce just enough, die at the same rate they were born. Hooray for the bunnies!

Unless, of course, the bunnies, like us, were immortal. If the bunnies were intelligent, but also immortal, they would have to limit population growth to a finite number of descendants. On average, over the infinite time immortals are condemned to live, only zero growth can be sustained. This means that the children they have today, they cannot have tomorrow. How quickly they choose to approach the point where none of them has any chance of procreating is their decision, but since they are immortal, they know for certain that, at the end of time, and for an infinite time still to come, they will in practice have to live deprived of offspring.

Just like the mortal bunnies, the immortal bunnies will try to push back the limits of their world. They will extend it to the oceans, to space, to other planets and other galaxies, and they will do it to feel alive, to feel free, to feel they are not prisoners of martial law meant to stop them from having children. They will fight for the right to exercise their freedom to give life. Being immortal will make them wise bunnies, which will help them push the limits of their world out to the limits of the universe within their reach. And then the situation will have come full circle. The foolish bunnies are stuck on a limited plot and have used up all the alfalfa, and nothing is left to them.

Perhaps the caring, considerate bunnies would hold one last supper, in which each would eat their last little leaf of alfalfa, or their last hidden seed in the ground. All together, and then certain death, for all of them. The death of the immortals.

And yet, given how bunnies cling to life, probably once the final exhaustion of the world's resources came into view — that is, once the bunnies realized they had not, after all, been intelligent bunnies — clever, but not wise — they would grow afraid of death, would steal alfalfa from other bunnies, would kill them so they couldn't eat it, would exterminate every bunny they could in order to survive themselves. Individually or in organized fashion, in wars or in fratricidal struggles, some would set about finishing off the others. Perhaps some would renounce violence. These would die at the hands of those who did not. In the end, only those who, by seizing the resources and the lives of the others, had truly been clever — truly been stupid — would survive. Perhaps some would manage to adapt to cannibalism before dying and, as long as there remained bunny remains, bunny corpses, they would keep themselves alive. Life, that abstract entity. Existence, our existence. But the last bunny left in the universe would have waited for the death of, or would have killed, its last friend, descendant, or forebear, and devoured it before dying. Perhaps, however, after a long series of atrocities, it would decide that the life of that other bunny was worth as much as its own, and it would die at its side like a good, repentant, community-minded bunny returning to the fold. It would understand, finally, that its life is worth no more than the lives of others. They would then eat together the last little paw of the last murdered bunny and die in peace without reflecting on their actions or, perhaps, even in regret, because nothing they did saved them from death.

Prologue to Foreverness