In 1985 British engineer Paul Birch (1956-2012) published an article in which he defends the eternal growth of human population. Birch criticizes people like the club of Rome who believe there fundamental limits to growth, both of population and economy. The main point of critique in his article is that neo-Malthusians only take terrestrial resources into consideration and ignore the potential of space colonization.
Of course, Birch acknowledges that the resources in our Solar System are also limited, but he points that the universe is much larger than just our Solar System. But then the next question is whether the universe does contains unlimited resources? Though the universe does definitely vast amounts of matter, it is not unlimited.
Maybe somewhat surprisingly Birch does not seek to challenge that assumption. Instead he argues that we could make other universes and move to those new universes. Since we could this over and over again, Birch believes that we could pursue unlimited growth.
Since the unlimited creation of new universes is the crucial point in his argument, it is also the weakest link. First we need to establish that we can indeed create new universes and second we should determine whether we could get into those new universes. It is far from obvious that this will be actually possible, and Birch does not provide any evidence himself.
Alan Guth, one of the principal authors of cosmic inflation, argues that you could create a complete universe in your basement, but he also states that this new universe is almost immediately detached from ours. Hence we could not move into the universes we create. For those among us with some interest in theology, this would imply that the creator of the universe is unable to intervene with its creation.
If Guth is right, then Birch’s argument for eternal growth fails. The creation of inaccessible universes is pointless, at least from the perspective of space colonization.
But let’s for minute suppose that Birch is actually right and we can create accessible universes at will. That will have several implications. Imagine that we succeed in creating such universes during the next few centuries, before we start with interstellar space colonization, than we could wonder why we should bother with colonizing the galaxy?
If Paul Birch is right and every sufficiently developed civilization can create accessible universes at will, then such civilizations will probably not waste their time with colonizing the galaxy and our universe. Instead they will move to their new universes. This might be a solution for the Fermi paradox – the question if intelligent life is common, why we haven’t discovered them yet.
Nevertheless Birch’s argument for indefinite growth is pure speculation, though his proposal is an intriguing one.
Can population grow for ever? Paul Birch article.
Cosmic inflation on Wikipedia