When we look at the natural world, it’s important to acknowledge the difference between something’s purpose and its function. Purpose is a matter of perspective; if you belong to a fairly traditional religion, you may believe that the primary purpose of the universe is to make human beings. But regardless of whether or not you believe the universe has a purpose, and regardless of what you feel the primary purpose of the universe is, there’s still the matter of establishing what it mostly does. That’s where function comes in.
And Waterloo astrophysicist Lee Smolin might have just figured out the primary function of the universe: to make black holes. He calls his theory cosmological natural selection, and it’s attracting quite a bit of attention. Here’s the basic premise:
- Our universe is one of an indeterminate number of inflationary bubble universes, each created by a new black hole.
- Each inflationary bubble universe has different laws of physics, reflecting the characteristics of the universe that produced it.
- The more a universe’s particular laws are amenable to creating black holes, the more universes it will create and the more universes those universes, in turn, will create. Therefore…
- Our universe, like the vast majority of universes, has “adapted” to create a maximum number of black holes.
It’s similar to the idea of evolution by natural selection: the creature (or universe) that stands the best chance of producing offspring will reproduce, and the new entities (or universes) that it creates will tend to inherit those characteristics. Of course, postulates #1 and #2 above are highly speculative—we haven’t proven that there are bubble universes, we haven’t proven that black holes create universes, we haven’t proven that each universe has different laws of physics, and so on. Smolin’s theory is, at present, little more than a brilliant daydream.
But even if our universe has adapted to create a maximum number of black holes, that isn’t necessarily bad news for us—and it may, in fact, have been an essential component in the formation, and preservation, of our own galaxy (which has a supermassive black hole in its nucleus). Here, Oxford astronomer Joseph Silk explains how a black hole might create a galaxy—and then, ultimately, protect that galaxy from itself: