Yesterday I asked a big question – where is everybody?
It was based around the seminal Drake Equation, named for the man who put it together, that quantified a way of addressing the number of extra-terrestrial intelligences there are in our galaxy (and, by extension, our universe).
There could simply be nobody out there but us, but then again, with somewhere around 200 to 400 billion star systems in our galaxy alone, if physics everywhere is the same as here and if therefore chemistry everywhere is the same as here, then the chances of there being not only life but intelligent life are beyond a mere certainty.
So where is everyone?
Well, one reason that there may not be life as we know it anywhere within reach is because we may not be real.
…I’ll qualify that some. Our universe, argue some very intelligent folks, could be, and shows signs of being, a vast simulation. It’s called the Bostrom Simulation Hypothesis.
To be fair, the idea itself is very old. Descartes famously said I think, therefore I am. This harkens to the fact that, outside of our own senses, we have no absolute knowledge of the universe. Therefore, each of us start with certain axioms about the world we apparently inhabit. The first is “I exist”, the second is “my senses are, largely, true” and the third is “using my senses, I can discover a coherent, constant sense of what is around me”.
Basically put, if you turn out the lights and fumble around in a pitch-black room, you will trip over objects that are in that room if you’re not careful. From this simple proof of concept, you can be reasonably assured that things exist in a continuous fashion, and do not rely on your observing them to exist apart from yourself.
This is what science and the scientific method is built upon – not faith, but a basic logical axiom that states that what is true yesterday is true today and will be true tomorrow, and that therefore one can make predictive statements based on repeated observations and experiments.
As a side note, anybody who tells you that “believing in science requires faith” has a screw loose in their logical reasoning circuit – if they’re not even sure they exist, and that the universe can be made sense of, then there’s little point reasoning with them.
But essentially, Nick Bostrom argues that we could be living in a simulated universe. Some very clever folks have spent a lot of time working out how we can tell, and certain facts about how things really, truly work point towards this hypothesis being true.
In simplified terms, though, our universe could be a skybox that ends somewhere beyond the Oort cloud, or it could simply be that the rest of the universe lacks resolution as observing inhabitants decrease, or it could be exactly as large as it needs to be, and only exists when it is observed.
Why could this be true? Well, just look at how popular games like the sims are. Thanks to the growing pace of change, it has become possible to simulate more and more of a fantasy world in more and more detail. One day, it may be possible for us to create entire worlds and populate them with people indistinguishable from our own.
In fact, the logical consequence of there being no theoretical reason why we cannot do this means that we almost certainly will… and therefore almost certainly already have. To paraphrase Bostrom (and his trilemma is in wikipedia):
* either becoming a civilization capable of massive simulation is highly unlikely, or it probably already has happened.
* if possible, either ancestor simulations (or, indeed, natural simulations) are not interesting to observers, or they are already being run (and our own civilization is doing that now, so… they seem to be popular enough)
* given both of the above, it becomes increasingly likely (given that there is only one “real” universe, but billions of possible “simulated” universes) that our entire universe is in some form of computer.
In other words, chance being what it is, it’s far more likely you have been born into a simulated universe than in the real one, seeing as the chance of being born into the “real” universe is billions to one against.
But don’t fret, because that thing about not being real? It’s not worth worrying about – you’re as real as you think you are. Our universe appears to be one which just happens, and whoever or whatever is running it doesn’t appear to be considering shutting it off any time soon.
And trust me, if they do, you’ll never know.