My previous blog post took a look at the far future - a timeline of events predicted to occur in our known universe assuming it exists infinitely (no Big Crunch).
Well, if it exists for an infinite amount of time, there will logically be an infinite number of physical occurrences/interactions. So theoretically, though seemingly improbable, there could potentially be the formation of what's known as a Boltzmann brain.
Entropy is increasing in our universe as it expands - chaos - and according to this particular hypothesis, it is possible that a self-aware entity could emerge from all of this disorder. Random quantum fluctuations can result one of these brains floating into existence, complete with thoughts, memory/data storage, etc.
As a matter of fact, there's a slight paradox going on here. It would seem as though the probability of us, self-aware entities existing within an organized environment, is far less likely than those of single, dispersed entities existing in thermodynamic "soup" - again, another term for chaos and entropy.
So our evolved brains are technically pretty unlikely compared to a Boltzmann one - feel special, you've earned it.
How did he even come to this conclusion? Well, our observable universe is fairly low in entropy - lower than it seems it should be. So it's possible that we inhabit some bubble of lower entropy. After all, entropy is constantly fluctuating, though it's generally on the "up" trend, as the universe slowly tends towards heat death. Yay!
Not to creep anyone out, but I'll end with a question. What if you were merely one of these Boltzmann brains, imagining yourself in a physical body that doesn't really exist? And what if everything we see in our observable universe is nothing but a hallucination?