In an infinite universe where random configurations of particles spontaneously pop in and out of existence, somewhere — albeit somewhere far away — a brain has improbably materialized, floating through outer space for a few milliseconds before dying, the most perfect symbol for existential despair since Kafka wrote about a big cockroach or this cat video was posted.
Other things have appeared too: a horse, a Skeksis, a catdog, anything and everything; it’s simply a matter of a few googol light-years before objects like the infinity gauntlet show up. In fact, since a perfectly tweaked clockwork universe like ours is so enormously unlikely, it’s much more probable you’re just a space brain, or what physicists call a Boltzmann brain. Your memories are a random configuration of images and events that just happen to make sense. You are a meaningless aberration, a fluctuation in the endless entropy.
So how can you tell if you’re a Boltzmann brain? First of all, examine your world and ask yourself if there are any illogical features like, say, pet psychics, dark matter, or manatees. Does your universe contain uniform microwave background radiation temperature uncharacteristic of an expanding universe? Have you ever greeted someone you thought was a friend, but then you realized it was a stranger, and you were like, “Oh, uh, I don’t, uh, I thought you were someone else…”? Do fuzzy pens exist? Are there clowns? Do more people watch Two and a Half Men than Community? These are the cracks in the simulation, the glitches in the system indicative of a fake imaginary world.
Second of all, most of your past, being implanted, would seem hazy and vague. For example, you wouldn’t remember being a baby or what you ate for dinner on this day twelve years ago or every word of every book you ever read. It sounds crazy, but Boltzmann brains wouldn’t even remember how many cats they’d seen in their lives. If you can’t summon up a cumulative number of cats observed during your life (for me, it’s 2,452), you’re definitely a Boltzmann brain. Your memories are a random construct, a blur of empirical details and visceral sensory information fed into your brain as it floats through the void past asteroids and nebulas.
A Boltzmann brain would secretly suspect he/she was the only one who mattered, the only one who was “real.” Do you feel on a primal level your life is more important than other lives, that your existence is the gigantic glowing sun around which the all of humanity revolves? Perhaps you have the odd feeling everyone you meet is a realistic robot programmed to interact with you in a convincingly reasonable way like The Truman Show but with robots. If you answered yes, it’s not because you’re a psychopath (well, you might be a psychopath); it’s because, as a lonely space brain floating through the void, you have no real friends, family, or acquaintances — only imaginary people embedded in your dumb brain by the ceaseless machinations of an apathetic universe.
You might be thinking, ‘I know I’m not a Boltzmann brain because they die after, like, a few seconds, and I’m conscious of way more time than that. That is, I experience the passage of time.’ Oh, do you, though? Do you, Mister/Miss Space-Brain? By the time you’re conscious of any given moment, it’s already slipped off into memory, and besides, it could be your perception of time is elongated by your crazy space brain. This exact moment could be your first and last moment of genuine self-awareness. Right now, your space brain could be on the verge of becoming freeze-dried space-brain-meat for hungry space-cats om nom nom.
With this helpful information in mind (space-mind), hopefully you know now whether your world is real or you’re a sad lump of tissue surrounded by infinite nothingness. But if, God forbid, it’s the latter, what can you do with this newfound cognizance, particularly in light of the fact you only have a matter of seconds left before becoming a hunk of jerky for Uatu the Watcher to observe with bemusement and maybe a touch of melancholy. How shall you spend these last few instants since nothing you do matters, and the people you love aren’t real? Hmm?
Why not invest your last moment in a profound thought, something deep and meaningful and life affirming. Like kittens. Like a cute kitten that’s trying to jump on top of a watermelon but keeps sliding off because its claws can’t get traction. Oh, that’s a good thought. Maybe the watermelon almost rolls over the kitten, but it jumps out of the way and meows at the watermelon. That’d be so cute. That makes it all worthwhile, doesn’t it?