While at a conference in California back in May this year Elon Musk suggested, picking up on a theory originally put forward by philosopher Nick Bostrom called 'Are You in a Computer Simulation?', that puts forward a theory that we may all actually be living in a computer simulation or highly advanced video game.
It might sound totally insane, but as this video by Vox points out, we used to think that the earth was the centre of the universe, it was known as the geocentric model. We also used to think the earth was flat too, and look how that played out. Reality isn't always what we think it is.
What Musk is saying, or what Bostrom is saying, is that 40 years ago we had Pong, now we have photorealistic 3D simulations with many people playing at the same time. That's a relatively big advancement in a short period of time (although, personally i still quite like playing a game of Pong).
Now lets say we went 10,000 years into the future, if we're still here and we haven't been wiped out by global warming, advanced AI or some other catastrophe, then there will come a time when we're able to simulate ourselves. A simulation so complex that it's able to replicate virtually every synapse in the human brain for everyone on earth.
To get the computing power to run such a powerful simulation Bostrom proposes that we'll send self-replicating robots to other planets and they'll turn the whole planet into a computer. Some of the simulations will also be so advanced that they themselves will begin to run simulations.
Which means that they'll be billions of simulations running that are replicating the entirety of human history and experience—we, therefore, could be in one of those simulations, we just don't know it.
Musk implies that this is something we should hope is true because the alternative means that humanity has ceased to exist. So, we either create advance simulations that are indistinguishable from reality, which we're living in now, or we die out as a race.
If you don't like the sound of those two options though, in the video Vox proposes a third option. Which is maybe our descendants wouldn't want to run ancestor simulations, because there is just too much suffering in the past or they don't want to live like us, because it's just not desired. Or they deem it to boring to consider.
It's brain-frying stuff to think about, but certainly good conversation fodder. It's not for every occasion though—maybe like Musk and his brother, refrain from discussing it in a hot tub.
You can check out Musk's full answer to the simulation question below.