The “is the Universe a simulation” question seems to be returning every so often to the headlines, as one or other academic or celebrity (or both) makes a stab at conjecturing either way. The most recent case of this, a claim made by Elon Musk, shows – if anything – that people don’t get tired of rerunning the same arguments. However, I think that what position one should take is less interesting a question than why should anyone bother to take any.
The starting point – as mentioned – is the extraordinary claim by the tech magnate Musk that there is a “one in billions” chance that we are not living in a simulated world. The gist of his claim is that the progress of technology is so rapid that it is almost certain that we will have access to perfect virtual reality environments. Given that these virtual reality games would be playable on the same type of set-top boxes that we use today (just with more processing power), and there would be billions of them, Musk’s claim is that there is a very slim (specifically, one to billions) chance that what we’re experiencing right now is “base reality” (his term for real world). But this argument is spurious because there is no actual data underlying this estimate. Musk could just as well have chosen “millions”, “trillions” or “hundreds”, and it wouldn’t have mattered, since the devices he proposes are – for now – mere fiction. We don’t know for sure if we will ever have fully immersive virtual reality.
But even assuming that such VR devices would be common household items in the future doesn’t automatically mean that everyone (or anyone) will be using them for their entire life. Why wouldn’t those be like games that people play nowadays, or like Star Trek’s holodeck – something that you use for entertainment for a while, and then turn off? The argument here:
- Technology is advancing very fast.
- We will likely have the capacity to perfectly simulate reality for everyone.
- Therefore, everyone will be (and likely is now) in such a simulated reality.
is a classical example of a non sequitur – which simply means “doesn’t follow” in Latin. There is nothing connecting the premises 1 and 2 with the conclusion, although people wishing to live inside a virtual reality might take the leap and assume there is no gap.
There are lengthier responses to Musk available online. All that I’ve seen were dodgy to a greater or lesser degree, but I won’t be reviewing them here. The question I’m interested in is “what does it matter?” Think of it as follows:
- Assume that we are living in a virtual reality. The basic physical constants are what we know them to be. The interactions of matter that follow from them are – just like the constants – simulated.
- Assume that we are in the real world – in other words, there is no “deeper” level to go in terms of probing reality. The basic physical constants are what we know them to be. The interactions of matter that follow from them are – just like the constants – ultimately real.
The problem should become obvious now – while there might be a difference between a perfectly simulated world and the real, underlying one, we would never be able to see it. Both versions would be perceived to be apparently correct. Our very act of perception is nothing more than interaction with the world, but then perceiving this (or any) world as “real” or “virtual” is nothing more than making an assumption that some of our sensory data is not as it should be. However, people in both worlds could make such a claim. We thus cannot see this world as fake or genuine, because no matter which one it is, all that we’re seeing is dictated by the world. It is like claiming that the whole world you live in – your house, the town, the places you’ve been on vacation – is really just a big, fancy room. When you then claim that there is something “beyond the room”, and you go and stand where you say “outside” is, how do you know that that isn’t a part of the room too? Here the only difference is that the room is always with you, because it is your senses. Therefore, even if someone were to show you the “real world” – assuming you were in a simulation – you would have no reason to believe them.
Thus, wondering about whether this Universe is real or simulated seems pointless to me. We have no way of telling, because everything we could do to tell the two apart – all measurements and experiments – would take place in the one we’re in right now. The whole notion that we could “look outside” of a simulated world to see the difference is based on the assumption that we would be able to tell when we’re really looking outside and when we’re being duped by the simulation. But by the nature of the simulation we wouldn’t be able to tell which is the case, since the simulation is all that we got to experience.
A more interesting question could probably be: why would people want to think of the Universe as a simulation? At least, why would Musk want to believe so?
Arguably we should hope that that’s true, because if civilization stops advancing, that may be due to some calamitous event that erases civilization.
It’s interesting that there’s little commentary that I’ve seen on this comment. In a world riddled by economic and environmental crises, one could easily think of calamitous events that erase civilization. Some of them could even have something to do with producing more and more consumer electronics to feed our escapism. Perhaps it’s more comforting to think that the world is just a simulation, and that we will soon be making more like it, so whatever we do is not that big of an issue. But – for the reasons I mentioned – trashing this world will feel real to us, no matter whether we’re in a simulation, so it seems important to take care of it, regardless of the odds.