Are we real? How do we know if we really exist or whether we could be living in a computer simulation, somewhat like The Matrix? The simulation argument puts forward the view that we are almost definitely living in a computer simulation.
At the core of the simulation argument, there are three points:
The argument says that one of these three points will be true.
This is a difficult one as we still don't know whether we are alone in the universe and how life started. There's the whole panspermia theory which argues that life was brought to Earth by asteroids and that we're all descended from alien organisms. Or perhaps life started on Earth? The game of life shows us how complex patterns can come from simple rules.
We can also look at the Drake Equation which is a way of speculating how many civilizations there are in the universe. And the Hubble Deep Field shows us really how big our universe is.
But still to this date we haven't found any life out there. The Wow! Signal is the closest SETI has ever got.
Because of the sheer size of the universe, and the fact that we've managed to evolve to such a point without getting wiped out, we can take the first point - that all life will be wiped out before it is technologically mature - to be false.
If we now assume that there are technologically advanced civilizations with the technology to simulate life, we now have to ask whether they would. This could happen for ethical or scientific reasons.
Perhaps civilizations would not be interested in running a simulation of life. But would they really have become so advanced if they lacked the scientific curiosity?
Would technologically advanced civilizations have a moral objection to creating simulations of life?
At the moment - as a civilization - we haven't reached the point where we are sophisticated enough technologically to simulate a universe in a computer.
If we look back 25 years to the BBC Micro or even further to the days before personal computers, we see how far computers have come in a short space of time. In a few decades time, it is perfectly feasible that we'll be able to build a computer which could simulate a civilization. Some analysts believe we'll reach the technological singularity in 2045 when computers will surpass humans and become "conscious".
Looking at our own world, we already see scientists modelling life and the world on computers. We have gamers controlling their avatars on The Sims. The upcoming game Spore takes it one step further. And cloning and genetic modification are slowly becoming more accepted. We're already playing god. When computers be sufficiently powerful, we'll still be playing god.
There's no reason to assume that other technologically advanced civilizations will behave any differently. And even if such a thing was sanctioned, individuals or groups will still be able to find ways around such rules and control.
We can argue that if there are civilizations out there with the technological sophistication to simulate life in a computer then they will probably do so.
This means the second point - that all technologically mature civilizations will not be interested in running simulations - is incorrect.
The simulation argument says that if we take the previous two points to be false - the third is true. Therefore, if we believe that there are technologically advanced civilizations out there with the technology to run a simulation of life, and that those civilizations are interested in running a simulation, we will almost definitely be living in a simulation.
It's simply a matter of probability and statistics. One computer simulating a universe would have to contain billions of organisms and each technologically advanced civilization will probably have many "Matrices" running simulations. And each of these simulated worlds could have their own technologically advanced civilizations running simulations. And inside those simulations, there could be more simulations.
Statistically, the vast majority of organisms will be living in a computer simulation (by several powers).
Whether we live in a computer simulation or not doesn't really affect how we should live our lives. The world is still going to the same - the same things make us happy and the same problems will still have to be solved.
Even if we're not real, we perceive our world to be real. This is similar to the brain in a vat thought experiment. We can never be totally sure whether we are materialistically real. We could be inside a computer simulation but we are still real in the sense that we have thoughts and feelings.
"If real is what you can feel, smell, taste and see, then 'real' is simply signals interpreted by your brain."
- Morpheus in The Matrix
More controversially, we could also link it back to religion and creation. If we believe that we are almost definitely living in a computer simulation, we should ask "who built that simulation?" and "why was it built?". If we are indeed living in a computer simulation, then it reasons that the simulation was created by somebody - our "creator".
The argument doesn't tell us anything about why we are here. Could we be part of a huge social or scientific experiment? In The Matrix, the human population is used as a energy source.
And there will be people who will see the simulation argument as a way to prove the existence of God. Though it does suggest a omniscient and omnipotent creator it doesn't say anything about such a creator. Besides, would a creator create a whole universe of simulated organisms to worship him?
"I think, therefore I am"
- René Descartes
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