Thursday, December 20, 2012

Not living in the matrix

Physicist Silas Beane explains:
The idea that we live in a simulation is just science fiction, isn't it?
There is a famous argument that we probably do live in a simulation. The idea is that in future, humans will be able to simulate entire universes quite easily. And given the vastness of time ahead, the number of these simulations is likely to be huge. So if you ask the question: 'do we live in the one true reality or in one of the many simulations?', the answer, statistically speaking, is that we're more likely to be living in a simulation. ...

But can we improve our own simulations?
The size of the universe we simulate is a just fermi, that's a box with sides 10-15 metres long. But we can use Moore's Law to imagine what we might be able to simulate in future. If the current trends in computing continue, we should be simulating a universe the size of a human within a century and within five centuries, we could manage a box 1026 metres big. That's the size of the observable universe.
This is a pretty crazy extrapolation of Moore's Law. The law might be good for another 10 years, but that's all. Yes, the idea that we are living in a simulation is pure science fiction.

I also don't know how to reconcile this with the recent SciAm claim that fermions cannot be simulated on a computer. How can we hope to simulate the universe if we cannot even simulate a single proton?

1 comment:

  1. Not necessarily. We could be living in a simulation in which various things e.g. protons are hard to simulate. Or we could be living in a simulation of a simulation ["ad uncountabulum"]. And of course, it's one thing to be living in a simulation, and quite another to be running it.