•  If light leaves the Alpha Centauri system, wouldn’t it be 4.5 years old when it reaches Earth?

  • A clock traveling so fast that it arrives just 1 second after a ray of light from Alpha Centauri would have measured a little under 5 hours for the entire 4.5-light-year trip.
  • And a clock that arrives just a microsecond after the ray of light would have me assured less than a minute for the same trip.
  • Elon Musk’s argument: “the probability that this universe is base reality and not a computer simulation is one in a billion” is a sound and logical argument. (If you’re not aware of his full argument, google the video.)

However, the argument seems to lack an understanding of meta-probability. Understanding meta-probabilities allows us to better contextualize and interpret the argument.

  • If you are told a red team is playing a blue team at soccer this afternoon and you are asked to predict the result, what is the probability that the blue team will win? 50%
  • schoolchildren3. If you are now told that the “blue team” is the French national soccer team and the “red team” is local schoolchildren, what is the probability that the blue team will . Now that we have more information, it’s no longer 50%… it’s now more like 99.999%
  • What’s going on here? Whilst in examples 1. and 2. both probabilities are 50% at face-value, they are actually quite different. The problem stems from the fact that, when stating a probability, the uncertainty of the probability is rarely stated. The reality, when comparing the probabilities of a fair coin toss with a random soccer game (1. and 2.), looks like this:
  • As you can see above, whilst both probabilities are stated as 50%, the meta-probabilities are shown by the curves. The curves reveal that the coin toss result is known to be a 50% chance fairly accurately, but the soccer game result is known to be 50% with a large amount of uncertainty.
  • There is a one in a billion chance we are not in a simulation”, the information we have about the universe is but a speck of the total information available about the universe (the entire system/process). We mainly know a lot about ourselves and Earth in this time-period. This is highly likely to skew predictions and give them bias.
  • I’m not pretending to know whether we live in base reality or in a simulation. But I can say that the uncertainty in Elon’s probability is so great that it is no longer a meaningful/reasonable prediction.