Apparently, time is on my side. Which is funny if you’ve followed my twitter fades the last century. (Obviously time is relative, what may seem like two months to you is almost certainly an eternity to tweeters of guaranteed fades, c’est moi, FML, c’est moi.)
It all started with this thought experiment. In a back room in a Las Vegas casino, you are handed a fair coin to flip. You will not be allowed to see the outcome, and the moment the coin lands you will fall into a deep sleep. If the coin lands heads up, the dealer will wake you 1 minute later; tails, in 1 hour. Upon waking, you will have no idea how long you have just slept.
The dealer smiles: would you like to bet on heads or tails? Knowing it’s a fair coin, you assume your odds are 50/50, so you choose tails. But the house has an advantage. The dealer knows you will almost certainly lose, because she is factoring in something you haven’t: that we live in a multiverse.
Oh god.
In any infinite multiverse, everything that can happen, will happen – an infinite number of times…How can we say that anything is more or less probable than anything else?
One procedure physicists are fond of is to draw a cut-off at some finite time, count up the number of events – say, heads and tails – that occur in the multiverse before the cut-off time, and use that as a representative sample.
It seems reasonable, but when tackling the casino experiment, something strange happens. Wherever the cut-off is drawn, it slices through some of the gamblers’ naps, making it appear as if those gamblers simply never woke up. The longer the nap, the more likely it is to be cut off, so if you do awaken, it’s more likely that you have taken a shorter nap – that is, that you flipped heads. So even though the odds seemed to be 50/50 when the coins were first flipped, heads becomes more probable than tails once you and the other gamblers wake up.
Somewhere deep down this is what J. L. Kelly, Jr. had in mind. Accidental prescience? I knew it.
Upon waking, you have new information: you know that time didn’t end. That now means it is more likely that you only slept for a minute than for an hour. After all, time could end at any minute, and an hour has an extra 59 of those to spare. Heads wins.
Ultimately, younger universes are more numerous than older universes, thus if I interpret each possible side as if its occurring primarily in younger universes, my probability increases at the rate proportional to y/u, where y is the number of younger universes, and u the number of older universes. I’ve figured it out, guys.
New Scientist. August 13, 2011
