Multiverse theory and the two die allegory

In my last post, I described an allegory I'd created that illustrates why life on Earth, even if it is extremely unlikely, does not serve as evidence that God exists. (I emphasize "if" because there is actually no empirical data I know of that has established this probability.)

The same allegory can be used to understand a thought experiment which is one of my favorites. I forget where I read it and who it's by, but it serves as a proof of multiverse theory. That's the theory that says that there are infinite parallel universes. At each moment, every decision or random act that's possible happens in one of those multiple universes.

So, here's the thought experiment: Find a reliable pistol, load it, put it to your head, and pull the trigger. There is a high probability that you'll have just killed yourself, but a small probability that the gun will fail. Repeat this several times. For good measure, after you've pulled the trigger a few times, fire it at the wall to make sure that the gun really works; then put it to your head and pull the trigger a few more times.

If the multiverse theory is wrong, you're almost definitely going to die. In fact, you probably died at the first pull of the trigger.

But if multiverse theory is right, then at every pull of the trigger, you die in the vast majority of universes — but live in the very few in which the gun failed. "Very few" of infinity is infinity, so you're still alive in infinite universes. Moreover, you only go on testing out the experiment and analyzing its results in those [rare] universes in which you're alive. (That's where the evolution allegory comes in.)

The result is that, if you're still alive after having tried to kill yourself a couple hundred times, you can be relatively sure that multiverse theory is correct. You'd have a very, very small chance of being alive if it's not correct, but a 100% chance of being alive if it is.

The kicker, of course, is that you can't communicate with any of the other parallel universes. So while you can be fairly sure that multiverse theory is right, that information doesn't help the versions of you that are dead. Also, since outside observers haven't eliminated all versions of themselves in which you're dead, they won't be able to share your knowledge: even if multiverse theory is right, the chance that an outside observer is in the right universe to see you alive is the same as the chance that the gun has failed. So even if they do see you live, there's no way for them to know if that's because multiverse theory is right or if you're just very, very lucky.

Needless to say, for both your sake if multiverse theory is wrong and for your loved ones' sakes even if it's right, I highly recommend not trying this out.

Evolution and chance: to live, perchance two die

I recently came up with an allegory in a discussion over at Economist.com on evolution that I'm a bit proud of. The question it seeks to address is: If God didn't create life on Earth, then how did it come about, given the minuscule chance of life evolving on its own?

For life as we know it to exist, you have to have the right mix of situations — a suitable solar system, a planet with liquid water, atoms that can form amino acids, amino acids that can self-replicate, etc. The chance of any one of these things happening is very small, and the chance of all of them happening in the same place is virtually nil. Only God, the argument goes, could have tipped the balance to create life here on Earth.

I should preface the allegory by stating that although I do believe in evolution (though I also believe it'll have to be amended, and possibly significantly, as any theory is), the following isn't a proof that God doesn't exist. As an agnostic, I don't believe such a proof exists. But I do treat this allegory as an illustration of the fallacy that God must exist for humans to have formed.

So, now: An allegory two die for

Imagine a simple game involving two players and a 100-sided die (hence the pun in the title, for which I apologize... kinda). The players each roll the die, and if one rolls higher than the other, the player with the higher number wins. Otherwise, they both lose.

Now consider a single-elimination tournament with a million players. At each round, you kill the losers and put the winners in the pool for the next round, randomly seeded. For simplicity, let's say that anyone who isn't matched in a given round (ie, the "odd man out") dies before the round starts. There's a minuscule chance that any one person will win the tournament, but a very high (99%) chance that somebody will win.

At the end of the tournament, you interview the remaining player, if there is one (if the last round was a draw, there's nobody left). Sure enough, that player says he's extremely lucky to be alive. There was less than a million-to-one chance he'd live, and it wasn't even guaranteed that there would be anyone alive at all. He's so lucky, in fact, that only the existence of God explains it.

In fact, God doesn't explain it. It's just that by the very nature of the game, you only get to interview the fortunate winner. God may exist and he may not, but the existence of a survivor isn't evidence one way or the other.

It's the same with us coming from evolution, except that the losers (those without suitable solar systems, or who didn't have water, or who didn't create amino acids, etc) didn't die — they never existed in the first place. We're left with us, the fortunate few survivors in a game of chance, who look at our situation and are fooled into thinking that the question was "will humans evolve on Earth" and not "will something evolve somewhere."

When people look out to the universe and ask, "if it's all just luck, how come we don't see any other life forms?" they're missing the point. The winner in our allegory could ask the same question, especially if he didn't understand the rules of the game he just played.

NASA should stop making rockets

A colleague of mine at work sent me a link today about an astronaut losing a tool bag in space during a space walk to work on the international space station. That seems as good a lede

lead[ing sentence]

as any to introduce a thought I've had for a while: NASA needs to be gutted.

Now, I like scientific research as much as the next guy — probably more than the typical next guy, actually. And despite my general preference for a small federal government, I do think the federal government needs to play a major part in funding science. Some of the most interesting and useful things we enjoy in the modern world have their origins in pure scientific research, and that's the kind of research that individuals and private companies have the least to gain from in terms of ROI.

My problem with NASA isn't that the government is spending so much money on research, it's that we're getting virtually nothing in return. We're not even trying to do real research anymore; manned missions these days are just excuses to fix whatever piece of the shuttle broke on the way up, and maybe pop another module to a space station that seems to be its own raison d'être.

In fact, one of NASA's points of pride is that its rovers and probes now use cheap, off-the-shelf parts. NASA sees that as proof that it's learning to work on a budget; I see it as proof that its innovative days are over. I'd rather spend $500 million and have learned something new than spend $100 million for what is, essentially, an expensive toy.

And while I'm trying my best to bite my tongue and not delve into a rant about the agency's all-consuming obsession to find water on Mars, suffice it to say that my world would be not be rocked in the least if they found ice there, or even evidence of Martian bacteria.

Where does that leave space research? At the risk of shedding my usual pinko hue for a deeper red, it's time for government to just get out of the private sector's way. The X Prize produced more innovation in space travel in eight years than NASA has since inventing the shuttle in 1981. If we want to make space travel a part of daily life, NASA's space missions should be gutted and the money appropriated to incentives in the private sector.

To be fair, there is still a substantial amount of pure research the government does through NASA. In particular, space telescopes and probes are giving us fascinating new insights to the universe. We've all but confirmed that black holes exist, and much of that research has been in the past decade; we're seeing farther and farther out, and thus farther and farther back in time. NASA should keep these research projects; but it should start shifting away from the job of getting the satellites themselves into orbit.

And please, can we stop talking about manned missions to Mars until we have a reason to go there? "Because it is there" is a great reason to go where no man has gone before, but George Mallory didn't cost taxpayers billions of dollars.