A lucky man

... sorry I could not travel both

And be one traveler – Robert Frost

It was a typical hot and humid summer's day, so I entered a nice dark bluestone pub, hoping the dark would offer some cool and beer. As it was about 11 in the morning, the bar was empty save for one fellow sitting at a table - one of three next to the pool table - so I got my lager, icy cold as God intended, and went to practice my trick shots. I have found that after exactly two and a half beers, I can hit shots that professionals would blanch at, and this persists from the remaining half glass. At least once I managed to lighten an American tourist of $100 after two really bad games and really good beers, up in Cairns.

Anyway, I was just entering that blessed state of hand eye coordination, making the cue ball spin on its vertical axis and travel around a snookering ball, when I apparently caught the eye of the solitary drinker.

"I'm impressed," he muttered into his beer.

"Thanks," I replied. "If I could stay exactly this drunk, I'd be a hell of a pool shark," and we got to talking.

My friend was a bit morose, so after some small talk I asked if anything was the matter.

"Yes," he said, "I'm going to be killed shortly."

Now this is a rare opening gambit in a conversation, so he had my full attention. "What? Why?" I blustered, a little shocked and unsure if he was having me on or not.

"Well, it's a bit hard to explain. Do you know of the scam where you send 10,000 random people the outcomes of a given sporting match?"

"Uh, yeah, sure," thinking of some mob tie-in or theft. "Actually, no."

"OK, it works like this: pick a large number of people and send them, say, a prediction that has a small number of possible results. Win-lose is best. Next week send the 5,000 who got the right prediction, another random prediction, and so on each week until you have both a highly improbable sequence and a relatively large number of possible charlies. Then ask them for $1,000 for the next week's predictions, and then, when the money is in, scarper. The fact is, you will have to have some charlies left, and they will all think of you as a real prophet."

"Yeah, I think I heard of that happening in Melbourne once," I replied.

"So, imagine if you could scan all the possible outcomes and pick the one which was optimal at every point in your life."

"I don't get where this is going," I said.

"Bear with me. So when I was an undergraduate physics student, they told us about a view of quantum mechanics that said that every possible outcome actually occurs, but that each time a superpositional state collapses in one world, it collapses in all other possible ways in other worlds. All physically possible worlds exist, only they are inaccessible for the world in which you exist."

I was just drunk and hot enough that this was a standard sort of pub conversation, so I went with it. "OK."

"OK. Except, when I heard this, I wondered if by concentrating I could find my way to these other worlds. You know, undergraduate philosophical ramblings at three in the morning. Only, one morning I woke up and found that a bad decision I had taken the night before (to not chat up a girl, as it happened) had been undone by the morning. There was the girl I hadn't taken home last night, and what was more, I remembered both worlds. I remembered not chatting her up, and also screwing up my courage and doing so."

He drew a deep breath, and regarded me with the eyes of a condemned prisoner.

"As time went by I found that not only could I 'undo'" (he used his fingers to draw quote marks in the air) "the past, but I could 'see' 'around' me for the possible world that had the best outcome for me. I finally figured out that I wasn't changing my world, but which world I saw things from. I changed, you might say, my perspective from possible world to possible world."

"So this isn't the world you started in?" I asked.

"Not really, but then it isn't the world you started in either. You just happen to be the final perspective that this line of possibilities generated. The difference between you and I is that I can sense, somehow, nearby possible worlds and the... I don't know... satisfaction rating for me. You might say that I surf from world to world to the best of accessible worlds for me."

I had done some literature at university, and I recalled something relevant.

"Holy Pangloss!" I said.

He chuckled at that. "Not exactly Pangloss. I'm no Leibniz, arguing that the world from which I see things from is the best of all possible worlds. There must be an infinity or something very like it of possible worlds, and I can't leap to any one of them, just those that are within some, ah, distance in terms of bifurcating wave collapses from 'here'. So I can't pick stocks that are going to be high payoff in the future, but I can pick worlds where a recent choice of mine or recent events left me better off than I am in my present world."

"So, the obvious question: what happened?"

Again, he came at it obliquely.

"Have you read the famous poem by Robert Frost, "The Road Not Taken"?"

"I think so."

"You know, the one where he says of two tracks in a forest:

And both that morning equally lay

In leaves no step had trodden black.

Oh, I kept the first for another day!

Yet knowing how way leads on to way,

I doubted if I should ever come back."

"Mmmhmm." I didn't, then, but I know it now, word perfect.

"Well you can't go back in time to a prior choice or splitting of the worldways, as I call them. Once you leap into a worldway, you are committed. Alternative worlds that used to be accessible fade into the 'distance'. The track not taken is never again accessible to you. You have to take the tracks that this worldway leads to.

"It's rather like evolution: a species that takes one 'choice' can't backtrack to fix a suboptimal character. You know the human seminal vesicle? That's the tube that delivers semen from the testicles. It loops over the urethra, which delivers urine from the kidneys, because our ancestors were four legged, and the whole geometry was different. This is like that. I found myself in an increasingly more constrained set of possible worldways."

He proceeded to tell me about his involvement in corporations, shady figures, organised crime and corrupt politicians. I won't repeat it here, because too many people could be hurt, including me, but the upshot was that he increasingly found his choices of worldways that were better or equal to his present one narrowed. Eventually, he found his way to this one, and this pub, with many people out to kill him. This worldway was the last remaining one in which he had a perspective. In short, this world was the only one he still lived, within his "reach". And this worldway, it seemed, ended for him in a few minutes.

After this, we sat quietly for a few minutes, and then he said to me, "You had better finish up that beer and leave. It happens in a few minutes, whatever it is, and you don't want to be nearby."

I told him, I'd take my chances. They didn't want me, after all. He started to object, but then his fatalism overcame him, and he just shrugged. So we sat and finished our beers. Then, without any warning, he had a fatal heart attack. Given that he was about 40kg overweight and smoked, it was no surprise, I guess. While we were trying to give CPR, this guy wandered into the pub, with a worrying trenchcoat, and stayed until we were sure he'd died. He left. After the ambulance had come, so did I.