A mind is like a parachute
It might save your life,
but you have to know how to use it first.

Friday, July 27, 2012

Of Course We Can Predict the Future

We often hear that the future is unknown, and (in the words of Yogi Berra) "It's tough to make predictions, especially about the future."

We generally accept it on the face of it that we can't predict the future, but of course this is about as far away from the truth as we could be.  The fact is we predict the future all the time.  Our survival and our civilization depend upon it.  And we're very good at it.

Imagine you are at a park and you see a boy who has gotten his frisbee stuck in a tree.  He tries to shake the tree but it is too big and it doesn't budge.  He tries to throw things at the frisbee to knock it down, but he keeps missing.  He almost gets his baseball glove stuck as well before he decides to abandon the idea of throwing other objects into the tree.  Then he gets an idea.

The boy runs off and returns shortly with a jump-rope.  He throws one end of the rope up onto the limb of the tree and, after succeeding in getting it sufficiently stuck, he pulls hard on the tree limb to loosen his toy.  He lets go of the rope and the tree limb bounces back into the air, jump-rope dangling and swinging just above his head.  But the frisbee is really wedged in the branches and doesn't move.  The boy starts to pull hard on the jumprope.  The limb bends down and then bends some more.  It is apparent to you that the limb is near its breaking point.  But the boy keeps pulling until finally, SNAP.  The branch gives way and swings wildly toward the ground, striking the boy in the head.  He starts to cry.  You run over but by the time you get there, others have come to his aid and have determined he is not seriously hurt.

You walk back over to your bench in the park and tell your friend, "I knew that was going to happen." And the thing is, you did know what was going to happen.  From your vantage you could see the limb bending and you sensed it was about to break.  Further you could see that it was likely to swing down and strike the boy when it did.  Was this simply a blind guess or were you telling the future?

I'm not sure where Little Orphan Annie ranks in the pantheon of financial planners, but she has assured us that we can bet our bottom dollar that the sun will come out tomorrow.  Is she some sort of all seeing sorceress?  (She does have the spooky eyes for the job.) How can she possibly predict the future?

Now some folks will insist that I am playing word games or splitting hairs.  Surely the idea that the sun will rise is not telling the future, it's just science, right?  And so is the understanding that a branch pulled by a child to the breaking point will come snapping back and hit him in the face.  This is not what we mean when we talk about predicting the future is it?  And what about the chance that the branch will miss the child as it swings through the air?  Or the one in a gazillion chance that something will happen and the sun will not in fact come out tomorrow? (In which case our bottom dollar is worthless anyway, so it's still a good bet to take.)

Well, what do we mean when we talk about predicting the future?  We usually mean calling for things that will happen or are very likely to happen.  If you learned from a reliable source that you had a 99% chance of being in the path of the oncoming wild-fire, would you really think that it didn't matter because the prediction lacked 100% certainty?  Absolute certainty is clearly not a requirement for us to assess a credible threat, so it can not be a requirement in any of our predictions about what is about to happen.

So what is going on here?  How can the future be both unknowable and so readily predicted in so many ways -- in many cases to accuracy that approaches 100%? Does anything that is "too obvious" not count as predicting the future?  Are we really only concerned with our inability to predict things we don't see coming?  If that is the case, then we are simply defining the future as what we don't know, so who's playing word games now?

No, it is clear that a better assessment of the situation may be something like:

"Our long history of curiosity about our surroundings has lead us to a level of understanding that makes many things appear reasonably certain.  Highly regular events can be predicted to a great degree of accuracy, as can things in the very near future.  However, things subject to a lot of input variables (those containing many "moving parts") are harder to predict.  And events in the distant future which may be subject to the as yet undetermined outcomes of other events which we can not accurately predict become harder still."

I like Yogi Berra's quote better.

But more poetically, it is as if the future is shrouded in fog.  We can make out the details of only those things which are very close.  Further off we can make out shapes, and further still we can not see anything.  Additionally, we can make inferences about things in our environment which appear unchanging.  For example if we stood next to a long stone wall in the fog, we would not need to see it in the distance to be able to infer that it extended out in front of us.  The longer we walk along the wall, the more confident we can be that it continues in front of us -- similar to how we have as a species observed so many sunrises that we understand the almost certainty that sunrises extend into our future for as long as our mortal selves can see.

What are the specific factors that influence our ability to predict the future?  How can we know if we are predicting the future or merely think we are?

The answer to these questions and many other interesting ones lie in the nature of how we perceive information.  And as we have already discussed "perception of information" is merely another way of saying "context".  So we'll be looking at context and the role it plays in our ability to tell the future.

No comments:

Post a Comment