Monday, July 16, 2012

Probability

The probability that any one of us will live for ever: P(liveforever)=0.

The probability the each one of us going to die: P(die)=1

So I'm taking statistics in a five week gulp two evenings a week at Providence College. Much to my surprise, having expected to hate it and struggle with every problem, I am finding it fascinating and accessible. The work we did last week in probability - how to calculate probability, and how to interpret probability data - was especially interesting, because somehow it dovetailed with my particular vexation du jour, which is the constant stream of health pundits (yeah, I'm talking about you, Dr. Oz ) and articles suggesting we can indeed live forever, if we just drink enough wheatgrass, or do enough sit ups, or subscribe to whatever nutritional/fitness fad is current.

All probabilities lie between 0 and 1 - things that will never happen are 0 and things that are absolutely sure to happen are 1. Everything else fits in between. So even things with very low probability are possible (yes, even winning the lottery or being struck by lightning). Where it gets interesting is when you start looking at multiple probabilities.

We did a problem about the 1987 Challenger disaster - when the space shuttle exploded as it lifted away from the launch pad, killing the crew and the first ever civilian passenger, a school teacher from New Hampshire. The problem: The space shuttle had 748 separate critical "events" that each had a .0001 chance of going wrong. That sounds minute, inconsequential. But then you do the math - there's a .9999 chance of everything going right (and raise that number to 748) and you get .9279. Every flight had a 93% chance of being successful, and a 7% chance of disaster. That is very different from .0001.

Probability was on my mind when I read the heartbreaking article in the New York Times about a 12 year old's death from sepsis. Maureen Dowd followed that up with an even more poignant column on Sunday. Reading the comments on both pieces reveals many people who are certain they can point to exactly what went wrong and that Rory's death was "preventable". It's a tragic story, and there may very well have been medical negligence or malpractice, and perhaps it's just human nature to try and quickly bring a horrifying event under control by saying if just this one thing had been different, then it would never have happened.

Buried deep down in the comment thread are just a few remarks from physicians who say that this kind of sepsis creates such a cascade of organ and tissue failure that, especially in children, even when caught early, just can't be stopped. It is possible that even had the physicians who first saw Rory diagnosed him correctly, he would still have died. Again - I'm not suggesting that something did not go terribly wrong in his treatment, only commenting that it is false to assert that an event like this is ever truly "preventable."

I suppose this resonates with me because I am still wondering - if I had done something differently, would Gerry still be alive? What if we had never left Blacksburg? What if I had nagged him more to get the lump in his neck checked? What if the sarcoidosis in his lung had been recognized as the red herring it was? Was his death in some way preventable, and was I the agent who could have prevented it?

I'll wonder all the rest of my life.

Complex systems - like churches, hospitals and the human body - are unpredictable. Every tiny possible outcome sits on that 0-1 probability scale and with millions of possible outcomes, who knows what tips any one event into being inevitable? Right now, there's lots of commentary about our recent General Convention. From both sides of the theological and political spectrum, folks are sure they understand what happened, why it happened and what the consequences are going to be.

Well, I'm wondering about all that, too. I'm not so sure we can draw big conclusions. I'm never sure that I have the absolute answers. I find human behavior the most complex and mysterious phenomenon of all. I am daily surprised in personal interactions and in groups. Systems don't work by linear cause and effect. It may be years before we can really understand what was happening in the church here at the beginning of the 21st century. And maybe there are some things we'll never know.

I am oddly comforted by all this uncertainty. Perhaps it allows me to be content with being human and finite and limited. It teaches me humility and acceptance. It encourages me to focus my energies on things that are within my power to change (which has a .9999 probability of being my own self). It reminds me that I am mortal after all.

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