realthog

I can't remember for sure when or where I bought Alan Lightman's Time Travel & Papa Joe's Pipe (1984; pretty illustrations by Lazlo Kubinyi), but I have a feeling it was during a stay with us by dear friend and wonderful artist Martina Pilcerova. The three of us went out yard-saling and came across a sale where there were lots of yummy science books with very low prices on them. Squeals of delight from Ms Pilcerova and myself; rolling of the eyeballs from Pam. I think most of the contents of that yard sale went back to Slovakia in due course, but a few goodies remained here in NJ, and one of that number was, I believe, Time Travel & Papa Joe's Pipe.

At the time this collection of essays was published, Lightman was at the Smithsonian; he later moved on to MIT and to greater literary fame with the novel Einstein's Dreams (1993).

Time Travel & Papa Joe's Pipe is one of those old-fashioned essay collections that has no real theme to it: it's just a random walk through various scientific topics that for one reason or another caught Lightman's attention. One of the delights of such books, if they're good ones, is that they, as it were, comprise so much more than just their own texts: included also in the package are all the ideas of one's own that the texts spark off.

The essays here were almost all published individually elsewhere before being assembled for this book; one of the two original to the book ("Students and Teachers") stands out as the dullest, the other ("Mirage") is a fantasia that's remarkable for its charm. All in all, the book gave me the feeling I was being entertained over the port by a series of after-dinner conversations with a genial, whimsically knowledgeable host. And from time to time there'd be a passage that whopped me between the eyeballs with its insight. One of these I noted a while back (http://realthog.livejournal.com/36414.html) when I first started the book (I've been reading it an essay or two at a time alongside other books). Here's another, from the last essay in the collection, "Jam Tomorrow", in which Lightman's talking about probability and its laws:

Weighing the odds in personal decisions involves a morass of perceptive and emotional factors seeping past the neat analysis of binomial theorems, combinatorics, and Gaussian distributions. What were the perceptions of the citizens of Tacoma, Washington, who were recently asked to choose between an uncertain risk of cancer from arsenic in the air and the loss of 800 jobs from the closing of a copper smelting factory?

It's a question that stopped me in my mental tracks for a few moments. Although I'm far from any kind of expert in probability and the application of its laws to real life, I've had for years a sort of complacent assumption of working familiarity with the general notion. In a very simple, graceful fashion Lightman had shown me that this assumption of mine was quite false.

It's hard (and anyway pointless) to pick a standout essay among these: they're not all as good as each other, but there are several which are very, very good. The one that's had me thinking the most, though, is "Is the Earth Round or Flat?". A silly question, you might think, because of course we all know the answer . . . yet Lightman points out, perfectly correctly, that with the exception of a very few people we don't know it: we believe it to be the case that the Earth is approximately spherical. Far from all of us have ever observed ships or landmasses disappearing from the bottom up as they recede over the horizon. Very few of us have been astronauts. We've seen the photos that astronauts and space probes have taken, but photos can mislead.

Our belief in the oblate sphericity of our planet is obviously extremely well founded, but there are still a few Flat Earth societies scattered around, and the members of those would doubtless say their belief was well founded, too. (I remember years ago reading a flat-Earther explanation of the bit about ships disappearing from the bottom up: it involved atmospheric refraction.) There are people who believe we live in the inside of a hollow Earth. And so on.

It struck me that here we see a perfect exemplification of the reason why I become so distressed by the constant misapplication of the term "belief system", a misapplication that arises because the word "belief" has more than one meaning: there is its meaning of "rational conclusion based on all available evidence" and there is its almost diametrically opposed meaning of "faith". The former implies an openness to change, perhaps in light of fresh evidence or a reappraisal of the logic that led to the conclusion; the latter implies an impermeability to the notion of change. Products of the latter can, I think, be rightfully described as belief systems. Products of the former are -- like the sphericity of the Earth -- the nearest things we have to cast-iron facts. They are not merely belief systems.

In any contest between a scheme of interlinked rational conclusions (or "theory", to use the term in its scientific as opposed to its popular meaning) and a belief system, the burden of proof lies upon the belief system. There is no need for me to advance a proof that the world is round; if you believe it's really flat, the onus is entirely upon you to do the proving. There is no need for me to prove that the basic mechanism of evolution is by natural selection, or that evolution is (ahem) a fact of life; if you think otherwise, you must present proof -- and a whole stack of astonishingly convincing proof at that. Similarly, rationalism is the default view of the universe, and in no way describable as a belief system; whereas any explanation of reality that invokes the supernatural is. That the Earth is approximately 4.6 billion years old is a statement for which I do not need to offer supporting evidence, because that's a conclusion reached by countless independent researchers working in a multiplicity of scientific fields; that the Earth is some 6000 years old is a statement relying on a belief system -- indeed, on a belief system within a belief system. And so on.

I've spent more wordage here talking about the ideas of mine that Lightman's short essay sparked off than I have about the essay itself. That's exactly as it should be, I feel, with the best of scientific essays: they're not just entertainments or elucidations, they're catalysts.