In Context #12 (Fall, 2004, pp. 3-4); copyright 2004 by The Nature Institute
The Building-Block Universe
In his essay on "Newtonianism, Reductionism, and the Art of Congressional Testimony," physicist Steven Weinberg (2001) tries to get a grip on why "we all do have a sense that there are different levels of fundamentalness"why, for example, DNA is "fundamental to biology," and particle physics is "fundamental to everything." In science, he says, "we try to discover generalizations about nature," and these, it turns out, give us a sense of direction because "some generalizations are 'explained' by others." After all, "does anyone doubt that real materials exhibit [higher-level] phenomena because of the properties of the particles of which the materials are composed?" So it is that
There are arrows of scientific explanation, which thread through the space of all scientific generalizations .... These arrows seem to converge to a common source! Start anywhere in science and, like an unpleasant child, keep asking "Why?" You will eventually get down to the level of the very small.
no biologist today would be content with an axiom about biological behavior that could not be imagined to have an explanation at a more