"Continued on Next Rock" is one of the most evocative titles ever crafted; it belongs to a story by R. A. Lafferty (1914-2002). The phrase came to mind again when I got to wondering: If you had only one piece of paper on which to record the key elements of modern human knowledge for the future, what would you put on it?

To play the game one must, of course, assume a lot of context—the meanings of common English words, for starters. In one of his Lectures on Physics Richard Feynman responded to a more restricted variant with:

If, in some cataclysm, all scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or atomic fact, or whatever you wish to call it) that all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence you will see an enormous amount of information about the world, if just a little imagination and thinking are applied.

But one sentence, even an unwieldy-long one, is just too short to have much fun with. Suppose you had a medium-sized stone on which to chisel your clues? Zipping across a few dozen orders of magnitude, from an admittedly idiosyncratic physicist's perspective:

Quarks interact via a strong nuclear force to form positively charged protons and neutral neutrons of sizes about 10^-15 meters and masses about 10^-24 grams. Protons and neutrons are bound tightly together in atomic nuclei. Electrons, negatively charged and ~2000 times lighter, are held by electromagnetic forces in quantum-mechanical orbitals around those nuclei. A different number of electrons corresponds to each chemical element. Electronic forces bind atoms to make chemical compounds, each with its own structure. Pure compounds can form crystals with shapes related to the arrangements of their constituent atoms. Mixtures of complex chemical compounds can, in the right environment, replicate themselves—life. Copies of genetic material are not always perfect, so complex lifeforms can evolve via natural selection. Larger creatures are built from specialized microscopic cells. Neurons carry electrochemical impulses which convey information and instructions from one part of an animal's body to another. Entities with ~10¹⁰ interconnected neurons can be conscious and intelligent.

Electricity and magnetism are linked through coupled differential equations. Light is a self-propagating oscillation of the electromagnetic field which travels at a constant velocity as seen by any observer. Gravitation is a long-range force between pairs of masses caused by spacetime curvature. In ordinary circumstances gravitational attraction is proportional to the products of the masses and the inverse-square of the distance between them. Aggregations of ~10²⁷ grams of matter can form planets with enough surface gravity to retain atmospheres and sustain life. Accumulations of ~10³³ grams of matter can form stars which typically shine for billions of years via fusion in their hot compressed cores, thereby transforming lighter elements into heavier ones. The products of stellar nucleosynthesis are distributed by supernova explosions and can coalesce into planets and other stars. Agglomerations of ~10¹⁰ stars form galaxies of sizes ~10²¹ meters across, which can in turn gather into clusters. The universe appears to be expanding in all directions from a hot, dense state ~10¹⁰ years ago.

Continued on next rock ...

(the influence of Charles and Ray Eames's Powers of Ten is perhaps obvious in the above; cf. TopDownBottomUp (1999-05-16), UniversalKnowns (2002-06-13), HighPrecision (2002-07-16), ...)

TopicScience - TopicLiterature - 2005-06-20

(correlates: HalloweenEqualsChristmas, TopDownBottomUp, Comments on BitsOfConsciousness, ...)