Essay; Science Squints at a Future Fogged by Chaotic Uncertainty

Published: September 22, 1998
(Page 3 of 3)

Correction Appended

Predicting life spans in the absence of detailed knowledge has long interested scientists as well as insurance statisticians. A forecast of life expectancy based on the average age at death of a person's four grandparents is a simple example of statistical forecasting. But a much more daring approach was devised a few years ago by Dr. J. Richard Gott 3d, a professor of astrophysics at Princeton University.

Dr. Gott's scheme is based on the ''Copernican principle,'' which assumes that the odds are overwhelmingly against any particular place or time being ''special.'' From this, Dr. Gott reasoned that the mere knowledge of how long something (or someone) has been around is sufficient to estimate how much longer it could last. Based on this system, and the assumption that Homo sapiens appeared on earth about 200,000 years ago, Dr. Gott calculated that intelligent human beings are 95-percent certain to survive a minimum of 5,128 years more, and a maximum of 7.8 million years more.

There are those who contend that predictions like these are so vague that they are scarcely more useful than the prophecies of the Delphic oracle in ancient Greece, which was consulted by Socrates, Oedipus and other luminaries of the day. The oracle (operated by a concealed priest or priestess) was so ambiguous it could nearly never be proved wrong.

Scientists will never be able to answer all our questions about future events or to satisfy a deep-seated human yearning to foresee what's coming at us. Some scientific efforts at prediction will always be defeated by the nature of Nature.

Mystic oracles have never shed light on future events either, but even 1,398 years after Socrates' suicide, legions of people continue to visit palmists, astrologists and psychics. It's human to prefer something to nothing at all.

Correction: September 23, 1998, Wednesday An essay in Science Times yesterday about predictions misstated the time elapsed since the suicide of Socrates, who relied on oracles. It was 2,397 years ago, not 1,398.