The lifetime of civilizations in the Drake equation
for estimating extraterrestrial ntelligences
is greatly exaggerated

In science there is arguably no more suppositional formula than that proposed in 1961 by radio astronomer Frank Drake for estimating the number of technological civilizations that reside in our galaxy: N = R fp ne fl fi fc L

In this equation, N is the number of communicative civilizations, R is the rate of formation of suitable stars, fp is the fraction of those stars with planets, ne is the number of Earth-like planets per solar system, fl is the fraction of planets with life, fi is the fraction of planets with intelligent life, fc is the fraction of planets with communicating technology, and L is the lifetime of communicating civilizations. (continue reading…)

The voice of the people reveals why
evolution remains controversial

There is no more contentious subject in science today than evolution. This fact was brought to light for me in the overwhelming response to my February column on evolution and “intelligent design” creationism. I typically receive about a dozen letters a month, but for this one no less than 134 were submitted (117 men, four women and 13 whose identity was not revealed). I found reading the critical letters mildly disconcerting until I hit on the idea that these are a form of data to be mined for additional information on what people believe and why. Conducting a content analysis of all 134 letters, I discovered patterns within the cacophonous chaos. First I read them quickly and then separated them into about two dozen one-line categories that summed up the reader’s main point. I next condensed these into six taxonomic classes and reread all the letters carefully, placing each into one or more of the six (for a total of 163). (continue reading…)

On the occasion of Stephen W. Hawking’s 60th
trip around the sun, we consider a social phenomenon
that reveals something deep about human nature

In 1998 God appeared at Caltech.

More precisely, the scientific equivalent of the deity, in the form of Stephen W. Hawking, delivered a public lecture via his now familiar voice synthesizer. The 1,100-seat auditorium was filled; an additional 400 viewed a video feed in another hall, and hundreds more squatted on the lawn and listened to theater speakers broadcasting this scientific saint’s epistle to the apostles. The lecture was slated for 8 P.M. By three o’clock a line began to snake around the grassy quad adjoining the hall. By five, hundreds of scientists flipped Frisbees and chatted with students from Caltech and other universities. (continue reading…)

Science helps us understand the essential tension
between orthodoxy and heresy in science

In a 1987 lecture entitled “The Burden of Skepticism,” astronomer Carl Sagan succinctly summarized the delicate compromise between tradition and change: (continue reading…)

The following essay on the politically-charged issue of abortion was originally written for my regular Scientific American monthly column, Skeptic, but we decided that it was too political and not grounded enough in science for Scientific American, so we shelved it. I ended up expanding that column into a chapter section in my book The Science of Good and Evil.

In 1959 astronomers were polled for their opinion on the then undecided debate between two competing cosmological theories. “Did the universe begin with a Big Bang several thousand million years ago?” A third answered yes. “Is matter continuously created in space?” Almost half answered yes. Most telling, to the question “Is a poll of this kind helpful to scientific progress?” all answered no.

The reason for this unanimity is that scientific questions are not settled by consensus opinion. Unfortunately, in complex human and social issues, separating fact from opinion is not so easy, and for no issue is this more apparent than abortion. Setting aside the emotionally charged moral and political aspects of abortion for a moment, how can science inform this debate? (continue reading…)