• In a 3.8 billion-year-old rock, you find a ratio of carbon isotopes typical of living things today, and different from inorganic sediments. Do you deduce abundant life on Earth 3.8 billion years ago? Or could the chemical remains of more modern organisms have infiltrated into the rock? Or is there a way for isotopes to separate in the rock apart from biological processes?
• Sensitive measurements of electrical currents in the human brain show that when certain memories or mental processes occur, particular regions of the brain go into action. Can our thoughts, memories and passions all be generated by particular circuitry of the brain neurons? Might it ever be possible to simulate such circuitry in a robot? Would it ever be feasible to insert new circuits or alter old ones in the brain in such a way as to change opinions, memories, emotions, logical deductions? Is such tampering wildly dangerous?
• Your theory of the origin of the solar system predicts many flat discs of gas and dust all over the Milky Way galaxy. You look through the telescope and you find flat discs everywhere. You happily conclude that your theory is confirmed. But it turns out the discs you sighted were spiral galaxies far beyond the Milky Way, and much too big to be nascent solar systems. Should you abandon your theory? Or should you look for a different kind of disc? Or is this just an expression of your unwillingness to abandon a discredited hypothesis?
• A growing cancer sends out an all-points bulletin to the cells lining adjacent blood vessels: ‘We need blood,’ the message says. The endothelial cells obligingly build blood vessel bridges to supply the cancer cells with blood. How does this come about? Can the message be intercepted or cancelled?
• You mix violet, blue, green, yellow, orange and red paints and make a murky brown. Then you mix light of the same colours and you get white. What’s going on?
• In the genes of humans and many other animals there are long, repetitive sequences of hereditary information (called ‘nonsense’). Some of these sequences cause genetic diseases. Could it be that segments of the DNA are rogue nucleic acids, reproducing on their own, in business for themselves, disdaining the well-being of the organism they inhabit?
• Many animals behave strangely just before an earthquake. What do they know that seismologists don’t?
• The ancient Aztec and the ancient Greek words for ‘God’ are nearly the same. Is this evidence of some contact or commonality between the two civilizations, or should we expect occasional such coincidences between two wholly unrelated languages merely by chance? Or could, as Plato thought in the Cratylus, certain words be built into us from birth?
• The Second Law of Thermodynamics states that in the Universe as a whole, disorder increases as time goes on. (Of course, locally worlds and life and intelligence can emerge, at the cost of a decrease in order elsewhere in the Universe.) But if we live in a Universe in which the present Big Bang expansion will slow, stop, and be replaced by a contraction, might the Second Law then be reversed? Can effects precede causes?
• The human body uses concentrated hydrochloric acid in the stomach to dissolve food and aid digestion. Why doesn’t the hydrochloric acid dissolve the stomach?
• The oldest stars seem to be, at the time I’m writing, older than the Universe. Like the claim that an acquaintance has children older than she is, you don’t have to know very much to recognize that someone has made a mistake. Who?
• The technology now exists to move individual atoms around, so long and complex messages can be written on an ultra-microscopic scale. It is also possible to make machines the size of molecules. Rudimentary examples of both these ‘nano-technologies’ are now well demonstrated. Where does this take us in another few decades?
• In several different laboratories, complex molecules have been found that under suitable conditions make copies of themselves in the test tube. Some of these molecules are, like DNA and RNA, built out of nucleotides; others are not. Some use enzymes to hasten the pace of the chemistry; others do not. Sometimes there is a mistake in copying; from that point forward the mistake is copied in successive generations of molecules. Thus there get to be slightly different species of self-replicating molecules, some of which reproduce faster or more efficiently than others. These preferentially thrive. As time goes on, the molecules in the test tube become more and more efficient. We are beginning to witness the evolution of molecules. How much insight does this provide about the origin of life?
• Why is ordinary ice white, but pure glacial ice blue?
• Life has been found miles below the surface of the Earth. How deep does it go?
• The Dogon people in the Republic of Mali are said by a French anthropologist to have a legend that the star Sirius has an extremely dense companion star. Sirius in fact does have such a companion, although it requires fairly sophisticated astronomy to detect it. So (1) did the Dogon people descend from a forgotten civilization that had large optical telescopes and theoretical astrophysics? Or, (2) were they instructed by extraterrestrials? Or, (3) did the Dogon hear about the white dwarf companion of Sirius from a visiting European? Or, (4) was the French anthropologist mistaken and the Dogon in fact never had such a legend?
Why should it be hard for scientists to get science across? Some scientists, including some very good ones, tell me they’d love to popularize, but feel they lack talent in this area. Knowing and explaining, they say, are not the same thing. What’s the secret?
There’s only one, I think: don’t talk to the general audience as you would to your scientific colleagues. There are terms that convey your meaning instantly and accurately to fellow experts. You may parse these phrases every day in your professional work. But they do no more than mystify an audience of non-specialists. Use the simplest possible language. Above all, remember how it \vas before you yourself grasped whatever it is you’re explaining. Remember the misunderstandings that you almost fell into, and note them explicitly. Keep firmly in mind that there was a time when you didn’t understand any of this either. Recapitulate the first steps that led you from ignorance to knowledge. Never forget that native intelligence is widely distributed in our species. Indeed, it is the secret of our success.
The effort involved is slight, the benefits great. Among the potential pitfalls are oversimplification, the need to be sparing with qualifications (and quantifications), inadequate credit given to the many scientists involved, and insufficient distinctions drawn between helpful analogy and reality. Doubtless, compromises must be made.
The more you make such presentations, the clearer it is which approaches work and which do not. There is a natural selection of metaphors, images, analogies, anecdotes. After a while you find that you can get almost anywhere you want to go, walking on consumer-tested stepping-stones. You can then fine-tune your presentations for the needs of a given audience.
Like some editors and television producers, some scientists believe the public is too ignorant or too stupid to understand science, that the enterprise of popularization is fundamentally a lost cause, or even that it’s tantamount to fraternization, if not outright cohabitation, with the enemy. Among the many criticisms that could be made of this judgement – along with its insufferable arrogance and its neglect of a host of examples of highly successful science popularizations – is that it is self-confirming. And also, for the scientists involved, self-defeating.
Large-scale government support for science is fairly new, dating back only to World War Two – although patronage of a few scientists by the rich and powerful is much older. With the end of the Cold War, the national defence trump card that provided support for all sorts of fundamental science became virtually unplayable. Only partly for this reason, most scientists, I think, are now comfortable with the idea of popularizing science. (Since nearly all support for science comes from the public coffers, it would be an odd flirtation with suicide for scientists to oppose competent popularization.) What the public understands and appreciates, it is more likely to support. I don’t mean writing articles for Scientific American, say, that are read by science enthusiasts and scientists in other fields. I’m not just talking about teaching introductory courses for undergraduates. I’m talking about efforts to communicate the substance and approach of science in newspapers, magazines, on radio and television, in lectures for the general public, and in elementary, middle and high school textbooks.
Of course there are judgement calls to be made in popularizing. It’s important neither to mystify nor to patronize. In attempting to prod public interest, scientists have on occasion gone too far – for example, in drawing unjustified religious conclusions. Astronomer George Smoot described his discovery of small irregularities in the ratio radiation left over from the Big Bang as ‘seeing God face-to-face’. Physics Nobel laureate Leon Lederman described the Higgs boson, a hypothetical building block of matter, as ‘the God particle’, and so titled a book. (In my opinion, they’re all God particles.) If the Higgs boson doesn’t exist, is the God hypothesis disproved? Physicist Frank Tipler proposes that computers in the remote future will prove the existence of God and work our bodily resurrection.