During my 81 years, many scientific discoveries have struck me as remarkable. This is my personal list, and doesn’t purport to identify all that are truly revolutionary, only those that dramatically changed how I think about the world. Typically, I would hear about these discoveries through Scientific American, which I have read faithfully for the last 65 years, and through books aimed at the informed layperson. Sometimes I hear about them directly from scientists; most often, they cross my attention two or more years after they appear in the scientific literature.
Sadly, magazines that try to popularize science are caught in the crossfire between the growing complexity of significant discoveries, the right-wing attack on science in general and evolution in particular, competition from visual media, lack of training among scientists on presenting material to the public, and the reduced attention span of their potential readership. The response of Scientific American is that articles are often written by science writers instead of the scientists themselves, excess coverage is given of “sexy” subjects such as extraterrestrial planets and cosmology, and complex subjects are dumbed down to the point of incomprehensibility. I have almost given up on Scientific American.
Throughout my life, the technology for making scientific observations has developed at an accelerating pace. In the typical case, theoretical advances follow breakthroughs in the sensitivity of scientific tools: more powerful telescopes and microscopes, computers and electronics, spacecraft, rapid gene sequencing, finer instruments, more powerful particle accelerators, etc. There is a dialectic between theory and the particular tools that are developed: theory informs their design, while new data uncovered by the tools suggests new theories.
I recall giving a report in an ROTC class on Alfred Wegener’s proposal that continents drifted. Despite the extensive evidence he presented supporting his ideas, the geology establishment dismissed his ideas because they couldn’t think of any physical mechanism that could move continents. However, various theorists were gradually assembling data that would coalesce by 1965 into a coherent theory of plate tectonics. It was a beautiful, comprehensive theory that, like Darwin’s theory of evolution by natural selection, made sense out of an entire scientific discipline. It had special meaning for me because the Alvin submersible that explored the Mid-Atlantic Ridge to help verify the theory was invented by and named for a friend and neighbor, Allyn Vine.
DNA and the Genetic Code
In 1953, during my first semester at UC Berkeley, I lived in a dormitory. One evening we were treated to an informal talk by the famous scientist George Gamow (sitting on one of the dining tables), who was closely following the race between the team of Watson, Crick, Franklin and Wilkins at Cambridge and Linus Pauling at Caltech. At that moment, Pauling had settled on a triple-helix structure for DNA, which Gamow explained to us. It was only a few weeks later that Watson and Crick, thanks to the exquisite X-Ray crystallographic images produced by Rosalind Franklin, came up with their theory, which they quickly published in their famous paper on the double-helix.
Later, in 1964, Crick correctly determined that triplets of nucleotide bases in DNA coded for specific amino acids, which were then transcribed by RNA. Like the double-helix, this discovery was accessible to the general reader, and the results were widely published.
Year after year new fossils are discovered, and gene sequencing has resolved many issues, while raising new ones. Recently it was determined that the ancestors of modern humans left Africa about 70,000 years ago, and had made it to Australia by 50,000 years ago. They had a sophisticated culture, including art and very likely fully developed language.
Another surprise was the fossil hominin Ardipithecus ramidus (nicknamed “Ardi”). Hominins are those species of ape that branched off from chimpanzees about six or seven million years ago and include humans. Ardi lived about 4.4 million years ago and was a tree-dweller that also walked upright. Upright stance frees the arms to attack prey with projectiles, a key advantage that led to the dominance of hominins – in my view the key advantage.
The discovery of Homo floresiensis, nicknamed the Hobbit, was another surprise. Only three and a half feet high and descended from some other line of hominin, lived until the arrival of modern humans about 50,000 years ago (megafauna also disappeared from the island after humans arrived, as usual).
The timing and interdependence of various key human traits (bipedalism, large brains, opposable thumbs, control of fire, hairlessness, language, etc.) is still far from settled. For example, was the control of fire (increasing the amount of protein in the diet) a necessary condition for a larger brain? When and how did language evolve?
The discovery that our prized rationality has little control over our behavior, and that the “self” is an artifact of our brains has had the effect of knocking humans almost completely off our pedestal. Granted that after the Copernican and Darwinian revolutions there wasn’t much of a pedestal left, we still could pretend we were the masters of reason. In parallel we have discovered that animal cognition is far more subtle and complex than we thought.
The Death of Progress
Science has extended lifespan and for the top tier of humans, making life fabulously safe and comfortable. But as we move into the Anthropocene (yet to become an officially sanctioned era) we are awakening to the fact that the dominance of humanity and our population explosion is a death-knell for vast numbers of organisms on the planet, and potentially for ourselves. Global warming, the Sixth Extinction, pollution, resource depletion and the threat of nuclear annihilation have forced us to re-evaluate what we mean by “progress,” since its normal implication of “improvement” increasingly is a source of irony. We had better make some major changes in how we live very soon. The alternative is unimaginable.
I am sure I have omitted a few discoveries that changed how I view reality, but this will do for the nonce.