On being baffled: stop the presses! To scientists, the universe is a source of endless puzzlement

Natural History, May, 2002 by Neil deGrasse Tyson

Maybe it's the need to attract and keep readers. Maybe the public just likes to hear about those rare occasions when scientists are clueless. Is that why science reporters can't file an article about the universe without describing some of the astrophysicists they interview as being "baffled" by the latest research headlines?

Scientific bafflement so intrigues journalists that, in what may have been a first for media coverage of science, an August 1999 front-page story in the New York Times reported on a mysterious object in the universe whose spectrum could not be classified. Top astrophysicists were stumped. In spite of the high quality of the data (obtained from the enormous Keck telescope), the object didn't fit into any known category of planet, star, or galaxy. It was as though a biologist had sequenced the genome of some newly discovered organism and still couldn't classify it as plant or animal. Because of this fundamental ignorance, the article contained no analysis and no conclusions.

In this particular case, the object was eventually identified as an odd quasar, but not before millions of readers had been exposed to some ignorant astrophysicists saying, "I dunno what it is." This type of reporting is rampant, and it grossly misrepresents our state of knowledge at the frontier. It's not that some astrophysicists are occasionally baffled, it's that all astrophysicists are baffled daily. Scientists cannot claim to be at the research frontier unless one thing or another baffles them.

Bafflement drives discovery, but it will occasionally lead you to make errors. The late Princeton astrophysicist Martin Schwarzschild, who pioneered the study of stellar evolution, would always tell his graduate students, "The day you stop making mistakes is the day you will stop making discoveries." A widely repeated colloquial version of Schwarzschild's refrain is "Research is what you're doing when you don't know what you're doing."

Even Isaac Newton, who formulated some of history's most successful theories of the universe, remained candidly baffled. In his later years, he said of himself:

   I do not know what I appear to the world; but to myself I seem to have been
   only like a boy playing on the seashore, and diverting myself in now and
   then finding a smoother pebble or a prettier shell than ordinary, whilst
   the great ocean of truth lay all undiscovered before me.

Richard Feynman, the celebrated twentieth-century physicist, made a similarly humble observation when he compared figuring out the laws of physics to observing a chess match when you know nothing about the game. Worse yet, you only get to peek at the game in progress every now and then. Starting with these handicaps, your task is to deduce the rules of the game. You may eventually notice that bishops stay on a single color, that pawns don't move very fast, or that the queen is feared by other pieces. But how about late in the game, when only a few pieces are left? Suppose you come back and find one of the pawns missing and the previously captured queen resurrected in its place? Try to figure that one out.

Not all scientists are as deeply baffled as astrophysicists are. This could mean that we are stupider than other breeds of scientists, but probably not. A more likely explanation is that astrophysical bafflement flows from the staggering size and complexity of the cosmos. By this measure, astrophysics has much in common with neurology: neurologists will assert without hesitation that what they do not know about the human brain vastly exceeds what they do know. This is why so many popular books on the universe and on human consciousness are published annually--nobody's got it right yet. One might also include meteorologists in the ignorance club. With so much going on in Earth's atmosphere that can affect the weather, it's a wonder meteorologists predict anything accurately. The weather people on the local news are the only reporters on the program who are expected to predict the future. They try hard to get it right, but in the end, all they can do is quantify their ignorance with statements like "50 percent chance of rain."

I wonder if the more profoundly baffled you have been in your life, the more open your mind becomes to new ideas. During an appearance on PBS's Charlie Rose Show, I was pitted against a well-known biologist to discuss and evaluate the evidence for extraterrestrial life as revealed in the nooks and crannies of the now-famous Martian meteorite ALH 84001. This potato-shaped, potato-sized interplanetary traveler was thrust off the Martian surface by the impact of a massive, fast-moving meteor--rather like the fate of loose Cheerios as they get thrust off a bed when you jump up and down on the mattress. The Martian meteorite then traveled through interplanetary space for a hundred million years, crashed into Antarctica, stayed buried in ice for an additional 13,000 years, and was finally recovered in 1984.

The original 1996 research paper on the possibility of life in the meteorite was written by David McKay, of NASA's Johnson Space Center, and several colleagues. In it, they offered a string of circumstantial evidence for Mars having once harbored life. The authors were quick to admit that each item, taken alone, could be explained by nonbiogenic processes. But taken together, they made a strong case. One of McKay's most intriguing, although scientifically empty, pieces of evidence was a simple photograph of part of the rock, taken through a high-resolution microscope. It showed a teeny-weeny worm-looking thing, less than one-tenth the size of a filamentous bacterium. I was (and still am) quite enthusiastic about these findings. But my co-panelist was argumentatively skeptical. After he had chanted Carl Sagan's mantra "extraordinary claims require extraordinary evidence" a few times, he declared that the wormy thing could not possibly be life because there was no evidence of a cell wall and because it was much too small to be life.