An English literature professor remarked to his graduate students in a class on 20th century American novelists, “Point of view is everything in fiction.” He was talking about the central role of the narrator in novels. In life as in fiction, what is told depends on who does the telling, as historians have long recognized. Scientists, however, like to think that what they see and tell is more or less independent of the identity of the see-er, despite the admonitions of Heisenberg, who pointed out that the see-er himself or herself is implicated deeply at the quantum level in what is seen (i.e., our ability to measure a particle’s position or momentum, but not both).
Thomas Gregor made a movie of fruitfly embryo development. He began his scientific career in Europe as a physicist, came to Princeton in the United States as a theoretical chemist, and made the fruitfly movie in conjunction with a research collaboration among three Princeton scientists: William Bialek, a theorist and professor of physics; David Tank, an experimentalist who is professor of both physics and molecular biology; and Eric Wieschaus, a developmental biologist who is professor of molecular biology and co-recipient of the 1995 Nobel Prize for Physiology or Medicine.
The movie features the half-millimeter-long fruitfly embryo. Supporting roles are played by the earlier sub-micron stages of embryo development: Cell nuclei come to the surface of the embryo; they are somewhat ordered but not completely ordered as in a perfect lattice. The nuclei divide and duplicate, and the lattice disorders. The cells rearrange and order again. That process repeats. For some stages, the duplication of the nuclei seems almost perfectly synchronous. Then the action becomes asynchronous in such a way that a wave appears to pass over the embryo.
“Physicists watching the movie immediately want to know how ordered things are in space,” said Bialek. “And how accurately synchronized in time — and ask what is the signal that generates the synchronicity. On the other hand, biologists watching the movie are much more engaged by the slightly later phenomenon of gastrulation — whereby the embryo assumes a form consisting of a hollow, two-layered cellular cup. Biologists focus on the large-scale movements of the embryo turning into itself. Physicists are attracted to the early stage of simple but rich dynamics.”
Admittedly the findings about disciplinary points of view are merely anecdotal, but Bialek said, ”It is fascinating to me to watch the reactions. There is something about our culture as physicists that means that when confronted with this movie, physicists who know absolutely nothing about the relevant biology will ask similar questions, which are different from the questions the biologists ask.”