Science "faction": Is theoretical physics becoming "softer" than anthropology?

Two recent science stories, one in anthropology and the other in physics, have me wondering which field is "hard" and which "soft." The first story involves the decision of the American Anthropological Association to delete the word "science" from its mission statement. That step provoked squawks from anthropologists who've struggled to counter the image of their field as a branch of the humanities. Whereas sciences are "empirical," the humanities are "analytic, critical or speculative," as Nicholas Wade put it in The New York Times.

Science-oriented anthropologists want their field to be lumped together not with historians and literary critics—God forbid!—but with physics, supposedly the gold standard of hard science. The irony is that parts of physics are less empirical and more speculative than the most humanistic anthropology. I'm not talking about what the physicist Sean Carroll calls the physics of "everyday life"; as Carroll pointed out last fall on his blog Cosmic Variance, physicists' understanding of the reality we can access in experiments is rock-solid.

But in part because of this success, some ambitious physicists have increasingly ventured beyond the boundaries of measurable reality into the unmapped realms where dragons roam. That brings me to the physics story in the news. Roger Penrose and V. G. Gurzadyan recently proposed that minute ripples in the cosmic microwave background—the afterglow of the big bang—originated from the collision of monster black holes in another universe that preceded our cosmos, and may have spawned it; moreover, our universe might be just one of an infinite series spawned by such cataclysms.