Biology largely retains its faith in the unguided Darwinian mechanism, despite mounting evidence against its power to generate complex life forms. Is it any wonder that this insouciance would rub off on neighboring fields, with offices just a floor above or below in the Science Building?

No, it’s not a wonder. Not at all! Everyone who has raised kids can confirm this: If your child spends too much time with someone else’s kid who’s got bad character traits, those are likely to influence your own darling progeny. So we see how the commitment to Darwinian evolution — in defiance of the evidence, adhered to as a defense against theism — has rubbed off, indirectly, on physicists. I don’t mean that physicists are crossing the frontier between disciplines to take up the Darwinian banner itself, but they are showing signs of the same casual attitude to evidence, and with similar motivations.

A fascinating piece in the New York Times by astrophysicist Adam Frank and physicist Marcelo Gleiser describes “A Crisis at the Edge of Physics.” They ask, “Do physicists need empirical evidence to confirm their theories?”

Answer: not necessarily, not anymore. Supersymmetry, string theory, and multiverse theory are the cases in point:

How are we to determine whether a theory is true if it cannot be validated experimentally? Should we abandon it just because, at a given level of technological capacity, empirical support might be impossible? If not, how long should we wait for such experimental machinery before moving on: ten years? Fifty years? Centuries?

Consider… the cutting-edge theory in physics that suggests that our universe is just one universe in a profusion of separate universes that make up the so-called multiverse. This theory could help solve some deep scientific conundrums about our own universe (such as the so-called fine-tuning problem), but at considerable cost: Namely, the additional universes of the multiverse would lie beyond our powers of observation and could never be directly investigated. Multiverse advocates argue nonetheless that we should keep exploring the idea — and search for indirect evidence of other universes.

The opposing camp, in response, has its own questions. If a theory successfully explains what we can detect but does so by positing entities that we can’t detect (like other universes or the hyperdimensional superstrings of string theory) then what is the status of these posited entities? Should we consider them as real as the verified particles of the standard model? How are scientific claims about them any different from any other untestable — but useful — explanations of reality?

Recall the epicycles, the imaginary circles that Ptolemy used and formalized around A.D. 150 to describe the motions of planets. Although Ptolemy had no evidence for their existence, epicycles successfully explained what the ancients could see in the night sky, so they were accepted as real. But they were eventually shown to be a fiction, more than 1,500 years later. Are superstrings and the multiverse, painstakingly theorized by hundreds of brilliant scientists, anything more than modern-day epicycles?

Note the telling language. Imagining a multiverse “could help solve some deep scientific conundrums about our own universe (such as the so-called fine-tuning problem), but at considerable cost.” The conundrum, cosmic fine-tuning, is a problem for materialists because it points to intelligent design. The cost is asserting a scientific idea untethered from the available evidence. For many in the field of physics, the cost is worth it if it seems to dissolve the conundrum.

If a scientific idea provides a weapon to ward off theism, then grab it and hold on no matter what nature itself seems to demand that you conclude. Where have you heard thinking like that before?

Image credit: NASA.