A big scientific discovery proves to be a mirage

About 2.5 months ago, I posted an entry here about a major recent discovery in cosmology that was already being called into question at that time.  (See “A Waste of Good Champagne?”)

The definitive verdict now appears to be in:

An article in the Economist for 7 February 2015 reports on a joint paper in Physical Review Letters written by 274 scientists associated with Planck, the orbiting telescope belonging to the European Space Agency, and with BICEP2, an astronomical instrument functioning from Antarctica.

One of the biggest science stories of 2014 was BICEP2’s apparent discovery of primordial gravitational waves — essentially ripples in space-time — produced mere microscopic fractions of a second after the Big Bang.  Such waves would confirm the cosmological model called “inflation,” which holds that the universe expanded extremely rapidly (far faster, indeed, than the speed of light) during the first instants of its existence.

“This theory,” the Economist observes, “solves several knotty problems in cosmology, and so most astrophysicists work on the assumption that it is true.”

Unfortunately, the scientists working with BICEP2 were misled, despite their best efforts, by interstellar dust.  They thought that they had been able to factor such dust out of their calculations, but, as it turns out, they were mistaken.

Besides the obvious extrinsic interest of the question and of the research that has gone and continues to go into it, I’m struck by at least two things:

First, there is science’s admirable capacity for self-correction.  Some critics like to contrast this with what they love to depict as religion’s obstinate insistence on demonstrable falsehoods.  But it’s not that simple.  The physical sciences self-correct fairly neatly and easily and quickly.  The biological sciences rather less so.  And the social sciences much less so.  This isn’t because physics and chemistry are superior modes of seeing the world that should be adopted everywhere.  It’s because of the special properties of their particular area of investigation.  Experimental verification is far more difficult in sociology — and, for that matter, in geology — than it is in particle physics.  And it’s essentially impossible in such fields as literary criticism, Palestinian archaeology, and cultural history.  Applying the thought-processes of physics to Shakespeare, to the excavation of Tel Gezer, or to the rise of the Renaissance would be silly and fruitless.

Experimental verification and falsification are virtually impossible, too, in the very fields that deal with the most humanly-significant questions.  It’s not obvious that Kantianism represents a linear progress upwards and onwards from Aristotelianism, and that it has now been eclipsed by existentialism, say, or by logical positivism.  Neither philosophy nor religion works that way.  Not because thinkers in those fields are stupid, or dishonest, but by reason of the special properties of their subject matter.

Second, I think it significant to note that scientific theories (as, here, in the case of the inflationary model of the Big Bang) don’t always, as many imagine, simply flow from the data.  Cosmological inflation is an elegant theory still awaiting empirical confirmation.