Science Is Not about Getting More "Likes"

Loeb, Scientific American

Social media measures the success of an idea by how many “likes” it gets. Scientific success is measured by how close the idea is to the truth. [..] Surprisingly, this naive expectation is not manifested throughout the current landscape of theoretical physics.

The mathematical constructions of supersymmetry, string theory, Hawking radiation, anti-de Sitter/conformal field theory (AdS/CFT) and the multiverse are currently considered irrefutable and self-evident by the mainstream of theoretical physics, even without experimental evidence to support them. In the words of a prominent physicist at a conference that I attended a few months ago: “These ideas must be true even without experimental testimony in their favor, because thousands of physicists believe in them and it is difficult to imagine that such a large community of mathematically-gifted scientists would be wrong.”

Once a mainstream culture grows to this self-sustaining phase, it does not need external verification. The ideas it advocates are reasoned to be inherently correct based on their mathematical beauty, with experiments serving the optional role of narrowing down the wide range of possibilities allowed by the flexible mathematical framework. Past generations of theoretical physicists were less arrogant; among the possibilities they contemplated was one that allowed their theories to be proven wrong by experimental data.

But the current self-sustained culture thrives in its own theoretical sauce, dismissing alternatives because they are getting fewer “likes.” When award or grant-allocation committees are populated by advocates of the popular paradigm, it could take centuries to correct a path that should not have been taken in the first place. Large enough groups can legitimize speculative concepts without adhering to Carl Sagan’s statement “Extraordinary claims require extraordinary evidence.”

To his I would add the basic lesson from Galileo Galilei that experimentation is crucial because extraordinary groupthink leads to extraordinary ignorance. Before Galileo’s observations, it was popular to construct beautiful abstract frameworks on the assumptions that heavy objects fall faster than light objects under gravity and that the sun revolves around the Earth.

Is there anything new and alarming about the self-sustaining culture of some current physicists or was it always around, even after Galileo? My personal impression is that half a century ago, theoretical physicists were far more disposed to the concept of experimental vindication. But right now, if we double down on supersymmetry as being just around the corner when the Large Hadron Collider did not find evidence for it; if we insist that Hawking radiation must exist despite the paradox that is spells between Einstein’s general relativity and the fundamental principle of no information loss in quantum mechanics; if we posit that the multiverse must exist, and anything that can happen will happen in it an infinite number of times—without evidence to support this notion—then we are betraying the trademark of physics as an effort to describe the reality we live in.