30 Scientific American, September 2019 Illustration by Brook VanDevelderVIRTUALLY
REALITY
HOW CLOSE CAN PHYSICS BRING US TO A TRULY
FUNDAMENTAL UNDERSTANDING OF THE WORLD?By George Musser
George Musser is
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PHYSICSPhysics seems to be one of the only domains of human life where truth is
clear-cut. The laws of physics describe hard reality. They are grounded in
mathematical rigor and experimental proof. They give answers, not endless
muddle. There is not one physics for you and one physics for me but a single
physics for everyone and everywhere. Physics often seems weird, but that’s
a good sign—it is not beholden to preconceptions. In a world that can seem
claustrophobic, where the same debates go round in circles, physics injects
some genuine novelty into life and jolts us out of the ruts we fall into.Physics is also the bedrock of the broader search for
truth. If you follow the chains of explanation in other
sciences, you eventually wind up in physics. The suc-
cess of physics and its role in grounding other scienc-
es support a broadly naturalistic, or physicalist, world-
view: that all phenomena have physical ex planations
and that notions such as élan vital or in corporeal souls
have no place in serious thought anymore. Physics
does not dictate how we run our lives or resolve press-
ing moral dilemmas, but it sets the backdrop against
which we decide these questions.
Yet if physics strikes most people as truth seeking at
its purest, it doesn’t always seem that way to physicists
themselves. They sometimes seem to be struck by a col-
lective imposter syndrome. Although they may pre sume
that the truth is out there and they are capable of find-ing it—they have to, or what would be the point?—they
have their doubts, which surface in informal discus-
sions, at conferences devoted to the broad di rection of
their subject, in renewed efforts to reach out to philoso-
phers for help, and in books and blogs for the general
public. These worries are most acute in fun damental
physics, which is not the entire subject but does play an
outsized role in it. Many fret that the Large Hadron Col-
lider has yet to turn up any new phenomena, giving them
nothing to work with to derive the next level of laws. They
worry whether proposed unified theories, such as string
theory, can ever be tested. Some deem their subject over-
ly mathematical; others think it mathematically sloppy.
Truth can be elusive even in the best-established theo-
ries. Quantum mechanics is as well tested a theory as
can be, yet its interpretation remains inscrutable.