I was recently reading a very interesting article in Science News, and came across this part of it. (The payoff sentence is at the end, but bear with me.)

When physicists smash heavy atomic nuclei together with sufficient energy, the atoms’ protons and neutrons break up. For less than a sextillion of a second they melt into a blob called a quark-gluon plasma. It’s similar to the state of all matter in the first microseconds after the big bang.

Beginning in 2000, Dam Son, now at the University of Washington in Seattle, and his collaborators wanted to calculate a quark-gluon plasma’s viscosity—roughly speaking, a measure of how quickly the plasma will dampen turbulence within it. In principle, one should be able to do such calculations using the known equations of particle physics. When quarks are not bound together, though, those equations become extremely hard to solve.

But in a quark-gluon plasma, quarks will experience extremely intense forces, whose strength does not vary appreciably as the particles move. That makes the plasma’s behavior a good approximation of the conformal field theory that rules Maldacena’s sphere at infinity. Starting from that assumption, Son showed that Maldacena’s duality translates the physics of plasma turbulence into that of black hole earthquakes.

A gravitational disturbance, Son says, will alter a black hole’s shape, which is otherwise that of a perfect sphere. In response, the black hole will “oscillate, radiate energy, and settle down to be spherical again.” Son and his collaborators calculated how quickly the seismic waves on the black hole’s surface will dampen down. Translated back, the calculation suggested that the viscosity of a quark-gluon plasma could be much smaller than physicists thought possible.

Initially, some nuclear physicists were nonplussed, to say the least, about the idea of doing nuclear physics using black holes. “The first time I heard about it, I literally thought it was crazy,” says William Zajc of Columbia University in New York City.

In 2005, however, physicists at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, N.Y., announced the results of an experiment that collided nuclei of gold atoms, melting them into a quark-gluon plasma (SN: 4/23/05, p. 259). The stuff’s viscosity seemed close to Son’s prediction, says Larry McLerran, a RHIC (pronounced “rick”) experimentalist.

Many physicists working at RHIC—Zajc being one of them—changed their minds about Son’s calculation. “It’s far more useful than we ever imagined,” he says. “The fact that it was done in some higher-dimensional space and it involved black holes—well, that just added to the intrigue.”

Since then, some of the RHIC physicists have revisited certain theoretical assumptions used to interpret the experiment’s data. As a result, some say it’s no longer so clear that the viscosity is as low as Son claimed it could be. Not everyone buys the black hole model of a quark-gluon plasma. “It’s certainly interesting, but you have to be very skeptical about it,” he says.

Get that? Although the statement is interesting and seems at first blush to work, one must be skeptical about it. In other words, more evidence is demanded. It must be justified by actual observations and experiments. It is not simply accepted.

Very refreshing. And no wonder this country is frightened of science—the last thing the ruling establishment wants is skeptical citizens.