The day before he was elected as Pope Benedict XVI, Cardinal Joseph Ratzinger addressed the cardinals assembled in St Peter's and warned that society was "building a dictatorship of relativism that does not recognize anything as definitive." The "I" becomes "the ultimate measure."

That was in April 2005. Just 100 years earlier, Albert Einstein published his special theory of relativity.

Relativism and relativity are said to be quite different. One is a philosophy in the realm of culture and morals; the other is strictly scientific. But I wonder how different they really are. When I wrote "Questioning Einstein: Is Relativity Necessary?" (Vales Lake, 2009) I realized that the central claims of relativity and relativism are very similar.

My book was based on work by Petr Beckmann, a Czech immigrant who defected to the U.S. and taught electrical engineering at the University of Colorado. He was a genius, and a friend of mine, but his book was technical and a plain-language version was needed. He died before I could finish it.

His main point was that the physical anomalies that led to relativity can be explained without it. For example, the famous equation "E = mc2" was derived using relativity theory. But later Einstein re-derived it, this time without relativity.

A frequently heard statement of cultural relativism goes like this: "If it feels right for you, it's OK. Who is to say you're wrong?" One individual's experience is as "valid" as another's. There is no "preferred" or higher vantage point from which to judge these things. Not just beauty, but right and wrong are in the eye of the beholder. The "I" indeed is the "ultimate measure."

The special theory of relativity imposes on the physical world a claim that is very similar to the one made by relativism. Here is a brief summary.

In the 1880s a scientist named Albert Michelson searched for the "ether" - the medium in which light waves were thought to travel. But his equipment could not detect it, and that came as a big surprise. It was as though a man running with his shirt off could feel no wind on his chest.

Einstein resolved the problem by claiming that a light ray keeps moving toward you at the same speed no matter how fast you move toward it. Light's speed is unaffected by the observer's velocity, Einstein said. That was strange because other waves don't behave that way. Move toward a sound wave, and you must add your speed to that of the oncoming wave to know its approach velocity. That didn't apply to light, apparently.

So how come the speed of light always stays the same? Einstein argued that when the observer moves relative to an object, distance and time always adjust themselves just enough to preserve light speed as a constant. Speed is distance divided by time. So, Einstein argued, length contracts and time dilates to just the extent needed to keep the speed of light ever the same.

Space and time are the alpha and omega of the physical world. They are the stage within which everything happens. But if they must trim and tarry whenever the observer moves, that puts "the observer" in the driver's seat. Reality becomes observer-dependent.

Again, then, we find that the "I" is the ultimate measure. Pondering this in Prague in the 1950s, Beckmann could not accept it. The observer's function is to observe, he said, not to affect what's out there.

Relativity meant that two and two didn't quite add up any more and elevated science into a priesthood of obscurity. Common sense could no longer be trusted.

The contraction of space and the dilation of time are deductions from relativity. But they have not been observed. In easy Einstein books, drawings of spaceships that are shortened because they are moving at high speed are imagined by artists in accordance with theory. No physical experiment has ever detected length contraction.

Atomic clocks do slow down when they move through the gravitational field. But the slowing of clocks and the slowing of time are very different things. GPS has "relativistic" corrections to keep its clocks synchronized. But those corrections depart significantly from Einstein's theory. They refer clock motion not to the observer but to an absolute reference frame, centered on the Earth.

So there are reasons to think that experiments with atomic clocks have falsified special relativity. (The general theory is another matter. Beckmann said it gave the right results by a roundabout method.) Anyway, consider this: Relativity and relativism arose at about the same time, and the scientific claims surely bolstered the cultural applications. Now there is skepticism about both. Maybe, in time, they also will fade together.

Tom Bethell is a senior editor of the American Spectator.

© Copyright 2010 The Washington Times, LLC.