The Business of the Holes

April 25, 1995|By ROBERT BURRUSS

KENSINGTON — Kensington. -- The cultural effects of the main physical-science discovery of this century have not yet even begun to reach the world.

It's easy to imagine that Isaac Newton's ideas about force and mass, in the late 1600s, took at least a century to move Western culture fully into its deterministic mode -- namely, to the view that destiny is predetermined, and that with enough information about the present state of the world, we'd be able to predict the future absolutely. No more of this 30 percent chance of rain on Wednesday, stuff; we'd know, absolutely, that, yes, it'll rain precisely at 3 p.m. on Wednesday next week . . . or next century.

Part of what scares people away from science is the feeling that scientists are unusually smart people who actually know things. In fact, the work of science is increasingly one of figuring out how best to pose new questions as basic research uncovers more evidence that material reality might forever be beyond ultimate understanding.

An irony here is that we can shape matter, build with it, drive it, that we are made of it, but . . . matter -- us -- cannot comprehend itself. No scientist has more insight into the ultimate nature of matter than you, me, Einstein or Elvis.

The thing that science conjured early this century was best labeled by the late physicist Richard Feynman as ''the business of the holes.'' And it's worth noting that not even the guys who assembled the machinery used to ''see'' this ''business of the holes'' can explain it.

Imagine two holes in a steel plate. Each hole is maybe an inch in diameter, and they are two inches apart. If you fire a machine gun in the general direction of the hole, most of the bullets will be stopped by the plate, but some will get through one hole or the other.

If a second plate or a screen or sheet of paper is placed several feet behind the plate with the holes, the bullets that pass through one hole will hit that second screen in a certain area, while bullets passing through the other hole will hit an adjacent area.

Electrons instead of bullets were used in the actual experiment. And one of two things happened.

If the experimenter used detectors to ''see'' which hole each electron passed through, then the electrons behaved just like bullets: they got through one hole or the other or were stopped by the plate. But if the electrons were not watched -- if instead the experimenter simply examined the second screen where the electrons piled up, well . . . the pattern could best be interpreted as if each electron had passed through BOTH holes.

How could that be?

The interpretation in the 1920s, as now, is that the electrons, when not observed in their trajectories, act like waves; that is, each electron approaches the two holes as if it were an expanding wave front, analogous to a wave front that expands across the surface of a pond when a stone is dropped in, and part of the wave passes through each hole.

In summary, if an experimenter is -- by whatever means -- watching the electrons, they act like particles; if not watching, they act like waves.

Feynman said, ''When referring to quantum mechanics, don't ask how that can be, because no one knows how that can be.''

The business of the holes is at the foundation of quantum mechanics, a byproduct of which -- and not directly related to LTC the holes -- is the Uncertainty Principle, which, by the way, is as incomprehensible yet nearly as simple to describe as the business of the holes.

Newtonian determinism, and its siblings, cause and effect, are firmly part of Western culture, including its science, where, really, they have no further business; a scientist cannot say that smoking causes cancer, only that the two correlate.

Within the next century or so, the implications of quantum mechanics and wave/particle duality will displace Newtonian determinism from its place in world culture. Cause and effect might pass from our style of thinking where, especially in the West, it has endured for three centuries. Or, perhaps, determination will peacefully coexist with free will in a kind of determinism/free-will duality.

There is another irony. Even though Western religion says God created the world, one product of God -- the base matter at our feet -- is generally considered by Western culture to be profane, boring, cheap and ''nothing but matter.'' In the meantime, science looks upon this creation of God and sees mysteries that might forever be beyond the understanding of the eyes and hands of the soil, us humans of the humus . . .

There's a joke about a little old lady who goes up to the stage at a local school where a physicist has just completed a popular lecture on the present theory of the universe. She says, ''You're completely wrong, the world is on the back of an elephant.''

The physicist replies, ''Yes, but what is the elephant standing on?''

The lady says, ''Another elephant -- and don't even bother asking, sonny boy, it's elephants all the way down.''

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