Houston, We Have a Problem

Plato was the first philosopher to point out that achieving a conceptual understanding of the physical world is trickier than we might think at first. In more recent times, Immanuel Kant should be given credit for trying to figure out what knowledge can be known with and without the "filtering of reality." That is, we have a notion that there is an "objective" reality, but in some sense we can never get to it, because it is filtered through our human apparatus for experiencing itour senses, minds, and emotions. What we are capable of experiencing, both as individuals and as a species, is a "subjective" realityand that limitation introduces lots of doubt as to what "reality" is. This doubt has permeated our thinking, and sometimes its effects can be less than subtle, or even subconscious. Consider how often we say, "Things are not always what they seem."

Our knowledge of physics, in some sense, compounds the problem. As far back as Galileo and then Newton, scientists have been formulating theories that seemed, in their time, very counterintuitivefor example, that bodies in motion, left to their own devices, would continue in motion forever. As the centuries passed, however, many (but not all) of these counterintuitive ideas became accepted by educated people as reasonable; the ideas became common knowledge and were assimilated as accepted doctrine. Another trendy way of saying this is that certain ideas achieved mind sharethat is, they became part of our collective consciousness.

But "modern" physics is only about 100 years old. Although the rate at which the general population accepts new scientific ideas has accelerated, many of these ideas have not actually been absorbed. There are some very good reasons for this. For one, "new"theories such as relativity and quantum mechanics deal with realms of reality outside our everyday experiencevelocities near the speed of light and subatomic distancesand turn out to be governed by laws that are very counterintuitive, even to our "modern" way of thinking. Both physicists and non-physicists alike recognize that it is very hard to explain these fundamental theories, in part because the mathematical apparatus that makes them clear to the practitioner is simply not accessible to most people. So physicists have a problem: Although their theories are correct and powerful, they are not explainable in any detail to the non-physicist.

Nonetheless, people want to understand. So what happens in most cases is that popularizers attempt to explain by analogy. This is perfectly valid. But throughout the years, the analogies themselves acquire the status of fundamental truth for the lay public and are bandied about as common clichés. Each time this happens, people like me who have some understanding of the underlying science become baffled by these overused analogies because we don't see the applicability.

Because of my training as a physicist, I want to be sure to state up front that I don't think physics, or science and mathematics in general, is the exclusive province of some exalted priesthood, and that the layperson "shouldn't talk about what they don't understand." I would like everyone to understand science and technology better. But I am also a realist about the magnitude of the problem. What I would settle for is a better understanding of what those scientific clichés actually mean so that people can either use them only when they are appropriate or replace them with better arguments. In particular, I would like to discourage the practice of smugly quoting scientific jargon to impress an audience with the correctness of one's position. This is akin to the "appeal to authority" school of persuasion. And, for my money, the best way to do this is to point out when the popular analogies actually apply and when they don't.

So here goes. See if you can spot the faux pas as we proceed. Let's start with some leftovers from classical physicsthat is, ideas that are still poorly understood, even after a few centuries of simmering in the intellectual pot.