In science, an anomaly refers a new observation or experimental result that seems to fly in the face of conventional, well established scientific wisdom.
Anomalies are an important part of the scientific discovery process. Sometimes a particular anomaly or the collection of anomalies can precipitate a revolution in scientific thinking – dethroning an old way of thinking and bringing in a new one. A canonical example of this is the Michaelson Morley Experiment, which started the ball rolling towards the Theory of Relativity.
Anomalies are important, but they are also frequently misunderstood and frequently misused.
Peddlers of pseudo-science love anomalies. Anomalies are the raison d’etre of crank scientists the world around. It gives them a justification for their “new paradigm”. When asked what the scientific basis is for their claims they answer “because anomalies”. And there is an easy bait and switch going on:
“These anomalies falsify the scientific orthodoxy! So you might as well buy my theory instead, <wink> <wink>.”
The whole thing boils down to a confusion about falsifiability in science. Falsifiability is one of the key hallmarks of science. Philosopher Karl Popper defined science by the very idea that it makes claims that are testable and can therefore be proven wrong (falsified) by contradicting observations. Science, in the Popplerian sense, is always tentative. But, Richard Feynman says it better than I can:
(His whole segment on the scientific method can be found here. it’s great.)
Scientists take falsifiability very seriously. We take anomalies very seriously. But, the relationship between the two is where some people get confused. A good number of people are under the impression that theories are falsified with a dramatic moment of unmasking, as in “Scooby Doo, et al” (pictured above). But, science rarely happens this way. It is not so simple.
What we often refer to as a theory in science is not a singular thing. A theory is a collection of many ideas and explanations that systematically explain observations. Perhaps any one observation may be falsified, but it’s hard to falsify an entire theory in one fell swoop. In fact, if we were to throw away conventional scientific wisdom at the first sight of any anomalies, science would fundamentally lack stability.
A good scientist has the discipline to abandon an idea when it’s wrong. But, equally important is the discipline not to immediately give up on an otherwise good theory. A well-established or mature scientific framework is built on decades of observations, empirically established first-principles, and countless successful predictions. To dismiss mature science on the basis of a few anomalies would be premature, and in many cases wrong headed.
Scientists are constantly looking for new ways to push the envelope. We like anomalies because they’re way more interesting than confirming what we already know. We seek them out. We develop new instrumentation to give ourselves new sensitivity. We design new experiments to look in places we never looked before. And, the thing about venturing to new places is: you end up with a lot of false starts – mistakes, misunderstandings, experimental artifacts.
Anomalies are thus inevitable. So the right attitude is “trust but verify”, bearing in mind that verification takes time and work.
Sometimes anomalies completely dethrone the current paradigm. Far more often….they. just. don’t.
Here are some of the common fates of anomalies, from most likely to least:
1) It turns out to be an experimental artifact, a mistake. In my own field, the observation of neutrinos traveling faster than light turned out to be a consequence of a loose cable.
2) It is a real effect, but incomplete. A missing piece of the the observation, once found, restores consistency with the theory. Feynman gives a good example of this – superconductivity. At first, the discovery of superconductivity seemed to completely contradict the known understanding of atomic physics. Eventually it was realized that a very subtle quantum mechanical phenomena explained the effect. Once this is taken into account, atomic theory is again fully consistent.
3) It represents a real problem with the theory, but the essence of the theory survives with some modification (ranging anywhere from minor to major).
4) By itself or in combination with other anomalies, it dethrones the prevailing wisdom
If you’re a person who rejects broadly accepted science, you’re inclined to see any anomaly as your own Scooby Doo ending! It’s the moment you’ve been waiting for, when orthodoxy collapses and you are vindicated! It is also too easy to use these anomalies to draw inexperienced skeptics away from established science and into the rabbit hole of quack science. Which brings me to one last essential point:
Old theories are almost never dethroned by anomalies, UNTIL there is a superior alternative that explains both the old observations and the new anomalies. The really frustrating part of the pseudo-scientific bait-and-switch is the innuendo:
“Well if the mainstream science is wrong, then anyone’s guess is as good as anyone else’s. So, you might as well choose mine”
This is simply not true. In the face of deep rooted anomalies, one would be naive to blindly hold on to the established model. On the other hand, it is naive and unskeptical to settle for the first new theory to pass your way. The old paradigm survived a serious shaking and any new theory should do the same…and then some. Only hindsight is 20×20, and few people in history can claim to have successfully “picked winners” early in a scientific crisis.
So when people without any scientific credentials drive up in tinted vans, offering you the sweet indulgence of “anomalies”, just say NO and run to someone you trust :).
But seriously: I may sound like a defender of the orthodoxy. My colleagues and I take anomalies very seriously. They are the constant talk of the lunch table. The faster-than-light neutrino measurement, ridiculous as it seemed, prompted a serious and genuine discussion of theories that could violate relativity. A lot of work went in to understanding the measurement. The measurement was redone by two other experiments and neutrinos went back to being slower-than-light. And, in it’s own Scooby Doo style ending, the culprit turned out to be a loose wire.
An important, if not THE important, value of science is the willingness to revise or replace wrong ideas. But, as with anything, this is not a carte blanch principle. When anomalies appear, we should welcome them but we must also exercise care and patience.