Monday, April 2, 2012
Sadly, science is coming under increasing attack from those who would like the world to be different from what science demonstrates it to be. In doing so, critics attempt to turn one of science's greatest assets into a liability.
Science strives for objectivity. Its methods have been developed to eliminate all biases, or reduce them to the greatest extent possible. Corollary to this is the concession that all knowledge is tentative. New data might cause us to change the way we look at how things work.
Scientists embrace the proclamations of some of the most renowned thinkers on the foundations of science. Popper, Kuhn, Hawking and Feynman have all expounded on science's provisional nature.
However, these philosophers/scientists would not deny that some bodies of knowledge have so much corroborative evidence they are treated as if they were "settled sciences." This is not to say contrary evidence is impossible or would be ignored, only that the chances of its occurring are miniscule.
In the maturation of any body of knowledge, the confidence one has for its validity accrues with the amount and quality of supporting evidence. That can include having explanatory power for a breadth of phenomena that would otherwise seem to require each to have an independent explanation.
The atomic theory of matter is such a theory. It accounts for everything we can say about the physical properties of ordinary matter. The theory is tested constantly in such things as chemical reactions, the behavior of electronic devices and the lift generated as air flows around the wings of airplanes.
It has never failed to explain anything for which it is relevant. Is this "settled science?" Strictly, no, but nearly every modern technology is based on the central organizing idea of atoms. It is "settled" in the sense that no one seriously thinks it will ever be discredited.
That does not discount the fact we've discovered atoms are made of even more fundamental particles. Rather than upending atomic theory, these discoveries reveal why atoms have their diverse properties. Understanding those properties explains why atoms have such utility as natural building blocks.
Neither does the theory depend on there never being discoveries of new forms of matter. Black holes and neutron stars certainly are not composed of atoms as we conceive of them in more mundane circumstances.
The notion of "confidence level" can be made quantitative and rigorous in the case of specific experimental data. Recent public news releases from physicists at the Large Hadron Collider in Europe illustrate the rigor scientists ask of themselves before making official pronouncements.
They are searching for a particle called the Higgs boson. Its discovery will tell which of the competing hypothesis explaining the most fundamental properties of the physical world is correct.
They have accumulated enough data to suggest they are on the right track, but not enough to announce a definitive discovery. What is restraining them from making an announcement?
Their experiments involve sifting through very large numbers of individual registrations in arrays of detectors. If the elusive boson exists, it will leave a characteristic pattern of registrations in these detectors -- a unique fingerprint.
Each of those detectors is also being bombarded by huge numbers of particles giving registrations unrelated to the sought boson events. They are looking for the proverbial "needle in a haystack." Additionally, measurements made on the registrations are subject to uncertainties.
Experimenters must be able to show the fingerprints they uncover are real boson events and not the result of chance coincidences of unrelated registrations. This is done with statistical analysis of the registrations and their associated measurement uncertainties.
Before announcement of discovery of the Higgs boson, the scientific community requires what is called a 5-sigma confidence level. That means the experimentalists must demonstrate, at a 99.99994% confidence level, that what they have seen is real.
With this level of certainty, they can objectively state they have not been misled by happenstance or limitations in their measuring devices.
Despite this kind of rigor, the provisional nature of science is often cited as evidence that it has no explanatory power at all. If this mindset were taken seriously we would have remained in the Dark Ages. We would be huddled in the corner of our hovels for warmth and plowing our fields with oxen.
But can we pick and chose? Are the only valid ideas those that bring us comfort? Or, is it the methodology that is important? If it is the methodology that brings us closer to valuable truths, then this same methodology must work whether it affirms our previous ideas or not.
Critics of science exploit the fact that they are held to a different standard than those who do science. There are countless hypothetical statements that can be generated by someone wanting to sow doubt. No matter how absurd the assertion, it seems some segment of the public takes it as credible.
The disparity becomes evident when one considers how little rigorous thought or analysis has been invested in questions that are posed. Often they make no sense or are so vague and ill-defined that preparation of a meaningful rebuttal is next to impossible.
Since scientists feel an obligation to address issues with the kind of rigor expected of science, rebutting every assertion -- no matter how implausible -- drags scientists into an endless morass.
For the scientific community to have high standards is not a burden. This is what is required to establish credible knowledge that can be built upon. Critics who have no standards SEmD and are held to no standard by the public SEmD take inexcusable liberties in their attacks on science. Such critics deserve to be taken to task for turning the admirable attributes of science against it.
Steve Luckstead is a medical physicist in the radiation oncology department at St. Mary Medical Center. He can be reached at firstname.lastname@example.org.