Thursday, February 18, 2010

Settled Science


Science is the means by which we attempt to understand our universe. It is attractive to think in terms of black and white “settled” science, where grand truths are discovered and understood and embraced, unchanging forever. But reality is always a bit more complex, and a bit more messy, than we know.


For instance, we are often told that “the skin absorbs vitamin D through direct sunlight.” This conjures up a vision of swarms of vitamin D particles emanating from the sun which are then absorbed into our skin upon impact.


In reality, the sun emanates nothing but photons, some of which in the UVB wavelength (270-300 nm) interact with cholesterol molecules in the skin to create vitamin D. A more thorough understanding reveals that we must both synthesize cholesterol in the body and be exposed to unfiltered ultraviolet B sunlight (with no sunscreen or glass to block it) in order to manufacture vitamin D.


Scientific reality is always more complicated than the common understanding. And settled science is often found to be resting on quicksand. Here are a few examples:


  • For centuries, the geocentric model of the universe was believed to be settled science and was tightly embraced by the Catholic Church. According to this theory, the Earth is the center of the universe and all other objects (the Sun, other planets, and stars) revolve around it. The theory had no serious challenge until 1534 when Copernicus published his hypothesis that the Earth and other planets revolve around the Sun. But it was not until 1610 that Galileo Galilei used the newly invented optical telescope to prove the theory. (Galileo was convicted by the Roman Inquisition for his trouble and spent the rest of his life under house arrest).


  • More contemporarily, the British medical journal Lancet recently retracted a 1998 study that had associated certain vaccines with autism. Many concerned parents and consumer groups waged a 10-year campaign against vaccines based on this study, but aren't expected to be mollified that it was found invalid.


  • Functional MRI brain scans had become wildly popular among neuroscientists as a means to relate human emotions to physical areas of the brain. Many experiments were performed to determine which parts of the brain were involved with pain, love, joy, and other emotions. That was until a recent study that duplicated the results... with a salmon. A dead salmon. So much settled science out the window.

  • The UN Intergovernmental Panel on Climate Change (IPCC) was recently forced to retract its Nobel Prize winning claim that the Himalayan glaciers would melt by 2035. It was determined that the “science” behind that claim was a magazine article written by an advocacy group.

These are only a few of many cases of settled science becoming very unsettled. It seems that we, the poor, ignorant general public, should believe with reservation, keep an open mind, and maintain a healthy skepticism of things scientific. Especially when they are wrapped in an aura of religious fervor.