It’s Just a Theory – Not!

During any given week, someone on a television show will be asked about the perpetration of a crime or some other mysterious act and in response will utter words to the effect of “I’ve got a theory about that.” What the person will mean is that he or she has a suspicion, a hunch, a guess based on little if any physical evidence. When scientists talk about a theory, they are talking about something entirely different.

I have a suspicion/hunch/guess that so many in the general public are so easily mislead on issues concerning climate change and evolution because they do not understand what the term “theory” means in science. My guess is that their understanding of the term “theory” comes from watching TV crime shows because most of them also seem to give far more weight to the term “law.” They don’t question the “law of gravity” as they do the “theory of evolution.” By this measure, since Newton’s ideas about gravity are expressed as a “law” and Einstein’s ideas are expressed as the “theory” of general relativity, Newton’s ideas must have been proven to be superior. But that’s not how it works in science, where for all intents and purposes, theories trump laws!

I think one of the major failings of science over the centuries has been its conscription of terms that are very much a part of the common vernacular but are put to use by scientists in completely different context. When scientists use the term “theory,” they are talking about an explanation of observed physical phenomena, facts, an explanation that fits all physical evidence and has been vetted over and over again. Most importantly, it is an explanation that has been successfully used to predict new observations and evidence. Contrast this to a “law,” which is a description of a well-observed phenomenon, and a “hypothesis,” which is probably the term that most closely approximates a guess, but a guess that is highly educated and based on observations and evidence. Some in the scientific community would dispute my equating a hypothesis with an educated guess and would argue that it, like a theory, is an explanation of a narrowly defined phenomenon.

This is not to say that scientific theories are set in stone. In the face of new and verified observations and evidence, theories can be refined or in some cases even discarded altogether. However, the longer a theory stands the test of time and repeated challenges, and the greater the number of new observations and evidence it has successfully predicted or explained, then the stronger that theory becomes. Let us take, as a prime example, the theory of evolution. This has become the favored punching bag of politicians who are either scornfully ignorant or shamelessly cynical. With a general public that was better informed, these politicians would be exposed and dismissed as the charlatans they are.

Since Charles Darwin set sail in 1831 on the HMS Beagle, and published in 1859 On the Origin of Species, scientists have made discoveries and advances in genetics and molecular biology that this extremely modest and unassuming English naturalist could not possibly have imagined. Darwin based his explanation of evolution most famously on his observations of finches in the Galapagos Islands, focusing primarily on how different species had adapted differently shaped beaks in response to different environmental pressures. Today, scientists can compare the DNA that comprises the human genome to the DNA that makes up the genomes of chimpanzees, mice and numerous other vertebrates. Through such comparisons, they can determine with remarkable precision when two different species last shared a common ancestor. For example, based on the number and location of conserved DNA sequences, mice and humans last shared a common ancestor about 75 million years ago. Humans and chimpanzees shared a common ancestor as recently as six million years ago. No surprise then that the human and chimpanzee genomes are 98-percent identical (the dramatic differences arise from how and when the genes are turned on/off and the combinations in which two or more genes act together).

Yet, despite the rigorous challenges that modern science has brought to bear on Darwin’s theory, the old naturalist’s original explanation of evolution has held up surprisingly well and is universally accepted by the entire scientific community. The slogan often bandied about by those ignorant and/or cynical politicians I mentioned a moment ago reads: “Teach the controversy!” There is no controversy. The notion that there exists an ongoing scientific controversy regarding the theory of evolution is a fiction fabricated and deployed to exploit the uninformed. Why would anyone foster such a fraud? For the same two reasons most frauds are fostered – political or monetary gain.

This leads me to a few words about “creationism,” but only a few as this blog is about science. Creationism is neither a theory, a hypothesis nor a law. It does not offer an explanation of observed phenomenon or physical evidence, nor does it describe any observations or evidence. It cannot be used to predict new observations or the discovery of new evidence. Creationism, and its twin-by-another-name, “intelligent design,” attributes the world in which we live to the actions of a supernatural being. End of story. There is no way to test the validity of this idea nor is there any need to conduct such test for no further understanding is necessary. The supernatural being did what the supernatural being did and that is all you or anyone else needs to know. Forget this trying to understand stuff and go do something useful – like mow the lawn or clean your house.

Let’s be honest. If you remove the religious element from creationism, what you have is magic. The idea of a supernatural being creating the universe and Earth within the past 10,000 years is as whimsical as the idea of a rabbit that once a year hides color-dyed chicken eggs for children to find, or an overweight elderly white man in a red suit delivering presents to those same children a few months later.

I have stones in my backyard that are more than 10,000 years old (radiometric dating of terrestrial and lunar rocks puts the age of Earth at approximately 4.5 billion years) but hey, it’s magic right? And when it comes to magic there are no rules and logic takes a holiday. I can see the appeal of magic because it is easy – all you have to do is believe. The science fiction writer Arthur C. Clarke famously noted that to a society of primitives, advanced technology will seem like magic. Apparently in a society of advanced technology, there will always be those members who prefer to stick with magic and remain primitives.