I adore the creativity of the human mind. There is enough wonder in the world that you could be rendered breathless on a daily basis and still not drink the well dry. We’re capable of coming up with what seems to be a never-ending supply of amazing ideas. I enjoy theses flights of fancy even if they’re not true—as long as they’re not erroneously presented as such. It would be easy to compose a nearly infinite list of things that I would love to have be true, but no amount of wishing is sufficient to make something imaginary become something real (side note: if it’s already true, then you aren’t making).
The problem is that it’s a lot easier to invent an idea than it is to test it, and this means that bad ideas vastly outnumber good ones. “True” hypotheses exist adrift in a sea of error and noise until rigorous scientific study pulls them ashore. Science isn’t always a benevolent force, however, and sometimes things that had been mistakenly believed to be true are cast back into the ocean to drown. “Survival of the fittest” is the guiding rule in the marketplace of scientific ideas, and the strongest models destroy their weaker competitors with ruthless conviction.
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What makes a given model strong? Two things:
- accurate descriptions of reality
- predictive power
This means it is not sufficient to accurately describe the current state of affairs. To become worthy of consideration, your model must also be useful in accurately predicting the future. You should be able to use your hypothesis to reliably and correctly make claims ahead of time—”If x happens, y will be the outcome.” If a model cannot follow this pattern, it isn’t testable. If it isn’t testable, it isn’t falsifiable. If it isn’t falsifiable, it isn’t science.
Once enough evidence mounts to support your model (and outweigh any contradictory evidence—this is absolutely crucial, so I’m really doing a terrible disservice by including it only parenthetically), and you have verified that both its descriptions of reality and predictive power are superior to that of its competitors, your model can graduate into the realm of scientific theory. In science, this is a Really Big Deal™. In everyday conversation, theory basically means guess, but in science, it actually refers to a model with lots and lots of support behind it. Thus, the sentence “Evolution is just a theory!” serves only to illustrate the speaker’s complete lack of understanding of the scientific method. This is a depressingly common misconception.
This particular post does not answer the question, “What is evidence?” I intend to address this at some point because there does seem to be some confusion about what scientists are willing to accept as evidence. While that post will have to come at a later date, this article, in which Harriet Hall addresses an evidentiary claim about a form of energy healing, is an excellent example of what scientists do when they’re presented with an observation offered as evidence. She considers its full potential impact and compares it to other scientific findings. It’s a really cool exercise in taking a critical approach. There’s a lot there to deduce, if you have the desire.