Welcome to “Dave’s universe,” the new blog by Dave Eicher, editor of Astronomy magazine, and astronomy and science popularizer. I’ll be bringing you new thoughts about astronomy, cosmology, nature, the hobby of astronomy, the sometimes disturbingly pseudoscientific culture we live in, and other miscellany. I hope you’ll enjoy it!
Isaac Newton — someone who knew the difference between a theory, a hypothesis, and a law. Credit: Wikimedia Commons
Ya know what really ticks me off? When people talk about some developing idea in science that may or may not be right, and they call it a theory. “NASA scientists theorize that Mars had lots of flowing water on the surface long ago, and now it’s dry and cold,” they say. You know what I say? Go back to school, skeezicks.
Scientists — and the science-literate public — let’s get the terms straight. A theory is an accepted generalization that is regarded as correct or true. So you can’t say, “Is this fact or just theory?” Modern theories are tested and confirmed by repeated observational or experimental evidence to confirm them — that’s how they become theories. They include those of gravity, electromagnetism, evolution, radioactivity, and relativity. If one believes the scientific method is the way to determine what is true, then you must accept theories as fact until they are revised or updated by more recent or nuanced knowledge.
So what do people mean when they say theory? Most people really refer to a hypothesis (from the Greek hypo, meaning less, and thesis, meaning theory). These are working ideas that are really educated guesses that may or may not turn out to be true with more investigation, information, or analysis. They are generally more reliable than sheer speculation.
On another plane are laws, which do not explain the mechanisms as theories do, but simply state principles. These are derived from experience and may be rather specific, expressed in logical or mathematical form. Examples are Kepler’s laws of planetary motion, Newton’s law of universal gravitation, and Ohm’s law of electrical current.
So let’s respect what words actually mean, people. There’s enough simple-minded confusion in this society without the people who should know better contributing to it. The next time you hear someone say, “I have a theory about why people are wearing fewer hats,” you might point out what the word actually means, or maybe you’ll just smile to yourself, or you just won’t care. Maybe you’ll think it’s uncool to say, “My hypothesis on the smaller number of bananas in the grocery store this week is still developing, but I do have an idea.”
But whether you speak correctly or not, at least be aware of what the words mean. This society has enough staggering ignorance throughout it without the science types being that way, too.