Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, G is for:
We’ve all heard the story about how Isaac Newton discovered gravity.
But Newton’s discovery was not just that objects fall to the ground. Other people had noticed this before.
Newton’s real breakthrough was realizing that the same force which causes apples to fall also holds the Moon in its orbit around the Earth. Previously, it had been assumed that earthly physics here on the ground must be different from the celestial physics of the Moon, the planets, and the stars.
This is why Newton called his discovery the law of universal gravitation: because he believed his law must apply no matter where you are in the universe. Of course Newton didn’t know the planet Mercury was “breaking the law,” so to speak, nor did he know about black holes.
But I don’t want to get into Einstein and general relativity. Not today, at least. For today’s post, I just want to focus on the word gravity itself. Where did that word come from?
I used to think it was really cool how a scientific term like gravity had spread out and acquired additional shades of meaning in the English language. Think of a phrase like “the gravity of the situation,” where gravity means something like importance or seriousness.
But I’ve since learned that it actually happened the other way around. English originally borrowed gravity from French, and the word can be traced back to Latin. It originally meant something like dignified or serious. It could also mean weighty, in the sense of either metaphorical or literal weightiness.
But the idea of defining gravity as a physical force permeating the universe, causing objects to be attracted toward one another—that’s apparently an invention of Newton and his contemporaries. So now I think it’s really cool how science can take a word we already had and give it a whole new meaning.
Next time on Sciency Words: A to Z Challenge, we’ll talk about humans. Oh no, wait… that’s not my pick for the letter H. I have a much more interesting H-word to talk about; but humans will be involved.