Most of the essay 5 scientific myths you probably believe about the universe is stuff only a science geek could love. However, item number five is a wonderfully concise explanation of the scientific term “theory” that anyone can understand.
The Big Bang: just a theory. Gravity: only a theory. Even the entire field of putting these ideas together is called theoretical physics. It’s not like these are facts, truths or even laws. They’re only theories.
But that completely misses the point of what a scientific theory is. Facts are the most basic elements of science. You make an observation and that’s a fact. You make a measurement and that’s a fact. A single experimental data point is a fact, and so we collect as many of them as we can, and devise setups to collect even more. When you notice that things are correlated, that relationships between various measureables/observables obey a particular form or equation, that’s a law. It’s only when you can put together an overarching framework that not only explains the facts and encompasses the laws, but also makes new predictions about things you can go out and observe that you’ve got a scientific theory. If you then go out, validate and verify your theories and push them to the absolute limits, that you’ve got a theory as good as the Big Bang or General Relativity.
In other words, science requires a very high threshold of evidence before a hypothesis rises to the level of a commonly accepted theory. Even then, it’s still not the final answer.
And it’s true: even a theory as robust and accepted as these examples will never be the final answer. There’s always more to learn, more boundaries to cross and more questions to uncover and probe. But the best accepted theories of the day are as close to the truth as science can ever get, even as we always strive to get closer. Better to understand reality, with all the nuance involved with it, as best as we actually can, than to persist in a comforting myth.
Now maybe your uncle who says “theories” the earth is 6000 years old are just as valid as that of the Big Bang can better understand the use of the word theory.
Or maybe not.