Is it really "just" a theory?

Climate change, evolution, plate tectonics, gravity. What do these things all have in common? They’re often called “just theories” by critics and in a way, they’re right! All of these things, including gravity, are “just” theories, scientific theories. However, what naysayers don’t understand is what exactly is a scientific theory? So, let’s get into it.


A scientific theory is a general explanation of a wide range of phenomena that is concise, systematic and applicable to the world we live in. To be concise and systematic means that theories are constructed through the careful and studious examination and interpretation of facts. 

When we think of scientific theories like gravity we often think that this is an inherent truth, I mean it’s been around ever since Newton got hit on the head with that Apple in the 1600’s, so it must be true, right? Unfortunately, the answer is a little more complicated than yes or no. Most people would like to think gravity is true because they see it working every day of their lives. They wake up and feel the effects of gravity, they drop things, have weight, etc.

However, just because we have an extremely large data set that all points towards the theory of gravity being true, in the universe there is an infinitely larger amount of unknown information about gravity. Maybe it will just cease to exist tomorrow, or maybe it only occurs in the parts of the universe we can observe. Because we cannot know everything, it makes our quite large data set of proof that gravity exists almost insignificant next to the infinite expanse of the universe, meaning we can never conclusively say that something is true in science. 


This is not to say that gravity is just a ‘guess’. Gravity is a well thought out examination and interpretation of the how’s and why’s of the universe which is general and applicable. It has undergone many revisions (aka Einstein’s theory of relativity) when new information was discovered that could not be accounted for under the current theory. This means that the current theory is, to the best of our knowledge, the most accurate interpretation of how things are happening around us. Because, as I said before, nothing is ever conclusively true, but things can be an accurate representation of what we know so far. 

So just like gravity isn’t conclusively true, but it is the best explanation we have for the phenomena we can observe, so too is the theory of evolution, the theory of plate tectonics and the theory of climate change! All of these theories were carefully constructed and analysed to provide insight into why things are the way they are and are always getting revised when new data is discovered so they remain the best explanation.

Science is always changing and updating when we get new facts and information. Science isn’t stagnant! If compelling evidence is presented that falsifies a theory, the theory is changed so that it remains the most up to date explanation we have for how the universe works.  It’s one of the great things about science, there’s always something new to learn because our understanding of how things work is always improving.

By Jocelyn Glencross