As ripples through space arising from distant gravitational waves pass through our Solar System, including Earth, they ever-so-slightly compress and expand the space around them. Alternatives can be constrained incredibly tightly thanks to our measurements in this regime. (EUROPEAN GRAVITATIONAL OBSERVATORY, LIONEL BRET/EUROLIOS)

How To Overthrow A Scientific Theory In Three Easy Steps

The hallmark of a good scientist is changing your mind when new evidence arises. Here’s what that looks like.

Science, like many things in life, is always a work-in-progress. While a successful scientific theory has questions it can answer, natural phenomena it can accurately describe, and robust predictions it can make, it’s also fundamentally limited at any point in time. Any theory, no matter how successful, has a finite range of validity. Stay within that range and your theory works very well to describe reality; go outside of it, and its predictions no longer match observations or experiments. This is true for any theory you pick. Newtonian mechanics breaks down at small (quantum) scales and high (relativistic) speeds; Einstein’s General Relativity breaks down at a singularity; Darwin’s evolution breaks down at the origin of life.

Even our best theories of today may be superseded with tomorrow’s science. Here’s how it happens.

One of the great puzzles of the 1500s was how planets moved in an apparently retrograde fashion. This could either be explained through Ptolemy’s geocentric model (L), or Copernicus’ heliocentric one (R). However, getting the details right to arbitrary precision was something neither one could do. As interesting as both of these models are, neither one would have very much to say if another, new planet were discovered. (ETHAN SIEGEL / BEYOND THE GALAXY)

Step 0: recognizing successes and failures of the leading theory. The proverbial holy grail of scientific theories is what’s…