Social media was abuzz with the news that gravitational waves have been detected.

Gravity waves were predicted by general relativity (even though Einstein was uncertain whether or not they really existed)

In the same way that light waves are produced by electromagnetic interactions, gravity waves are produced by the gravitational interactions between masses. But because gravity is a much weaker force than electromagnetism, only the interactions of incredibly massive objects are within our ability to measure.

While the fact that gravity waves even exist is astounding, one of the other things they confirmed was that the speed of gravity equals the speed of light.

This means that the graviton (if it exists) must be massless.

There is something really strange and bizarre about imagining that your body is being stretched and squeezed by waves in spacetime generated more than a billion years ago, even if the expansion and compression is in fractions of a picometer.¹