Did you know?

Gravitational waves, like light waves, get more and more feeble the further away we are from the source. Experiments like LIGO and VIRGO that detected the first gravitational waves have an incredible precision. In fact they can observe displacements as small as 10⁻¹⁸ meters.

Gravitational waves are waves of the spacetime so their passage make object moves with respect to each other and we can measure that displacement. 10⁻¹⁸ is an incredibly small number: To comparison the size of an atom is around 10⁻¹⁵, so the displacement they can measure is 1000 times smaller than the size of an atom.