This is how a lot of science works. You guess that something exists and works a certain way, you build a model, then you see what measurable things that model

This is how a lot of science works. You guess that something exists and works a certain way, you build a model, then you see what measurable things that model predicts. Gravitational waves themselves were "imaginary" for a century or more (depending on who you credit) until they were directly measured in 2015.