No one’s ever “seen” an electron, or a proton or a neutron. Or a neutron star or a black hole.
We infer their existence by applying the known “laws of physics” to observations.
But the “Laws of Physics” keep changing. I’m all a’twitter over the seven (eight?) new dimensions holding string theory together. And what about that dark matter sneaking around every where?
Don’t even get me started on the Universe’s expansion actually accelerating. Whew!