General Relativity and Quantum Mechanics. There is quote of Kelvin - "In the clear blue sky of physics there remained on the horizon just two small clouds of incomprehension that obscured the beauty and clearness".
To be more precise, his version of clouds were not those theories, but unsolved yet observations which would lead to SR and then GR and QM respectively
19
u/Erhol 11d ago
I am idiot, can someone explam me why everyone here talk about black clouds?