popper progress

Science makes progress by putting forward falsifiable conjectures  -  theories which say as much as possible about the world, and which thus expose themselves as much as possible to the risk of empirical refutation; they are then subjected to a ruthless onslaught of attempted observational and experimental refutation.  When finally a scientific theory is falsified empirically, the task then becomes to think up an even better theory, which says even more about the world.  The new theory must predict all the success of the old theory, predict successfully the phenomena that falsified the old theory, and predict new phenomena as well.
...According to Popper, then, science makes progress by means of wild imagining, bold guesswork, on the one hand, controlled by ferocious attempted empirical refutation on the other hand.