When it comes to science, ever since the Renaissance period, we believe or at least like to believe that scientific principles are based on observations and experiments. Newton’s apple and Galileo’s falling bodies’ experiments are what ushered in the scientific mode of thinking.
If we look at its early beginnings, seeing was believing in science (especially if you did not want to be declared a heretic) and several theories were deduced empirically from observations like the work of Archimedes, Copernicus, Galileo et al , which then paved way for the likes of Newton and Kepler. In modern times however, we also see that theories are first being propounded based on individual facts or ideas or assumptions and then being generalized to a scientific theory.
In Physics as with most other natural sciences, a theory can be falsified if any one conclusion derived from these theories yields false results. True premise should lead to true consequences. That is, if the theory fails to prove a point, either the assumptions (the premise) is rejected or is modified. Hence the Bohr Model of an Atom, which was one of the main hypotheses propounded by the Nobel winning physicist Niels Bohr, was trashed when it failed to explain among other things spectra of larger atoms. Same with Newton’s classical mechanics. They all gave way to the now generally accepted quantum physics (They are still taught to under grad students but are not included in any modern research currently happening in the field of physics)
Now however, consider some of the latest research going on in the fields of physics like understanding the universe in its entirety, or unifying the laws of physics. The string theory is possibly the most fiercely debated theory which attempts to explain above mentioned. But as we know now, its validity is still to be established which essentially means that we are still on the premise part.
Curiously enough, this does seem to be the case with many modern principles in science - the elusive Higgs boson, supersymmetric particles, black hole radiations and many more - most are a priori or thought experiments or based on assumptions which in turn are based on either past theories/observations or failures. That is somewhat how quantum mechanics emerged.
So we come to the following –
Even though unlike economics and other social sciences, physics is the natural science which can explain everything about the universe and all that it contains, however, premises are shaped by certain thought process of the times we live in and by past observations, theories and most certainly past failures.
Consider what if Einstein had not propounded his idea of the theory of relativity based on certain assumptions (constant speed of light and the independence of physical laws from the choice of co-ordinate system) neither of which were validated with any known laws of thermodynamics and mechanics in 1905 and were also contradictory to the classical mechanics, then where would have the world of physics been?
Most of Einstein’s research in fact was based on the a priori thought experiments and his own viewpoint that a single theory in physics should explain all observations which he then set out to prove. Special relativity was one of first a priori principles
Therefore, we get an interesting thought experiment - propounding a scientific premises is an art and when it is vindicated by sophisticated experiments several years later does it become science.
