“Most branches of science involve a great deal of observation…
“Most branches of science involve a great deal of observation and experimentation. Even young students are familiar with the scientific method: we advance a hypothesis and construct an experiment that could potentially falsify the hypothesis.
Observations from the result of the experiment either falsify the hypothesis or confirm it. If many such experiments are performed under a variety of different controlled conditions, and none falsify the hypothesis but do falsify the alternatives, then the hypothesis becomes a theory and we have some degree of confidence that it is probably a correct explanation or at least a good approximation of truth.
Technically, we can never really know for certain that our theory is correct, because all it takes is one experiment to falsify it.
Most scientific knowledge is discovered in this way–but not relativity.
Einstein never did any physical experiment to test his theory. And yet it is one of the most well-established theories of science.
How is this possible? While most scientific discoveries are made by inductive, observational methods, relativity was discovered primarily through deductive logical reasoning.”
— The Physics of Einstein: Black Holes, Time Travel, Distant Starlight, E=mc^2 by Jason Lisle