The Scientific Process
Before the twentieth century, science largely used the principles of induction- making discoveries about the world through accurate observations, and formulating theories based on the regularities observed.
Newton’s Laws are an example of this. He observed the behavior of physical objects (e.g. apples) and produced laws that made sense of what he observed.
The scientific process is now based on the hypothetico-deductive model was proposed by Karl Popper (1935). Popper suggested that theories/laws about the world should come first and these should be used to generate expectations/hypotheses which can be falsified by observations and experiment.