Science is the simple idea of observing what happens in our world, making a hypothesis regarding how these observations on a particular subject seems to lead to a certain rule on how those things observed seem to behave in a certain consistent way. And then testing whether the hypothesis and its predictions bear out. It is really very, very simple. And yet very, very good at determining how the world world works. As shown by the light you switch on, the computer you use, the drugs you are prescribed, etc, etc.

However, all scientific results are always philosophically and scientifically "tentative" as even vast amounts of evidence that A is true can never prove that A will always be true. We don't have the source code of the Universe after all.

So, although exploration of how our world works, also called science, can never say anything about how our world works with iron-clad certainty, the microwave ovens and lasers still continue to function. And things for which there is no evidence continue not to work and continue to be things for which there is no evidence.