Science theory is guesswork. Science law is fact. So, science as a whole is guesswork. The wise person depends on science law.
You don't know if there is anything behind the wall. If you are in construction, your experience might suggest it. Smash through your wall to see if there is anything back there.
NO, Fluffer! Don't really do this. I had to tell you not to do it. Otherwise you just might go around smashing walls to see if there is anything behind them.

You seem very unfamiliar with science.
Science theory is not guesswork
A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge.
Even a hypothesis isn't guesswork

A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used synonymously, a scientific hypothesis is not the same as a scientific theory. A working hypothesis is a provisionally accepted hypothesis proposed for further research.
A different meaning of the term hypothesis is used in formal logic, to denote the antecedent of a proposition; thus in the proposition "If P, then Q", P denotes the hypothesis (or antecedent); Q can be called a consequent. P is the assumption in a (possibly counterfactual) What If question.
The adjective hypothetical, meaning "having the nature of a hypothesis", or "being assumed to exist as an immediate consequence of a hypothesis", can refer to any of these meanings of the term "hypothesis".
You might not see what's behind a wall, but you can use science to prove what lies beyond with utmost certainty
