Question

What is a possible explanation for a set of observations?

Answer 1

An hypothesis is a proposed explanation for a set of observations, a phenomenon. Scientific hypotheses must satisfy a defining criterion: that they be testable. In other words there must be an experiment that can be performed which supports or undermines the hypothesis.

If the experiment is performed, and the results are not consistent with the hypothesis, then the hypothesis may be rejected. If the results support the hypothesis, then the hypothesis is a useful basis for further experiments.