Final answer:
Scientists are most convinced by evidence that supports their theories and laws, but it is not always feasible to obtain such evidence. Continuous retesting and refinement of scientific theories allow for future discoveries. New technologies have led to significant changes in scientific understanding.
Step-by-step explanation:
Scientists are most convinced by evidence that supports their theories and laws. However, it is not always feasible to conduct experiments or observations that provide this level of evidence. Many scientific theories and laws are continuously retested and refined, leaving room for future discoveries. For example, the discovery of new technologies like the microscope or viewing Earth from space has led to major changes in scientific understanding.