Why is the Big Bang Theory considered a "theory" and not a fact?

We create models and make observations in the natural sciences.

We can draw predictions from those models and test them against additional observations if they agree with our observations.

We can determine that our models are incorrect or require revision if certain observations run counter to them.

Newton's laws of physics, for instance, give us reasonably accurate models that enable us to calculate the landing of a man on the moon. But are they true? Not quite. We can tell that Newton's laws need to be adjusted because they become less effective at speeds that are close to the speed of light.

More accurate models are provided by Einstein's special and general theories of relativity. But are they true? They seem to offer helpful models, but they don't explain everything; for instance, extreme conditions in a black hole or those we believe existed at the beginning of the universe present some challenges to General Relativity. They also predict a wide range of strange behavior that we have actually observed.

From a practical standpoint, it is helpful to work within theoretical frameworks that we treat as fact. Since we must make assumptions in order to draw meaningful conclusions, we frequently act as though theories like the Big Bang theory are true, even though we are unable to prove them.

The honesty of science basically lies in the fact that we cannot prove anything to be true in any natural science, but we can show that theories are false.

This theory cannot be verified as true, and it is also unlikely to be refuted.

In science, a theory is a comprehensive framework that explains a phenomenon. The Big Bang Theory is supported by substantial empirical evidence, but it is called a theory because scientific understanding is subject to refinement and further exploration. The term "theory" in the Big Bang Theory signifies a well-substantiated scientific explanation based on observations and evidence.