How much do we know about our world from direct observation? Consider a pretty basic law at work all around us all the time. Newton’s first law of motion is that “a body at rest stays at rest, and a body in motion stays in motion, unless it is acted on by an external force.” Doesn’t this contradict what you have directly observe–that is, things in motion eventually come to rest.
At some point in high school you learned that when a body moves over any surface there is a force that action opposite to the direction of motion. That force, which we call friction, is different for different surfaces and proportional to the normal force against the surface. So the heavier the object, the higher the Force of Friction, but if you put the body on an incline, the Force of Friction decreases. By the way, while you are pushing on an object that doesn’t move, the force of friction increases exactly to keep pace with the force you are putting on the body. (How does it know to do that?)
Anyway, friction is also why things in motion tend to come to rest; there is a force acting on them. Or so we’ve been told. Which is my point, do we directly observe Newton’s first law, or is it a convention we learned? Do we, everyday folks, have any reason to feel any more certain about it than people from the Dark Ages had to feel certain that if you knocked on wood it would scare away the fairies that caused bad luck?
And this isn’t even talking about carbon dating or evolution or red shift; it’s about what really happens when we push a box across the floor.