As I Understand It, science is not about discovering truth. If we say it is, we run the continual risk of truth changing with each new discovery, and increased public misunderstanding and lack of trust in our scientific endeavors. When people claim that Newton was proven wrong by Einstein, it belittles the incredible accomplishments of Newton and then sets the genius of Einstein up for failure when the next discovery is made.
Instead, we should promote the idea that science is all about development of increasingly useful models: Ones which are better at explaining the past and predicting the future.
As an analogy, my grandfather once told me that his first car was a Model A Ford. Over the years, I've wondered about his car, so I found an old black and white picture of a Model A. With this picture, I could see certain details and understand proportions of the car, but it only showed one side, so I had no good idea of the top, bottom or inside. In order to better understand the car, I got a small scale model of the car. It had working doors and you could open up the hood and trunk to see the engine. The wheels turned and it provided a 360 degree view of the car. This model was a lot more useful than the picture, but it did not prove the picture "wrong". It also didn't tell me everything about my grandfather's experience.
So I tracked down a fully restored Model A. Now, I could sit behind the wheel, drive the car and see how it handled around corners, smell the exhaust and experience the rattling of the steering wheel. It was the best guide yet to what my grandfather's car must have been like, but still, if I were to take a DNA sample of the leather in the seat, it would not match that of his original car. It was a better model than the last one, but didn't prove the old ones "false" and neither was this model "true". Instead, I had developed increasingly detailed models that were useful for different needs.
Our scientific endeavors are the same.
of the atom
If we look at the history of atomic theory, we find a series of models of the atom. J. J. Thomson's plum pudding model explained the presence of electrons, which Dalton's model did not. Ernest Rutherford obtained data with his gold foil experiment that was not explained by the plum pudding model, so he developed the planetary model. Atomic spectrum were not consistent with the planetary model, so Neils Bohr developed an atomic model with electron shells, which better explained the spectra. Despite this "progress", we still use an old billiard ball model of atoms to explain thermodynamics and ideal gases. Each model is useful for a different set of circumstances, yet we should not be so arrogant as to claim that even our current model is "true".
When some students in biology class feel that evolutionary theory contradicts their religious views, perhaps an understanding that evolution isn't "true" would help to ease their objections. Instead, evolution provides us with an incredibly useful model. It helps to explain the common properties of life on earth and allows us to predict where to find the next transitional fossil -- things that a six-day-creation model may not be entirely useful for. But just because it is useful doesn't make it true.
Another obvious risk to claiming scientific truth is the all too common case of groundbreaking discoveries that reshape our understanding. We should avoid the arrogance of thinking that what we understand today will be looked upon as anything more than quaint to scientists a hundred or a thousand or ten thousand years from now. And yet, some of our models may still prove useful to our distant descendants. Remember, we needed little more than 300 year old Newtonian mechanics to calculate the trajectories that would put humans on the moon.
At least that's How I Understand It.