Science keeps changing
Some people criticize the reliability of Science because it "keeps changing". They ask, "How can we rely on science when it keeps changing its mind?" Additionally, other examples of the supposed unreliability of science are brought up:
- Different studies keep contradicting each other about whether table salt is healthy, or not.
- Everything science knows now will be proven wrong, eventually. So why rely on it now?
In order to understand this issue, it must first be understood what this nebulous "change" is, that the objectors speak of. There's two different kinds of "changing":
- Updating - A process of learning and improving where the knowledge or object is changed into a better state.
- Resetting - A process of replacing the knowledge or object with a completely new, and contradictory set of knowledge or objects.
Science gets accused of #2, when it's really doing #1.
- We don't consider computer technology unreliable because they're changed to be faster, with more memory.
- We don't consider a cook unreliable because he/she learned how to prepare a particular meal faster and more healthily.
- We don't consider an archer to be unreliable because he/she found a new way to increase his/her precision at hitting the bulls-eye.
To criticize science for changing is to criticize the very act of learning. That's what it is, after all - an ongoing activity of learning about the universe, and how it works. Of course science isn't going to gain 100% of all knowledge in zero-time. When science changes, it isn't so much that it was wrong before, so much as it wasn't completely right. When it makes an update, now it's more right.
It's like trying to bring an overhead projector into focus using a knob. One turns the knob to change the focus. It'll often take several iterations of adjusting the knob, and checking the status of the focus of the image, before converging to the correct answer. Even if one overshoots the desired rotation of the knob a couple times, generally the image becomes more and more sharp, until it's satisfactorily readable. We wouldn't deny the ability to bring sharply display the image because we had to change the focus a few times. That would be silly.
For a real-life example, Newtonian mechanics is a model for things like projectile motion, but it was fairly primitive. General relativity, as a new and improved scientific theory, explains Newtonian mechanics, and more. It expands on the prior theory. In fact, we still use Newtonian mechanics, and teach in schools, because it works great within its proper context - even though it's understood to be incomplete as far as explaining motion in the universe.
Unlike claims to other sources of knowledge, such as the Bible, the scientific method can verify, test and generally correct its own mistakes, if it makes any, whereas if the Bible is wrong about a particular claim, it's wrong forever.
Science has taken us to the moon, created incredibly fast and sophisticated computer technology, annihilated Small Pox from the face of the planet, and duplicated the nuclear fusion process of the sun. What advanced knowledge has the Bible accurately claimed? Some say plenty, but that is debatable.