Science is a process not a set of facts. Yes the process is "true" in as much as it is correct, but that's not to suggest the results are ever complete. Newtonian physics made good predictions as long as you don't approach light speed. General relatively makes good predictions as long as you are on certain scales, at very small scales (quantum) it fails, and there are some hints that it may not do so well at very large scales. So we go on to try to bring these together and come up with a new even better theory but at some point that will undoubtably break down and something else will follow it, and so it goes indefinitely.