Answer:
The first thing to do here is to accept that what the friend is saying, about science not always being one hundred percet accurate, of having to be updated and knowledge relearned because of constant new discoveries that may make a previous belief true and absolute, but that later was refuted due to new evidence and research, is true. There will always be doubt associated with scientific knowledge.
However, there is one thing that makes science an accurate, and very reliable way of gaining certain knowledge; not all. When it comes to matters that can be seen, measured, touched, or easily monitored with the senses, science provides the best way to knowing these matters because it has a series of already proven steps that lead to accurate aswers and results. This series of steps is what we know as the scientific method. This scientific method ensures that the steps taken during scientific research can be proven, re-tested, re-evaluated and verified. In essence, science does not claim to be the absolute truth, but be a way to find answers that provide a sense of security that the answers found are as accurate as possible.
