I mentioned this on the other thread on Flat-Earth: A Flat Earther Tried Convincing Her School Board to Teach the Controversy
Their main problem is not with science per say but with authority. They found inadmissible proof relying on authority, but it does not mean that there is no scientific common ground between them and mainstream science (most of them, for example, believes in electromagnetism). This common ground should be the launching pad for arguments that disproves the Flat-Earth, not evidence like pictures from space which inherently have argument to authority baked into it.