The "-computing" is redundant given the nature of this site. How about we pick either "scientific" or "science" and move everything in the other two tags into that one?
Scientific computing is a subset of software used for sciences. For example iOS: Chemical/Molecule Viewer is about science but not about scientific computing. Real Time (<10ms response) Graphing/Charting isn't particularly about science.
I think we can drop science (which I'm guilty of having created) and stick with tags for individual sciences such as chemistry, with scientific-computing used when appropriate (I haven't reviewed whether the current uses are appropriate).
I think we should synonym scientific-computing to science, thus making science the main tag. We don't serve non-computing stuff here, but it seems that people think its necessary to explicitly say that they need computing to be done.