Post-processual archaeologists would disagree archaeology is a science, and others bedside. But I thought we were talking about history?
And of course new, other, things can be discovered in science. But on the question what conducts electricity better plastic or copper the answer will not change. You can't say the same for: what caused the collapse of the Soviet Union? It's a different kind of knowledge with different methods and different kind of results. But no less knowledge.
I should confess I have dozens of books on historical theory on my shelf and I've read most of them. Even the most empirical of current scholars like Richard Evans would not claim history is a science. Maybe in the old days positivists like Marwick and conservatives like Elton might have claimed history is a science I would need to go back and check. Probably Marwick, if anyone. I do tend to focus on postmodern history, but I've read Evans and Marwick too.
I am interested to know if you have actually read any contemporary academic work on history that categorises history as a "science". I would be surprised, but I could certainly have missed something!