Why is Sam Harris wasting so much time asking whether science can do morality? By definition it can’t. period. But we can indeed twist the definitions, expand the meaning of science, but with what result? Certainty? No, the same ambiguity we find in extra-scientific morality.
I see no inherent impossibility an exotic new form of science in the future might resolve ethical issues. But at the present time scientists are such morons this discussion is pointless: it is a side dish of bad coleslaw for the new atheist agenda eager to discredit religion. It is a waste of time.