In 2012, a number of well-known scientists and philosophers gathered for a weekend to discuss hot-topics or unresolved issues within naturalism. Basically they were trying to scope out and/or develop a more coherent world-view from a strictly scientific/materialist perspective. The entire series is still available online and worth watching if you missed it.
One video is dedicated to their discussion of morality. To my surprise Steven Weinberg, a physicist, presented a solid argument against so-called science-based moral theories. His portion begins about 7 minutes into the video, and he remains pivotal to the remaining discussion.
