That would be a valid point if that particular forum of physicists were insisting that people can't possibly be expending energy (beyond normal life-sustenance) to hold heavy objects because, "They aren't applying force to the object through a distance."
There's probably a parallel disconnect in there somewhere that AlexMennen is concerned about.
Huh? When you're holding something, you expend energy because your hand shakes. The longer you hold it, the more it shakes.
It seems to me that usually, when someone says "ethics" on lesswrong, ey usually means something along the lines of decision theory. When an average person says "ethics", ey is usually referring to a system of intuitions and social pressures designed to influence the behavior of members of a group. I think that a lot of the disagreement regarding ethics (i.e. consequentialism vs deontology) is rooted in a failure to properly distinguish between decision theory and what society pressures people to do. Most lesswrong users probably understand the distinction fairly clearly, but we only ever talk about decision theory. Why don't we talk about the social meaning of ethics?