Why can't humans photosynthesize?
Last October I asked whether you could engineer a human, or any mammal, to run on sunlight the way a plant does. I expected a biology answer, something about genes and organelles and immune rejection. What I got was arithmetic, and the arithmetic ends the argument before biology gets a turn. The answer everyone gives is the weakest one Search this question and the first thing you will read is that humans cannot photosynthesize because we have no chloroplasts and produce no chlorophyll. ...