One possible reason for adopting a vegetarian/vegan diet is the desire not to have to cause the deaths of living creatures in order to survive, where sufficiently-nutritious alternatives exist. Taking this desire to its logical extreme, and thereby precluding the killing of any living thing, including plants and fungi, has me wondering:
Is it possible to survive on a diet that comes exclusively from non-living sources?
Do we have the technological means of producing energy and nutrients from sunlight without requiring plants as photosynthesing intermediaries? Can nutrients be extracted from mineral sources? Can the full range of vitamins a human needs be synthesized in a lab?