Relax,” the Soylent spokesperson reassured me as I prepared for one of the stranger challenges of my life: replacing my conventional food intake with a thick nutritional sludge for an entire month. The smoothie-like substance, which began life as a crowdfunding sensation last year before attracting heavyweight investors like Andreessen Horowitz, is basically powdered science — human nutrition reduced to its most basic essentials. The name “Soylent” is a reference to the 1973 film Soylent Green, in which it’s revealed that a futuristic new food designed to feed an overcrowded Earth is made of people.