Comment Lost forever (Score 3, Interesting) 189
Or maybe impossible to regenerate (for certain values of impossible). I remember reading a classified technical report (dating from the 1940s) related to military life-jacket development, wherein the question arose as to whether a particular design would reliably turn an unconscious person face-up in the water. The experimental design used was to dress some servicemen (sailors, possibly, but I don't recall) in the prototype design, anaesthetise them and drop them in a large body of water, checking for face-down floaters to disprove the null hypothesis. Somehow, I don't think that those data are going to be regenerated any time soon. I hope to God not, anyway.