If humans one day become extinct from a catastrophic collision, there would be no greater tragedy in the history of life in the universe. Not because we lacked the brain power to protect ourselves but because we lacked the foresight. The dominant species that replaces us in post-apocalyptic Earth just might wonder, as they gaze upon our mounted skeletons in their natural history museums, why large headed Homo sapiens fared no better than the proverbially peabrained dinosaurs.
Neil deGrasse TysonSo much of what we understand comes from knowing what something is and what that something used to be, which allows us to figure out, or at least imagine, what happened in between.
Neil deGrasse TysonA common way to compute density is, of course, to take the ratio of an object's mass to its volume. But other types of densities exist, such as the resistance of somebody's brain to the imparting of common sense.
Neil deGrasse TysonIf there's something that someone else can do, let them do it. If I couldn't do it uniquely, let someone else do it and I would get back to the lab.
Neil deGrasse Tyson