Calendario de la historia de la ciencia, El

Why do we say that the rainbow has seven colors? What is planned obsolescence? To whom do we owe the invention of atomic numbers? How did we come to know that the Andromeda galaxy does not belong to the Milky Way? What was the largest volcanic eruption ever recorded? When was an effective vaccine against tuberculosis obtained? Is it possible that a creature has become extinct twice? Which European nation experienced a 30-day month of February? The Calendar of the History of Science is an in...