Higgs predicted the existence of the Higgs boson particle, helping explain how matter formed after the Big Bang. His death at 94 was announced by the University of Edinburgh, where he was a professor.
When siblings share a womb, sex hormones from a male fetus can cause lasting changes in a female littermate. This effect exists for all kinds of mammals — perhaps humans too.
A sibling can change your life — potentially even before birth. The sex of one fetus can affect its neighbors in the womb. The "intrauterine position effect" was first discovered in cattle farming.