Sometimes two quanta, separated by a great distance, seemingly sense something about each other's condition and become deeply linked, a situation called entanglement.
While physicists expended their intellectual energy on uniting quantum mechanics with relativity (a quest that continues, still without success), information scientists graduated from telephones to computers with only occasional concern for quanta. But then in the 1980s and '90s, quantum and information science met, married and produced offspring--specifically, the intellectual enterprise known today as quantum information theory.