Today is the birthday of Irish Chemist Thomas Andrews, born to a linen merchant in Belfast Ireland in 1815. Andrews was the first scientist to understand and demonstrate that ozone is a form (O3) of oxygen. Ozone is known for its peculiar smell-humans can discern the presence of Ozone in concentrations of as little as ten parts per billion in the air. This unusual property gave ozone its name, which comes from the Ancient Greek word ὄζειν (ozein) meaning to smell. The word was coined by Christian Friedrich Schöenbein with his discovery in 1840. Schöenbein recognized that the peculiar smell after lightning strikes was due to ozone.
Image of the ozone hole courtesy NASA, in the public domain. See a very short animation of the changing size of the hole here.