ROCHESTER, N.Y. — For the past four nights in a row, Rochester has been treated to one of Mother Nature’s most amazing phenomena, the Northern Lights. But what exactly are the Northern Lights, and how ...

What is the purpose of light? How does light work? Why does light exist? This video explores the longstanding debate over ...

This is the next article in our ‘Light and health’ series, where we look at how light affects our physical and mental health in sometimes surprising ways. Read other articles in the series. Exposure ...