Thunderstorms are one of the most fascinating meteorological events which have attracted the attention of scientists over the centuries. The contributions of Benjamin Franklin are very famous. They are characterized by their electrical activity in the form of lightning and thunder—caused by the rapid expansion of the air surrounding the path of a lightning bolt. But now it is found that there is much more happening during a thunderstorm than one can actually see and hear.

   In 2013, scientists from the University of Bergen, Norway, detected the presence of another kind of lightning during a thunderstorm, one that is not visible to the naked eye and does not produce any sound. The phenomenon was not really new.

   When it was first detected in 1991, it had been named ‘dark lightning’, but at the time, scientists considered that they were dealing with gamma rays coming from space. However, later research....