Sunshine | The long path to discovery A little more than one century ago, in 1919, a nagging question received the beginning of an answer. Almost simultaneously, two eminent scientists, Jean Perrin (1870-1942) in France and Arthur Eddington (1882-1944) in the United Kingdom, speculated that the energy source at the core of the Sun was to be found in sub-atomic reactions. Their intuition was a huge departure from the theories that had prevailed for the previous seven decades. Jean Perrin's intuition that the energy source at the core of the Sun was to be found in sub-atomic reactions was a hu...