Niels Bohr (1885–1962): On the Wing of a Butterfly, Johann J. Balmer (1825–1898)

AbstractBy the year 1913, a number of revolutionary events had begun to transform the landscape of physics. In 1900, Max Planck (1858–1947) had proposed that energy radiated in quanta or packets. The announcement of the photoelectric effect in 1905 by an unassuming Swiss patent worker by the name of Albert Einstein (1879–1955) clearly implicated that light energy, or the photon, later coined by Gilbert N. Lewis (1875–1946) in 1926, was also quantized and showed unprecedented particle‐like properties. More startling was the discovery by Ernest Rutherford (1871–1937) who demonstrated that the atom consisted of a hard positive center surrounded by electrons. Niels Bohr (1885–1962), then a young postgraduate, was deeply involved in understanding the structure of the atom. He needed physical or experimental evidence to substantiate his intuitive ideas. Ironically, that evidence had already been published in the year of his birth by Johann J. Balmer (1825–1898), a Swiss mathematics teacher at a secondary school for girls.