The same year, Seth Neddermeyer and Carl David Anderson, among others, also reached similar conclusions in independently published papers in Physical Review. Before pions were discovered, observers often confused muons with mesons. When Bhabha's collaborator Heitler made him aware of Hideki Yukawa 's 1935 paper on the theory of the meson, Bhabha realized that this particle was the postulated "heavy electron". In a 1939 note to Nature, Bhabha argued the particle should be christened the "meson" in line with the word's Greek etymology, not "mesotron" as Anderson had proposed. Bhabha later concluded that observations of the properties of the meson would lead to the straightforward experimental verification of the time dilation phenomenon predicted by Albert Einstein 's theory of relativity.