Standing on their shoulders

Reading the obituary for Lev Okun (Physics Today, May 2016, page 64 ), I realized that one very important contribution is omitted: Okun wrote an excellent Physics Today article, “The concept of mass” (June 1989, page 31 ). Although there had been several related journal papers between the mid 1970s and the mid 1990s on speed-dependent mass being a misconception, Okun’s article seems to have been the one that triggered the correction of high school and college physics textbooks that had favored it almost since the introduction of E = mc². (Actually, Einstein first introduced this concept as Δm = ΔE/c².)

In the Soviet Union, Okun actually took up the problem two years before the Physics Today article, when in 1987 the Ministry of Education sent him a new high school textbook for review. He hadn’t been aware of the error before, and he failed to convince the ministry that there was a problem. He told the story of that controversy in Energy and Mass in Relativity Theory (World Scientific, Eng. trans. 2009).

The Commentary “The dangerous growth of pseudophysics” by Sadri Hassani, also in the May 2016 issue (page 10 ), touches on the misconception when discussing “spirit energy.” Incidentally, Hassani did not mention that the laypeople who show interest in spirit energy relate positive energy with attractive personalities, whereas, as is well known, in physics it’s just the opposite!