Language of science I: Theories and laws

Abstract

In his letter, “Why No Einstein’s Laws?” (Physics Today, January 2007, page 12), Richard Kadel suggests defining three laws based on Einstein’s theory of special relativity. However, Albert Einstein is not the only author of the theory of special relativity. The early publications on special and general relativity were collected and published with comments by Arnold Sommerfeld in Des Relativitatsprinzip (4th ed., Teubner, 1922), which was later translated and published in English. The book started with two papers by Hendrik Lorentz dated 1895 and 1904, in which he established the so-called Lorentz transformations that are actually the basic formulas of special relativity. The book also includes two papers by Einstein published in 1905 and a 1908 paper by Hermann Minkowski.Minkowski died soon after his paper was published. Einstein gave many public lectures on special relativity, and public opinion now erroneously assigns authorship of the theory only to him. However, both Lorentz and Einstein were nominated for the Nobel Prize for special relativity, and Lorentz was number one in that nomination. (The nomination was not supported by the Nobel Committee, probably because of the insufficient experimental confirmation of the theory at that time.) Therefore, it is fair to call it the Lorentz–Einstein theory of special relativity. Einstein was the founder of general relativity. The first of Kadel’s proposed Einstein’s laws states that the laws of physics are identical in all non-accelerating (inertial) frames. However, in his publications Einstein referred to that as the principle of relativity of classical mechanics; some textbooks call it Galileo’s principle.Sommerfeld made a comment directly related to the second proposed law, that the vacuum speed of light, c, is the same for all inertial frames. He wrote, “The principle of the constancy of the velocity of light is of course contained in Maxwell’s equations.”I can agree that Kadel’s third law, that the total energy E of a body of mass m and momentum p is given by E=m2c4+p2c2, may be defined as Einstein’s law.© 2007 American Institute of Physics.