All known members of the group up until 1965 had almost identical orbital inclinations at about 144°, as well as very similar values for the longitude of perihelion at 280–282°, with a couple of outlying points probably due to uncertain orbital calculations.
Early calculations suggested that there might be white dwarfs whose luminosity varied with a period of around 10 seconds, but searches in the 1960s failed to observe this., § 7.1.1; The first variable white dwarf found was HL Tau 76; in 1965 and 1966, Arlo U.
However, the terminology comes from a simplistic calculation that ignores the effects of quantum mechanics; in reality, the so-called classical electron radius has little to do with the true fundamental structure of the electron.
In 1950, calculations by the Polish mathematician Stanisław Ulam and his collaborator Cornelius Everett, along with confirmations by Fermi, had shown that not only was Teller's earlier estimate of the quantity of tritium needed for the H-bomb a low one, but that even with higher amounts of tritium, the energy loss in the fusion process would be too great to enable the fusion reaction to propagate.
John Fine, on the other hand, suggests that the first peace between Athens and Persia was concluded in 450–449 BC, as a result of Pericles' strategic calculation that ongoing conflict with Persia was undermining Athens' ability to spread its influence in Greece and the Aegean.