{'fraction_non_alphanumeric': 0.019393336648433616, 'fraction_numerical': 0.02138239681750373, 'mean_word_length': 4.69971671388102, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The first war of physics

This message was recorded by the US authorities in its VENONA project [2] but not decrypted for four years. It shows that the Soviet spy codenamed CHARLES [ChARL’Z in Russian] knew the most secret information at the heart of the Manhattan Project, the attempt by the US together with Britain and Canada to build an atomic bomb during the second world war before Germany built one. In particular, CHARLES showed that he knew not only the critical mass of Pu239 but also the implosion method using explosive lenses that was needed to detonate plutonium (because of the presence of spontaneously fissile Pu240, the gun mechanism used in U235 whereby a critical mass is obtained by firing a U235 bullet into a nearly critical U235 cylinder cannot be used in plutonium) and moreover he knew details of the methods used to separate the fissile uranium isotope U235 from the predominant isotope U238, which does not fission with slow neutrons. ENORMOZ started as the code word for the enormous gaseous diffusion isotope separation plant at Oak Ridge in Tennessee. It was then used to describe U235 itself and sometimes the whole Manhattan Project. BAL was probably short for BALLON (balloon). The number of scientists in the Manhattan Project who knew in detail about the work on critical mass calculations, uranium isotope separation and plutonium implosion was very small. One of those who did was Rudolf Peierls. He was the senior British theorist at Los Alamos; his memorandum [3] with Otto Frisch of March 1940 on the critical mass of U235 led directly to the precursors of the Manhattan Project in Britain and the United States; he had written (with Klaus Fuchs) one of the first British papers on uranium isotope separation [4] and he was section head of T-1 responsible for implosion dynamics at Los Alamos [5]. Furthermore, his wife Genia was Russian. He was an obvious candidate to be CHARLES. Another message from Moscow to New York dated 16 November 1944 [6] was decrypted to read