Latest news with #X-rays
Spectator
3 days ago
- Science
- Spectator
The race against Hitler to build the first nuclear bomb
Ettore Majorana vanished in March 1938. According to Frank Close in Destroyer of Worlds, the 31-year-old Sicilian physicist 'probably understood more nuclear physics theory than anyone in the world', and was hailed by Enrico Fermi as a 'magician', in the elevated company of Newton and Galileo. Majorana was also an ardent fascist; yet he was haunted by the destructive potential of his work on mapping the nucleus. His disappearance – perhaps a suicide; more likely a new, incognito life in South America – has been related to an anguished remark he made to a colleague: 'Physics has taken a bad turn. We have all taken a bad turn.' Majorana is just one arresting character in a bustling cast of scientists whose 50-year pursuit of knowledge – a chain reaction of discoveries starting in 1895 with Wilhelm Roentgen's X-rays – led ineluctably to the atomic bomb. Close's ensemble drama is a powerful corrective to the myth of the solitary genius. He notes that Fermi's 1934 papers on irradiating elements pioneered the now standard practice of crediting multiple authors: 'Here for the first time was teamwork, a new way of doing science in increasingly large collaborations.' Unusually, many of the key players were women, among them Lise Meitner, Ida Noddack and Irène Joliot-Curie. Close convenes these fascinating personalities so deftly that when a group photograph of the atomic all-stars at the 1933 Solvay conference appears halfway through the book it is electrifying. The dream team assembles. An eminent theoretical physicist, Close walks us step by step through what he calls the 'Third Industrial Revolution'. Despite his best efforts, I cannot honestly claim to have followed all the physics, but I did understand the scientific method like never before. Insistent on the role of luck, he argues that the great breakthroughs happened when 'chance made the revelation to prepared minds'. But even the greatest mind can't be prepared for everything. Every titan of physics has been waylaid at some point by a missed connection, dead end or overconfident prediction. The best scientists, then, delight in being proved wrong. The discovery of nuclear fission in December 1938 (typically, one pair of physicists achieved the splitting of a uranium nucleus but it took another duo to identify what had happened) astounded both Fermi and Niels Bohr, who smacked his forehead and exclaimed: 'Oh what idiots we have all been not to have seen this before! This is wonderful!' Self-criticism mingled with elation. Ego bowed before knowledge. H.G. Wells had imagined and named the atomic bomb as far back as 1913, based on the speculations of the radiochemist Frederick Soddy. With the arrival of fission, it suddenly left the realm of theory and fiction. In geopolitical terms, the timing could not have been worse. Close's stirring tale of a largely amicable international effort to unravel the secrets of the atom becomes a race against Hitler to build the first bomb. 'If it is not made in America this year,' wrote C.P. Snow in 1939, 'it may be next year in Germany.' As Close observes, had it not been for 'fear of an imminent collapse of society to fascism, nuclear power rather than nuclear weapons would have led the way'. The human drama accelerates at this point, too. The Manhattan Project relied on so many refugees from fascism that after Hiroshima the New York Times ran the startling headline 'Thanks to Hitler'. Fermi fled to the US straight from his Nobel Prize ceremony in 1938 and proceeded to conduct the world's first nuclear chain reaction, while Otto Frisch and Rudolf Peierls, both German Jews, sketched out the possibility of a uranium-235 bomb in Nissen huts in Birmingham. Their revelation, which put the UK in the nuclear vanguard but without the money to do much about it, spooked the physicist James Chadwick so badly that he became addicted to sleeping pills. The bomb was necessary; the bomb was horrifying. The depth of Close's knowledge throws up surprises even if you know the territory. While he races through the Manhattan Project in a dozen pages and barely mentions J. Robert Oppenheimer (perhaps he's had enough attention), Close shines a light on less familiar figures such as Ernest Rutherford's protégé Henry Moseley, who established the concept of atomic numbers shortly before dying at Gallipoli; Klaus Fuchs, the atomic spy who played a crucial role in the nuclear programmes of three different countries; and the French banker Jacques Allier, who spirited Europe's largest stockpile of heavy water (an essential moderator for nuclear reactors) out of Norway just weeks before the Nazi invasion by filling a second plane with dummy canisters. Close has an abundant supply of thrills, tragedy and gratifying trivia. It may not be consequential that Bohr used to be a top goalkeeper in the Danish football league but it's fun to know. A book in which it feels as if someone is winning a Nobel Prize on every other page closes elegantly with three Nobels that illuminate the fusion of science and politics. The fission pioneer Otto Hahn learned of his physics prize from reading the Daily Telegraph while he was interned in Cambridge-shire for his role in the Nazi bomb programme. Joseph Rotblat, the only scientist to quit the Manhattan Project on ethical grounds, and Andrei Sakharov, who spent the rest of his life atoning for giving Stalin the hydrogen bomb, were never honoured for their scientific work but for trying to correct physics's 'bad turn'. They won their prizes for peace.
The Independent
30-05-2025
- Science
- The Independent
Scientists can't figure out mysterious signal from deep space
Scientists have detected a mysterious, regular signal, named ASKAP J1832-0911, flashing from 15,000 light years away in space, emitting radio waves and X-rays every 44 minutes. The object was discovered using an Australian telescope and NASA 's Chandra X-ray Observatory, marking the first time an LPT (long-period transient) has been observed emitting both X-rays and radio signals. Researchers note that the X-ray and radio wave emissions from ASKAP J1832-0911 have decreased over time, an unprecedented phenomenon in the Milky Way galaxy. The nature of the object remains unknown, with theories suggesting it could be a magnetar or a binary star system involving a highly magnetised white dwarf, but these theories do not fully explain the observed behaviour. Scientists aim to continue studying ASKAP J1832-0911 and search for similar objects, hoping the X-ray emissions will provide insights into the origin and mechanism of the signals, potentially indicating new physics or stellar evolution models.
