“Within every American nuclear weapon sits a bowling-ball-size sphere of the strangest element on the planet. This sphere, called a plutonium pit, is the bomb's central core. It's surrounded by conventional explosives. When those explosives blow, the plutonium is compressed, and its atoms begin to split, releasing radiation and heating the material around it. The reaction ignites the sequence of events that makes nuclear weapons nuclear. In early nuclear bombs, like the ones the U.S. dropped on Japan in World War II, the fission of plutonium or uranium and the fatal energy released were the end of the story. In modern weapons, plutonium fission ignites a second, more powerful stage in which hydrogen atoms undergo nuclear fusion, releasing even more energy. The U.S. hasn't made these pits in a significant way since the late 1980s. But that is changing. The country is modernizing its nuclear arsenal, making upgrades to old weapons and building new ones. The effort includes updated missiles, a new weapon design, alterations to existing designs and new pits. To accomplish the last item, the National Nuclear Security Administration has enacted a controversial plan to produce 50 new pits a year at the Savannah River Site in South Carolina and 30 pits a year at Los Alamos National Laboratory in New Mexico, the birthplace of the bomb. The first pits will be designed for a weapon called W87-1, which will tip the new intercontinental ballistic missile, called Sentinel. After that the complex will produce pits for other bomb designs.” (Scientific American)

“How might science be done on an alien planet? It would be remarkable if the little green men had invented universities, funding committees, a tenure system and all the other accoutrements of modern academic life. This thought experiment, dreamed up by Michael Nielsen, a physicist, and Kanjun Qiu, an entrepreneur, was not merely a flight of fancy. It was part of an essay published last year pointing out that the way modern science is organised is not the only way it could be done, and perhaps not even the best way. Experimenting with different sorts of institutions, or novel ways to hand out research money, might help fix what the authors say is a “discovery ecosystem in a state of near stasis.” Dr Nielsen and Ms Qiu are among a band of researchers concerned that scientific progress is slowing. A paper published in 2020 by economists from the Massachusetts Institute of Technology (mit) and Stanford University concluded that American research productivity was falling, with more effort required to produce smaller gains in knowledge. A second paper, published in January this year, argued that the “disruptiveness” of both scientific papers and patents, as measured by citation patterns, fell by over 90% for papers, and more than 80% for patents, between 1945 and 2010” (The Economist)