Quadruple jump controversy the early days of the Olympic Winter Games, skaters performed single jumps. By the middle of the 20th century, they had graduated to double jumps. By the 1980s, the triple Lutz was the benchmark for men. Throughout the '80s, it was the triple Axel, though attempts at a quad were already being made. Finally, a quadruple jump became an essential element in the programs of many men in the '90s and into the new millennium. The fact that fewer skaters than ever before attempt to land the toughest element in figure skating, opting to go for points instead, does not
Double beta decay or double beta decay are predicted to be very long; hence, quadruple beta decay is unlikely to be realized. The eight candidate nuclei for quadruple beta decay include Zr, Xe, and Nd capable of quadruple beta-minus decay, and Xe, Ba, Gd, and Dy capable of quadruple beta-plus decay or electron capture. In theory, quadruple beta decay may be experimentally observable in three of these nuclei, with the most promising candidate being Nd. Double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa,