👉 In physics and astrophysics, a protanomalous effect is a phenomenon observed in certain types of cosmic-ray showers. It occurs when neutrons are produced from two different nuclei (such as uranium-235 or plutonium-239) at the same time, leading to a significant increase in the energy of the particles emitted by the showers. This effect can be understood through the principle of nuclear fission, which is a process that releases energy when an atom splits into two