Cosmic Rays and the GZK Effect
Abstract: In 1966, Greisen, Zatsepin, and Kuz’min predicted that the spectrum of cosmic rays should end abruptly at 1020 eV due to interaction with the cosmic microwave background. However, the cutoff, named the GZK Effect after its discoverers, has not been observed, and cosmic rays with energy 1021 and even higher have been observed. In my talk, I will discuss cosmic rays and their interactions with the cosmic microwave background, leading to why there should be such a sharp cutoff at 1020 eV, as well as look at experiments that are attempting to find indirect evidence of the GZK effect.