Exchange interaction independently by physicists Werner Heisenberg and Paul Dirac in 1926. The exchange interaction is sometimes called the "exchange force". However, it is not a true force and should not be confused with the exchange forces produced by the exchange of force carriers, such as the electromagnetic force produced between two electrons by the exchange of a photon, or the strong force between two quarks produced by the exchange of a gluon. Although sometimes erroneously described as a force, the exchange interaction is a purely quantum mechanical "effect" unlike other forces. Quantum mechanical particles are classified as bosons or fermions. The
3 Quarks Daily had reached thirty-five thousand. Since then, "3 Quarks Daily" has culled content from hundreds of sources, from blogs such as Salon, Science Daily, and The Huffington Post, from major publications such as "The New York Times", "Nature", and "The Guardian", to smaller outlets such as "Guernica Magazine", "The Awl", and "The American Scholar". The name "3 Quarks Daily" comes from the elementary nuclear particles of physics which in turn were named after the word "quark" which James Joyce had used in Finnegans Wake. The confluence of references to both science and literature in a single word suited the intent of