Papal tiara papal tiara. For instance, the Rider-Waite tarot deck, currently the widest-circulated deck in existence, depicts "The Hierophant" or pope as wearing a papal tiara and carrying a papal cross. Papal tiara The papal tiara is a crown that was worn by popes of the Catholic Church from as early as the 8th century to the mid-20th. It was last used by Pope Paul VI in 1963 and only at the beginning of his reign. The name "tiara" refers to the entire headpiece, no matter how many crowns, circlets or diadems have adorned it through the ages, while the three-tiered form
Cross section (physics) to the sum of cross sections over all events. The differential cross section is extremely useful quantity in many fields of physics, as measuring it can reveal a great amount of information about the internal structure of the target particles. For example, the differential cross section of Rutherford scattering provided strong evidence for the existence of the atomic nucleus. Instead of the solid angle, the momentum transfer may be used as the independent variable of differential cross sections. Differential cross sections in inelastic scattering contain resonance peaks that indicate the creation of metastable states and contain information about their energy