History of paintingThe history of painting reaches back in time to artifacts and artwork created by pre-historic artists, and spans all cultures. It represents a continuous, though periodically disrupted, tradition from Antiquity. Across cultures, continents, and millennia, the history of painting consists of an ongoing river of creativity that continues into the 21st century. Until the early 20th century it relied primarily on representational, religious and classical motifs, after which time more purely abstract and conceptual approaches gained favor.
Western paintingThe history of Western painting represents a continuous, though disrupted, tradition from antiquity until the present time. Until the mid-19th century it was primarily concerned with representational and Classical modes of production, after which time more modern, abstract and conceptual forms gained favor. Initially serving imperial, private, civic, and religious patronage, Western painting later found audiences in the aristocracy and the middle class. From the Middle Ages through the Renaissance painters worked for the church and a wealthy aristocracy.
Alpha particleAlpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+ or 42He2+ indicating a helium ion with a +2 charge (missing its two electrons).
Particle physicsParticle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos.
