Quarter

A quarter is one fourth, ¹⁄₄, 25% or 0.25 and may refer to:

Other uses

See also

Modern physics

Modern physics is an effort to understand the underlying processes of the interactions of matter utilizing the tools of science & engineering. It implies that nineteenth century descriptions of phenomena are not sufficient to describe nature as observed with modern instruments. It is generally assumed that a consistent description of these observations will incorporate elements of quantum mechanics & relativity.

Small velocities and large distances is usually the realm of classical physics. Modern physics often involves extreme conditions; in practice, quantum effects typically involve distances comparable to atoms (roughly 10⁻⁹ m), while relativistic effects typically involve velocities comparable to the speed of light (roughly 10⁸ m/s).

Overview

In a literal sense, the term modern physics, means up-to-date physics. In this sense, a significant portion of so-called classical physics is modern. However, since roughly 1890, new discoveries have caused significant paradigm shifts: the advent of quantum mechanics (QM), and of Einsteinian relativity (ER). Physics that incorporates elements of either QM or ER (or both) is said to be modern physics. It is in this latter sense that the term is generally used.

Stanford University

Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California, and one of the world's most prestigious institutions.

Stanford was founded in 1885 by Leland Stanford, former Governor of and U.S. Senator from California and leading railroad tycoon, and his wife, Jane Lathrop Stanford, in memory of their only child, Leland Stanford, Jr., who had died of typhoid fever at age 15 the previous year. Stanford admitted its first students on October 1, 1891 as a coeducational and non-denominational institution. Tuition was free until 1920. The university struggled financially after Leland Stanford's 1893 death and again after much of the campus was damaged by the 1906 San Francisco earthquake. Following World War II, Provost Frederick Terman supported faculty and graduates' entrepreneurialism to build self-sufficient local industry in what would later be known as Silicon Valley. By 1970, Stanford was home to a linear accelerator, and was one of the original four ARPANET nodes (precursor to the Internet).

Leonard Susskind

Leonard Susskind (born June, 1940) is the Felix Bloch professor of theoretical physics at Stanford University, and director of the Stanford Institute for Theoretical Physics. His research interests include string theory, quantum field theory, quantum statistical mechanics and quantum cosmology. He is a member of the National Academy of Sciences of the US, and the American Academy of Arts and Sciences, an associate member of the faculty of Canada's Perimeter Institute for Theoretical Physics, and a distinguished professor of the Korea Institute for Advanced Study.

Susskind is widely regarded as one of the fathers of string theory, having, with Yoichiro Nambu and Holger Bech Nielsen, independently introduced the idea that particles could in fact be states of excitation of a relativistic string. He was the first to introduce the idea of the string theory landscape in 2003.

Susskind was awarded the 1998 J. J. Sakurai Prize.

Early life and education

Leonard Susskind was born to a Jewish family from the South Bronx section of New York City, he now resides in Palo Alto, California. He began working as a plumber at the age of 16, taking over from his father who had become ill. Later, he enrolled in the City College of New York as an engineering student, graduating with a B.S. in physics in 1962. In an interview in the Los Angeles Times, Susskind recalls the moment he discussed with his father this change in career path: "When I told my father I wanted to be a physicist, he said: ‘Hell no, you ain’t going to work in a drug store.’ I said, "No. Not a pharmacist." I said, ‘Like Einstein.’ He poked me in the chest with a piece of plumbing pipe. ‘You ain’t going to be no engineer’, he said. ‘You’re going to be Einstein.’" Susskind then studied at Cornell University under Peter A. Carruthers where he earned his Ph.D. in 1965. He has been married twice, first in 1960, and has four children.

Special relativity

In physics, special relativity (SR, also known as the special theory of relativity or STR) is the generally accepted and experimentally well confirmed physical theory regarding the relationship between space and time. In Einstein's original pedagogical treatment, it is based on two postulates:

It was originally proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies". The inconsistency of Newtonian mechanics with Maxwell’s equations of electromagnetism and the lack of experimental confirmation for a hypothesized luminiferous aether led to the development of special relativity, which corrects mechanics to handle situations involving motions nearing the speed of light. As of today, special relativity is the most accurate model of motion at any speed. Even so, the Newtonian mechanics model is still useful (due to its simplicity and high accuracy) as an approximation at small velocities relative to the speed of light.