In topology, a branch of mathematics, the Klein bottle is an example of a non-orientable surface; it is a two-dimensional manifold against which a system for determining a normal vector cannot be consistently defined. Informally, it is a one-sided surface which, if traveled upon, could be followed back to the point of origin while flipping the traveler upside down. Other related non-orientable objects include the Möbius strip and the real projective plane. While a Möbius strip is a surface with boundary, a Klein bottle has no boundary. For comparison, a sphere is an orientable surface with no boundary.
Naomi A. Klein is a Canadian author, social activist, and filmmaker known for her political analyses, support of ecofeminism, organized labour, left-wing politics and criticism of corporate globalization, fascism, ecofascism and capitalism. As of 2021 she is Associate Professor, and Professor of Climate Justice at the University of British Columbia, co-directing a Centre for Climate Justice.
The Klein–Gordon equation is a relativistic wave equation, related to the Schrödinger equation. It is second-order in space and time and manifestly Lorentz-covariant. It is a quantized version of the relativistic energy–momentum relation. Its solutions include a quantum scalar or pseudoscalar field, a field whose quanta are spinless particles. Its theoretical relevance is similar to that of the Dirac equation. Electromagnetic interactions can be incorporated, forming the topic of scalar electrodynamics, but because common spinless particles like the pions are unstable and also experience the strong interaction the practical utility is limited.
Ralph Philip Klein, was a Canadian politician and journalist who served as the 12th premier of Alberta and leader of the Progressive Conservative Association of Alberta from 1992 until his retirement in 2006. Klein also served as the 32nd mayor of Calgary from 1980 to 1989.
Calvin Richard Klein is an American fashion designer who launched the company that would later become Calvin Klein Inc., in 1968. In addition to clothing, he also has given his name to a range of perfumes, watches, and jewellery.
Mark Klein is a former AT&T technician and whistleblower who revealed details of the company's cooperation with the United States National Security Agency in installing network hardware at a site known as Room 641A to monitor, capture and process American telecommunications. The subsequent media coverage became a major story in May 2006. He wrote a book about the NSA and AT&T's cooperation in surveiling everyone on the internet and his experience in discovering it and trying to tell the public called Wiring Up The Big Brother Machine...And Fighting It.
Klein Field at Sunken Diamond is a college baseball stadium on the campus of Stanford University in Stanford, California. It is the home field of the Stanford Cardinal of the Pac-12 Conference.
Robert Owen "Bob" Klein is an American retired American football tight end.
Ezra Klein is an American journalist, political analyst, New York Times columnist, and the host of The Ezra Klein Show podcast. He is a co-founder of Vox and formerly served as the website's editor-at-large. He has held editorial positions at The Washington Post and The American Prospect, and was a regular contributor to Bloomberg News and MSNBC. His first book, Why We're Polarized, was published by Simon & Schuster in January 2020.
Room 641A is a telecommunication interception facility operated by AT&T for the U.S. National Security Agency, as part of its warrantless surveillance program as authorized by the Patriot Act. The facility commenced operations in 2003 and its purpose was publicly revealed in 2006.
Vistas High School Program is an alternative public high school program based in unincorporated Harris County, Texas, United States, and part of the Klein Independent School District. Vistas serves grades 9 through 12. The program has a Houston, Texas mailing address but is not located in the Houston city limits. The Director is Peggy Ekster.
The Grieshorn is a mountain of the Lepontine Alps, located on the Swiss-Italian border. With an altitude of 2,969 metres above sea level, it is the culminating point of the group lying between the Gries Pass, the San Giacomo Pass and the Nufenen Pass.
Manfred Klein is a competition rower and Olympic champion for West Germany.
Hans Hugo Klein is a German politician. He was a representative of the German Christian Democratic Union from 1983 to 1996 and he a justice of the Federal Constitutional Court.
Klein Glacier is a broad glacier near the edge of the Antarctic polar plateau, flowing northwest into Scott Glacier immediately south of the La Gorce Mountains. It was mapped by the United States Geological Survey from surveys and U.S. Navy air photos, 1960–63, and was named by the Advisory Committee on Antarctic Names for Lieutenant Commander Verle W. Klein, a pilot with U.S. Navy Squadron VX-6 on Operation Deep Freeze, 1966 and 1967.
Vox is an American news and opinion website owned by Vox Media. The website was founded in April 2014 by Ezra Klein, Matt Yglesias, and Melissa Bell, and is noted for its concept of explanatory journalism. Vox's media presence also includes a YouTube channel, several podcasts, and a show presented on Netflix. Vox has been described as left-of-center and progressive.
h3h3Productions is a YouTube channel hosted by Ethan Klein and Hila Klein, an Israeli-American husband and wife duo. The majority of their content consists of reaction videos and sketch comedy in which they satirize internet culture. The H3 Podcast is their podcast channel that has been running since 2017.
Karsten Klein is a German politician of the Free Democratic Party (FDP) who has been serving as a member of the Bundestag from the state of Bavaria since 2017.
Jari Jones is an American trans Femme activist, performance artist and creative. Jones was a cast member, script consultant, acting coach, and producer of Port Authority.
Hans Klein was a German politician (CSU) who served as Vice President of the Bundestag from 1990 until his death in 1996.
