Stellar nucleosynthesis

Stellar nucleosynthesis is the process by which the natural abundances of the chemical elements within stars change due to nuclear fusion reactions in the cores and overlying mantles of stars. Stars are said to evolve (age) with changes in the abundances of the elements within. Core fusion increases the atomic weight of its gaseous elements, causing pressure loss and contraction accompanied by increase of temperature. Stars lose most of their mass when it is ejected late in their stellar lifetimes, thereby increasing the abundance of elements heavier than helium in the interstellar medium. The term supernova nucleosynthesis is used to describe the creation of elements during the evolution and explosion of a presupernova star, as Fred Hoyle advocated presciently in 1954. One stimulus to the development of the theory of nucleosynthesis was the variations in the abundances of elements found in the universe. Those abundances, when plotted on a graph as a function of atomic number of the element, have a jagged sawtooth shape that varies by factors of tens of millions. This suggested a natural process other than a random distribution. Such a graph of the abundances can be seen at History of nucleosynthesis theory. Stellar nucleosynthesis is the dominating contributor to several processes that also occur under the collective term nucleosynthesis.

Steward Observatory

Steward Observatory is the research arm of the Department of Astronomy at the University of Arizona (UA). Its offices are located on the UA campus in Tucson, Arizona (USA). Established in 1916, the first telescope and building were formally dedicated on April 23, 1923. It now operates, or is a partner in telescopes at five mountain-top locations in Arizona, one in New Mexico, and one in Chile. It has provided instruments for three different space telescopes and numerous terrestrial ones. Steward also has one of the few facilities in the world that can cast and figure the very large primary mirrors used in telescopes built in the past decade.

History

Steward Observatory owes its existence to the efforts of American astronomer and dendrochronologist Andrew Ellicott Douglass. In 1906, Douglass accepted a position as Assistant Professor of Physics and Geography at the University of Arizona in Tucson, Arizona. Almost immediately upon his arrival in Tucson, Douglass established astronomical research programs using an 8-inch refracting telescope on loan from the Harvard College Observatory and actively began to pursue funding to construct a large research-class telescope in Tucson. Over the next 10 years, all of Douglass’ efforts to secure funding from the University and the Arizona Territorial (and later State) Legislatures ended in failure. During this time period, Douglass served the University of Arizona as Head of the Dept. of Physics and Astronomy, Interim President, and finally Dean of the College of Letters, Arts, & Sciences.

Creative Commons

Creative Commons (CC) is a non-profit organization devoted to expanding the range of creative works available for others to build upon legally and to share. The organization has released several copyright-licenses known as Creative Commons licenses free of charge to the public. These licenses allow creators to communicate which rights they reserve, and which rights they waive for the benefit of recipients or other creators. An easy-to-understand one-page explanation of rights, with associated visual symbols, explains the specifics of each Creative Commons license. Creative Commons licenses do not replace copyright, but are based upon it. They replace individual negotiations for specific rights between copyright owner (licensor) and licensee, which are necessary under an "all rights reserved" copyright management, with a "some rights reserved" management employing standardized licenses for re-use cases where no commercial compensation is sought by the copyright owner. The result is an agile, low-overhead and low-cost copyright-management regime, profiting both copyright owners and licensees. Wikipedia uses one of these licenses.

Spaceflight

Spaceflight (also written space flight) is ballistic flight into or through outer space. Spaceflight can occur with spacecraft with or without humans on board. Examples of human spaceflight include the U.S. Apollo Moon landing and Space Shuttle programs and the Russian Soyuz program, as well as the ongoing International Space Station. Examples of unmanned spaceflight include space probes that leave Earth orbit, as well as satellites in orbit around Earth, such as communications satellites. These operate either by telerobotic control or are fully autonomous.

Spaceflight is used in space exploration, and also in commercial activities like space tourism and satellite telecommunications. Additional non-commercial uses of spaceflight include space observatories, reconnaissance satellites and other Earth observation satellites.

A spaceflight typically begins with a rocket launch, which provides the initial thrust to overcome the force of gravity and propels the spacecraft from the surface of the Earth. Once in space, the motion of a spacecraft—both when unpropelled and when under propulsion—is covered by the area of study called astrodynamics. Some spacecraft remain in space indefinitely, some disintegrate during atmospheric reentry, and others reach a planetary or lunar surface for landing or impact.

Crash Course

Crash Course (also known as Driving Academy) is a 1988 made for television teen film directed by Oz Scott.

Plot

Crash Course centers on a group of high schoolers in a driver’s education class; many for the second or third time. The recently divorced teacher, super-passive Larry Pearl, is on thin ice with the football fanatic principal, Principal Paulson, who is being pressured by the district superintendent to raise driver’s education completion rates or lose his coveted football program. With this in mind, Principal Paulson and his assistant, with a secret desire for his job, Abner Frasier, hire an outside driver’s education instructor with a very tough reputation, Edna Savage, aka E.W. Savage, who quickly takes control of the class.

The plot focuses mostly on the students and their interactions with their teachers and each other. In the beginning, Rico is the loner with just a few friends, Chadley is the bookish nerd with few friends who longs to be cool and also longs to be a part of Vanessa’s life who is the young, friendly and attractive girl who had to fake her mother’s signature on her driver’s education permission slip. Kichi is the hip-hop Asian kid who often raps what he has to say and constantly flirts with Maria, the rich foreign girl who thinks that the right-of-way on the roadways always goes to (insert awesomely fake foreign Latino accent) “my father’s limo”. Finally you have stereotypical football meathead J.J., who needs to pass his English exam to keep his eligibility and constantly asks out and gets rejected by Alice, the tomboy whose father owns “Santini & Son” Concrete Company. Alice is portrayed as being the “son” her father wanted.