Wormhole

Black hole A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. History General relativity

Loop quantum gravity More precisely, space can be viewed as an extremely fine fabric or network "woven" of finite loops. These networks of loops are called spin networks. The evolution of a spin network over time is called a spin foam. Today LQG is a vast area of research, developing in several directions, which involves about 50 research groups worldwide.[1] They all share the basic physical assumptions and the mathematical description of quantum space. Research into the physical consequences of the theory is proceeding in several directions. History[edit] The canonical version of the dynamics was put on firm ground by Thomas Thiemann, who defined an anomaly-free Hamiltonian operator, showing the existence of a mathematically consistent background-independent theory. General covariance and background independence[edit] In theoretical physics, general covariance is the invariance of the form of physical laws under arbitrary differentiable coordinate transformations. LQG is formally background independent. .

String theory String theory was first studied in the late 1960s[3] as a theory of the strong nuclear force before being abandoned in favor of the theory of quantum chromodynamics. Subsequently, it was realized that the very properties that made string theory unsuitable as a theory of nuclear physics made it a promising candidate for a quantum theory of gravity. Five consistent versions of string theory were developed until it was realized in the mid-1990s that they were different limits of a conjectured single 11-dimensional theory now known as M-theory.[4] Many theoretical physicists, including Stephen Hawking, Edward Witten and Juan Maldacena, believe that string theory is a step towards the correct fundamental description of nature: it accommodates a consistent combination of quantum field theory and general relativity, agrees with insights in quantum gravity (such as the holographic principle and black hole thermodynamics) and has passed many non-trivial checks of its internal consistency.

Dark matter Dark matter is invisible. Based on the effect of gravitational lensing, a ring of dark matter has been detected in this image of a galaxy cluster (CL0024+17) and has been represented in blue.[1] Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Overview[edit] Estimated distribution of matter and energy in the universe, today (top) and when the CMB was released (bottom) Baryonic and nonbaryonic dark matter[edit] Observational evidence[edit] Galaxy rotation curves[edit] Detection[edit]

Physics Various examples of physical phenomena Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy.[8] Over the last two millennia, physics was a part of natural philosophy along with chemistry, certain branches of mathematics, and biology, but during the Scientific Revolution in the 17th century, the natural sciences emerged as unique research programs in their own right.[b] Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms of other sciences[6] while opening new avenues of research in areas such as mathematics and philosophy. Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs. History Ancient astronomy Astronomy is the oldest of the natural sciences. Natural philosophy Classical physics Modern physics

Astrophysics Astrophysics (from Greek astron, ἄστρον "star", and physis, φύσις "nature") is the branch of astronomy that deals with the physics of the universe, especially with "the nature of the heavenly bodies, rather than their positions or motions in space."[1][2] Among the objects studied are galaxies, stars, planets, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. In practice, modern astronomical research often involves a substantial amount of work in the realm(s) of theoretical and/or observational physics. Astrophysics can be studied at the bachelors, masters, and Ph.D. levels in physics or astronomy departments at many universities. History[edit] See also: Observational astrophysics[edit] Early 20th-century comparison of elemental, solar, and stellar spectra See also[edit]

Particle physics Subatomic particles[edit] Modern particle physics research is focused on subatomic particles, including atomic constituents such as electrons, protons, and neutrons (protons and neutrons are composite particles called baryons, made of quarks), produced by radioactive and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles. Dynamics of particles is also governed by quantum mechanics; they exhibit wave–particle duality, displaying particle-like behavior under certain experimental conditions and wave-like behavior in others. In more technical terms, they are described by quantum state vectors in a Hilbert space, which is also treated in quantum field theory. History[edit] Standard Model[edit] The current state of the classification of all elementary particles is explained by the Standard Model. Experimental laboratories[edit] In particle physics, the major international laboratories are located at the: Theory[edit] Future[edit] See also[edit]

Stargate In addition to film and television, the Stargate franchise has expanded into other media, including books, video games, and comic books. These supplements to the film and television series have resulted in significant development of the show's fictional universe and mythology. In 2008, the films Stargate: The Ark of Truth and Continuum were released direct-to-DVD, which in total grossed over $21 million in Australia. In 2009, the original pilot was re-cut and released as a direct-to-DVD film. In 2002 the franchise's first animated series, Stargate Infinity, began airing, which holds no canonicity in the franchise despite its Stargate SG-1-inspired plot. In 2004, the TV series Stargate Atlantis was released as a spin off from Stargate SG-1. Premise[edit] In the story, this is explained as being the result of alien interference in Earth's past—the concept influenced by the ideas of Erich von Däniken. Franchise releases[edit] Media releases[edit] Game releases[edit] Theatrical films[edit]

Mythology of Stargate Plot summary[edit] Stargate SG-1[edit] Stargate Atlantis[edit] Stargate Atlantis is set in the Pegasus Galaxy and explores the adventures of an "elite expedition" from Earth. The gate address to the legendary city Atlantis is discovered on Earth by Daniel Jackson at the end of 7th season start of the 8th season of Stargate SG-1. The Earth expedition has a multi-nation civilian leadership and a predominantly United States military faction providing security. Stargate Universe[edit] Stargate Universe was conceived as "a completely separate, third entity" in the live-action Stargate franchise.[14] Although it is firmly entrenched in pre-established Stargate mythology, Stargate Universe has diverged in a new direction.[15] Like the first two series in the franchise, Stargate Universe takes place during the present time, not in the distant future.[14] Technology[edit] Stargate device[edit] Species[edit] Ancients/Alterans/Lanteans[edit] Aschen[edit] Asgard[edit] Asurans[edit] A't'trr[edit] Furlings[edit]

Stargate (device) A Stargate from Stargate SG-1. Much of the inspiration for the functioning of the device is drawn heavily from theoretical astrophysics, particularly that of black holes and wormholes, a staple of science fiction, often used to create "shortcuts" through space. Although these may exist in reality, it is not widely held to be true that any such phenomenon could safely transport a human being,[8] as such wormholes would most likely be created by excessive gravity (e.g., from a black hole) which would destroy any potential traveler.[9] In Stargate however, this is circumvented by transporting a traveller through as an energy signature, and reintegrating them at the other end. The alien race encountered in the original movie is later developed in SG-1 as the Goa'uld, the dominant evil power in the Milky Way. For most of the run of Stargate SG-1, Earth was under constant threat from the Goa'uld, and is no match for their superior technology. sbȝ n sbȝw "gate/portal/door of stars