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Brane cosmology

Brane cosmology
Brane cosmology refers to several theories in particle physics and cosmology related to string theory, superstring theory and M-theory. Brane and bulk[edit] The central idea is that the visible, four-dimensional universe is restricted to a brane inside a higher-dimensional space, called the "bulk" (also known as "hyperspace"). Why gravity is weak and the cosmological constant is small[edit] Some versions of brane cosmology, based on the large extra dimension idea, can explain the weakness of gravity relative to the other fundamental forces of nature, thus solving the so-called hierarchy problem. Models of brane cosmology[edit] One of the earliest documented attempts to apply brane cosmology as part of a conceptual theory is dated to 1983.[5] The authors discussed the possibility that the Universe has dimensions, but ordinary particles are confined in a potential well which is narrow along spatial directions and flat along three others, and proposed a particular five-dimensional model. Related:  docs à revoirdocs à revoir

Ultimate fate of the universe The ultimate fate of the universe is a topic in physical cosmology. Many possible fates are predicted by rival scientific theories, including futures of both finite and infinite duration. Once the notion that the universe started with a rapid inflation nicknamed the Big Bang became accepted by the majority of scientists,[1] the ultimate fate of the universe became a valid cosmological question, one depending upon the physical properties of the mass/energy in the universe, its average density, and the rate of expansion. There is a growing consensus among cosmologists that the universe is flat and will continue to expand forever.[2][3] The ultimate fate of the universe is dependent on the shape of the universe and what role dark energy will play as the universe ages. Emerging scientific basis[edit] Theory[edit] The theoretical scientific exploration of the ultimate fate of the universe became possible with Albert Einstein's 1916 theory of general relativity. Observation[edit] Big Rip[edit]

The Brane multiverse John C. Lilly John Cunningham Lilly (January 6, 1915 – September 30, 2001) was a American physician, neuroscientist, psychoanalyst, psychonaut, philosopher, writer and inventor. He was a researcher of the nature of consciousness using mainly isolation tanks,[1] dolphin communication, and psychedelic drugs, sometimes in combination. Early life and education[edit] John Lilly was born to a wealthy family on January 6, 1915, in Saint Paul, Minnesota. His father was Richard Coyle Lilly, president of the First National Bank of St. Paul. Lilly showed an interest in science at an early age. While at St. Despite his father's wishes for him to go to an eastern Ivy-league college to become a banker, Lilly accepted a scholarship at the California Institute of Technology to study science. In 1934, Lilly read Aldous Huxley's Brave New World. Lilly became engaged to his first wife, Mary Crouch, at the beginning of his junior year at Caltech. At the University of Pennsylvania, Lilly met a professor named H. S.E.T.I.

The Inflationary universe extra dimensions, parallel universes Hidden Space Dimensions May Permit Parallel Universes, Explain Cosmic Mysteries By Tom Siegfried / The Dallas Morning News Hidden space dimensions may permit parallel universes, explain cosmic mysteries Imagine a mansion with a secret room - the perfect setting for a mystery. Now imagine that the room is vastly bigger than the mansion itself - and contains more mansions. That would make the mystery pretty bizarre. Drake equation The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. The equation was written in 1961 by Frank Drake not for purposes of quantifying the number of civilizations,[1] but intended as a way to stimulate scientific dialogue at the world's first SETI meeting, in Green Bank, West Virginia. The equation summarizes the main concepts which scientists must contemplate when considering the question of other radio-communicative life.[1] The Drake equation has proved controversial since several of its factors are currently unknown, and estimates of their values span a very wide range. History[edit] In September 1959, physicists Giuseppe Cocconi and Philip Morrison published an article in the journal Nature with the provocative title "Searching for Interstellar Communications Soon thereafter, Drake hosted a "search for extraterrestrial intelligence" meeting on detecting their radio signals. where: and

The quilted universe Quantum information In physics and computer science, quantum information is information that is held in the state of a quantum system. Quantum information is the basic entity that is studied in the growing field of quantum information theory, and manipulated using the engineering techniques of quantum information processing. Much like classical information can be processed with digital computers, transmitted from place to place, manipulated with algorithms, and analyzed with the mathematics of computer science, so also analogous concepts apply to quantum information. Quantum information[edit] Quantum information differs strongly from classical information, epitomized by the bit, in many striking and unfamiliar ways. A unit of quantum information is the qubit. The study of all of the above topics and differences comprises quantum information theory. Quantum information theory[edit] The theory of quantum information is a result of the effort to generalize classical information theory to the quantum world.

Eternal inflation Eternal inflation is predicted by many different models of cosmic inflation. MIT professor Alan H. Guth proposed an inflation model involving a "false vacuum" phase with positive vacuum energy. Parts of the Universe in that phase inflate, and only occasionally decay to lower-energy, non-inflating phases or the ground state. In chaotic inflation, proposed by physicist Andrei Linde, the peaks in the evolution of a scalar field (determining the energy of the vacuum) correspond to regions of rapid inflation which dominate. Alan Guth's 2007 paper, "Eternal inflation and its implications",[1] details what is now known on the subject, and demonstrates that this particular flavor of inflationary universe theory is relatively current, or is still considered viable, more than 20 years after its inception.[2] [3][4] Inflation and the multiverse[edit] Both Linde and Guth believe that inflationary models of the early universe most likely lead to a multiverse but more proof is required. History[edit]

dark flow Something strange appears to be tugging a 'dark flow' of galaxies across the universe. is this evidence that parallel universes really exist? SYDNEY: Astronomers have found the best evidence yet for the weird idea that our universe is one of many in the ‘multiverse’. What’s more, these parallel universes seem to be exerting a strange force on our own, causing galaxy clusters to stream across space towards the edge of the known universe. The new evidence comes from studies of ‘bumps and wiggles’ in the temperature of the cosmic background radiation (CMB), the leftover afterglow of the Big Bang. Dark flow U.S. cosmologist Sasha Kashlinsky of the Goddard Space Flight Centre in Greenbelt, Maryland, and co-workers measured slight changes in the CMB using NASA’s Wilkinson Microwave Anisotropy Probe (WMAP). Last year, Kashlinsky’s team found an unusual pattern in the movements of galaxy clusters. Best evidence for the multiverse Fits the data

Dark flow The researchers had suggested that the motion may be a remnant of the influence of no-longer-visible regions of the universe prior to inflation. Telescopes cannot see events earlier than about 380,000 years after the Big Bang, when the universe became transparent (the Cosmic Microwave Background); this corresponds to the particle horizon at a distance of about 46 billion (4.6×1010) light years. Since the matter causing the net motion in this proposal is outside this range, it would in a certain sense be outside our visible universe; however, it would still be in our past light cone. The results appeared in the October 20, 2008, issue of Astrophysical Journal Letters.[2][3][4][5][non-primary source needed] Since then, the authors have extended their analysis to additional clusters and the recently released WMAP five-year data. Location[edit] The dark flow. Criticisms[edit] See also[edit] References[edit] External links[edit]

The Cyclic multiverse 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.

Spacetime In non-relativistic classical mechanics, the use of Euclidean space instead of spacetime is appropriate, as time is treated as universal and constant, being independent of the state of motion of an observer.[disambiguation needed] In relativistic contexts, time cannot be separated from the three dimensions of space, because the observed rate at which time passes for an object depends on the object's velocity relative to the observer and also on the strength of gravitational fields, which can slow the passage of time for an object as seen by an observer outside the field. Until the beginning of the 20th century, time was believed to be independent of motion, progressing at a fixed rate in all reference frames; however, later experiments revealed that time slows at higher speeds of the reference frame relative to another reference frame. Such slowing, called time dilation, is explained in special relativity theory. Spacetime in literature[edit] Mathematical concept[edit] is that