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Dark Matter (Wikipedia)

Dark Matter (Wikipedia)
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. Other than neutrinos, a form of hot dark matter, it has not been detected directly, making it one of the greatest mysteries in modern astrophysics. 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] Baryonic and nonbaryonic dark matter[edit] Observational evidence[edit]

Dark Energy (Wikipedia) Adding the cosmological constant to cosmology's standard FLRW metric leads to the Lambda-CDM model, which has been referred to as the "standard model" of cosmology because of its precise agreement with observations. Dark energy has been used as a crucial ingredient in a recent attempt to formulate a cyclic model for the universe.[8] Nature of dark energy[edit] Many things about the nature of dark energy remain matters of speculation. The evidence for dark energy is indirect but comes from three independent sources: Distance measurements and their relation to redshift, which suggest the universe has expanded more in the last half of its life.[9]The theoretical need for a type of additional energy that is not matter or dark matter to form our observationally flat universe (absence of any detectable global curvature).It can be inferred from measures of large scale wave-patterns of mass density in the universe. Effect of dark energy: a small constant negative pressure of vacuum[edit] .

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.

The Mayan Prophecy of 2012 Is 2012 going to be the "End of The World?" No, not in terms of the complete destruction of the Earth and some kind of annihilation scenario. 2012 is not bringing the end of the planet. When we contemplate the expression "end of the world" let us realize the term "world" can refer to a cycle; a period of time; a world age era. Therefore 2012 is signalling the completion of one World Age Cycle, transitting into an emerging New World Age to come. It is said that the world we are ending is the one that is dominated by materialism and ego consciousness, therefore it may be that the world to follow will be founded on different values that honor the spirit of the interdependence of all of life. There are ideas in the collective mind that assert that 2012 is bringing the "end of the world as we know it," which may be linked with its other association of heralding "the end of linear time," and no one can say how valid these claims may be. "The world will not end. As Mr. Is 2012 just the next Y2K?

Dynamic method The dynamic method is a procedure for the determination of the masses of asteroids. The procedure gets its name from its use of the Newtonian laws of the dynamics, or motion, of asteroids as they move around the Solar System. The procedure works by taking multiple position measurements to determine the gravitational deflection caused when two or more asteroids move past each other. The method relies on the fact that the large number of known asteroids means they will occasionally move past one another at very close distances. Because the method relies on detecting the amount of gravitational deflection induced during an interaction, the procedure works best for objects which will produce a large deflection in their interactions with other objects. Mathematical analysis[edit] The simplest way to describe the deflection of the asteroids is in the case where one object is significantly more massive than the other. Here References[edit]

New transparent solar cells can be used on windows, smartphone screens (Science Alert) This new type of transparent solar cell can be used to cover windows, buildings or smartphone screens to produce solar energy. Named a transparent luminescent solar concentrator and developed by researchers in Michigan State University in the US, this material can be used to cover anything that has a flat, clear surface. Transparent solar cell technology has been attempted before, but the energy the cells produced was poor and the materials they were made out of were highly coloured. "No one wants to sit behind coloured glass,” said one of the researchers behind the technology, chemical engineer Richard Lunt, in a press release. "It makes for a very colourful environment, like working in a disco. We take an approach where we actually make the luminescent active layer itself transparent.” The new transparent solar cells are made from tiny organic molecules that absorb invisible wavelengths of sunlight such as ultraviolet and near infrared light.

Inflation (Wikipedia) In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds. Following the inflationary period, the Universe continues to expand, but at a less rapid rate.[1] Inflation was developed in the early 1980s. In 2002, three of the original architects of the theory were recognized for their major contributions; physicists Alan Guth of M.I.T., Andrei Linde of Stanford and Paul Steinhardt of Princeton shared the prestigious Dirac Prize "for development of the concept of inflation in cosmology".[5] Overview An expanding universe generally has a cosmological horizon, which, by analogy with the more familiar horizon caused by the curvature of the Earth's surface, marks the boundary of the part of the Universe that an observer can see. Space expands . . Few inhomogeneities remain Duration Reheating Notes

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. The predicted size of this structure is the Planck length, which is approximately 10−35 meters. According to the theory, there is no meaning to distance at scales smaller than the Planck scale. 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. LQG is formally background independent. and . . .

MANUSCRIPT EDITING -- FICTION AND NONFICTION BOOK EDITOR Dark flow A possible non-random component of the peculiar velocity of galaxy clusters In astrophysics, dark flow is a theoretical non-random component of the peculiar velocity of galaxy clusters. The actual measured velocity is the sum of the velocity predicted by Hubble's Law plus a possible small and unexplained (or dark) velocity flowing in a common direction. 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. The results appeared in the October 20, 2008, issue of Astrophysical Journal Letters.[1][2][3][4][non-primary source needed] Location[edit] Panoramic view of galaxies beyond the Milky Way, with the Norma cluster and the Great Attractor shown by a long blue arrow at the bottom-right in image near the disk of the Milky Way The team has so far catalogued the effect as far out as 2.5 billion light-years, and hopes to expand its catalog out further still to twice the current distance. The dark flow.

What’s New in 3D Printing? :: ChemViews Magazine 3D Printing is Coming to Our Lives! 3D printing is not a novelty, it is more than 20 years old. However, the first monograph on it has only just appeared [1]. I learned about it only recently, when this manufacturing technique made its way into chemistry [2,3]. Today, rapidly developing 3D printing offers numerous marketed applications. Figure 1. The article “Print me a Stradivarius” with a cover picture of a printed violin was published in The Economist two years ago [8, 9]. Figure 2. 3D-printed lampshade. © (Designer: Dizingof) Contrary to “complex structures made in expensive and complex ways that come together in even more complex ways” [10], applying 3D printing consists of consecutive depositing of layers of an appropriate material and their subsequent fusion. Mary Gehl states that the 3D printing was patented in the late 1970s but no source has been given for this information [12]. The Process of 3D Printing and Its Advantages The advantages of 3D printing are:

Black Hole (Wikipedia) 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

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