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Spider & the Web. Space. Beyond space and time: Fractals, hyperspace and more. Universe. There are many competing theories about the ultimate fate of the universe.


Physicists remain unsure about what, if anything, preceded the Big Bang. Many refuse to speculate, doubting that any information from any such prior state could ever be accessible. There are various multiverse hypotheses, in which some physicists have suggested that the Universe might be one among many or even an infinite number of universes that likewise exist.[11][12] Historical observation XDF size compared to the size of the Moon – several thousand galaxies, each consisting of billions of stars, are in this small view.

XDF (2012) view – each light speck is a galaxy – some of these are as old as 13.2 billion years[13] – the visible Universe is estimated to contain 200 billion galaxies. XDF image shows fully mature galaxies in the foreground plane – nearly mature galaxies from 5 to 9 billion years ago – protogalaxies, blazing with young stars, beyond 9 billion years. History Etymology, synonyms and definitions. 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.

Black hole

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. Observable Universe. The surface of last scattering is the collection of points in space at the exact distance that photons from the time of photon decoupling just reach us today.

Observable Universe

These are the photons we detect today as cosmic microwave background radiation (CMBR). However, with future technology, it may be possible to observe the still older neutrino background, or even more distant events via gravitational waves (which also should move at the speed of light). Galaxy. Galaxies contain varying numbers of planets, star systems, star clusters and types of interstellar clouds.


In between these objects is a sparse interstellar medium of gas, dust, and cosmic rays. Nebula. Portion of the Carina nebula A nebula (from Latin: "cloud";[1] pl. nebulae or nebulæ, with ligature, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases.


Originally, nebula was a name for any diffuse astronomical object, including galaxies beyond the Milky Way. The Andromeda Galaxy, for instance, was referred to as the Andromeda Nebula (and spiral galaxies in general as "spiral nebulae") before the true nature of galaxies was confirmed in the early 20th century by Vesto Slipher, Edwin Hubble and others. Spiral Galaxy. Virgo. The Virgo Supercluster (Virgo SC) or Local Supercluster (LSC or LS) is the irregular supercluster that contains the Virgo Cluster in addition to the Local Group, which in turn contains the Milky Way and Andromeda galaxies.


At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs (110 million light-years). Galaxies Gone Wild. Star. For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space.


Supernova. A supernova (abbreviated SN, plural SNe after "supernovae") is a stellar explosion that is more energetic than a nova.


It is pronounced /ˌsuːpəˈnoʊvə/ with the plural supernovae /ˌsuːpəˈnoʊviː/ or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months. During this interval a supernova can radiate as much energy as the Sun is expected to emit over its entire life span.[1] The explosion expels much or all of a star's material[2] at a velocity of up to 30,000 km/s (10% of the speed of light), driving a shock wave[3] into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. Nova means "new" in Latin, referring to what appears to be a very bright new star shining in the celestial sphere; the prefix "super-" distinguishes supernovae from ordinary novae which are far less luminous. First Organic Molecule on Extrasolar. Technology Review: The Authority on the Future of Technology. - Science News, Technology, Physics, Nanotechnology, Space Science, Earth Science, Medicine. The Tech Report - PC Hardware Explored. Science news and science jobs from New Scientist. InnerSuper. The Engineer's Ultimate Resource Tool. Electronics.

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Basic Electronics - Course Table You are at the best, free online "Basic Electronics Course". Just read the brief blocks of text, view the videos, and check out some of the screened internet links. This is the easiest, fastest way to learn basic electronics. {*style:<b><b>Maybe you already know some basic electronics and want to test yourself to see exactly how much you do know. </b></b>*} {*style:<b>Explanation of AC and DC currents. </b>*} {*style:<b><b><b> P - I*V </b></b></b>*} {*style:<b>Watch the video . If you don't have a clue as to what electrical current and voltage are - read on. Electronic Circuits. Theban Mapping Project.