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Sub-Topics Cosmology Dark Matter Intergalactic Medium Multiverse Theories of the Universe Also Try Particle Physics Quantum Mechanics Relativity Lists Universe - Pictures (Association of Universities for Research in Astronomy - Levay) Provides spectacular pictures of the universe. Materials Earth from Far, Far Away and Very, Very Close (Florida State University - Davidson) "View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree just outside the buildings of the National High Magnetic Field Laboratory in Tallahassee, Florida. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons." 9-02 Universe (Scott) Provides dramatic photos of the universe, called The Gallery, along with short explanations. News -01-16-07 Superstrings May Sing in Gravitational Waves (MSNBC News) "String theory posits that hidden dimensions are tightly wound in strings of elementary particles. An offshoot of this theory suggests that some such strings can form into narrow tubes of energy stretched across vast distances by the expansion of the universe. These theoretical cosmic superstrings, which researchers described as ultra-thin tubes filled with ancient vacuum created in the early universe, can coil into galactic-sized, vibrating loops that emit gravitational waves as they decay into oblivion." 01-07 -05-21-08 Scientists Observe Supernova in Action (New York Times) "Far away on the day of Jan. 9, Earth time, a satellite telescope by the name of Swift, which happened to be gazing at the star’s galaxy, a smudge of stars 88 million light-years away in the constellation Lynx, recorded an unexpected burst of invisible X-rays 100 billion times as bright as the Sun." 05-08 -06-06-07 The Universe Is Expanding Beyond Understanding (New York Times) "When Albert Einstein was starting out on his cosmological quest 100 years ago, the universe was apparently a pretty simple and static place. Common wisdom had it that all creation consisted of an island of stars and nebulae known as the Milky Way surrounded by infinite darkness." 06-07 -06-11-06 New Observatory "Seeing" Gravity (LATimes.com) "What makes LIGO different from other observatories is that it doesn't "see" the cosmos by detecting electromagnetic energy in the form of light, radio waves or X-rays. It feels it, measuring waves of gravity that wrinkle space-time like ripples on a lake." 06-06 -11-23-05 Supernovae Back Einstein's Constant (Scientific American) "Now new observations from an international team of astronomers seem to show that dark energy is like the cosmological constant, unvarying throughout space and time. By measuring the distances to 71 far-off supernovae, the scientists were able to ascertain with a high degree of confidence that the effect dark energy exerts on supernovae light does not vary with distance. The researchers also plugged this data into a so-called equation of state, which measures the relationship between pressure and density, and found that dark energy must be less than -0.85--awfully close to Einstein's cosmological constant at -1. 'Our observation is at odds with a number of theoretical ideas about the nature of dark energy that predict that it should change as the universe expands and, as far as we can see, it doesn't,' says team member Ray Carlberg of the University of Toronto." 11-05 Papers 08-17-04 X-Ray Technology to Improve View of Universe (BBC News) "The researchers have successfully tested a small prototype which if scaled up could be a million times more powerful than today's observatories." "Professor Cash said a fully scaled-up version of the design could resolve a region the size of a dinner plate on the surface of the Sun." 8-04 Age of the Universe (Wikipedia.org) "The age of the universe, according to the Big Bang theory, is the time elapsed between the Big Bang and the present day. The current scientific consensus holds this to be about 13.7 billion years." 01-07 Astronomical Distances (Wikipedia.org) "The parsec (symbol pc) is a unit of length used in astronomy. It stands for 'parallax of one arc second'." "One parsec is defined to be the distance from the Earth to a star that has a parallax of 1 arcsecond. It is, therefore, approximately:...3.261630751 light years." "One kiloparsec, abbreviated 'kpc', is one thousand parsecs, or 3,262 light years. Kiloparsecs are typically used to measure distances between parts of a galaxy." "One megaparsec, abbreviated 'Mpc', is one million parsecs, or 3,261,564 light years. Megaparsecs are typically used to measure distances between neighboring galaxies and galaxy clusters." "One gigaparsec, abbreviation 'Gpc', is one billion parsecs — one of the largest distance measures used. One gigaparsec equals 3.261564 billion light years, or roughly ¼ the distance to the horizon of the observable universe (dictated by the cosmic background radiation). Gigaparsecs are typically used to measure distances to supergalactic structures, such as clusters of quasars or the Great Wall." 01-07 Big Bang (Wikipedia.org) "In astrophysics, the term Big Bang is used both in a narrow sense to refer to the interval of time roughly 13.7 billion years ago when the photons observed in the microwave cosmic background radiation acquired their black-body form, and in a more general sense to refer to a hypothesized point in time when the observed expansion of the universe (Hubble's law) began." 10-04 Birth of the Universe - Photo and Animation (Nasa) "NASA today released the best 'baby picture' of the Universe ever taken, containing such stunning detail that it may be one of the most important scientific results of recent years." "In addition, the new portrait precisely pegs the age of the Universe at 13.7 billion years old, with a remarkably small 1 percent margin of error." 2-03 Dictionary or Glossary of Astronomy Terms (KidsAstronomy.com) Provides short definitions of dozens of astronomy terms. 11-00. Evolution of the Universe (NASA) "The myriad galaxies in the Hubble Deep Field represented the first big step for Hubble astronomers to understand galaxy evolution. But studying galaxy evolution in the Hubble Deep Field is like trying to understand the population of a country by sampling a small village. Astronomers don't know if the galaxies in that village are representative of the universe's galactic population. The GOODS survey, on the other hand, is akin to sampling the population of a large city to make inferences about galaxies in the cosmos." 6-03 General Relativity (Wikipedia.org) "General relativity (GR) or General relativity theory (GRT) is the theory of gravitation published by Albert Einstein in 1915." 10-04 Groups and Clusters of Galaxies (Wikipedia.org) "Galaxy groups and clusters are super-structures in the spread of galaxies of the cosmos. Matter throughout the visible Universe has, over the course of the Universe's history, aggregated into a range of large-scale structures under the influence of gravity. Groups and clusters may contain from ten to thousands of galaxies. The clusters themselves are involved in larger groups called superclusters." 10-04 How Far Can We See at Night? (Space.com - Weinstock) "On a clear dark night away from city lights, the star-spangled heavens can create an overwhelming sense of infinity. Seemingly countless points of light, so far away, urge one to contemplate the insignificance of a lone planet amid the incomprehensible breadth of the universe." "Almost all of the sky objects visible to the naked eye are stars that reside in our galaxy. In fact the bulk of those you can see are relatively nearby, within a few thousand light-years. Most are actually within a few hundred light-years, with the exception of a few intrinsically brilliant stars that are many thousands of times more luminous than the Sun." "For comparison, the Sun is about 26,000 light-years from the galactic center, orbiting on an outer spiral arm. The galaxy itself is about 100,000 light-years wide. We see most of its contents only with powerful telescopes working at various wavelengths of light not visible to humans." 12-03 Hubble Constant for Size and Age of Universe (AmericanScientist.org - Freedman) "A newly refined value of Ho, the expansion rate of the universe, may herald a first step toward a new era of 'precision" cosmology.' " "The new result suggests that our universe is about 13 billion years old, give or take a billion years, and it's a value that sits comfortably alongside the 12 billion years estimated for the age of the oldest stars." 12-03 Infinity (Wikipedia.org) "Infinity is a theoretical value that is larger than any other value. To count to infinity is to count forever, without end." 10-04 Issues - The Universe (Washington Post - Achenbach) Provides a summary of new findings on the nature of the Big Bang and expansion of the universe. 4-01 Issues - The Universes (PBS - Hawking) Provides theoretical papers related to the nature of the universes. Includes Ptolemy, Copernicus, Kepler, Steady-State, Big Bang, and other theories. Life May Go On Indefinitely (Scientific American - Graham) "Even if the universe does turn out to be dominated by a cosmological constant, Freese and Kinney are reluctant to give up hope. One day, they speculate, we might figure out how to synthesize a new universe in a laboratory, set off a Big Bang, and move into it, abandoning our present universe as a lost cause." 1-03 Light - Speed of Light May Be Changing (New Scientist) Provides a summary of research that shows that the speed of light, one of the most important constants in physics and astronomy, may be changing. 8-01 Light Year (Wikipedia.org) "A light year, abbreviated ly, is the distance light travels in one year...." "The light year is often used to measure distances to stars: A light year is not a unit of time. In astronomy, the preferred unit of measurement for such distances is the parsec which is defined as the distance at which an object will generate one arcsecond of parallax when the observing object moved one astronomical unit. This is equal to approximately 3.26 light years. The parsec is preferred because it can be more easily derived from observations without including conversion terms, whose value is imprecisely known." Visitors sometimes spell as light-year. 10-04 Planetarium - Hayden (American Museum of Natural History) Describes the most technologically advanced planetarium in the world. The Hayden Planetarium provides a state of the art exhibit of the Big Bang, as well as the most advanced star projector that allows visitors to fly through the galaxy to the edge of the universe. 3-00 Space-Time (Wikipedia.org) "In special relativity and general relativity, time and three-dimensional space are treated together as a single four-dimensional manifold called spacetime (alternatively, space-time)." 10-04 Special Relativity (Wikipedia.org) "The Special relativity (SR) or Special theory of relativity is the physical theory published in 1905 by Albert Einstein. It replaced Newtonian notions of space and time, and incorporated electromagnetism as represented by Maxwell's equations. The theory is called "special" because it is a "special" case of Einstein's principle of relativity where the effects of gravity can be ignored." 10-04 Structure and Evolution of the Universe (NASA) Attempts to research and describe the structure and evolution of the universe. Scientists call it "Cosmic journeys to the edge of gravity, space, and time." In PDF format. 4-01 Structure of the Cosmos (Wikipedia.org) "A galaxy is a large cluster of stars held together by gravity." Includes Galaxy clouds, Galaxy clusters, Galaxy filaments, Galaxy subclusters, and Galaxy superclusters. 10-04 Structure of the Universe (KidsAstronomy.com) Provides a description and picture of the universe. Also shows distances between objects in the universe. 11-00. Understanding the Universe (Discovery.com) Suggests activities and questions to help students understand the sizes and distances involved with the universe. 3-02 Universe (Wikipedia.org) "The terms known universe, observable universe, or visible universe are often used to describe the part of the Universe that we can see or otherwise observe. Those who believe it is impossible to observe the whole continuum may use our universe, referring only to that knowable by human beings in particular." 10-04 Universe (Wikipedia.org) "In materialist philosophical terms, the universe is the summation of all matter that exists and the space in which all events occur which has an equivalent idea amongst some theoretical scientists known as the total universe. In cosmological terms, the universe is thought to be a finite or infinite space-time continuum in which all matter and energy exist." 04-06 Universe Was Hit By Another Universe (New Scientist) Provides a summary of a theory that the Big Bang started when our universe was hit by another universe. 8-01 Projects Projects About the Universe (School.Discovery.com) Provides a project on galaxies and one on the "big bang" theory of the beginning of the universe. 1-04

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