Skip to main content

Home/ Astronomy/ Group items tagged generator

Rss Feed Group items tagged

hanz444

Einstein's Theory of General Relativity - 0 views

  •  
    Einstein's theory of general relativity predicted that the space-time around Earth would be not only warped but also twisted by the planet's rotation. Gravity Probe B showed this to be correct.Credit: NASA In 1905, Albert Einstein determined that the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers.
Janos Haits

spaceengine - Home page - 1 views

  •  
    SpaceEngine - is a free space simulation software that lets you explore the universe in three dimensions, starting from planet Earth to the most distant galaxies. Areas of the known universe are represented using actual astronomical data, while regions uncharted by human astronomy are generated procedurally. Millions of galaxies, trillions of stars, countless planets!
Janos Haits

Planetary Habitability Laboratory @ UPR Arecibo - 2 views

  •  
    "The Planetary Habitability Laboratory (PHL) is a research and education virtual laboratory dedicated to studies of the habitability of Earth, the Solar System, and exoplanets. Check the projects link for more details about the scientific projects. There are also links to scientific and educational materials, data and software tools related to planetary science and astrobiology that might be of interest to scientists, students, and the general public. The PHL is managed by the University of Puerto Rico at Arecibo."
Kalyan Roy

Cosmic Rebirth - Science News - 3 views

  • Most cosmologists trace the birth of the universe to the Big Bang 13.7 billion years ago. But a new analysis of the relic radiation generated by that explosive event suggests the universe got its start eons earlier and has cycled through myriad episodes of birth and death, with the Big Bang merely the most recent in a series of starting guns.
Todd Suomela

[astro-ph/0511440] Varying Constants - 0 views

  •  
    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that are consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying-alpha cosmologies is outlined in the light of all the observational constraints.
Todd Suomela

[0806.0377] A Hemispherical Power Asymmetry from Inflation - 0 views

  •  
    Measurements of temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multi-field inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a pre-inflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming CMB experiments.
Janos Haits

SKY-map.org/ - 0 views

  •  
    Our on-line system is a detailed sky map. We generate the map automatically using our database with the positions and basic characteristics of space objects.
Todd Suomela

Guest Post: Evalyn Gates on Cosmic Magnification (or - Invasion of the Giant Blue Space... - 0 views

  • This is not just a pretty picture, however – the image packs a lot of scientific information. The authors extract the mass distribution in the cluster (which has implications for cosmological models), measure the mass-to-light ratio of the bright galaxy in the center of the cluster, and use the magnifying power of the lens to search for even more distant galaxies. The basic idea is to construct a model of the lens, starting with the cluster galaxies and a dark matter halo; then refine the model to reproduce the multiple images that are seen. Using this refined model it’s possible to predict the location of additional images of a given source, and to identify regions of high magnification that can then be examined for multiple images of other sources. Any additional images that are found can be used to further refine the model and so on.
  • This galaxy has been lensed by the warp in spacetime created by the cluster. Light from the galaxy, which lies almost directly behind the center of the cluster but much farther away from us, travels along several curved paths through the cluster lens, producing multiple magnified images of the galaxy. The inset box shows a computer generated model of the unlensed source galaxy, enlarged by a factor of four so that the details, including the spiral arm structure, are visible. Without the lensing power of the cluster, we would see this galaxy as a single small blue smudge. In general, lensing will both magnify and distort (shear) images of a background source. This lens is fairly unique in that we see large but relatively intact images of the spiral galaxy, which implies that the mass distribution in the central region of the cluster must be nearly uniform.
Sandra Flores

Experimental Demonstration of space-time distortion - 0 views

Experimental Demonstration of space-time distortionAccording to the general theory of relativity deform very large rotating masses spacetime around him. This Frame-dragging was detected by the sate...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

Experimental Demonstration of space-time distortion - 0 views

Experimental Demonstration of space-time distortionAccording to the general theory of relativity deform very large rotating masses spacetime around him. This Frame-dragging was detected by the sate...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Sandra Flores

Archaeology in the universe - 0 views

image

started by Sandra Flores on 30 Oct 14 no follow-up yet
Janos Haits

Sloan Digital Sky Survey - 0 views

  •  
    The Sloan Digital Sky Survey (SDSS) is one of the most ambitious and influential surveys in the history of astronomy. Over eight years of operations (SDSS-I, 2000-2005; SDSS-II, 2005-2008), it obtained deep, multi-color images covering more than a quarter of the sky and created 3-dimensional maps containing more than 930,000 galaxies and more than 120,000 quasars. SDSS data have been released to the scientific community and the general public in annual increments, with the final public data release from SDSS-II scheduled for October 31, 2008. SDSS-III, a program of four new surveys using SDSS facilities, began observations in July 2008, and will continue through 2014.
Janos Haits

The Habitable Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo - 1 views

  •  
    "The Habitable Exoplanets Catalog (HEC) is an online database of potentially habitable worlds discoveries for scientists, educators, and the general public. The catalog identifies, classifies, and compares exoplanets of interest for the search for life in the universe. There is no guarantee that any of these worlds are habitable since we know very little of them now. The catalog is maintained by the Planetary Habitability Laboratory @ UPR Arecibo and is updated as new data is available."
Janos Haits

Open Exoplanet Catalogue - 0 views

  •  
    "The Open Exoplanet Catalogue is a catalogue of all discovered extra-solar planets. It is a new kind of astronomical database. It is decentralized and completely open. We welcome contributions and corrections from both professional astronomers and the general public."
Janos Haits

Planetary Habitability Laboratory @ UPR Arecibo - 0 views

  •  
    "The Planetary Habitability Laboratory (PHL) is a research and education laboratory dedicated to studies of the habitability of Earth, the Solar System, and exoplanets. Check the projects link for more details about the scientific projects. There are also links to scientific and educational materials, data and software tools related to planetary science and astrobiology that might be of interest to scientists, students, and the general public. The PHL is managed by the University of Puerto Rico at Arecibo."
Janos Haits

Sloan Digital Sky Survey - 0 views

  •  
    The Sloan Digital Sky Survey (SDSS) is one of the most ambitious and influential surveys in the history of astronomy. Over eight years of operations (SDSS-I, 2000-2005; SDSS-II, 2005-2008), it obtained deep, multi-color images covering more than a quarter of the sky and created 3-dimensional maps containing more than 930,000 galaxies and more than 120,000 quasars. SDSS data have been released to the scientific community and the general public in annual increments, with the final public data release from SDSS-II scheduled for October 31, 2008. SDSS-III, a program of four new surveys using SDSS facilities, began observations in July 2008, and will continue through 2014.
Sandra Flores

Fifth ATV's Georges Lemaître - 1 views

The fifth and final current proposed Automated Transfer Vehicle (ATV) of the European Space Agency will carry the name "Georges Lemaître". The Belgian theologian and astrophysicists is considered t...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Kalyan Roy

Why Are Quark Stars So Strange? : Discovery News - 1 views

  • First things first, neutron stars, quark stars and black holes are all born via the same mechanism: a supernova. But each of the three are progressively more massive, so they originate from supernovae produced by progressively more massive stars. So, what if a star exploded, producing something a little too massive to be called a neutron star? Well, neutron stars resist collapsing under their own gravitational pull by a characteristic of matter known as neutron degeneracy. This produces an outward force called neutron degeneracy pressure. What if the neutron star born after a supernova is too massive for this neutron degeneracy pressure to hold up against the neutron star's own gravity? In this case, it's up to the quarks that make up the neutrons to take over, preventing the body from collapsing any further. Single neutrons are composed of three quarks (two "down" quarks and one "up" quark). When quark degeneracy pressure kicks in, a quark star may be produced; the free "up" and "down" quarks get converted into "strange" quarks. Therefore, a quark star (also known as a "strange star") is made up of strange matter.
  • Using what we know from the Standard Model of particle physics, a massive quark star may have enough gravitational energy to start 'burning' strange matter. The quarks inside the core of the quark star may be abused so badly by gravitational pressure that the quarks will be converted into pure energy and neutrinos.
  • The fascinating thing with this scenario is that the quark star matter will be so dense that even the neutrinos cannot escape. However, this release of energy and generation of neutrinos creates an outward pressure countering the relentless inward gravitational pull.
  • ...2 more annotations...
  • Dai calls this extreme strange matter-burning quark star an "electroweak star"
  • Saving the best till last, the electroweak star's core would therefore be as extreme as the universe was only 10-10 seconds (that's 0.0000000001 seconds) after the Big Bang. These extreme objects would be like mini-Big Bang laboratories, maintaining a pressure where the electromagnetic and weak forces are so intertwined, they cannot be distinguished.
1 - 20 of 29 Next ›
Showing 20 items per page