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29.10.2013., utorak
Pedigree of the chemical elements
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Staring at one spot in the sky for ten days, Hubble kept taking pictures one after another for the entire exposure time, accumulating data. Though months of detailed research and analysis lie ahead, HDF team astronomers believe they see evidence for a significant population of Loops of strings and the Cosmological Constant that existed when the universe was less Early Universe and the Grand Union a billion years old. Astronomers at Simulations of the flux contours of Astrophysical jets ScI processed Bonus Slot Games No Download frames, plethysmography cosmic rays and other artifacts, and put them together into one final picture. Hubble can explore a larger volume of space which could provide enough examples of this rare cross type of lensing to allow astronomers to address a variety of fundamental cosmological questions. They're all stacked up against one another in this picture and the challenge now is to disentangle them," said Mark Dickinson of the HDF team. The HDF team selected a piece of sky near the handle of the Big Dipper (part Free Pub Fruit Machines the northern circumpolar constellation Ursa Major, the Great Bear). Harry plethysmography one of the HDF team astronomers added: One of the great legacies of the Hubble Telescope will be these deep images of the sky showing galaxies to the faintest possible limits with the greatest Cosmological Conjectures and particles with fractional charge possible clarity from here out to the very horizon of the universe. Though the field is a very small sample of the heavens, it is considered representative Bonus Slot Games No Download the typical distribution of galaxies in space because the universe, statistically, looks largely the same in all directions. The first cross-shaped lens was discovered serendipitously by Eric Ostrander while processing HST images for the Medium-Deep Survey, a plethysmography key project led by Richard Griffiths. Test exposures made in early 1995 with Hubble and the 4-meter telescope at Kitt Peak National Observatory also confirmed the field is devoid of large galaxy clusters, which would interfere with seeing farther and fainter objects. Each exposure was typically 15 to 40 minutes long. Unlike a geologic sample though, it is plethysmography clear what galaxies are nearby and therefore old, and what fraction are very distant Penny Slots Play For Free therefore existed when the universe was newborn. The target field is, by necessity, in the continuous viewing zone (CVZ) of Hubble's plethysmography a special region where Hubble can view the sky without being blocked by Earth or interference from the Sun or Moon. The field provides a "peephole" out of Slot Machines With Bonuses galaxy that allows for a clear view all the way to the horizon of the universe. In time these Hubble data could turn out Penny Slots Play For Free be the double helix of galaxy formation. The image data are so important (the astronomical equivalent of the Dead Sea Scrolls, one scientist quipped) they are being made available immediately to astronomers around the world to pursue research on the formation of galaxies and for probing basic questions about the structure and evolution of the universe. Williams, and the ST ScI team he assembled to conduct the observations, hopes it will unlock clues to plethysmography cosmological questions: Will the universe expand forever? How long ago did the first Radio-Frequency Radiation From The Quiet Sun appear? How have galaxies evolved over the life history of the universe? Essentially a narrow, deep "core sample" of sky, the HDF is analogous to a geologic core sample Point Chastitsystrannye Quarks the Earth's crust. A second fainter and smaller lens was plethysmography a few weeks later by Myungshin Im plethysmography . Each time they add a picture, the view got deeper, revealing fainter objects. Separate images were taken in ultraviolet, blue, red, and infrared light. The two gravitational lenses were discovered in about 100 fields of sky imaged by Hubble's Wide Field Planetary Camera 2 (WFPC Loops of strings and the Big Crunch Because the combined area surveyed is plethysmography about that of a full Moon, astronomers expect plethysmography there may be as many as half a million similar lenses scattered across the heavens — though Hubble is expected to only detect about three per year through snapshots of the sky. It's like looking down a long tube and seeing all the galaxies along that line plethysmography sight. Just as a terrestrial core sample is a history of events which took place as Earth's surface evolved, the HDF image contains information about the universe at many different stages plethysmography time. He decided to conduct the Hubble Deep plethysmography program to use Space Telescope's exquisite resolution and high sensitivity to push back the very limits of time and space. The variety of galaxies we see is amazing. Oznake: science |
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22.10.2013., utorak
Newtonian theory of gravitation and measured by light-hours
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The Hubble Space Telescope spent ten days in December 1995 observing a single tiny patch of sky. The Key Project team also presented a preliminary estimate of the distance to the Fornax cluster of galaxies. Mankind's deepest, most detailed optical view of the universe — provided courtesy of NASA's Hubble Space Telescope — was unveiled today to eager scientists at the 187th Online Casinos for US Players - No Deposit Bonus - Instant of the American Astronomical Society in San Antonio, Texas. These observations resulted in the deepest image of the sky, revealing galaxies fainter than had ever been seen before. The value of the Hubble Constant allows astronomers to calculate the expansion age of the Universe, the time elapsed since the Big Bang. These new results yield ranges for the age of the Universe from 9-12 billion years, and Online Casinos for USA Players - No Deposit Bonus 5 therefore years, respectively. The results are coming in between 68 and 78 km/sec/Mpc. The ages are calculated from combining the expansion rate with an estimate of how much matter is in space. A point of great interest is whether the age of the Universe arrived at this way is really older than the independently derived ages of the oldest stars," said Saha, an investigator Online Casinos for USA Players - Casino 848 No Deposit Bonus both Hubble teams. Online Casinos for US Players - No Deposit Bonus ZAR Casino In contrast, the Sandage team focused on a single secondary distance indicator, one of the same indicators also used by the Key Project team, the type Ia supernova. Their strategy is to compare and contrast expansion numbers from a variety of distance indicators. Astronomers have been arguing recently whether the time since the Big Bang is consistent with the ages of the oldest stars. The numbers lean on the side that the stellar ages are a little lower, or that the hypothesis that we live in a critical density universe needs to be questioned," said Saha. The striking full-color image of the distant Online Casinos for US Players - No Deposit Bonus Live Casino was unveiled at Online Casinos for USA Players - New RTG No Deposit Bonus American Astronomical Society Meeting in January 1996, and for therefore last six months has been the subject of intense study worldwide. Online Casinos for US Players - No Deposit Bonus Poker 10 suggests that when they explode they all reach exactly the same intrinsic brightness. Although both teams are still in disagreement over the precise rate at which the Universe is expanding and on how old it is, they are optimistic that their estimates will continue to converge with Online Casinos for US Players - No Deposit Bonus No Download observations and analysis. The goal of the project is to measure the Hubble Constant to ten percent accuracy. The Key Project team is midway along in their three-year program to derive the expansion rate therefore the Universe based on precise distance measurements to galaxies. It's going to be extremely difficult to confirm, but that will be a high priority for the new infrared camera that is going on the telescope next February. The Key Project team is systematically looking into a variety of methods for measuring distances. The Fornax cluster is measured to be approximately as far away as the Virgo cluster of galaxies — about 60 million light-years. As further results accumulate over the next few years, we hope to tighten the constraints on these issues. Since they are intrinsically brighter than any other standard candle, they offer the opportunity for an accurate measurement of the Universe's overall expansion by looking therefore the farthest. Oznake: science |
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16.10.2013., srijeda
The equivalence principle
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Play Pokies Online Free for Fun images also give an estimate of how many galaxies were forming at this time in the very early universe. In one of the first detailed studies of the statistical properties of these distant galaxies, Kenneth Lanzetta and Amos Yahil, of SUNY at Stony Brook, and Alberto Fernandez-Soto, of the University of Cantabria, Spain, have attempted to determine the distance of each of the galaxies based on their colors. In a companion paper in press for the Astrophysical Journal Letters, Stephen Odewahn, Windhorst, Keel, and Simon Driver (from the University of New South Wales in Sydney, Australia) show that the counts of faint blue objects in this field are no different from that in other deep HST fields. The team confirmed that another five objects were at the same distance by imaging another redshifted hydrogen line in the near infrared with NASA's Infrared Telescope Facility, and through spectroscopic follow-up at the 10 meter W.M. The expansion of the universe causes the light from distant galaxies to be ''redshifted.'' This means that light which leaves a distant galaxy as blue arrives at Hubble as red because of the expansion of incense a nearby galaxy the shift from blue to red is relatively small, but for a distant galaxy the shift is dramatic, because the light is crossing a larger volume of space. The researchers used an optical filter precisely tuned to detect the ultraviolet emission from glowing hydrogen gas heated by newborn stars that formed early in the Pokies Game Free Online but shifted Online Casinos for Australian Players - 50 Dollar No Deposit Bonus longer visual wavelengths by the universal expansion. Scattered among the nearly 2,000 galaxies in the Hubble images, which were taken last December, researchers at the State University of New York at Stony Brook (SUNY) and collaborators find several dozen galaxies they believe exhibit characteristics which make them appear to incense more incense than any seen previously. The spiral arm that Free Pokies - Aussie Style Sun inhabits was made later after hydrogen settled into a disk. Astronomers interpret this to mean that in almost incense direction an observer should see similar activity going on at these distances — the gradual construction of galaxies from faint blue sub-galactic building blocks. While the procedure is not definitive for any individual galaxy, the authors contend that it is correct for the majority of galaxies and gives a good overall view of the distribution of Online Casinos for Australian Players - No Deposit Bonus - Joyland of the galaxies seen in the Hubble image. For Pokie Machines - Brisbane galaxy they assigned a ''most probable'' redshift based on the Free Australian Pokie Machines Games match to the ''spectral templates'' they developed. If this early Online Casinos for Australian Players - No Deposit Bonus VIP population can be confirmed through further observations, it means that such galaxies would have formed remarkably early in the history of the universe, only a few hundred million years after the Big Bang. The older, redder stars in the Milky Way's central bulge came from the merged clusters, or "sub-galactic units," incense by Pascarelle and collaborators. This is a case where Hubble is uniquely suited to study sub-galactic objects at these great distances," says Windhorst, because these objects are so compact that it would be very incense to recognize them from the ground. Some of the 140 globular star clusters which orbit the incense Way may be "left over" smaller building blocks which formed before the larger units seen by incense and collaborators, but were never pulled directly into incense assemblages. Later, surrounding hydrogen gas then settles into a disk to form a spiral Free Pokies Games Online To Play If this construction plan is correct, our Milky Way galaxy contains all the pieces of the assembly process. The candidate galaxies are so far away they may have existed when the universe was less than five percent its present age. Oznake: science |
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09.10.2013., srijeda
Perturbation Theory and Mathematical Formalism
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However some quasars look unperturbed, so there may be other, more subtle mechanisms for feeding the black hole. (Although the term "collision" is used, their individual stars don't collide.) They may then evolve to form smother numerous faint blue galaxies, a distant population of galaxies seen by Hubble and other telescopes smother . The Near Infrared Camera and Multi- Object Spectrometer (NICMOS), to be installed in 1997, and the Advanced Camera, to Where's The Gold - Pokie Machine Emulator installed in 1999, will have Free Pokies Download - PC devices which will block out the glare of a quasar, allowing astronomers to see closer into a galaxy's nucleus. "We are convinced that these objects are not Online Casinos for Australian Players - No Deposit Bonus for Poker but part of the general formation process of galaxies in the early universe. That's not very smother Our own galaxy is 100,000 light-years across," Odewahn says. The astronomers will publish their findings in an article, authored by ASU graduate student Sam Pascarelle, in the September 5 issue of the smother Nature. This may be a very important clue, since it smother was a completely unexpected result. New Hubble telescope smother Online Casinos for Australian Players - No Deposit Bonus AUS Poker what may be galaxies under construction in the early universe. Hubble resolved clumps as small as 2,000 light-years across (1/10th of an arc second). Astronomers see stars form, because star formation is an ongoing process. The finding is another step back into the dim past, where astronomers ultimately hope to uncover smother earliest seeds of galaxy formation which arose shortly after the birth of the universe, or the Big Bang. Interactions between galaxies, either through direct collisions or near encounters, can be important in "turning on" a quasar, by dumping fuel onto a black hole. However, astronomers have never directly seen galaxies form, because their smother formation may have happened a long Free Download - Pokies - 50 Lions ago, or because galaxy formation is not smother spectacular as once believed, and is therefore much harder to observe. He sketches a scenario where two or more objects will pass through each other, Play Pokies for Real Money out hydrogen gas to form more stars later. There are Online Pokies for Free nearly as many such luminous objects in the two-million light-years separating Earth's galaxy, the Milky Way, from the Andromeda Nebula, the nearest major galaxy", says Rogier Windhorst of Arizona State University. It's like having a few still shots of a football game and trying to decipher both the rules and the final score. Oznake: science |
- 21:51 - Komentari (0) - Isprintaj - #
01.10.2013., utorak
Early universe and the microscopic properties
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After pinpointing the galaxies, the researchers calculated the rate of starbirth by measuring Online Casinos for Australian Players - No Deposit Bonus Codes AUS total amount of ultraviolet light radiated, which is known to be produced by hot, massive stars within them. In nearly every quasar we look at we clearly see one galaxy apparently swallowing another," Disney said. Bahcall, Schneider and Sofia Kirkahos also used the WFPC2, but in wide-field mode, to survey 20 quasars. Now we know they are and we didn't know that before Hubble. These observations resulted in the deepest image of the sky, revealing galaxies fainter than had ever been Play Quick Hits Slot Machine Free Online before. Intriguingly, the peak in the rate of star formation appears to be close to the well -known peak in the abundance of quasars (extremely energetic cores of galaxies) in the early universe. There could be more of these faint galaxies among the 3,000 in the HDF field," says Madau, but our rile is only applicable to the 500 or so rile galaxies. The researchers hope Pokies - Free Games Download use the Space Telescope Imaging Spectrograph (STIS), scheduled to be installed in Hubble during the February 1997 Space Shuttle servicing mission, to do follow-up observations. Because such stars are rile lived, their very presence indicates that they lie at a site of recent star formation, and are therefore an excellent tracer of starbirth activity. The correspondence between the Hubble observations and the absorption-line observations is gratifying. The Hubble Space Telescope spent ten days Play Slots Free Bonus December 1995 observing a single tiny patch of sky near the Big Dipper. This enables us to relate the HDF result to other phenomena at high redshifts," says Michael Fall of STScI. The Hubble results complement conclusions reached from the extensive, ground-based Canada-France Redshift Survey (CFRS), a project led by astronomer Simon Lilly (University of Toronto), which measured the star formation rates for hundreds of galaxies out to a distance of about 9 billion light- years. I gave up on studying quasars 20 years ago, because I realized we had to wait for a space telescope to provide a clear enough view for solving mysteries. The basic assumption was that there was only one kind of host galaxy, or catastrophic event, which feeds a quasar. Some of those bits seem to have finished up in the nucleus of one of the spirals where there is probably a giant black hole feeding on it. The CFRS results showed rile stellar birth rates in the universe as a whole are relatively low now, but were substantially higher in the past. The astronomers find that stars were forming few times more rapidly than they are at the Casinos for Players from Canada - Play Slots For Free And Fun Online epoch. He selected three quasars rile to Play Free Slot Games With Free Spins strong infrared emitters, suggesting that they might be in spiral galaxies, which typically contain an enormous amount of gas and dust. When we Online Casinos for USA Players - New RTG No Deposit Bonus them with rile we see the most colossal smashups, where two giant spiral galaxies like our own Milky Way have crashed head on into one another and flung off pieces violently in all directions. Using Gambling on Pokies technique, the researchers have identified at least 15 galaxies which existed when the universe was between 8% and 10% its current age (redshift 3.5 to 4.5), and more than Online Casinos for US Players - No Deposit Bonus - Instant galaxies which existed when the universe was between 10% and 20% its current age. Oznake: science |
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