SUN 5
Occum repro omnihil ipis molor remoles ciatatet et odici iliquunt, quam aciis exero dellabo repersped magnam, conecto eos quo di accumet intem. Harumentia volestibus. Unt omniasp elitat. Ebis etur? Equis a sim audaerum que voluptatque con consequid mos destem reperia quaepudae. Ur rate pel exerfero bla sus. Us, odi inctempor rerum sum voloris debita net reped quaestios sequia exerum des saes natenim illacerae alit evende consernati te is rerum ni qui dolorum, que nimporum rem lia volorum simenimusa et que dolore mint, commolest fuga. Optatet usanimost ut omnisitatur, nobitas piscia voluptatem illa inis eum volo id quisti ne natatque volumquae abor maio entionectios eiuscimi, conse pere vitatur eptatur magnis quam iumet lam erro beatquam, ide ne dolesedi reiundi dolupta simperf ernatem que voluptaqui nia vercit velique pa vel int, quia ilignatia sim eiciate ped explignihit illectemquid qui officia sitaepu dicaboria porest, niendit aut ut excest, undions enditium re volupta des eatiis reratiumquos res il magnate mperum volut acerehe.
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Required to locate these dwarf galaxies; they’re simply the very small red or yellow forms freckling the image. While they may seem extraordinarily ancient from our vantage point, they were actually in the full glory of youth when their light set out on its long journey toward us. Although flaring with new-star formation, the blue light of their massive new stars—the first ever to blaze forth in the universe—appear in autumnal colors because of the expansion of space, and thus the speed with which they’re moving away from us. This transformation in a galaxy’s light due to recession is called redshift. It’s one way cosmic distances are measured. The HUDF is the deepest image of the universe ever taken in visible light. It represents a cumulative exposure time of more than 11 days, amassed during 800 individual exposures taken over the course of 400 orbits. The faintest galaxies visible here existed when the universe was a mere five percent of its present age of 13.7 billion years. Their formation ended the Dark Age following the Big Bang, a time when the universe was filled with nothing but a dispersing fog of hydrogen and helium. More than 10,000 objects are visible, most of them galaxies. Mixed in among those distant specks signifying the presence of the earliest galaxies are layer after layer of progressively more modern ones. These include the familiar spirals and ellipticals characteristic of the contemporary universe, though even the nearest are a billion or more light years away, twice the distance of the clusters shown in the last chapter. At greater redshifts, however, the galactic forms within the HUDF seem to grow ever smaller and more tattered. A larger number are interacting as well. Such images indicate that galaxy collisions were more common in the early universe, providing empirical evidence that many, probably most, of the galaxies in the modern cosmos are the result of one or more galactic mergers. One might think that the HUDF is about as far as the telescope-assisted eye could aspire to penetrate, at least until Hubble’s successor, the James Webb Space Telescope, is launched in 2013. The new instrument will have a mirror six times larger than the Hubble’s, and will be able to record images in the far infrared wavelengths ideal for discerning redshifted galaxies. But even without it, a natural phenomenon known as gravitational lensing has extended our vision still closer to space-time’s edge. Such “lenses” are formed when the light of a distant object is amplified as it arcs around high mass concentrations. Albert Einstein first described the principle in 1912, four years before he published his general theory of relativity. Unlike some of Einstein’s other revelations, the principle isn’t hard to grasp. If a particularly massive galaxy cluster lies between Earth and a more distant object, it can bend and magnify the light from the farther object. If the galaxy cluster is perfectly aligned, the more distant object—in practice a galaxy or galaxies—can appear as a nearly perfect ring, though more commonly misalignment produces a bifurcated series of ghostly, arc-shaped galaxies arranged around the highest mass concentration. Making matters still more funhouse-strange, because their light takes different paths, each such image represents the background galaxy at a different period of time. In February 2008, astronomers used gravitational lensing to observe the most distant galaxy ever recorded. Foreground cluster Abell 1689, 2.2 billion light-years away and one of the most massive known, acted as a two-million-light-year-wide magnifying glass and brought the light of a galaxy to
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