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Astronomija - opšta tema


Jolly Roger

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Koliko je civilizacija u ovom sudaru uništeno? Možda nijedna, možda mnoge. Sličan scenario čeka i našu galaksiju u dalekoj budućnosti. U svakom slučaju, snimci su predivni:

A Galactic SpectacleA beautiful new image of two colliding galaxies has been released by NASA's Great Observatories. The Antennae galaxies, located about 62 million light-years from Earth, are shown in this composite image from the Chandra X-ray Observatory (blue), the Hubble Space Telescope (gold and brown), and the Spitzer Space Telescope (red). The imaging data were taken in 1999, 2003, 2004, and 2005. The Antennae galaxies take their name from the long antenna-like "arms," seen in wide-angle views of the system. These features were produced by tidal forces generated in the collision.http://www.youtube.com/watch?v=zWpD-fCC9lc
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Novi metod za kapiranje tamne energije:

First Use of Cosmic Lens to Probe Dark EnergyAn international team of astronomers using NASA's Hubble Space Telescope has devised a new method for measuring perhaps the greatest puzzle of our universe — dark energy. This mysterious phenomenon, discovered in 1998, is pushing our universe apart at ever-increasing speeds. The team's results appear in the August 20, 2010 issue of the journal Science.
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Zanimljivo razmišljanje...

22 August 2010Alien hunters 'should look for artificial intelligence'By Jason Palmer Science and technology reporter, BBC NewsA senior astronomer has said that the hunt for alien life should take into account alien "sentient machines".Seti, the Search for Extraterrestrial Intelligence, has until now sought radio signals from worlds like Earth.But Seti astronomer Seth Shostak argues that the time between aliens developing radio technology and artificial intelligence (AI) would be short.Writing in Acta Astronautica, he says that the odds favour detecting such alien AI rather than "biological" life.Many involved in Seti have long argued that nature may have solved the problem of life using different designs or chemicals, suggesting extraterrestrials would not only not look like us, but that they would not at a biological level even work like us.However, Seti searchers have mostly still worked under the assumption - as a starting point for a search of the entire cosmos - that ETs would be "alive" in the sense that we know.That has led to a hunt for life that is bound to follow at least some rules of biochemistry, live for a finite period of time, procreate, and above all be subject to the processes of evolution.But Dr Shostak makes the point that while evolution can take a large amount of time to develop beings capable of communicating beyond their own planet, technology would already be advancing fast enough to eclipse the species that wrought it."If you look at the timescales for the development of technology, at some point you invent radio and then you go on the air and then we have a chance of finding you," he told BBC News."But within a few hundred years of inventing radio - at least if we're any example - you invent thinking machines; we're probably going to do that in this century."So you've invented your successors and only for a few hundred years are you... a 'biological' intelligence."From a probability point of view, if such thinking machines ever evolved, we would be more likely to spot signals from them than from the "biological" life that invented them.'Moving target'John Elliott, a Seti research veteran based at Leeds Metropolitan University, UK, says that Dr Shostak is putting on a firmer footing a feeling that is not uncommon in the Seti community."You have to start somewhere, and there's nothing wrong with that," Dr Elliott told BBC News."But having now looked for signals for 50 years, Seti is going through a process of realising the way our technology is advancing is probably a good indicator of how other civilisations - if they're out there - would've progressed."Certainly what we're looking at out there is an evolutionary moving target."Both Dr Shostak and Dr Elliott concede that finding and decoding any eventual message from such alien thinking machines may prove more difficult than in the "biological" case, but the idea does provide new directions to look.Dr Shostak says that artificially intelligent alien life would be likely to migrate to places where both matter and energy - the only things he says would be of interest to the machines - would be in plentiful supply. That means the Seti hunt may need to focus its attentions near hot, young stars or even near the centres of galaxies."I think we could spend at least a few percent of our time... looking in the directions that are maybe not the most attractive in terms of biological intelligence but maybe where sentient machines are hanging out."&Why the alien hunt may be flawed
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Ipak izgleda nije bio samo 1:

27 August 2010Double meteorite strike 'caused dinosaur extinction'By Howard Falcon-Lang Science reporter, BBC NewsThe dinosaurs were wiped out 65 million years ago by at least two meteorite impacts, rather than a single strike, a new study suggests.Previously, scientists had identified a huge impact crater in the Gulf of Mexico as the event that spelled doom for the dinosaurs.Now evidence for a second impact in the Ukraine has been uncovered.This raises the possibility that the Earth may have been bombarded by a whole shower of meteorites.The new findings are published in the journal Geology by a team lead by Professor David Jolley of Aberdeen University.When first proposed in 1980, the idea that a meteorite impact had killed the dinosaurs proved hugely controversial. Later, the discovery of the Chicxulub Crater in the Gulf of Mexico, US, was hailed as "the smoking gun" that confirmed the theory.Double troubleThe discovery of a second impact crater suggests that the dinosaurs were driven to extinction by a "double whammy" rather than a single strike.The Boltysh Crater in the Ukraine was first reported in 2002. However, until now it was uncertain exactly how the timing of this event related to the Chicxulub impact.In the current study, scientists examined the "pollen and spores" of fossil plants in the layers of mud that infilled the crater. They found that immediately after the impact, ferns quickly colonised the devastated landscape.Ferns have an amazing ability to bounce back after catastrophe. Layers full of fern spores - dubbed "fern spikes" - are considered to be a good "markers" of past impact events.However, there was an unexpected discovery in store for the scientists.They located a second "fern spike" in a layer one metre above the first, suggesting another later impact event.Professor Simon Kelley of the Open University, who was co-author on the study, said "We interpret this second layer as the aftermath of the Chicxulub impact".This shows that the Boltysh and Chicxulub impacts did not happen at exactly the same time. They struck several thousand years apart, the length of time between the two "fern spikes".Uncertain causeProfessor Kelley continued: "It is quite possible that in the future we will find evidence for more impact events".Rather than being wiped out by a single hit, the researchers think that dinosaurs may have fallen victim to a meteorite shower raining down over thousands of years.What might have caused this bombardment is highly uncertain.Professor Monica Grady, a meteorite expert at the Open University who was not involved in the current study, said "One possibility might be the collison of Near Earth Objects".Recently, Nasa launched a program dubbed "Spaceguard". It aims to monitor such Near Earth Objects as an early warning system of possible future collisons.
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Rusi računaju da je bolje 2 nego 1, pogotovu ako je taj 1 van Rusije:

Rusija gradi novi kosmodrom28. avgust 2010. | 17:50 | Izvor: BetaMoskva -- Ruski premijer Vladimir Putin izjavio je da će Rusija od 2018. godine lansirati svoje svemirske misije iz novog centra na dalekom istoku Rusije.Putin je prisustvovao početku radova izgradnje novog kosmodroma kod Uglegorska,oko 5.800 kilometara istočno od Moskve, prema Kini.Rusija obično koristi kosmodrom izgrađen za vreme Sovjetskog saveza u Bajkonuru u Kazahstanu. Ugovor o korišćenju Bajkonura važi do 2050. godine a Rusija je prema dogovoru iz 2004. godine platila 115 miliona dolara Kazahstanu za upotrebu kosmodroma.Novi kosmodrom se nalazi na lokaciji bivše vojne baze Vostočni. Putin je rekao da će taj kosmodrom lansirati svemirske brodove sa ruskom posadom od 2018. godine. Prva lansiranja bez posade očekuju se 2015. godine.Putin je rekao da novi kosmodrom predstavlja "jedan od najvećih i najambicioznijih projekata moderne Rusije, čime će se dati mogućnost hiljadama mladih profesionalaca da koriste svoje talente".
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Imaju oni i jedan kosmodrom na krajnjem severu, negde kod Arhangelska.
Da, kosmodrom Pleseck. Imaju još jedan, raketni vojni poligon i kosmodrom Kapustin Jar, kod Znamenska. Ipak je Bajkonur po mnogo čemu najbolji, ali je van Rusije. Ozbiljnog konkurenta bi trebalo da dobije u kosmodromu sa čijom se izgradnjom krenulo... Edited by Jolly Roger
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Nemaju mira, evo novog povoda za žestoke polemike:

Stephen Hawking: God did not create UniverseThere is no place for God in theories on the creation of the Universe, Professor Stephen Hawking has said.He had previously argued belief in a creator was not incompatible with science but in a new book, he concludes the Big Bang was an inevitable consequence of the laws of physics.The Grand Design, part serialised in the Times, says there is no need to invoke God to set the Universe going."Spontaneous creation is the reason there is something," he concluded.'Planetary conditions'In his new book, an extract of which appears in the Times, Britain's most famous physicist sets out to contest Sir Isaac Newton's belief that the universe must have been designed by God as it could not have sprung out of chaos.Citing the 1992 discovery of a planet orbiting a star other than our Sun, he said: "That makes the coincidences of our planetary conditions - the single Sun, the lucky combination of Earth-Sun distance and solar mass - far less remarkable, and far less compelling as evidence that the Earth was carefully designed just to please us human beings."He adds: "Because there is a law such as gravity, the universe can and will create itself from nothing."Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist."It is not necessary to invoke God to light the blue touch paper and set the universe going."The book was co-written by US physicist Leonard Mlodinow and is published on 9 September.In his 1988 bestseller, A Brief History of Time, Prof Hawking appeared to accept the role of God in the creation of the Universe."If we discover a complete theory, it would be the ultimate triumph of human reason - for then we should know the mind of God," he said.
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http://edition.cnn.com/2010/WORLD/europe/09/02/hawking.god.universe/index.html?hpt=C2#fbid=r9iv9S9PTZr&wom=trueovde pise sledece:
LONDON, England (CNN) -- God did not create the universe, world-famous physicist Stephen Hawking argues in a new book that aims to banish a divine creator from physics.Hawking says in his book "The Grand Design" that, given the existence of gravity, "the universe can and will create itself from nothing," according to an excerpt published Thursday in The Times of London."Spontaneous creation is the reason why there is something rather than nothing, why the universe exists, why we exist," he writes in the excerpt."It is not necessary to invoke God to light the blue touch paper [fuse] and set the universe going," he writes.His book -- as the title suggests -- is an attempt to answer "the Ultimate Question of Life, the Universe, and Everything," he writes, quoting Douglas Adams' cult science fiction romp, "The Hitch-hiker's Guide to the Galaxy."
ja verujem da je covek pruzio rigorozan dokaz da ako postoji gravitacija da univerzum moze da se stvori ni iz cega, ali me zanima otkud gravitacija ako nema nikakve materije. tj, treba mi objasnjenje. ako nema univerzuma, da li ima materije te otud i gravitacije?
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treba mi objasnjenje.
Na pitanja tog tipa niko nema siguran odgovor, ma šta se tvrdilo. Postoji model koji se oslanja na činjenice i koji zadovoljavajuće opisuje proces postajanja. Sve pre postajanja je spekulacija. Pusti Hokinga, nije lako držati Njutnovu katedru (tačnije, držao ju je do pre godinu dana), najprestižniju akademsku poziciju na svetu koja nosi ime po verovatno najvećem naučniku svih vremena, stalno si u grču i dokazivanju. Možda bi trebalo ići manjim koracima, a ne odmah promišljati Božji um. Za početak, nek fizika lepo objasni veliku nepoznanicu - gravitaciju. S Bogom ćemo tada već lako...
Eh, Hoking bi pre svih morao da zna sta kazu nase kolege matematicari: Bog je stvorio 1, a covek sve ostalo... :P
Još kad bi matematičari znali odgovor na pitanje ko je stvorio Boga... ili se Bog svrstava u ovo "sve ostalo" što je čovek stvorio? :)
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Na pitanja tog tipa niko nema siguran odgovor, ma šta se tvrdilo. Postoji model koji se oslanja na činjenice i koji zadovoljavajuće opisuje proces postajanja. Sve pre postajanja je spekulacija. Pusti Hokinga, nije lako držati Njutnovu katedru (tačnije, držao ju je do pre godinu dana), najprestižniju akademsku poziciju na svetu koja nosi ime po verovatno najvećem naučniku svih vremena, stalno si u grču i dokazivanju. Možda bi trebalo ići manjim koracima, a ne odmah promišljati Božji um. Za početak, nek fizika lepo objasni veliku nepoznanicu - gravitaciju. S Bogom ćemo tada već lako...
Pa stvarno Dzoli, najskromnije sam se zapitala nesto. Pri tome sam samo procitala onaj majusni isecak. Da li njemu za taj iskaz treba da gravitacija vec postoji i deluje ili samo da se javi kad-tad, kad je proces stvaranja univerzuma vec zapoceo (a ovo drugo u tom slucaju ne bi trebalo posebno da se naglasava ako je vec objasnjeno pod kojim uslovima se javlja gravitacija).I veliki sam laik. Koliko vidim Ajnstajnova teorija kaze da sila nije potrebna da bi doslo do gravitacije, vec da je za to zasluzna zakrivljenost prostora i vremena. A ja ne znam da li postoje prostor i vreme tamo gde nema univerzuma. Nisam strucna. Do jaja glupa pitanja postavljam, ali eto...I uopste me ovde ne zanima rasprava o postojanju Boga. Burden of proof je na onima sto tvrde da postoji. Edited by MayDay
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