The Leader Posted February 28, 2005 Share Posted February 28, 2005 i posted this in crossfire but exactly 3 people responded. This is worthy of about 100 more posts than that Strong evidence for a massive galaxy totally devoid of stars has been found in the Virgo cluster, about 50 million light years away from Earth. If the existence of this "dark galaxy" is confirmed, it will vindicate the favoured theory of how galaxies form - and will present fresh puzzles to solve. The new galaxy, which consists of a gigantic cloud of hydrogen gas and exotic dark matter, contains enough material to give birth to tens of millions of stars. Yet something is preventing this from happening. Such dark galaxies have been predicted, and could outnumber normal galaxies by as much as a hundred to one, but this is the first time anyone has confidently claimed to have seen one. The discovery should come as a relief to astrophysicists developing theories of how galaxies form. "If there are no dark galaxies in the universe, then we must be missing an important piece of physics," says Michael Merrifield at the University of Nottingham, UK. For decades computer simulations have consistently predicted far more small galaxies than have been observed. For example, in our local group of galaxies there should be hundreds of dwarf galaxies, along with the gigantic Milky Way and Andromeda galaxies. Yet only 35 dwarf galaxies have been observed. One possibility is that these dwarfs exist as dark galaxies - starless clouds of hydrogen and dark matter. "The search for dark galaxies is crucial because there is a major disagreement between the theory of galaxy formation and observation," says Riccardo Giovanelli at Cornell University in Ithaca, New York, US. Cosmic stone's throw The theorists took heart in 2005 with the announcement that the dwarf galaxy I Zwicky 18, situated just a cosmic stone's throw from the Milky Way in a region where other galaxies are billions of years older, contained no stars older than 500,000 years (New Scientist print edition, 11 December 2004). Either the galaxy formed recently, or it has been hanging around as a dark galaxy for as long as 13 billion years. Apart from such tantalising but inconclusive findings, no evidence has turned up until now. The most recent failure was 2004's HIPASS survey, which used the 64-metre Parkes radio telescope in New South Wales, Australia. By definition, dark galaxies cannot be seen by optical telescopes. The only signs are radio waves with wavelengths of about 21 centimetres emitted by the hydrogen atoms that make up most of the gas in galaxies. Giovanelli says that HIPASS failed to find any dark galaxies because it was not sensitive enough. In the latest survey, an international team led by Robert Minchin at Cardiff University, UK, used the sensitive 76-metre Lovell radio telescope at the University of Manchester's Jodrell Bank Observatory, UK, to look for dark galaxies in the nearby Virgo cluster. There they found VIRGOHI21, a rotating cloud containing enough hydrogen gas to spawn 100 million stars like the sun and fill a small galaxy. All previous possible dark galaxies have turned out to be duds: observations made using high-powered optical telescopes showed they contained stars after all. But when Minchin and his team used the 2.5-metre Isaac Newton optical telescope on the island of La Palma, Spain, they found no stars. "This is the first object we can be confident is a dark galaxy," Minchin says. Speed of rotation But far from answering all the questions, VIRGOHI21 is throwing up a number of new ones. One concerns its mass. While the newly discovered galaxy is certainly dark, it may not be the dwarf that astrophysicists were hoping for. If galaxies were made up only of ordinary matter, their speed of rotation would tear them apart. The extra mass needed to provide the gravitational pull that holds them together is generally thought to come from what is called dark matter. When Minchin's team measured the speed of rotation of the hydrogen gas in VIRGOHI21, they found that it would have to contain about one-tenth of the dark matter of the Milky Way. But if that is so, it should also have a hundred times as much hydrogen gas as they actually detected. Far from being a dwarf, VIRGOHI21 seems to be a giant in its own right. Merrifield says that the shortfall in the observed amount of hydrogen may mean that what Minchin and his team have seen is not a dark galaxy after all. "Their story doesn't quite hang together, and I would speculate that they have been fooled by two passing hydrogen clouds." The difference in speed as one passes the other would give the illusion of rotation, he says. But Minchin is sticking to his guns. "There are so few known hydrogen clouds that to find two together would be extremely unlikely." He thinks they may have underestimated the mass of hydrogen in the dark galaxy. If ultraviolet light from distant quasars were ionising a large proportion of the hydrogen atoms, the gas would be rendered invisible to radio telescopes. http://www.newscientist.com/article.ns?id=dn7056 Quote Link to comment Share on other sites More sharing options...
why write? Posted February 28, 2005 Share Posted February 28, 2005 all science is a lie that will be tried to be proven into a different lie 2 years after....lies into more lies, science will never be a fact Quote Link to comment Share on other sites More sharing options...
The Leader Posted February 28, 2005 Author Share Posted February 28, 2005 ok.. is anything fact then? no. so stfu and read. Quote Link to comment Share on other sites More sharing options...
haunts Posted February 28, 2005 Share Posted February 28, 2005 i saw this article last week. Quote Link to comment Share on other sites More sharing options...
why write? Posted February 28, 2005 Share Posted February 28, 2005 Originally posted by The Leader@Feb 28 2005, 01:10 AM ok.. is anything fact then? no. so stfu and read. Quoted post i read you mother fucking mexican eating hamburger chomping 12oz addict crack whore child hindu looking doofy bitch :king: Quote Link to comment Share on other sites More sharing options...
Guest amorphic Posted February 28, 2005 Share Posted February 28, 2005 This article is tight. And to the guy that doesn't "believe" in Science...haha alright... Quote Link to comment Share on other sites More sharing options...
why write? Posted February 28, 2005 Share Posted February 28, 2005 keep hating...i love it Quote Link to comment Share on other sites More sharing options...
The Leader Posted February 28, 2005 Author Share Posted February 28, 2005 Did you just say I eat mexicans? Cool. Quote Link to comment Share on other sites More sharing options...
fermentor666 Posted February 28, 2005 Share Posted February 28, 2005 There was something the other week about a black hole that formed near two star systems, one was completely sucked in and the other was slingshot'd out of it's galaxy and some unfathomably fast speed. Space is wild, man. Quote Link to comment Share on other sites More sharing options...
Dr. Dazzle Posted February 28, 2005 Share Posted February 28, 2005 How the fuck can you not believe in science??? Quote Link to comment Share on other sites More sharing options...
Guest HESHIANDET Posted February 28, 2005 Share Posted February 28, 2005 so ill. i love knowing that every star in the sky could have a solar system around it like ours. i wanna see aliens so bad. wish i was military material so i could be an astronaut Quote Link to comment Share on other sites More sharing options...
Herbivore Posted February 28, 2005 Share Posted February 28, 2005 shit like this blows my mind. the concept of a light year is enough to make me cry. Quote Link to comment Share on other sites More sharing options...
trackstand Posted February 28, 2005 Share Posted February 28, 2005 Originally posted by Dr. Dazzle@Feb 28 2005, 02:26 AM How the fuck can you not believe in docking??? Quoted post Man, you're gross Dazzle. Quote Link to comment Share on other sites More sharing options...
Fondles Posted February 28, 2005 Share Posted February 28, 2005 Originally posted by why write?@Feb 28 2005, 02:06 AM all science is a lie that will be tried to be proven into a different lie 2 years after....lies into more lies, science will never be a fact Quoted post i'm speechless. you have got to be joking. *edit: and to stay on topic, I read about this couple days ago. Good thread. Quote Link to comment Share on other sites More sharing options...
imported_dowmagik Posted February 28, 2005 Share Posted February 28, 2005 why write, are you a theology major? Quote Link to comment Share on other sites More sharing options...
Gat Bush Posted February 28, 2005 Share Posted February 28, 2005 loco, ese. Quote Link to comment Share on other sites More sharing options...
High Priest Posted March 1, 2005 Share Posted March 1, 2005 Originally posted by why write?@Feb 28 2005, 06:06 AM all science is a lie that will be tried to be proven into a different lie 2 years after....lies into more lies, science will never be a fact Quoted post Duh, we all know that JESUS is the only true fact. Quote Link to comment Share on other sites More sharing options...
Mr. Peanut Posted March 1, 2005 Share Posted March 1, 2005 if a balding lumberjack farts in the woods and there's noone around to hear it...does it smell? Quote Link to comment Share on other sites More sharing options...
got_milk? Posted March 6, 2005 Share Posted March 6, 2005 Quote Link to comment Share on other sites More sharing options...
Kr430n5_666 Posted March 6, 2005 Share Posted March 6, 2005 "We were *so* toally born in the dark galaxy." Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.