Lab experiment done to figure out how quickly molecular hydrogenformed after Big Bang
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From: Yousuf Khan on 3 Jul 2010 01:34 You need molecular hydrogen clouds to form stars. However, nobody really knew until now how quickly they formed during the early days of the universe. Yousuf Khan First Stars Formed Fast - ScienceNOW "Even though the combination of H and H� is an "amazingly simple reaction, it's been poorly understood" because it's hard to bring the ingredients together in the lab, says Daniel Savin, one of the paper's authors and a researcher at Columbia University's Astrophysics Laboratory. To make it happen, Savin and his colleagues, including Holger Kreckel, who is now at the University of Illinois, Urbana-Champaign, first generated a beam of negatively charged hydrogen ions and sent it barreling down a tube. The beam passed through a chamber where a laser knocked the extra electrons off of about 7% of the ions, leaving a mix of hydrogen and negatively charged hydrogen ions to react with each other farther down the tube. In the final leg of the apparatus, the researchers counted how many hydrogen molecules the reaction produced. "It turns out that molecular hydrogen forms faster than previously thought," Savin says. "That means the first stars likely formed faster than previously expected." Knowing the rate at which the reaction proceeds is an improvement, but it's not enough to nail down the mass of the first stars. "Because we don't fully know the initial conditions from which the first stars formed," he says, "we don't yet reliably know the distribution of masses."" http://news.sciencemag.org/sciencenow/2010/07/first-stars-formed-fast.html |