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Space Science

The Starry Sky Just Got Starrier 186

An anonymous reader writes "Astronomers have surveyed eight elliptical galaxies, and found that we've vastly underestimated the number of dim red dwarf stars in these giant galaxies. When they used the new number of red dwarfs in their calculations, they tripled the total number of known stars in the universe."
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The Starry Sky Just Got Starrier

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  • by Hatta ( 162192 ) on Wednesday December 01, 2010 @07:17PM (#34411720) Journal

    Really? I thought that they used gravity to determine the approximate mass of the galaxy, and then subtracted the amount of visible matter to yield the amount of dark matter. If that's how they did it, then increasing the amount of visible matter would have to decrease the amount of dark matter.

  • by Dekker3D ( 989692 ) on Wednesday December 01, 2010 @07:54PM (#34412062)

    Actually, last I heard it was 5 to 1. So those tiny stars and any rocks orbiting them could have a bigger impact on those numbers than you think.

  • by geekoid ( 135745 ) <`dadinportland' `at' `'> on Wednesday December 01, 2010 @08:03PM (#34412138) Homepage Journal

    Since they can make predictions with it, and have tons a data supporting there is an effect going on, you're wrong.

    "Since no one has seen it, touched it, tasted it, smelt it, or felt it."

    the same can be said for gravity.

    Now if you added 'measured it' then it couldn't be said for gravity. Of course then it couldn't be said for dark energy and dark matter.

    a) There is no evidence of any other kind. Should some good evidence actually come in, then great.

    b) Every measurement we have made using our understanding of gravity seems consistent. Again, if there is actual evidence of something else, then thing will change.

    c) interesting evidences doesn't matter, strong* evidence does.

    Your post shows a large amount of ignorance on this matter, and ignorance on the scientific process.

    *no pun intended.

  • by poopdeville ( 841677 ) on Wednesday December 01, 2010 @08:43PM (#34412530)

    You're ignoring something important. The laws of conservation of matter and energy.

    These are stars that went supernova, but for which the remaining gravitationally bound matter did not turn into a black hole. It takes a lot of matter for a star to nova, and it doesn't just disappear.

    In short, they tripled the number of stars that were at one time on the order of 10 times more massive than average.

  • by Chris Burke ( 6130 ) on Wednesday December 01, 2010 @09:43PM (#34412916) Homepage

    Postulating Dark {Matter, Energy} is the height of hubris, since it implies that Astronomy Has Seen All There Is To See from our tiny little glasses on our tiny little rock in a backwater arm of the Galaxy.

    Thank The FSM that there are still a few rational scientists out there actually *looking* for stuff.

    There are observations that have been made which cannot be explained by any quantity of unseen "regular" aka Baryonic matter. This is the result of people actually looking for stuff, and not in their hubris assuming that we have Seen All There Is To See. Indeed it is very much a case of realizing that we have not seen it all.

    Hubris is dismissing (the non-Baryonic subset of) Dark Matter because it's not the same as the "regular" matter we are familiar with in a much more extreme case of assuming we have Seen All There Is To See. Red dwarfs are nothing new; and you're strongly implying you think such examples of normal objects will explain away the need for Dark Matter, as in we won't find anything new. We Have Seen It All.

    Even though what astronomers have seen strongly suggests that is not true, and there is stuff out there completely different than what you are comfortable with.

    It is kinda funny how often people give "arrogance" as the reason why scientists put forward certain hypothesis when they are completely unaware of the actual scientific reasoning behind the hypothesis. By attributing arrogance to others as a consequence of their own ignorance, they demonstrate tremendous hubris.

  • by Chris Burke ( 6130 ) on Wednesday December 01, 2010 @10:18PM (#34413126) Homepage

    Before Van Dokkum wrote his paper, the DM/DE proponents thought they'd found all the matter there is to find.

    No astronomer thought they had found all the normal matter there is to find. In fact the search for dim red dwarfs in specific was part of trying to answer the Dark Matter mystery -- which originally only meant matter we had not seen yet, and only came to mostly refer to non-Baryonic Dark Matter when observations suggested that most of it was.

    In fact, would you believe that when "DM Proporents" estimated the amount of non-Baryonic matter and added it to the known visible matter in galaxies, they still saw a discrepancy in observed gravity in elliptical galaxies? And that finding more normal matter was one prediction to explain it, and in fact this new observation may end up explaining the difference, solidifying our calculations of dark matter.

    Suddenly there's 3x more. Which is a slight reduction in the need for DM.

    3x the stars is not 3x the mass (particularly when the discovered stars are red dwarfs), but regardless...

    Who's to say that in 1-20 years other heretics find 10x more baryonic matter, thus reducing even more the necessity for DM.

    Indeed, who's to say? But as long as there are observations that cannot be explained by baryonic matter, it will be necessary.

    I really like the characterization of this researcher as a "heretic", btw. I like it because this "heretic" was given access to the Keck Interferometer -- the combination of two of the largest telescopes in the world and thus a highly sought-after instrument -- in order to conduct his research. And then said research was published in Nature.

    Because that's how we do things in science: we invite the "heretics" to make observations and disprove our current theories and hypothesis so we can create even better ones. They are not shunned, they are not shut out from access to the tools they would need to prove themselves,. Quite the opposite. Indeed, quite the opposite of a "Church" and "heretic" relationship. Which is why it's funny.

  • by Chris Burke ( 6130 ) on Wednesday December 01, 2010 @10:24PM (#34413160) Homepage

    The big bang is just hand-waving at this point in time.

    Hand-waving, one of the most successfully predictive theories [] of the last century, these are both the same. I'll make them seem like they're both the same by... wait for it... waving my hands.

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