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Space Science

Hubble Survey Finds Half of the Missing Matter 189

esocid sends along the news that scientists believe they have found about half the missing matter in the universe. The matter we can see is only about 1/8 of the total baryonic matter believed to exist (and only 1/200 the mass-energy of the visible universe). This missing matter is not to be confused with "dark matter," which is thought to be non-baryonic. The missing stuff has been found in the intergalactic medium that extends essentially throughout all of space, from just outside our galaxy to the most distant regions of space. "'We think we are seeing the strands of a web-like structure that forms the backbone of the universe,' Mike Shull of the University of Colorado explained. 'What we are confirming in detail is that intergalactic space, which intuitively might seem to be empty, is in fact the reservoir for most of the normal, baryonic matter in the universe.'"
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Hubble Survey Finds Half of the Missing Matter

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  • Ether (Score:4, Insightful)

    by teknopurge ( 199509 ) on Tuesday May 20, 2008 @05:35PM (#23482946) Homepage
    Haven't we known this for some time?
  • Dark Matter??? (Score:3, Insightful)

    by omnichad ( 1198475 ) on Tuesday May 20, 2008 @05:40PM (#23483040) Homepage
    Always wondered why a simple explanation like dust never took hold, and everyone started talking about invisible matter to explain what should be there.
  • Wow (Score:5, Insightful)

    by digitrev ( 989335 ) <digitrev@hotmail.com> on Tuesday May 20, 2008 @05:44PM (#23483096) Homepage
    That's actually pretty cool. I mean, the fact that matter was missing was a bit of a problem. The fact that it's in between galaxies even explains why it was missing. When it's that spread out, it's damn near impossible to see the gravitational effects of it.
  • Re:Dark Matter??? (Score:1, Insightful)

    by Anonymous Coward on Tuesday May 20, 2008 @05:57PM (#23483294)

    We know that there is some sort of matter missing due to weird graviational interactions. We also know that according our measurements of the cosmic microwave background, this matter doesn't exist, i.e., this matter doesn't interact with electromagnetic fields. That's why it's not normal baryonic matter.
    That would be one theory. Another would be that maybe, one in a billion chance, just possibly our confidence in our marvelous understanding of gravitational interactions and/or CMB is hopelessly misplaced. Hey, it could happen.
  • Re:Wow (Score:3, Insightful)

    by Tenebrousedge ( 1226584 ) <tenebrousedge AT gmail DOT com> on Tuesday May 20, 2008 @06:12PM (#23483506)
    Great, except the problem is that we're trying to figure out what we can measure by its gravitational effects but doesn't interact in any other way with normal matter. This is the solution to a different problem.
  • Re:Ether (Score:3, Insightful)

    by hardburn ( 141468 ) <hardburn&wumpus-cave,net> on Tuesday May 20, 2008 @06:13PM (#23483518)

    Not disproven, really, but fell away due to Occam's Razor. The difference between ether and this "web-like structure" is that ether was never directly observed.

  • Re:Dark Matter??? (Score:3, Insightful)

    by Tenebrousedge ( 1226584 ) <tenebrousedge AT gmail DOT com> on Tuesday May 20, 2008 @06:31PM (#23483820)
    Fine, find some sort of matter interacts gravitationally with the observable universe but not electromagnetically, and call it whatever you want when you do. We'll be over here calling it non-baryonic matter, or dark matter.
  • Re:Dark Matter??? (Score:4, Insightful)

    by CheshireCatCO ( 185193 ) on Tuesday May 20, 2008 @06:31PM (#23483830) Homepage
    Hydrogen and helium are not dust by any definition of "dust" I've ever known an astronomer to use. Dust is, by definition, solid matter which is microscopic, but much larger than atoms. To broaden the term to include plasmas and gases would pretty much make it so broad as to be useless.

    So no, not dust.
  • Re:Ether (Score:5, Insightful)

    by Uncle Focker ( 1277658 ) on Tuesday May 20, 2008 @07:09PM (#23484396)

    Because Einstein got everything perfect (cosmological constant) And light (which may or may not have mass) is bent by gravity (bending space time) Wouldn't it make more sense to go with an aether theory?
    Not when it's wrong. I'm sorry if reality is too complicated for you, but that's your problem not ours.

    You say light travels at the same speed regardless of direction or relative motion? I say bunk requiring some very sophisticated manipulations of time and space (Lorentz contractions) What's wrong with the 'entrained aether' theory? What, you never heard of frame-dragging?
    No, light travels at a constant speed in a vacuum. It's speed can be different based on a whole variety of factors.

    Gravitational lensing? How about gravity increasing the optical density of the aether?
    Have any evidence to back this up?
  • Re:Dark Matter??? (Score:3, Insightful)

    by Btarlinian ( 922732 ) <tarlinian@gm[ ].com ['ail' in gap]> on Tuesday May 20, 2008 @08:27PM (#23485560)

    Ok, sure I did. But I think you missed the point. I wasn't saying anything was dark matter. I'm saying we found more real matter. Those generous question marks were my pokes against people who want dark matter to explain everything away when perfectly normal matter will suffice.

    Except there aren't people like that. We knew this normal matter existed, we just didn't know where it was.

    Every time we talk about something new being found in the universe, someone likes to say, "Oh look at those stupid astronomers, making up stuff no one can prove. There never was any dark matter." I know that's not what you specifically said, but by bringing it into the conversation and conflating this observation with theories of dark matter, you essentially did the same thing. Your basically attempted to make other people look stupid by making an ill-informed, seemingly insightful comment. I'm rather disappointed to see that it that the mods fell for it.

  • Evidence... (Score:2, Insightful)

    by msauve ( 701917 ) on Tuesday May 20, 2008 @09:29PM (#23486192)
    he has exactly as much evidence as there is for the existance of gravitons or Higgs bosons or exotic dark matter.
  • by tjstork ( 137384 ) <todd.bandrowsky@gma i l .com> on Tuesday May 20, 2008 @11:29PM (#23487338) Homepage Journal
    Every time we talk about something new being found in the universe, someone likes to say, "Oh look at those stupid astronomers, making up stuff no one can prove

    That statement is essentially true. The best you can ever know about the universe is by inference. Standard candles are an approximation and you aren't really able to prove anything by duplication as much as you are trying to say this is a pretty good story based on a computer model kicking out a similar result. I mean, it all sounds pretty good on paper, but I could always make a computer model of the "real killer" stabbing Nicole and Ron, and not OJ.

"It takes all sorts of in & out-door schooling to get adapted to my kind of fooling" - R. Frost