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Space Science

Small Black Holes: Cloudy With a Chance of Better Visibility 27

Posted by Soulskill
from the precipitation-likely dept.
Rambo Tribble writes "As reported by the BBC, astronomers are hoping to reap a black-hole-hunting windfall when a giant gas cloud passes through an area within our galaxy thought to contain numerous small black holes (abstract). When the cloud interacts with the black holes, the resultant emission of X-rays should allow scientists to finally confirm their existence. 'The idea is that as the cloud speeds past these small black holes — some slightly more massive than our Sun but just a few tens of km across — gas will spiral around them faster and faster, heating up to millions of degrees and emitting X-ray light. It is a bit like allowing a giant sink to empty through thousands of tiny drains and looking for any evidence of swirling water.'"
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Small Black Holes: Cloudy With a Chance of Better Visibility

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  • I heard talks about black holes since I started taking an interest in science when I was 6 (I'm 27now). After 21 years have we still not discovered proof of black holes?
    • by meglon (1001833)
      http://en.wikipedia.org/wiki/Black_hole [wikipedia.org]

      The idea of a body so massive that even light could not escape was first put forward by geologist John Michell in a letter written to Henry Cavendish in 1783 of the Royal Society:

      If the semi-diameter of a sphere of the same density as the Sun were to exceed that of the Sun in the proportion of 500 to 1, a body falling from an infinite height towards it would have acquired at its surface greater velocity than that of light, and consequently supposing light to be attracted by the same force in proportion to its vis inertiae, with other bodies, all light emitted from such a body would be made to return towards it by its own proper gravity. —John Michell[4]

      In 1796, mathematician Pierre-Simon Laplace promoted the same idea in the first and second editions of his book Exposition du système du Monde (it was removed from later editions).[5][6] Such "dark stars" were largely ignored in the nineteenth century, since it was not understood how a massless wave such as light could be influenced by gravity.[7]

      In other equally shocking news, Rome was not built in a day.

    • Re:Really? (Score:4, Interesting)

      by TapeCutter (624760) on Saturday June 01, 2013 @12:03AM (#43880875) Journal
      We have had "proof" for a long time in the mathematical sense, what has been more difficult is collecting enough evidence to say (beyond reasonable doubt) they exist in reality (the movie of stars orbiting the milky way's central black hole is my favorite "smoking gun"). I'm 54, when I went to school we were told black holes were "mathematical curiosities" that might exist in reality but nobody was sure, it was also claimed that it was impossible to observe an exo-planet. We live in "interesting times", science in general and astronomy in particular are experiencing a "golden age" that has it's roots in WW2 and is still gathering momentum.

      Using maths to predict the existence of unobserved phenomena, and then looking for evidence of that phenomena in the real world is physics in a nutshell [youtube.com]. It's also the reason astronomers no longer laugh at the big bang theory.
    • by amaurea (2900163)

      No astronomers doubt the existance of black holes. Both black holes with masses comparable to stars, and supermassive black holes with millions to billions of solar masses are supported by a huge body of evidence. However, there is almost no evidence for black holes with masses in between these ranges, so-called intermediate mass black holes. But logically, they should exist - the way we think the supermassive black holes in the center of galaxies form is by a combination of accretion of matter and mergers

    • I heard talks about black holes since I started taking an interest in science when I was 6 (I'm 27now). After 21 years have we still not discovered proof of black holes?

      Well, they're really hard to study as when we find them, they tend to be wrapped in clouds of dust with only radiation spewing out to study. However, there is enough evidence that if somebody was to show that black holes don't exist, that explaining away all that awkward theory and evidence would require such a large jump in science that they could claim their Nobel and position as this century's Albert Einstein. We're pretty much in the same place with dark matter and some other "controversial" things in

  • by NEDHead (1651195) on Friday May 31, 2013 @05:53PM (#43878303)

    I have been trying to convince my wife that the dust around the house is an experiment and now I have something to show her!

    • by Anonymous Coward
      Don't forget the giant gas cloud :D
  • It will probably happen real soon now in astronomical terms; just give it a few thousand years.

  • It is a bit like allowing a giant sink to empty through thousands of tiny drains and looking for any evidence of swirling water.

    It's a bit like dusting for fingerprints on a cosmic scale.

    It's a bit like tossing handfuls of candy in a class room, then listening for quarreling and munching noises to detect school children.

    It's a bit like rolling around in the grass then waiting for stings to discover fire ant mounds.

    It's a bit like casting a net made out of fish and counting the holes to detect sharks.

    It's a bit like shouting, "You're all fat and ugly" into the woman's bathroom then counting the "Screw You Jerk"s to see if you should wait to clean it.

    It's a bit like making a bunch of posts on Slashdot to detect folks with mod points.

    It's a bit like observing the expected effect black holes cause in various conditions to further confirm their existence.

  • I would assume that these black holes are still on the scale of light years apart, and this cloud stretches across an area a few times the orbit of pluto. Something doesn't add up.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      I would assume that these black holes are still on the scale of light years apart, and this cloud stretches across an area a few times the orbit of pluto. Something doesn't add up.

      The area around the central black hole [wikipedia.org] is very crowded.

      The black hole itself is probably about the "size" of the solar system (an event horizon a few light-hours in radius), there are multiple stars within light-weeks of the black hole itself, with orbital periods measured in years/decades, and some of them (S2, S14) come with

    • Also, it already did happen and we're just seeing it now. So it's not really a "how long until it happens" thing.
      • Not exactly. If we accept that there's no globally valid frame of reference (via General Relativity) then no, it didn't already happen, at least not from our frame of reference. It has happened in some frames of reference, and after we see it happen will still not have happened in yet more frames of reference. But for us, it hasn't happened yet.
        • by Urkki (668283)

          If we accept that there's no globally valid frame of reference (via General Relativity) then no, it didn't already happen, at least not from our frame of reference.

          Second thing does not follow from the first. Light does not travel at infinite speed in any observer's reference frame. So we can actually easily estimate where the light from some event (which then needs to have already happened, or there would not be any light) is now travelling towards us (or not, if predicted event didn't actually happen, which we can't know until the light reaches us).

          There may be other reference frames where the event has not happened yet, where the light has not been emitted yet, but

  • by Anonymous Coward

    Dec. 15, 2011 — The normally quiet neighborhood around the massive black hole
    at the center of our Milky Way Galaxy is being invaded by a gas cloud that is
    destined in just a few years to be ripped, shredded and largely eaten.
    http://www.sciencedaily.com/releases/2011/12/111214135739.htm

    I like the way they put it better :}

    Here's a 19 second video of stars orbiting a suspected Black hole
    http://www.youtube.com/watch?v=c3PeC3bCPKg

    I grabbed it from "How the universe works: Black Holes"
    to show a friend, it's

  • How neat is this!? :-) Physics at its best. My late father, an astro-geo-physicist (and director of the National Science Foundation), would have been delighted to see this work!

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