Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?

Astronomers Discover 33 Pairs of Waltzing Black Holes 101

Astronomers from UC Berkeley have identified 33 pairs of waltzing black holes, closing the gap somewhat between the observed population of super-massive black hole pairs and what had been predicted by theory. "Astronomical observations have shown that 1) nearly every galaxy has a central super-massive black hole (with a mass of a million to a billion times the mass of the Sun), and 2) galaxies commonly collide and merge to form new, more massive galaxies. As a consequence of these two observations, a merger between two galaxies should bring two super-massive black holes to the new, more massive galaxy formed from the merger. The two black holes gradually in-spiral toward the center of this galaxy, engaging in a gravitational tug-of-war with the surrounding stars. The result is a black hole dance, choreographed by Newton himself. Such a dance is expected to occur in our own Milky Way Galaxy in about 3 billion years, when it collides with the Andromeda Galaxy."
This discussion has been archived. No new comments can be posted.

Astronomers Discover 33 Pairs of Waltzing Black Holes

Comments Filter:
  • Newton? (Score:5, Insightful)

    by sznupi ( 719324 ) on Monday January 04, 2010 @05:07PM (#30646214) Homepage

    At those masses, the choreographer is most likely Einstein (nvm that dark matter might be not the underlying cause of some discrepancy between how we think gravity works and what we are observing at galactic scales; we might as well have a different choreographer yet)

  • and this... (Score:4, Insightful)

    by owlnation ( 858981 ) on Monday January 04, 2010 @05:28PM (#30646530)
    ... is the only "Dancing with the Stars" I'd ever want to see.
  • Wow! (Score:4, Insightful)

    by gstoddart ( 321705 ) on Monday January 04, 2010 @05:33PM (#30646610) Homepage

    Wow, when I was in university, Black Holes were still a mostly theoretical idea and we had no real empirical evidence to support their existence.

    Now we've got 33 pairs of them entwined in death spirals, and we're pretty sure every galaxy has one.

    There's still a lot out there that we can't even conceive of ... I can't wait to see what the next 15-20 years brings us. I like the fact that the universe is vastly more complicated than we've ever really been able to guess at.


  • by photonic ( 584757 ) on Monday January 04, 2010 @05:40PM (#30646662)
    Great, the collision of these things is exactly the kind of event we need for detecting gravitational waves []. These kind of 'inspirals' emit very distinct pattern, which can be retrieved very efficiently from the noise with matched filter banks. The higher the mass, the lower the frequency of this 'chirped' signal, so it is probable that these colliding super-massive black-holes cannot be detected with the ground []-based [] kilometer long observatories, which are measuring right now. This is probably more something for the space-based LISA [] mission, which can probe much lower frequencies since it has a base-line of millions of kilometers.
  • Re:*golf clap* (Score:5, Insightful)

    by Chris Burke ( 6130 ) on Monday January 04, 2010 @06:14PM (#30647180) Homepage

    But most of all, explain what causes the observed effects of hypothetical "dark matter" and "dark energy". My young children are smart enough to know that the dark matter story sounds like total and utter bull. The story goes like this: "We see something that looks like it causes things to move, but we don't know what it is, and we can't see it, or measure it, create it, or understand it at all. These unobservable matter blobs (and energy) may be 95% of everything we observe! We see something we can't explain, so we're calling it 'dark matter' and moving on with the old story that has worked for a while and still gets us grant funding." Why no one with a brain is calling out this story for its absurdity is astounding.

    Because people with brains -- or at least those with brains and a bit of particle physics knowledge -- know that the idea of a type of matter that has mass but does not interact electromagnetically and is thus extremely hard to detect is not that outlandish. We already know of one such particle, the neutrino. A more massive neutrino-like particle is a prime candidate for dark matter, and is predicted by theory outside of dark matter. And while it's still highly speculative, there are teams out there right now who believe they are on the trail of detecting this particle.

    In other words, they are doing exactly what you think they should be doing, and working on the problem. But surprisingly, doing actual useful work in this area requires more education than your children, or you for that matter, possess. Sorry!

    The most dangerous hubris in science is the refusal to accept that we're far more ignorant about our physical environment than most would like to admit.

    Stand in front of a mirror, look yourself directly in the eye, and say that fifty times.

    All the things you point out, like what dark matter actually is, are holes in physics knowledge that physicists readily admit too. At least to the extent that you accurately describe the holes, rather than your gut feeling about what sounds too weird to be true. So who is showing hubris again?

Time to take stock. Go home with some office supplies.