Rogue Black Holes May Roam the Milky Way
It sounds like the plot of a B-rated sci-fi movie -- Rogue black holes roaming our galaxy, threatening to swallow anything that gets too close. In fact, new calculations by Astrophysicists at the Harvard-Smithsonian Center for Astrophysics suggest that hundreds of massive black holes left over from the galaxy-building days of the early universe may wander the Milky Way. The good news is that they think (and we hope) that the closest rogue black holes reside thousands of light-years away.
Comments:
In order for an object's gravity to observably bend light, the light must pass pass very close (relatively speaking) to the core of an intense gravitational field. <br><br>We have seen galaxies bend light, but do we really have the technology to discover abrupt changes in the apparent angular velocities,one time dimming, or "arcing"? <br> <br>We know how important eclipses were in laying down the fundamentals of the expanding universe theory; in order to prove rogue black holes, we need to detect their effects in terms of bending EM. <br><br>The only way I can imagine doing this is use the broadest range of interferometry and EM image processing on any star suspected to be between earth (line of sight) and a suspected rogue black hole. <br><br>It could be done, but look at the challenge our Milky Ways' central black hole has presented! Consider that we knew where to look. How do we get them to come out of hiding. What is their localized effect? How homogeneously distributed are they? Are they a common structural component of galactic entities?<br><br>Do current and future sky surveys really have a chance of identifying candidates and measuring masses (much less mapping and projecting movement through space)? <br><br>I believe definitive answers are beyond our current capability based on the vast amount of data and resources required for the search. <br><br><br><br>
<blockquote class="blockquote"><div class="italic"><i>Ronald Abraham said:</i><br>We have seen galaxies bend light, but do we really have the technology to discover abrupt changes in the apparent angular velocities,one time dimming, or "arcing"? <br> <br>We know how important eclipses were in laying down the fundamentals of the expanding universe theory; in order to prove rogue black holes, we need to detect their effects in terms of bending EM. <br><br>The only way I can imagine doing this is use the broadest range of interferometry and EM image processing on any star suspected to be between earth (line of sight) and a suspected rogue black hole. <br><br></div></blockquote><br>I'm not quite following your reasoning. First, if a star is used, the black hole would have to be between Earth and the star. As you can see from the diagram it is unlikely that there would be a star out there to be eclipsed by the black hole. So the black hole would have to lens a galaxy, unless they find a rogue star that is more distant than the black hole.<br><br>Second, in the scheme of science, the first lensing effects were discovered with light from single stars bending around our own sun. This is relatively un-massive; a black hole of a thousand suns would likely have detectable effects if it were in front of something. I don't think a black hole of several thousand solar masses would present a problem from that point of view. <br><br>Third, I think that the changes involved would be more slow-motion than abrupt, since we are talking about measuring lensing against galaxies, which are not pinpoints even at great distances, and the blackhole itself may take quite some time to traverse the light source at a distance of many thousands of light years. <br><br>So I don't think it is as formidable as you say, but I might be more skeptical about the proposed recreation of the orbit. I suppose it might be so. However, galaxies collect a lot of stuff at that distance from other galaxies, and I'm not sure why that would be ruled out.<br><br>But that's about as far as I can take the matter. <br><br>regards Greg N
