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Submission + - Another large Black hole in "our" Galaxy (arxiv.org)

RockDoctor writes: A recent paper on ArXiv reports a novel idea about the central regions of "our" galaxy.

Remember the hoopla a few years ago about radio-astronomical observations producing an "image" of our central black hole — or rather, an image of the accretion disc around the black hole — long designated by astronomers as "Sagittarius A*" (or SGR-A*)? If you remember the image published then, one thing should be striking — it's not very symmetrical. If you think about viewing a spinning object, then you'd expect to see something with a "mirror" symmetry plane where we would see the rotation axis (if someone had marked it). If anything, that published image has three bright spots on a fainter ring. And the spots are not even approximately the same brightness.

This paper suggests that the image we see is the result of the light (radio waves) from SGR-A* being "lensed" by another black hole, near (but not quite on) the line of sight between SGR-A* and us. By various modelling approaches, they then refine this idea to a "best-fit" of a black hole with mass around 1000 times the Sun, orbiting between the distance of the closest-observed star to SGR-A* ("S2" — most imaginative name, ever!), and around 10 times that distance. That's far enough to make a strong interaction with "S2" unlikely within the lifetime of S2 before it's accretion onto SGR-A*.)

The region around SGR-A* is crowded. Within 25 parsecs (~80 light years, the distance to Regulus [in the constellation Leo] or Merak [in the Great Bear]) there is around 4 times more mass in several millions of "normal" stars than in the SGR-A* black hole. Finding a large (not "super massive") black hole in such a concentration of matter shouldn't surprise anyone.

This proposed black hole is larger than anything which has been detected by gravitational waves (yet) ; but not immensely larger — only a factor of 15 or so. (The authors also anticipate the "what about these big black holes spiralling together?" question : quote "and the amplitude of gravitational waves generated by the binary black holes is negligible.")

Being so close to SGR-A*, the proposed black hole is likely to be moving rapidly across our line of sight. At the distance of "S2" it's orbital period would be around 26 years (but the "new" black hole is probably further out than than that). Which might be an explanation for some of the variability and "flickering" reported for SGR-A* ever since it's discovery.

As always, more observations are needed. Which, for SGR-A* are frequently being taken, so improving (or ruling out) this explanation should happen fairly quickly. But it's a very interesting, and fun, idea.

Submission + - Surado, formerly Slashdot Japan, is closing at the end of the month. (srad.jp) 1

AmiMoJo writes: Slashdot Japan was launched on May 28, 2001. On 2025/03/31, it will finally close. Since starting the site separated from the main Slashdot one, and eventually rebranded as "Surado", which was it's Japanese nickname.

Last year the site stopped posting new stories, and was subsequently unable to find a buyer. In a final story announcing the end, many users expressed their sadness and gratitude for all the years of service.

User Journal

Journal Journal: It is 2025 and Slashdot doesn't support IPv6?

I've been migrating all my stuff to IPv6 because I'm retarded and felt like (another) winter project.

So I have a Debian VM that is IPv6-only for testing things out, general browsing, etc. and see that Slashdot doesn't support IPv6? One would think a tech site would have been onboard with this years ago.

Comment An Ung Sung hero of the tech industry (Score 2) 10

He will be sorely missed. Gordon is the reason I've stayed in tech despite early setbacks in my career. I'll never be the deep knowledge holder of anyone one thing like a linux module, or dev of a universally used tool like WinDirStat. I'll never be the guy who knows why the motherboard traces got routed in that shape around the power supply for the processor, I'll never be the guy who configures the workflow for a technologist's software. But, now, I can confidently lead people who share the passion I have for technology and how we apply it, and I'd never have gotten to where I am without him.

Thank you old friend even though you never knew me. Sorry I never got the chance to meet you!

Comment Re:Are large scale quantum computers even possible (Score 1) 83

>These are problems with theories, not with physical reality.

Theories don't exist in physical reality? The model of a physical system doesn't share the same complexity?

> Your argument is complete nonsense.

You don't get the argument to begin with. Anyway we do agree that QCs are BS.

Comment Re:Are large scale quantum computers even possible (Score 1) 83

>That argument is nonsense. Using a part of a complex system as a computer is not a problem for the complex system. Otherwise you would run into this effect already with electronic computers or even an Abacus.

Actually a complex system talking or referring to itself is indeed a huge problem. See Godel's Incompleteness and the Halting Problem.

>Otherwise you would run into this effect already with electronic computers or even an Abacus.

You do run into these types of problems.. at least at sufficient scale. An Abacus is bad at math where the numbers are larger than the Abacus itself. Electronic computers are bad at quantum chemistry.

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