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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 Re:Oh yeah, great idea (Score 2, Informative) 83

I think you have confused the California coastline with other parts of the state. Not all of CA is an earthquake zone. The Central Valley has no no known faults and while there are faults east and west of it, there has been relatively little damage in the Central Valley from even the worst of the San Andreas events.

Comment Re:Proof is Easy (Score 2) 129

Your comments are highly misleading.

A classical computer can compute a quantum algorithm approximately and very slowly. The approximation can be very precise but it is very slow. These calculations are commonly done.

Real quantum computers also run quantum algorithms approximately, but quickly. All quantum computers have error.

There is no proof that a "classical" computer cannot be designed in the future that will run a quantum algorithm the same way a quantum computer can. It's not really worth thinking about because reality is quantum.

Comment Re:For what reason? (Score 1) 357

I did not claim the mutation happened anywhere near Wuhan. Maybe it did, maybe it did not. I would not expect to find out.

It is very unlikely to find the correct "intermediary animal." If somebody stole an apple from you three months ago, looking for the apple seeds today would be preposterous. Looking for the source of a zoonotic respiratory virus is just as preposterous.

Comment Re:For what reason? (Score 5, Informative) 357

Why this weird insistence here on Slashdot that the lab leak theory is somehow a "conspiracy theory" or a "right-wing talking point?"

Because we are skeptics and it is a conspiracy theory.

Does that not give the NIH an incentive to deflect attention away from the Wuhan Institute of Virology?

Well, maybe it gives them a very weak incentive. NIH is in no way responsible for how people in China might have used their money.

Also, this ridiculously tenuous link does not motivate the CIA to lie.

a false "grassroot" letter

The popularity of a theory or astroturfing about it has nothing to do with with its truthfulness.

HIGHLY unusual furin cleavage site in the virus

Unusual mutations happen all the time. That's how evolution has always worked.

the closest site where you find a potential bat species is a thousand miles away from the wetmarket.

Bats can fly. Also, nobody checked all the bats in Wuhan, including the dead and rotten ones.

You'd expect to find multiple infections along the path, or at the very least an infected animal somewhere,

You would not expect to "find" infections "along the path." First, nobody is systematically checking animals for viruses on the scale needed to find a "path." Second, the evidence biodegraded months before the investigations began. Third, experience shows that if you find a "link" along the path, conspiracy theorists will simply say that there are now two paths where nothing has been found; one before the link and one after. Fourth, transmission between animals has been extensively proven.

As a conclusion: Zoonotic infections are normal and have occurred frequently for a long time. Zoonotic infection is a simple theory. Simple theories that have been correct in the past are usually correct again.

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