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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.

Comment Re:Modern security products seem to increase... (Score 2) 30

I don't necessarily disagree with where you're going here, but can you elaborate on this:

The whole world has realized that they need to start air-gapping databases

I've worked at government contractors that had real air-gaps for things like their databases, but that does not seem to be the norm for the rest of the world. How would ordinary businesses make use of their databases if they are not network accessible under any circumstances, printed reports? Some sort of unidirectional transmission? What sort of data ingress are they using?

I ask this because I have been involved in the transfer of data in highly regulated, air-gapped systems, and they are incredibly expensive. Are you really indicating that true air-gap databases will be ubiquitous (or at least commonplace) in the forseeable future?

Comment Is this a surprise? (Score 3, Insightful) 18

It's a cool idea and they stand for a lot of great ideals, but laptops are incredibly hard to get right, drivers are hard to get right, and they are a small team trying to support a large number of possible configurations. Hardware gets more complicated by the year: forget the CPU and various GPUs, just look at how many other devices in a modern computer have a full-on processor, e.g. fancy touchbars, displays, even hard drives! Hell, your CPU probably has its own secondary general-purpose processors for things like security, and our CPUs themselves get firmware updates now to change how their instructions function. They are doing great work, but the deck is so stacked against them that it's not funny.

Comment Musk should thank his lucky stars for this (Score 5, Interesting) 222

Most space launch companies are inefficient and ineffective. SpaceX has the margin to pay these taxes, those unfortunates don't. If you want to kill competition in an industry, tax it enough that only the large corporations can survive the loss, and add some complicated regulations in for extra effect. No one else has anything close to what Starship may become, and further reduction in margins will ensure that SpaceX will have a defacto monopoly on non-military space launches while their competitors are strangled paying for FAA services that is disproportionately benefit owners of private jets and charter flights for the rich.

Comment Re:.3um (Score 2) 391

I agree smaller dose intuitively means less of a hazard of an infection putting down roots before the immune system wipes it out. However, I've never seen data for this.

IIRC coronavirus particles were around 0.1 um, but the virus would fall apart traveling bare. N95 do filter in that range in any event, just not at the advertised and tested level of an N95's 95% @ 0.3 um (you can get N100s which don't quite hit 100%; it's a rounding thing). Aerosols are typically much larger, 1+ um up, then transition to visible droplets around 20-100 um.

Comment Re: never underestimate stupidity (Score 2) 391

I'm afraid another pivotal concern may have been costs: inferior masks such as surgical are much cheaper. So, here in Virginia the hospital admin logic went, the mask they chose should be the standard for all purposes (our hospital required visitors to give up their personal N95s for a surgical mask, which was at least free).

As even more damning evidence of institutional thinking, the same hospital network required my PCP to wear a mask for telemedicine visits. I burst out laughing when I saw him and asked, "I don't mean to be rude, but are y'all familiar with the germ theory of disease?" He apologized and said the rule simply was that all patient-facing meeting required a mask. So there, standards.

Comment Re:To be fooled again. (Score 5, Interesting) 400

Q: Who is susceptible to deception? A: Everyone.

Deceivers don't appeal to logic.

I've been using this site for over twenty years, and it's a been most of a decade since I've commented. This is the best thing I've seen on here since then. Whatever you do, keep drumming up the fight against ignorance and propaganda, and the people who've fallen victims of it. I don't want to get personal, but lets just say that I know from intimate experience what brainwashing does to a person, and the tremendous cost of clawing one's way out of it. Division in modern society is inevitable--and we must fight against those who seek to destroy rational thought!--but without empathy for those infected by bad ideas, shortchanged by their personal experiences, we'll end up punishing and alientating those victimized by bad actors exploiting cognitive vulnerabilities that every one of us has, we will push them out of sheer self-defense into voting in the people who will undo us.

Comment Re:Did he file a VFR flight plan? (Score 1) 111

Show me a single biological female who has ever been involved in jetpack development or flying.

Go ahead, move the goalposts. And obviously, who ever heard of Amelia Earhart?

Not the person you're responding to, but I'm pretty sure their less-than-polite phrasing meant "biological female who has ever been involved in jetpack development or *jetpack* flying".

Everyone knows Amelia Earhart was a big part of aviation history in that era, but I strongly suspect that she didn't moonlight as the Rocketeer.

Education

University of Michigan Study Advocates Ban of Facial Recognition in Schools (venturebeat.com) 18

University of Michigan researchers recently published a study showing facial recognition technology in schools has limited efficacy and presents a number of serious problems. From a report: The research was led by Shobita Parthasarathy, director of the university's Science, Technology, and Public Policy (STPP) program, and finds the technology isn't just ill-suited to security purposes, it can actively promote racial discrimination, normalize surveillance, and erode privacy while marginalizing gender nonconforming students. The study follows the New York legislature's passage of a moratorium on the use of facial recognition and other forms of biometric identification in schools until 2022. The bill, a response to the Lockport City School District launching a facial recognition system, was among the first in the nation to explicitly regulate or ban use of the technology in schools. That development came after companies including Amazon, IBM, and Microsoft halted or ended the sale of facial recognition products in response to the first wave of Black Lives Matter protests in the U.S.

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