Black Holes in the News

[Dark Lightning]

I may've got 3 correct. That was back in October, so dim and misty past, at this point. People with one eye are allowed to drive; I know a few.

[zorkan]

I have had many of those things. If discovered early they are removed by a squirt of liquid nitrogen. If developed a bit more, then minor surgery, if left to grow for a long period of time, then more serious surgery. 

The least convenient BCC that I have had was one my eyelid. Hospital, general anasthesia, etc.  The guy who did the surgery was pretty good at it and did not wreck my eyeball.

Bccs and Sccs are manageable and are not likely to kill you. Melanoma, on the other hand, are potential widow makers.

Went out for a walk one May day without a hat. Back in the car I noticed a blister on the side of my head that wasn't there before.
Scalpel off the blister at the hospital. All done, or so I thought. More serious op later to remove what was beneath.
Then all clear.

With all that radiation the main reason why we never set foot on the moon?

[zorkan]

Don't mean to start a moon debate.
Just wondering how many black holes are up there and what would be the effect on health.
The universe is full of holes.
We might be living inside a mega massive one.

ISS is only 250 miles above us.

Why did we go to the moon in the first place?
Was it to see if it's hollow and artificial?
Why does it perfectly obscure the sun in an eclipse?
 

[The Magic Pudding..]

Why does it perfectly obscure the sun in an eclipse?

The why is a matter of mathematics
results in a world poetic symmetry
So we all look up and say just so

[zorkan]

Yes but supposing the moon is alien-made as a calling card to stabilize the earth.
We are too stupid to consider now, but one day it will dawn on us.

Did you know that if we could manufacture a black hole we could travel the universe in just a few earth years?
All is explained in this rare book, of which I own a copy of a copy.

https://www.amazon.co.uk/Iron-Sun-Crossing-Universe-Through/dp/0340232315

[billy rubin]

I may've got 3 correct. That was back in October, so dim and misty past, at this point. People with one eye are allowed to drive; I know a few.

yes, a class C civilian driver.

i have a class A commercial. i cant keep that category with only one eye in any jurisdiction i know of

[billy rubin]

fascinating.

the aenesthesia is something called  . . .brusic?

anyway, it keeps you conscious but groggy. during the procedure i could perceive the two ends of the forceps entering the corneal chambers to extract th e pieces of the destryed lens. i kept asking the surgeon to comment on what he was doing but i got no satisfaction there. thats a shame, because how often do you get to learn something like that?

anyway, it takes but a moment to do. the surgeon set the day aside for the procedure and closed his business office. did my surgery and ten others.

so far the incision is smoothing over. i wasnt supposed to drink alcohol for 24 hours, but after two beers everything appears to be going as well as i can expect.

more seriously, i have to stay in a dust-free environment for a week, and refrain from any contamination. that  makes sense, because the incision is left open-- no sutures , staples, or glue.  so any contaminants that get in there get permanently incoprporated into the schlera.

bad news.

[Recusant]

Glad to hear that the procedure seems to have been a success. I know several people who've had them done and been pleased with the results.

[Dark Lightning]

Not sure how an open incision ends up without some sort of bleb on the eyeball. I guess if it's far enough away from the lens, the effect would be minimal.

[billy rubin]

they go in from the side, break the lens up, then suction out the pieces.

so its just the lateral schlera rhat gets cut up.

eyes heal quick, and after about 6 hours most of the discomfort is gone. vision is already better, even with tbe normal inflammation and swelling.

no work for a week tho. im pissed because im forced to take time off but i cant do anything dirty.

dirty things are my life.

[Recusant]

This one got onto the US's public radio news, and perhaps elsewhere. I'd bet a fiver that it got onto at least Radio 4 from the BBC, if not their television news. So there's a good chance the remaining lucky few here have already heard tell of the vanishing star.

"A Giant Star Vanished, And Scientists Think a Black Hole Is to Blame" | ScienceAlert

One of the brightest stars in the Andromeda galaxy quietly collapsed into a black hole without any of the fanfare of a spectacular supernova.

What makes this startling discovery even more remarkable is that the first signs of the transformation were recorded back in 2014 – data that is crucial for understanding the different ways black holes can form after the death of a giant star.

"This has probably been the most surprising discovery of my life," says astronomer Kishalay De of Columbia University in the US, who led the research. "The evidence of the disappearance of the star was lying in public archival data, and nobody noticed for years until we picked it out."

When a massive star many times heavier than the Sun dies, it's not expected to go quietly. Once nuclear fusion in the core can no longer generate sufficient outward pressure against the inward pull of gravity, the core collapses.

This can send a giant shock tearing outward through the star, triggering a supernova explosion that sends the star's outer material flying, while the core transforms into either a neutron star or a black hole.

However, this is not the only way this transformation can take place. In some scenarios, the outward shock stalls. Instead of ripping the star apart, the explosion fizzles out, and the material ends up falling back onto the newly formed black hole. Because this is a much less dramatic process than a supernova, clear evidence of it is relatively rare.

"Unlike finding supernovae, which is easy because the supernova outshines its entire galaxy for a few weeks, finding individual stars that disappear without producing an explosion is remarkably difficult," De explains.

Only one such event had been documented previously, a star recorded vanishing around 2010 in a galaxy 22 million light-years away. Now, by carefully looking over archival observations of the Andromeda galaxy, De and his colleagues have found another, and it's even clearer than the previous example.

M31-2014-DS1 was a supergiant star that started out about 13 times the mass of the Sun and shone brightly, even across the 2.5 million light-year distance between the Milky Way and Andromeda.

Then, in 2014, NASA's NEOWISE telescope recorded it suddenly shining more intensely in infrared, increasing its brightness by about 50 percent over about two years.

Then, between 2016 and 2022, it dimmed dramatically to the point where, by 2023, it completely vanished from view in optical wavelengths.

[Continues . . .]

The paper is behind a paywall, but I found a revised preprint version. Though I haven't gone into the paper yet, the abstract from the preprint is identical to the published version.

"Disappearance of a massive star in the Andromeda Galaxy due to formation of a black hole" | arXiv

When a massive star reaches the end of its lifetime, its core collapses and releases neutrinos that drive a shock into the outer layers (the stellar envelope). A sufficiently strong shock ejects the envelope, producing a supernova. If the shock fails to eject it, the envelope is predicted to fall back onto the collapsing core, producing a stellar-mass black hole (BH) and causing the star to disappear. We report observations of M31-2014-DS1, a hydrogen-depleted supergiant in the Andromeda Galaxy. In 2014, it brightened in the mid-infrared, then from 2017 to 2022, it faded by factors of ≳ 10⁴ in optical light (becoming undetectable) and ≳ 10 in total light. We interpret these observations, and those of a previous event in NGC 6946, as evidence for failed supernovae forming stellar-mass BHs.