I noticed last week that the followers of my Twitter account had dropped by several hundred, and then I realized that a lot of people are going to the alternative site Bluesky, presumably because they don’t like Elon Musk because he gave a lot of dosh to Trump (and now has a job in the Trump Administration).
Matthew went from “X” to Bluesky a while back, and has been telling me to move as well. He said this:
People aren’t leaving (just) because they hate Musk – the site [X] doesn’t work. Posts aren’t seen, even if you follow people your timeline gets swamped with blue tick reply guy crap. To see what people post you have to go onto their timeline. And fewer and fewer people are there. You have 40,000 followers [JAC: it’s 36,400] – how many interactions with your tweets? How many of those followers are either a) human or b) active? And – though this isn’t why you use it – the fun component [like the tweet he sent about fat cheetah cubs]) has disappeared from X completely. The Guardian has stopped posting there. User numbers are dropping. Not a useful or fun place to be any more.
Yes, there appear to be advantages of Bluesky, which seem to include these:
The downsides seem less important, but include two:
I don’t particularly feel compelled to leave X just because Elon Musk runs it, as I have no strong feelings about that, but I suppose I’ll move after I check Bluesky. But I wonder about readers’ experience with these two cites. Please give your take below (not advice on whether to move, but the relative advantages of the two sites). Which site do you use or occupy? Are there any other advantages, issues or features that I don’t know about?
Eric Bailey, Public domain, via Wikimedia CommonsThere is a region of the sky where astronomers fear to look. Filled with dark clouds of dust, it hides an unseen mass. A mass so large it is pulling the Milky Way and other galaxies toward it…
Okay, maybe that’s overdramatic, but it is true. The region is known as the Zone of Avoidance, and it happens to be in the general direction of the galactic center. Our view of the Universe isn’t as perfect as we’d like. The Sun is located within the galactic plane of the Milky Way, about 30,000 light-years from its center. So if we look to the north or south of the galactic plane, we get a pretty normal view of the cosmos. We can peer deep into the sky and see distant galaxies. But if we look toward the galactic center, we don’t have a clear view. Instead, we see a bunch of stars, gas, and dust. This is fine if you want to study stars, gas, and dust, but it means our view of the distant Universe is obscured in that direction. So if you want to make an unbiased view of the cosmos, you avoid that region, hence the term.
It’s also true that we’re being pulled in that direction. There happens to be a supercluster of galaxies that way, called the Great Attractor. We can map it out a bit by studying the relative motion of nearby galaxies, and we can observe X-rays from the supercluster, so we know it’s out there. But with all the gas and dust in the Zone of Avoidance, we can’t study it in the optical. One thing we know so far is that the Great Attractor actually consists of multiple clusters. The closest one is known as the Norma cluster, while a larger and more distant one is called the Vela supercluster. Still, there is much we don’t know about the region.
Fortunately, radio light can penetrate the dust of the Zone, so radio astronomers have tried to map the region. One downside is that radio telescopes often don’t have a large field of view, so it’s difficult to map the region. But a new work is making progress.
Observed galaxies within the Vela supercluster. Credit: Sambatriniaina H. A. Rajohnson, et alThe new study uses data from the MeerKAT array telescope in South Africa. MeerKAT is particularly sensitive to the radio emissions of neutral hydrogen, known as the HI or [21-centimeter line.](https://briankoberlein.com/blog/dark-line/) Since hydrogen is so abundant in the Universe, the distribution of hydrogen tells us the distribution of galaxies and clusters. The study mapped the region of the Zone in the direction of the Vela supercluster with enough resolution to distinguish individual pockets of neutral hydrogen, each surrounding a galaxy. In this way, the team was able to discover 719 galaxies within the Vela cluster. Less than a third of them had been known previously.
This was just the first detailed survey of the Vela supercluster by MeerKAT, and it shows the real power of this relatively new observatory. Future studies should give us an even better understanding of the zone astronomers so often avoid.
Reference: Sambatriniaina H. A. Rajohnson, et al. “Revealing hidden structures in the Zone of Avoidance — a blind MeerKAT HI Survey of the Vela Supercluster.” arXiv preprint arXiv:2411.07084 (2024).
The post Astronomers Defy the Zone of Avoidance to Find Hundreds of New Galaxies appeared first on Universe Today.
In today’s Jesus and Mo strip, called “reason,” the barmaid suggests that both Jesus and Mo are going to hell. I am puzzled; why would they? They are prophets and, in Jesus’s case, the son of God/God.
Today we have photos from South Africa taken by reader Phil Frymire on a recent trip. Phil’s captions and IDs are indented, and you can enlarge his pictures by clicking on them.
Here are some more photos from an August trip to Timbavati and Mala Mala in South Africa that occurred at the same time as our host’s visit. I previously submitted some leopards, lions, elephants and rhinos. Rounding out the Big Five, here are some African buffalo (Syncerus caffer) along with some spotted hyenas (Crocuta Crocuta), Burchell’s zebras (Equus quagga burchellii) and Northern giraffes (Giraffa camelopardalis).
A resting buffalo:
A herd of buffalo. The male in the foreground has an impressive “boss” (the area where the horns grow together in the middle):
A “dagga boy” as Jerry’s guide Dan called them. Our guide Mike called them “retired”. These are old males that no longer travel with the herds. They will likely be taken by lions (but see the photo below). This one is accompanied by a red-billed oxpecker (Buphagus erythroryncha):
When we first encountered these lions at Mala Mala, they were walking with their left sides facing us. One of the females was limping pitifully. After we drove around for a better look, it became obvious why she was struggling. If you look carefully at the female on the right you will see a gaping, horrific wound on her right front leg running from the shoulder to the elbow. She never emerged from the bushes while we observed her so I couldn’t get a clear photo. Mike was very confident that the injury was caused by a buffalo horn. Predators fight for a meal, but prey fight for their life. Predators don’t always emerge from the fracas unscathed. Revenge of a dagga boy?:
Profile of a spotted hyena:
The same hyena intently staring at us:
Hyena with a black-backed jackal (Lupulella mesomelas) in the foreground:
The same hyena literally eating bone. The crushing sounds were very impressive:
A beautiful zebra:
Posing above a waterhole:
Why do zebras have stripes? Jerry mentioned in one of his posts that the scientific evidence supports the hypothesis that the stripes deter biting flies. I asked our guide Mike what he thought. He favored the idea that the stripes break up the body outline and confuse predators. He didn’t cite any scientific papers, but he did cite this view of a mother and foal:
Another mother and foal at a waterhole:
Four male giraffes:
Frontal view of a male showing the thick ossicones that they use in combat with other males:
Profile of a giraffe with an oxpecker on its neck:
When physicians spread medical misinformation, the potential harm to health is far greater than their direct patient care. And yet, in a recent study, medical boards rarely discipline physicians for spreading misinformation. The JAMA article looked at 3128 medical board disciplinary proceedings involving physicians. Spreading misinformation to the community was the least common reason, at 0.1%. Direct patient misinformation and inappropriate advertising […]
The post Physician Misinformation first appeared on Science-Based Medicine.