@random-thought-depository / random-thought-depository.tumblr.com
The nearest single star to the Solar System has just yielded up a rare and wonderful treasure. Around a red dwarf known as Barnard's star, which lies just 5.96 light-years away, astronomers have found evidence of an exoplanet. And not just any exoplanet. This fascinating world, known as Barnard b, is tiny, clocking in with a minimum mass of 37 percent of the mass of Earth. That's a little shy of half a Venus, and about 2.5 Marses.
The shape of a fish's caudal tail can tell you a lot about how fast the fish moves! A rounded tail is the slowest and a lunate tail is the fastest! The lunate tail has the most optimal ratio of high thrust and low draw, making it the fastest.
Ichthyology Notes 2/?
An analysis of the new Webb observations strongly excluded the mini-Neptune scenario, with tantalizing evidence suggesting exoplanet LHS 1140b is a super-Earth that may even have a nitrogen-rich atmosphere. If this result is confirmed, LHS 1140b would be the first temperate planet to show evidence of a secondary atmosphere, formed after the planet’s initial formation. Estimates based on all accumulated data reveal that LHS 1140b is less dense than expected for a rocky planet with an Earth-like composition, suggesting that 10 to 20% of its mass may be composed of water. This discovery points to LHS 1140b being a compelling water world, likely resembling a snowball or ice planet with a potential liquid ocean at the sub-stellar point, the area of the planet’s surface that would always be facing the system’s host star due to the planet’s expected synchronous rotation.
[...] Current models indicate that if LHS 1140b has an Earth-like atmosphere, it would be a snowball planet with a vast bull’s-eye ocean measuring about 4,000 km in diameter, equivalent to half the surface area of the Atlantic Ocean.
Reminds me of when observations with the James Webb telescope showed Trappist-1b doesn't have a thick atmosphere. It's cool that we're starting to get a sense of what some of these exoplanets are like as places!
The whole "the brain isn't fully mature until age 25" bit is actually a fairly impressive bit of psuedoscience for how incredibly stupid the way it misinterprets the data it's based on is.
Okay, so: there's a part of the human brain called the "prefrontal cortex" which is, among other things, responsible for executive function and impulse control. Like most parts of the brain, it undergoes active "rewiring" over time (i.e., pruning unused neural connections and establishing new ones), and in the case of the prefrontal cortex in particular, this rewiring sharply accelerates during puberty.
Because the pace of rewiring in the prefrontal cortex is linked to specific developmental milestones, it was hypothesised that it would slow down and eventually stop in adulthood. However, the process can't directly be observed; the only way to tell how much neural rewiring is taking place in a particular part of the brain is to compare multiple brain scans of the same individual performed over a period of time.
Thus, something called a "longitudinal study" was commissioned: the same individuals would undergo regular brain scans over a period of mayn years, beginning in early childhood, so that their prefrontal development could accurately be tracked.
The longitudinal study was originally planned to follow its subjects up to age 21. However, when the predicted cessation of prefrontal rewiring was not observed by age 21, additional funding was obtained, and the study period was extended to age 25. The predicted cessation of prefrontal development wasn't observed by age 25, either, at which point the study was terminated.
When the mainstream press got hold of these results, the conclusion that prefrontal rewiring continues at least until age 25 was reported as prefrontal development finishing at age 25. Critically, this is the exact opposite of what the study actually concluded. The study was unable to identify a stopping point for prefrontal development because no such stopping point was observed for any subject during the study period. The only significance of the age 25 is that no subjects were tracked beyond this age because the study ran out of funding!
It gets me when people try to argue against the neuroscience-proves-everybody-under-25-is-a-child talking point by claiming that it's merely an average, or that prefrontal development doesn't tell the whole story. Like, no, it's not an average – it's just bullshit. There's no evidence that the cited phenomenon exists at all. If there is an age where prefrontal rewiring levels off and stops (and it's not clear that there is), we don't know what age that is; we merely know that it must be older than 25.
I've noticed something I find somewhat concerning and it's that for a lot of people, 'pluto is a planet' has fallen into the stock list of examples for what one might call 'science denialism', along with things like antivaxx, denying the existence of feathered (non-avian) dinosaurs, and flat earthers
there's a sentiment that goes like 'well, sure, you learned in school that the solar system has nine planets, but Science Marches On and we now know it has eight' and while certainly people should not take what they learned in school to be immutable law they should also like. have a concept of the rather significant difference between 'we've learned something new about the world' and 'we've decided to slice up the world in categories along different lines'
slicing up the world into categories is one of the basic operations of human thought and if you do not understand it well enough that you think 'people used to think the earth flat -> now we know better' and 'astronomers used to call pluto a planet -> now they don't' are analogous processes then you fucked up somewhere.
and if you don't think they are analogous, if you understand the difference i am pointing out and think it does not matter to the quest of listing stock examples of people disagreeing with things scientists say, well. you fucked up in a different place, probably.
The reclassification of Pluto was a "we've decided to slice up the world in categories along different lines," but it was in response to new knowledge, namely that Pluto is less unusual than we thought it was. You're correct that "Pluto is still a planet to me" is different from and less objectionable than global warming denial, YEC, etc., but it's not wrong to see Pluto's reclassification as an example of "science marches on."
Scientists at UC Riverside have demonstrated a new, RNA-based vaccine strategy that is effective against any strain of a virus and can be used safely even by babies or the immunocompromised. Every year, researchers try to predict the four influenza strains that are most likely to be prevalent during the upcoming flu season. And every year, people line up to get their updated vaccine, hoping the researchers formulated the shot correctly. The same is true of COVID vaccines, which have been reformulated to target sub-variants of the most prevalent strains circulating in the U.S. This new strategy would eliminate the need to create all these different shots, because it targets a part of the viral genome that is common to all strains of a virus. The vaccine, how it works, and a demonstration of its efficacy in mice is described in a paper published today in the Proceedings of the National Academy of Sciences. “What I want to emphasize about this vaccine strategy is that it is broad,” said UCR virologist and paper author Rong Hai. “It is broadly applicable to any number of viruses, broadly effective against any variant of a virus, and safe for a broad spectrum of people. This could be the universal vaccine that we have been looking for.”
Malaria cells have plastids homologous to chloroplasts
"We now recognize that this large group of parasites had a photosynthetic ancestry and were converted into parasitism early in the evolution of animals."
What!
so this paper gives more context... ok first of all did you know that coral photosynthesize?? I didn't know that... but the way they do that is intracellular endosymbiotic uh protists or algae or whatever. The branch of parasites that malaria is from, plasmodium, their closest relatives seem to be these endosymbionts in coral. So we can guess that a long time ago the ancestors of plasmodium weren't parasitic, they were an endosymbiont in a photosynthesizing animal like coral
Blue whales have been considered the largest creatures to ever live on Earth. With a maximum length of nearly 30 meters and weighing nearly 200 tons, they are the all-time undisputed heavyweight champions of the animal kingdom. Now, digging on a beach in Somerset, UK, a team of British paleontologists found the remains of an ichthyosaur, a marine reptile that could give the whales some competition. “It is quite remarkable to think that gigantic, blue-whale-sized ichthyosaurs were swimming in the oceans around what was the UK during the Triassic Period,” said Dr Dean Lomax, a paleontologist at the University of Manchester who led the study.
No no, this is the present's one W over the age of the dinosaurs. You're not taking this away from us, fuck you
“Secular” Zionism is like saying you believe the Earth is 5,000 years old and the first humans were named Adam and Eve and lived in a place called Eden with talking animals but it’s secular because you don’t explicitly mention God
I mean aside from the age thing this is retrospectively totally true in that you know that if scientists could identify a specific first man and first woman that's what they'd call them and ditto a point of origin
"#mitochondrial eve anyone"
Mitochondrial Eve and Y chromosomal Adam are actually very different concepts from Biblical Adam and Eve, calling them that is basically ramming a square real science peg into a round mythology reference hole.
Mitochondrial Eve was not the first woman, she's just the most recent woman everyone alive today has an unbroken chain of matrilineal descent from (as far as we know, it's not like we've actually given every human alive a mitochondrial DNA test). There were plenty of other women alive at the same time as mitochondrial Eve, and we're almost certainly descended from some of them in the same way you're descended from your paternal grandmother (inherited nuclear DNA from them but not mitochondrial DNA, because mitochondria pass only from mother to daughter).
Ditto, Y chromosomal Adam was not the first man, he's just the most recent man every cis perisex man alive today has an unbroken chain of patrilineal descent from (as far as we know). There were plenty of other men alive at the same time as Y chromosomal Adam, and we're almost certainly descended from some of them in the same way you're descended from your maternal grandfather (inherited DNA from them but not their Y chromosome because the Y chromosome passes only from father to son).
There's no scientific reason to think Y chromosomal Adam was mitochondrial Eve's husband and there's no scientific reason to think they made children together. It's possible, but nothing about what we know of them raises the possibility above the (very low) background plausibility of any other science fiction we might dream up about what their lives might have been like. It's statistically more likely that one lived and died many thousands of years after the other (one of them might have been the other's distant ancestor; that's if anything a lot more likely than a scenario where they had overlapping lifespans and met each other).
Mitochondrial Eve and Y chromosomal Adam were likely completely ordinary people in their lifetimes; their genetic significance to present humanity is likely more-or-less a consequence of random genetic drift.
I think calling mitochondrial Eve and Y chromosomal Adam "Eve" and "Adam" is a pretty clear case of actual cultural Christianity; mitochondrial Eve and Y chromosomal Adam are not particularly similar to the Biblical Adam and Eve, but they get called that because Christian mythology references are a big part of Western society's default way of talking about the past.
There probably was no first man and first woman, because evolution is slow and probably never produced any single mutation change that you could point to as something that decisively separates the first humans from whatever their ancestors before that point were.
Don't know whether this has any applicability to politics, but I felt like it was worth pointing out.
But then around 30 million years ago — halfway through the Age of Mammals, give or take — something happened. The nautiloids started disappearing. Fewer species, less diversity. Bit by bit they shrank back into their current small range. What happened halfway through the Age of Mammals? Well, here’s one clue: the nautiloids’ long retreat showed a pattern. It wasn’t everywhere and all at once. They disappeared first in the northern arctic regions; then in the Antarctic; then in temperate zones; finally across most of the tropics except that one small patch. This pattern suggested a culprit: a warm-blooded predator that evolved in the Arctic and then spread around the world. But… the armored cephalopod design had been around forever. They’d been living with predators for half a billion years. Sharks. Primitive armored fish. Not-so-primitive modern fish. In the age of dinosaurs, they had to deal with ichthyosaurs, plesiosaurs, and mosasaurs. Back in the Paleozoic, they were hunted by eight-foot-long giant sea scorpions. Way back in the Cambrian, they had to live with the anomalocariids. In the early Age of Mammals, there were primitive whales and sea-going crocodiles. The armored cephalopod design took them all in stride and kept going. So what happened?
obsessed with this photo. the face of a slurper
The ability of mammals to create vacuum chambers in their mouth -- universal due to the necessity of sucking milk during infancy -- is a very useful, and very unappreciated one. Something as simple as sipping water from a cup would be impossible if not for all the layers of soft, wriggly flesh built on top of our jaws.
I recall some book recounting how mammals turned their face inside-out during our evolution in the latest Paleozoic -- reptiles and bird mostly have their head and jaw muscle inside their skulls, mammals mostly have them outside. This also allows us to have complex facial expressions, which are vital for mammalian communication, and only exist because of milk.
I was watching Attenborough and the Jurassic Sea Monster and I learned that parietal eyes are a thing.
A bunch of animals have a rudimentary third eye in the middle of their heads, that's so wild!
A leading expert on sperm whales has gathered the evidence and shown that the biggest-brained animals on Earth form large and complex clans with unique dialects and behaviors. Using some rough calculations based on sperm whale populations, Hal Whitehead from Dalhousie University in Canada estimates that many of these clans number in the tens of thousands.
A new study shows the Megalodon, a gigantic shark that went extinct 3.6 million years ago, was more slender than earlier studies suggested. This finding changes scientists' understanding of Megalodon behavior, ancient ocean life, and why the sharks went extinct. The Megalodon or megatooth shark is typically portrayed as a super-sized monster in popular culture, with recent examples in the sci-fi films "The Meg" (2018) and "Meg 2: The Trench" (2023). Previous studies assume that the shark likely reached lengths of at least 50 feet and possibly as much as 65 feet.
Moderna CEO Stephane Bancel told AFP his company's experimental vaccine against melanoma could be available in as little as two years, in what would amount to a landmark step against the most serious form of skin cancer. Globally there were an estimated 325,000 new melanoma cases and 57 ,000 deaths from the disease in 2020. "We think that in some countries the product could be launched under accelerated approval by 2025," he said in an interview.
