Science

One of the central factors in the evolution of galaxies is the rate at which stars form. Some galaxies are in a period of active star formation, while others have very little new stars. Very broadly, it’s thought that younger galaxies enter a period of rapid star formation before leveling off to become a mature galaxy. But a new study finds some interesting things about just when and why stars form.

The study looked at a type of galactic cluster known as Brightest Cluster Galaxies (BCGs), which are the largest and brightest galaxy clusters we can see. In this case, the team identified the 95 brightest clusters as seen from the South Pole Telescope (SPT). These galaxies are at redshifts ranging from z = 0.3 to z = 1.7, which spans the period of the Universe from 3.5 to 10 billion years ago.

That’s a good chunk of cosmic time, so you would think the data would show how star formation changed over time. At a high rate when galaxies were young and there was plenty of gas and dust around, then at a low rate after much of that raw material had been consumed. But what the team found was that within these clusters star formation was remarkably consistent across billions of years. They also found the key to when star formation occurs: entropy.

Entropy is a subtle and often misunderstood concept in physics. It is often described as the level of disorder in a system, where the entropy of a broken cup is higher than that of an unbroken cup. Since entropy always increases, you never see a cup spontaneously unbreak itself. But in reality, entropy can describe a range of things, from the flow of heat to the information required to describe a system.

A sample of galaxy clusters, with X-ray light seen in purple. Credit: X-ray: NASA/CXC/MIT/M. Calzadilla el al.; Optical: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/N. Wolk & J. Major

One of the things to keep in mind is that within a region of space, the entropy can decrease, as other areas increase. The most common example is your refrigerator. The interior of your fridge can be much cooler than the rest of your kitchen because electrical power pumps heat away from it. The same is true for life on Earth. Living things have a relatively low entropy, which is possible thanks to the energy we get from the Sun. A similar effect can occur within galaxy clusters. As gas and dust collapses on itself thanks to gravity, the entropy within can decrease. The material becomes denser and cooler over time, and thus stars can begin to form.

At first glance, this seems obvious. Of course stars can form when there is plenty of cool gas and dust around. That’s how it works. But what the team found is that there isn’t a specific temperature or density at which stars form. These factors play off each other in various ways, but the key is the overall entropy. Once the entropy within the cluster drops below a critical level, stars begin to form. They found that this critical level can be reached across billions of years, which is why star formation in all these clusters is so remarkably stable.

It’s an important result because it shows that rather than finding just how much gas and dust there is within a galaxy, or whether it’s at a sufficiently cool temperature, we only need to quantify the entropy of a galaxy. And when that entropy is just right, new stars will shine.

Reference: Calzadilla, Michael S., et al. “The SPT-Chandra BCG Spectroscopic Survey I: Evolution of the Entropy Threshold for Cooling and Feedback in Galaxy Clusters Over the Last 10 Gyr.” arXiv preprint arXiv:2311.00396 (2023).

The post Gigantic Galaxy Clusters Found Just Before They're Awash in Star Formation appeared first on Universe Today.

The multiverse may be a cool (and convenient) concept for comic books and superhero movies, but why do scientists take it seriously?

In a new book titled “The Allure of the Multiverse,” physicist Paul Halpern traces why many theorists have come to believe that longstanding scientific puzzles can be solved only if they allow for the existence of other universes outside our own — even if they have no firm evidence for such realms.

It’s easy to confuse the hypotheses with the hype, but Halpern says there’s a huge difference between the multiverse that physicists propose and the mystical realm that’s portrayed in movies like “Doctor Strange in the Multiverse of Madness.”

“Some people accuse scientists of trying to delve into science fiction if they even mention the multiverse,” Halpern says in the latest episode of the Fiction Science podcast. “But the type of science that people are doing when they talk about the multiverse is real science. It’s far-reaching science, but it’s real science. Scientists are not saying, ‘Hey, maybe we can meet another Spider-Man and attack Kingpin that way.'”

On one level, the concept of a multiverse — encompassing the paths that the universe takes as well as the roads not taken — addresses our instinct to wonder “what if” (which happens to be the title of a Marvel multiverse comic-book series). For example, what if Marty McFly’s mother missed out on meeting his father in “Back to the Future”?

“This whole idea of ‘which world is better, which world is worse’ — this is something people think about a lot, and inspires notions like the multiverse, where you imagine what would have happened if the universe developed differently, what would have happened if history was different,” Halpern says. “It’s a very popular question for us, and could well stem from our survival instincts in terms of planning.”

Multiplicity of multiverse motivations “The Allure of the Multiverse: Extra Dimensions, Other Worlds and Parallel Universes,” by Paul Halpern. (Basic Books)

For physicists, however, the multiverse isn’t a matter of wondering where they’d be if they went for an MBA rather than a Ph.D. Instead, the idea pops up in several scientific contexts. Quantum mechanics gave rise to deep questions about how the act of observation affects the reality being observed. The effort to answer those questions led some physicists to theorize that reality splits into different versions that go their separate ways, in line with what’s now known as the Many Worlds Interpretation.

On a different front, physicists have tried to reconcile the seemingly inconsistent implications of quantum mechanics and general relativity by proposing the existence of extra dimensions. These physicists say the inconsistencies can be mathematically resolved if there are, say, six or seven undetected dimensions in addition to our universe’s four-dimensional spacetime. A field of physics known as brane cosmology speculates that other realms of existence (or “branes,” short for membranes) could exist in parallel to our own realm.

And then there’s the Big Bang. To explain what they’re observing on the far frontiers of our accelerating universe, astrophysicists have proposed that the cosmos got its start in a bubble burst of inflation. Some have followed the trail even further, concluding that there’s no reason why our universe couldn’t spawn a multitude of bubble universes with different properties. (Sci-fi author Gregory Benford worked the idea into a 1998 novel titled “Cosm.”)

Where’s the evidence? Paul Halpern is a professor of physics at Saint Joseph’s University. (Image courtesy of Saint Joseph’s U. via Basic Books)

In his book — and in our podcast — Halpern traces the development of these theories, as well as efforts to track down evidence showing that a particular conception of the multiverse is correct.

Scientists have searched for traces of the multiverse at work in the temperature variations of cosmic microwave background radiation — the so-called afterglow of the Big Bang. They’ve tried to detect primordial gravitational waves that could tell them about the history of cosmic inflation. They’ve looked for signs of gravitons at the Large Hadron Collider, or small-scale variations in the force of gravity that could point to interactions with extra dimensions.

So far, these scientists have struck out. Some have even given up, after concluding that the multiverse hypothesis is an unprovable “theory of anything” and therefore shouldn’t be considered science.

Despite the strikeouts, Halpern hopes physicists will keep on swinging.

“The argument against even considering multiverse models is the lack of observational evidence,” he says. “However, there are many new tools in science that could be used to probe what happened at the beginning of our universe, right after the Big Bang.”

Fine-scale measurements of polarization patterns in the cosmic microwave background radiation could still turn up evidence of “scars” left behind by collisions with other bubble universes. There’s still a chance that gravitational-wave surveys could reveal evidence of interactions with other universes.

“And finally, there’s a burgeoning area of simulating cosmology, and looking to see what models suggest the production of other universes,” Halpern says. “That wouldn’t be experimental proof, but that would provide an important clue as to whether or not you can have our universe with what we believe is an initial state of ultra-rapid expansion called inflation.”

So, is the multiverse for real? Halpern is optimistic that scientists will eventually find ways to answer that question, even though they’ve found nothing but dead ends so far. “I look at the history of physics, and there are so many things that started with false starts,” he says.

Halpern points out that it took decades for physicists to find sufficient evidence for the existence of dark matter and dark energy, black holes and gravitational waves — long-shot efforts that led to Nobel Prizes.

“We have to be patient sometimes with theoretical physics and its predictions,” he says.

Head on over to the original version of this posting on Cosmic Log to get Paul Halpern’s reading recommendations for multiverse mavens. For still more about the multiverse, check out our previous Fiction Science interview with string theorist Brian Greene — plus a doubleheader with physicist Michio Kaku talking about “The God Equation” and “Quantum Supremacy.”

My co-host for the Fiction Science podcast is Dominica Phetteplace, an award-winning writer who is a graduate of the Clarion West Writers Workshop and currently lives in San Francisco. To learn more about Phetteplace, visit her website, DominicaPhetteplace.com.

Stay tuned for future episodes of the Fiction Science podcast via Apple,  Google,  Overcast, Spotify, Player.fm, Pocket Casts and Radio Public. If you like Fiction Science, please rate the podcast and subscribe to get alerts for future episodes.

The post Why Serious Scientists Are Mesmerized by the Multiverse appeared first on Universe Today.

The rules of statistical physics address the uncertainty about the state of a system that arises when that system interacts with its environment. But they've long missed another kind. In a new paper, researchers argue that uncertainty in the thermodynamic parameters themselves -- built into equations that govern the energetic behavior of the system -- may also influence the outcome of an experiment.

Researchers have developed a platform that combines automated experiments with AI to predict how chemicals will react with one another, which could accelerate the design process for new drugs.

Textbook models will need to be re-drawn after a team of researchers found that water molecules at the surface of salt water are organised differently than previously thought.

New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, a new paper shows.

New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, a new paper shows.

New research has cracked a vital process in the creation of a unique rock type from the Moon. The discovery explains its signature composition and very presence on the lunar surface at all, unraveling a mystery which has long-eluded scientists.

In organic optoelectronic devices, the control of molecular deposition on thin films is important for optimal surface arrangement and device performance. In a recent study, researchers developed a new method for achieving stable deposition on thin films effectively. They also developed a tool to track real-time potential changes on the surface. These findings are expected to aid the improvement of organic devices, such as organic light-emitting diodes, in terms of efficacy and durability.

The Atlantic is actually becoming a reasonable venue instead of a woke one.  Example in point: this article by podcaster and writer Josh Barro.  We’ve probably encountered most of his indictments before, but he explains why the problems with American universities is making most Americans—Democrats, Republicans, and independents—lose respect for the institutions. Click to read, or, if the article is paywalled,  you can find an archived version here.

First, the data that constitute the problem (Barro’s words are indented):

Over the past few years, conservatives have rapidly lost trust in higher education. From 2015 to 2023, Gallup found that the share of Republicans expressing “a great deal” or “quite a lot” of confidence in higher education fell by 37 points, from 56 to 19 percent. As conservatives have come to look negatively at these institutions, Republicans have engaged in political attacks on the sector, most recently in the fact-finding and pressure campaign that caused Claudine Gay to resign as president of Harvard.

This decline is something close to common knowledge. Less discussed is the fact that public confidence in colleges has fallen significantly across all ideological groups since 2015. Though Republicans’ confidence cratered the most, Gallup found that it fell by 16 points among independents (from 48 to 32 percent) and nine points among Democrats (from 68 to 59 percent, not far from where Republicans were nine years ago).

Below are some data I found from that Gallup poll (click to enlarge if you can’t see the figures).

First, the data for all Americans, showing a drop in just the last 8 years from 57% to 36% in those who have either a “great deal” or “quite a lot” of confidence in higher education:

And the data divided by demographics. Notice that confidence fell in other groups, too, especially those with no college degree, and also a greater decline among older than among younger people.

 

Why is this happening? According to Barro, and he seems on the mark to me, it’s largely because the institutions are perceived as dishonest and weaselly.  I’ll summarize his reasons, giving Barro’s quotes as either indented prose or with added quotation marks.

a.  Universities seem less interested in finding truth that in supporting an ideology, usually one aimed at social justice.  (Thinks of all the “studies” courses that exist now but didn’t in the past. Even the University of Chicago now has a Department of Race, Diaspora, and Indigeneity.)

b. “Their public accountings of the reasons for their internal actions are often implausible. They deceive the public about the role that race plays in their admissions and hiring practices.”  It’s clear that many universities now are trying to maintain race-based admissions though that’s been outlawed by the Supreme Court.  And there doesn’t seem to be any push to expand ideological or political diversity.

This also goes for hiring practices as well as undergraduate admissions. A quote from Barro:

Because using racial quotas in hiring is illegal, universities can’t explicitly admit to setting positions aside for candidates from underrepresented minorities. Instead they use ideological screens and diversity, equity, and inclusion (DEI) statement reviews as a proxy for race. This approach has many drawbacks—in addition to involving a concealment of the university’s true objectives, it is of no use to Black and Hispanic candidates who are not interested in “ideologically supercharged” areas of study, and sometimes it leads to the hiring of white candidates anyway, if they know best how to include the magic trendy words in a DEI statement.

And a quote about Harvard’s litigation about race-based admissions policy, about which they simply dissimulated. This went all the way up to the Supreme Court, of course:

The dishonesty at elite universities extends beyond their research output to how they describe their admissions processes. Like many universities, Harvard has long used race as a factor in college admissions, producing a class that is less Asian and more Black and Hispanic than it would be if it did not consider race. Throughout the litigation over this practice, the university’s representatives didn’t just defend the appropriateness of race-conscious policies to promote diversity; they denied that they were discriminating at all. They played word games—similar to the “what even is plagiarism?” bit deployed by Gay’s defenders—arguing somehow that race could be used as a positive factor for admission without ever being a negative one, a mathematical impossibility when awarding a fixed number of admission slots.

c. The degrees that universities give “will not justify the time and money that students invest in them.” I’m sure this is one factor, as some schools give degrees with ridiculous names, or “studies” degrees that would make it hard to get a job. And, of course, schools are expensive, especially for “elite” colleges. This is what it’ll take you to send a student to Harvard next year. If you multiply that by four, you get nearly $320,000, not counting books and other supplies.

Even at the state school where I went, The College of William & Mary, tuition for an out-of-state student is $63,967, not that much less than Harvard’s, while in-state students pay amore reasonable amount: $39,595 When I went there it was $1200 per year, which works out, with inflation, to be the equivalent of $10,800 today—a bit more than just half in real money of the student tuition-only fee of $18,252. But the point is that except for state schools if you’re a resident, college costs more than many parents make.

Of course you shouldn’t look at college as a way to get a pecuniary return on your investment, but that’s the way things have become. It’s this “consumerist” mentality that is in fact ruining many colleges, leading to lame “pop culture” courses, grade inflation, the decline of the humanities, and the fear of professors that their students will beef because they’re not getting a monetary return. (When I taught evolution to students who were mostly pre-meds, I got complaints that evolution wouldn’t help students become better doctors. And they’re largely right, but that’s not the point of studying evolution.)

d. The “replication crisis” affecting the reliability of data has led people to think that many researchers are either sloppy or dishonest, so what you learn in college may not be trustworthy.  This is Barro’s accusation, though I don’t see it as nearly as big a contributor to the problem as the first three issues above.

e.  The waffling, euphemisms, and plagiarism evidenced in the Claudine Gray scandal. This doesn’t play into the Gallup data above, which were compiled before Gay resigned as President of Harvard, but it’s surely embedded in the minds of the public now. They also remember the waffling that she, Liz Magill, and Sally Kornbluth showed during the House hearing. Granted, they were being bullied, but none of them made a particularly good showing, and Magill has resigned as well. This, I think, did a great deal to debase higher education in the minds of Americans. I’m not even mentioning the use of euphemisms like “duplicative language” instead of “plagiarism,” which didn’t fool anyone but made Harvard look defensive and weaselly.

f. Even science has been tarred by misguided advice by experts, especially during the pandemic. Barro:

Yet another distortion of  academic output is subject-matter specialists using the guise of expertise to impose their policy preferences on the public. This phenomenon exploded as a huge problem early in the coronavirus pandemic, and it wasn’t limited to universities—some of the public-health professionals who fought to turn transmission estimates into policies that closed schools, offices, and places of worship were on faculties, some were at hospitals, some worked for the government, and some just posted a lot on Twitter. But I’ll say that several years of hearing “science says” prior to claims that weren’t science as such but rather were applications of scientific claims through a specific value framework I didn’t share—part-communitarian, part-neurotic, part-left wing—made

I’m going to add two others, which are mine. Here they are. They’re coming now. First, the deplatforming of speakers. This mainly affects conservative speakers, like federal judge Kyle Duncan, who was shouted down at Stanford Law School, an incident for which the university had to apologize. This, of course, turns off more right-wing than left-wing Americans, but the problem is that all Americans are losing confidence in colleges, and many on the Left, like me, still favor free speech for everyone.

Second, the spread of identity politics and identity issues, which “intersects” with several of the issues above. These include “studies,” DEI, and the segregation of students by race, often in “affinity houses” or in race-specific graduations. This again is guaranteed to anger a lot of people, including members of minorities who don’t favor this kind of voluntary segregation.

Finally, I want to quote one bit from Barro’s piece that’s particularly invidious:

The commentator Matt Yglesias wrote a few weeks ago about a paper by Jenny Bulstrode, a historian of science at the University of London, who alleges that a moderately notable metallurgical technique patented in England in the late 1700s was in fact stolen from the Black Jamaican metallurgists who really developed it. The problem with Bulstrode’s paper is that it marshals no real evidence for its allegation—not only failing to show that the Englishman Henry Cort was aware of a Jamaican metallurgical technique similar to the one he patented but failing to show even that such a technique was ever used in Jamaica.

The paper, because it fit into the fashionable category of “historian finds yet another thing that is racist,” garnered credulous press coverage. And when people pointed out that the paper didn’t have the goods, the editors of the journal that published it came out with a “what is truth, anyway”–type word salad in defense of the article, including this:

We by no means hold that “fiction” is a meaningless category—dishonesty and fabrication in academic scholarship are ethically unacceptable. But we do believe that what counts as accountability to our historical subjects, our readers and our own communities is not singular or to be dictated prior to engaging in historical study. If we are to confront the anti-Blackness of EuroAmerican intellectual traditions, as those have been explicated over the last century by DuBois, Fanon, and scholars of the subsequent generations we must grasp that what is experienced by dominant actors in EuroAmerican cultures as ‘empiricism’ is deeply conditioned by the predicating logics of colonialism and racial capitalism. To do otherwise is to reinstate older forms of profoundly selective historicism that support white domination.

This ideology-first, activism-oriented, the-truth-depends-on-who’s-looking approach leads me to suspect that a lot of what’s happening at universities isn’t really research—it’s social activism dressed up as research, which need not be of good quality so long as it has the right ideological goals.

Look at that word salad in the penultimate paragraph! As best I can figure, it really says that a paper which is completely bogus is okay, so long as it adheres to the narrative of white oppression and cultural appropriation. For the kind of “selective historicism” that called out Bulstrode’s paper simply “supports white domination”—even if Bulstrode was dead wrong.

Is this loss of trust good? In two ways, yes; in another way, no.  The good bits are that this lack of trust may force colleges to clean up their act. Further, people who really don’t want to go to college or need to go to college (John McWhorter says that college isn’t necessary for many people, and others may want to go to trade school), this could put them on a better career path.

But the worst part is that for those who really want a good university education, the structure has to be in place to offer one.  All of the problems above reduce the quality of education on tap, and, if you’re concerned about such things, will make America sink even lower in the worldwide competition for good colleges. Although I don’t care much whether, say, Britain offers a better college education than does the U.S. (I don’t know if this is the case), you simply want every school to be as good as it can, no matter where it is.

Barro has put his finger on a serious issue, and perhaps now that GayGate has occurred and the Supreme Court has begun dismantling DEI, the decline in respect for colleges may slow or even reverse.

 

h/t: Carl

 

Efforts are underway to tidy up the ocean's biggest plastic hotspot. But this cleanup operation could be damaging a unique ecosystem and doing little to stop the overwhelming plastic problem

Athayde Tonhasca Júnior is back, taking us on a trip to Madeira. His captions are indented, and you can enlarge his photos by clicking on them.

Ilha da Madeira (Wood Island) sits some 900 km to the southwest of Portugal and 700 km west of Morocco. The island is the largest of the Madeira Archipelago, a Portuguese autonomous region. It has no beaches to speak of, but that doesn’t deter hordes of European tourists, mostly Continental Portuguese, Britons and Germans, who are lured by the island’s year-round mild climate and abundant sunshine. Inevitably, the horrors of mass-tourism are creeping in. But a judicious visitor that avoids the high season, festival days and resort hot spots near the capital Funchal, can have a memorable time – if in possession of strong legs and sturdy shoes.

Funchal is not at all a photogenic city, but it has several museums, gardens and monuments such as this homage to João Gonçalves Zarco (c. 1390-1471), winner of the Godzilla Prize for urban developer of the millennium. Prince Henrique the Navigator tasked Zarco with creating the right conditions for agriculture to encourage colonization in the hitherto uninhabited island. Zarco set to it, but faced a considerable obstacle hinted in the island’s name: a thick, luxurious forest blanketed it. But an easy solution was at hand – fire. Zarco set the island alight, and the inferno was reputed to have lasted seven years. The lowland native vegetation was wiped out, giving way to sugar cane © Vitor Oliveira, Wikimedia Commons:

A gondola lift from Funchal to the parish of Monte, a vertical climb of 560 m.:

In the 1850s, Monte residents were fed up with the long and boring slog to the city centre. So they came up with a speedier and more exciting alternative: to careen downhill in a carro de cesto (basket car), a wicker basket sledge mounted on wooden runners. Soon tourists wanted to hop on board, and today a carro de cesto journey is one of Madeira’s main attractions – Ernest Hemingway declared it to be one of the most exhilarating rides of his life. Gravity and greased runners propel the sledge forward at speeds nearing 30 km/h, while two sledge drivers negotiate crossings, moving cars, stray dogs, pedestrians and kerbs. Watch a safety-conscious Brit have a go at it:

Madeira is a piscivores’ paradise. Funchal’s fish market offers an enormous variety of seafood, some with odd shapes and appearances such as the peixe-espada preto, or black scabbardfish (Aphanopus carbo). Espada com banana is a local delicacy, but The World Health Organization recommends consuming the fish ‘in moderation’. Despite being an oceanic, deep-sea creature, the black scabbardfish is contaminated with cadmium, lead, mercury and other unsavoury ingredients. No corner of Earth is safe from human screw-ups:

While piscivores will be impressed in Madeira, frugivores will be dazzled. Thanks to the island’s generous climate and fertile volcanic soil, a range of aromatic, flavourful and exotic fruits are grown, such as guava, custard apple, pitanga, prickly pear, passion fruit, and physalis – without mentioning the run-of-the mill banana, papaya, mango, grape and avocado, among others:

Madeirans call their island the ‘floating garden of the Atlantic’. You can spend days hopping from one garden to another:

Cabo Girão: with a 580-m free fall, this the highest promontory in Europe (yes, Madeira is legally European, despite being much closer to Africa). The green carpet on the bottom is grapevines. A sphincter-tightening skywalk was installed at the edge of the chasm after this photo was taken. Madeira is small (57 x 22 km), but during most of its history of human occupation, the interior was uninhabited and uncultivated because of its unforgiving topography of mountainous gorges classed as Very Steep, Terrifying or Ohmygod. To this day, villages are confined to the few spots of gentler slopes:

You would expect cars, lorries, coaches and motorcycles to go slow in this Wile E. Coyote & Road Runner film set. You would be wrong:

Madeira has one the most impressive irrigation systems in the world. The island is intersected by some 200 levadas, which are channels cut into stone that carry water from altitudes of up to 1,800 m in the northern and central mountains to the dry, arable land in the south. The channels, 50-60 cm deep, cover more than 3,000 km, including 40 km of tunnels. Water from the levadas is strictly controlled, distributed to villages and farmers in rations that average 15 minutes every two weeks. Each of the channels’ exits has its levadeiro, a person in charge of monitoring and managing the operation. For tourists, the paths that run along the levadas are excellent avenues for exploration, and the only way to reach some parts of the island. Some levadas are easy going, others require hunchbacked trudges in dark tunnels or pacing narrow strips between the water channel and the void. Routes, maps and possible hazards can be consulted in a variety of levadas guidebooks © Jotbe1961, Wikimedia Commons:

Levadas were built mostly by hand: men often handled their picks and shovels from wicker baskets suspended from above or tied by ropes. Here a group of workers construct a levada sometime between 1947 and 1952 © Cultura Madeir:

Cultivated terraces (poios in the local dialect) seen from the Levada do Norte, which is 50-km long with 7 km of tunnels, bringing water from an altitude of 1,000 m through mountains and valleys. The Portuguese, like the Italians, are experts is putting any scrap of land into cultivation. These terraces are very good at controlling erosion; no tractors here, though:

Curral das Freiras seen from Eira do Serrado viewpoint (1,095 m). The village was originally called Curral (pen), but was changed to Curral das Freiras (nuns’ pen) – as one version of the story goes – in 1566, when Funchal was raided by French corsairs. The good sisters from a local convent suspected that a shared religion would not be sufficient to deflate the enthusiasm of French marauders in heightened stages of concupiscence, so they skedaddled to the mountains. The humble Brides of Christ knew a thing or two about the world:

The village of Casas Próximas (“nearby houses”), which are not that near – 600 m below:

Ecological field work in Madeira is not for the easily intimidated:

Back to Funchal, just in time for Carnaval. According to a native historian, the island’s festival of debauchery inspired the Brazilian version. If so, Brazilians adapted it by tackling the Madeiran revellers’ overdressing, which must be a health and safety hazard in tropical climates:

Several enormous craters left by explosions have been spotted in Siberia over the past 15 years, and a new explanation links them to hot gas – and climate change

An antivaxxer by the 'nym "A Midwestern Doctor" makes an argument that COVID-19 vaccine "shedding" is not impossible despite the basic science that concludes it is. Sound familiar?

The post Why antivax arguments for COVID-19 vaccine “shedding” remind me of homeopathy first appeared on Science-Based Medicine.

Using artificial intelligence to scan surgery patients' medical records for signs of risky drinking might help spot those whose alcohol use raises their risk of problems during and after an operation, a new study suggests. The AI record scan tested in the study could help surgery teams know in advance which patients might need more education about such risks, or treatment to help them reduce their drinking or stop drinking for a period of time before and after surgery.

The term space plane conjurs up all sorts of images and NASA, with their new X-59 (even the name sounds mysterious) they have definitely not dissapointed. Their new quiet supersonic aircraft has been designed to minimise the sonic boom it creates when it crosses the speed of sound. It will fly at 1.4 times the speed of sound and is set for its maiden flight later this year. 

The plane is the result of a joint project between NASA and Lockheed Martin and it has a simple yet ambitious aim. The dream is to revolutionise air travel by producing a new generation of commercial jets that can travel faster than the speed of sound. It’s important to note that these will be the next generation of supersonic aircrat because Tupolev TU-144 (maiden flight 31 Dec 1968) and Concorde (maiden flight 2 March 1969) were the first. 

Concorde (Image Credit : Eduard Marmet)

Supersonic flight is the ability to fly at speeds in excess of the speed of sound. The value for the speed of sound varies based on air density but at sea level, it is 1,224 km/hour. Fly slower than this and the flight is subsonic, fly faster and it goes supersonic. Aircraft that break the sound barrier produce the famous sonic boom but this does not occure at the moment an object crosses the sound barrier. 

The sonic boom, which is the effect of compressed shock waves, is a continuous sound that occurs all the time the aircraft travels faster than sound. To observers on the ground, you only experince the boom when the pressure wavse pass over you. The sound can be quite distressing so the X-59 hopes to address the disturbance that it causes. 

The design of the X-59 looks like it is straight out of a science fiction movie. It is 30 metres long and 9 metres wide. It has a thin tapered nose which takes up about a third of the overall length and it is hoped it will significantly break up the shockwaves that create the sonic boom. Because of the design and the long nose, the pilot sits about half way along making it difficult to get a suitable forward view out of a window. To address this, high resolution cameras feed a signal to 4K monitors in the cockpit as part of the eXternal Vision System. 

Concorde was decomissioned in 2003 having flown for 27 years. Since then, we have been limited to subsonic flights and ocean crossing lasting many hours. In comparison, Concorde could complete a trans-atlantic crossing from JFK to Heathrow in a little under 3 hours while today’s jets takes more like 7 hours. If the test flights of X-59 later this year are a success then maybe we can all look forward to faster travel times around the globe in years to come. 

Source : Lockheed Martin Reveal X-59 Quiet Supersonic Aircraft

The post Shhh, NASA Reveals its New Quiet Supersonic Aircraft appeared first on Universe Today.

China has a rich history in rocketry. It’s even found its place into Chinese legends with the wonderful tale of Wang Tu, who allegedly strapped himself to a chair adorned with rockets to experiment with rocket flight. The story goes that he launched and was never seen again! More recently however, a Chinese company has claimed to have launched the ‘World’s most powerful solid rocket’ capable of producing 600 tonnes of thrust and carrying 6,500kg into low Earth orbit. 

The earliest rockets were made using solid propellants, typically materials like gunpowder. The predecessors to modern rockets were used in warfare by the Chinese, Indians, Mongolians and Persians as far back as the 13th Century. During the 20th Century, liquid propellants were introduced which offered far more control and efficiency but solid rockets are still used today chiefly due to the ease of use and longevity of the fuel when in storage. 

The Chinese aerospace company Orienspace has just launched Gravity-1 a solid fuel propelled rocket. The launch, from a modified cargo ship in the Yellow Sea, just off the coast of Haiyang City has sent three Yunuao-1 meteorology satellites into orbit. Before take off, the short and stubby rocket stood 30 metres high and weighed in at 400 tonnes.

Unusually for modern rockets, Gravity-1 has three core stages and four boosters, all powered by solid fuel. Many modern rockets have a combination of fuel types or favour liquid propellent due to its controllability. In addition to the engines, it has flexible swinging nozzles to aid in flight control. One of the stages has been designed so that it can be adjusted to accomodated liquid fuel to improve its payload capacity. 

It’s not uncommon now to see ships involved in space exploration. Space X has demonstrated this with the landing of its Falcon-9 first stage enginges. The Chinese teams have favoured sea based launch aboard a converted cargo ship because it offers greater flexibility. The weather has often forced launches to be cancelled so a ship based launch gives mobility and a greater chance of success.

A SpaceX Falcon 9 rocket carrying the company’s Crew Dragon spacecraft is launched from Launch Complex 39A on NASA’s SpaceX Demo-2 mission to the International Space Station with NASA astronauts Robert Behnken and Douglas Hurley onboard, Saturday, May 30, 2020, at NASA’s Kennedy Space Center in Florida. The Demo-2 mission is the first launch with astronauts of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. The test flight serves as an end-to-end demonstration of SpaceX’s crew transportation system. Behnken and Hurley launched at 3:22 p.m. EDT on Saturday, May 30, from Launch Complex 39A at the Kennedy Space Center. A new era of human spaceflight is set to begin as American astronauts once again launch on an American rocket from American soil to low-Earth orbit for the first time since the conclusion of the Space Shuttle Program in 2011. Photo Credit: (NASA/Joel Kowsky)

Just whether Gravity-1 is the largest solid rocket ever built will I’m sure be the cause of many debates. After all, the solid rockets of NASAs Space Launch System can deliver 1,632 tonnes of thrust. Regardless, it’s great to see another country investing further in rocket technology and it will be interesting to see how this unfolds in the months and years ahead.

Source : China launches world’s most powerful solid fuel rocket

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Astronomers have discovered a planet closer and younger than any other Earth-sized world yet identified. It's a remarkably hot world whose proximity to our own planet and to a star like our sun mark it as a unique opportunity to study how planets evolve.

Invasive mink, which are native to North America, have been eradicated from most of East Anglia in England after a trial used the scent of the animals' anal glands to lure them into traps

On October 19th, 2017, astronomers with the Pan-STARRS survey detected an interstellar object (ISO) passing through our Solar System for the first time. The object, known as 1I/2017 U1 Oumuamua, stimulated significant scientific debate and is still controversial today. One thing that all could agree on was that the detection of this object indicated that ISOs regularly enter our Solar System. What’s more, subsequent research has revealed that, on occasion, some of these objects come to Earth as meteorites and impact the surface.

This raises a very important question: if ISOs have been coming to Earth for billions of years, could it be that they brought the ingredients for life with them? In a recent paper, a team of researchers considered the implications of ISOs being responsible for panspermia – the theory that the seeds of life exist throughout the Universe and are distributed by asteroids, comets, and other celestial objects. According to their results, ISOs can potentially seed hundreds of thousands (or possibly billions) of Earth-like planets throughout the Milky Way.

The team was led by David Cao, a senior student at Thomas Jefferson High School for Science and Technology (TJSST). He was joined by Peter Plavchan, an associate professor of physics and astronomy at George Mason University (GMU) and the Director of the Mason Observatories, and Michael Summers, a professor of astrophysics and planetary science at GMU. Their paper, “The Implications of ‘Oumuamua on Panspermia,” recently appeared online and is being reviewed for publication by the American Astronomical Society (AAS).

Artist’s impression of the ISO 1I/2017 U1 ‘Oumuamua, detected on October 19th, 2017, by the Pan-STARRS survey. Credit: ESO/M. Kornmesser

To briefly summarize, panspermia is the theory that life was introduced to Earth by objects from the interstellar medium (ISM). According to this theory, this life took the form of extremophile bacteria capable of surviving the harsh conditions of space. Through this process, life is distributed throughout the cosmos as objects pass through the ISM until they reach and impact potentially habitable planets. This makes panspermia substantially different from competing theories of how life on Earth began (aka. abiogenesis), the most widely accepted of which is the RNA World Hypothesis.

This hypothesis states that RNA preceded DNA and proteins in evolution, eventually leading to the first life on Earth (i.e., which arose indigenously). But as Cao told Universe Today via email, panspermia is difficult to assess:

“Panspermia is difficult to assess because it requires so many different factors that need to be incorporated, many of which are unconstrained and unknown. For instance, we must consider the physics behind panspermia (how many objects collided with Earth prior to the earliest fossilized evidence for life?), biological factors (can extremophiles endure supernova gamma radiation?), and so on.

“In addition to each of these factors are questions we do not have answers to yet, or we cannot model effectively, for example, the number of extremophiles that actually reach the Earth even if a life-bearing object collided with Earth, and the probability that life can actually start from the foreign extremophiles. The collection of these factors, along with many more, such as the changing star formation rate and the recent detection of several rogue free-floating planets, makes panspermia difficult to assess, and therefore, our understanding of the plausibility of panspermia is constantly changing.”

The detection of ‘Oumuamua in 2017 constituted a major turning point for astronomy, as it was the first time an ISO was observed. The fact that it was detected at all indicated that such objects were statistically significant in the Universe and that ISOs likely passed through the Solar System regularly (some of which are likely to be here still). Two years later, a second ISO was detected entering the Solar System (2I/Borisov), except there was no mystery about its nature this time. As it neared our Sun, 2I/Borisov formed a tail, indicating it was a comet.

A Hubble image of comet 2I/Borisov speeding through our Solar System. Credit: NASA/ESA/D. Jewitt (UCLA)

Subsequent research has shown that some of these objects become meteorites that impact on Earth’s surface, and a few have even been identified. This includes CNEOS 2014-01-08, a meteor that crashed into the Pacific Ocean in 2014 (and was the subject of study by the Galileo Project). As Cao explained, the detection of these interstellar visitors also has implications for panspermia and the ongoing debate about the origins of life on Earth:

“‘Oumuamua serves as a novel data point for panspermia models, as we can use its physical properties, particularly its mass, size (spherical radius), and implied ISM number density, to model the number density and mass density of objects in the interstellar medium. These models allow us to estimate the flux density and mass flux of objects in the interstellar medium and, with these models, we can approximate the total number of objects that impacted Earth over 0.8 billion years (which is the hypothesized period of time between Earth’s formation and the earliest evidence for life).

“Knowing the total number of collision events on Earth over that 0.8 billion-year period is vital for panspermia, as a greater number of collision events with interstellar objects over that period would imply a higher probability for panspermia. In short, the physical properties of the interstellar ‘Oumuamua allow for the creation of mathematical models that determine the plausibility of panspermia.”

In addition to the mathematical models that consider the physics behind panspermia – i.e., number density, mass density, total impact events, etc. – Cao and his colleagues applied a biological model that describes the minimum object size needed to shield extremophiles from astrophysical events (supernovae, gamma-ray bursts, large asteroid impacts, passing-by stars, etc.). As addressed in a previous article, recent research has shown that cosmic rays erode all but the largest ISOs before they reach another system.

These additional considerations ultimately affect the number of objects that will impact Earth (that were not sterilized by astrophysical sources) and the plausibility of panspermia. “In order to derive the minimum object size, we applied various models, for instance, the sphere packing method to give a rough estimate of an ejecta’s distance to the nearest supernova progenitor (using Orion A, a dense star cluster, as our model), the gamma radiation that reaches that ejecta, and the attenuation coefficient (how much radiation the ejecta absorbs) based on the most probable chemical composition of ejecta (water ice),” said Cao.

Artist’s Concept of ‘Oumuamua. Credit: William Hartmann

Based on their combined physical and biological models, the team derived estimates for the number of ejecta that struck Earth before life emerged. According to the oldest fossilized evidence found in western Australia (from rocks dating to the Archaean Eon), the earliest life forms emerged ca. 3.5 billion years ago. Said Cao:

“We conclude that the maximum probability that panspermia sparked life on Earth is on the order of magnitude of 10-5, or 0.001%. Although this probability appears low, under the most optimistic conditions, potentially 4×109 total habitable zone exoplanets exist in our Galaxy, which could indicate a total of 104 habitable worlds harboring life.

“Additionally, we restricted our analysis to the first 0.8 billion years of Earth’s history prior to the earliest fossilized evidence for life, but because life can be seeded at any point in a planet’s lifetime, and planets have significantly longer habitable lifespans (up to 5-10 billion years), we boosted our estimate for the total number of habitable worlds harboring life in our Galaxy by one order of magnitude.”

From this, Cao and his colleagues obtained a final result of about 105 habitable planets that could harbor life in our galaxy. However, these estimates are based on the most optimistic projections regarding planetary habitability. In other words, it assumes that all Earth-sized rocky planets orbiting within habitable zones are capable of supporting life, meaning they have thick atmospheres, magnetic fields, liquid water on their surfaces, and all life-bearing ejecta that survive entering our atmosphere are capable of depositing microbes on the surface.

As Cao summarized, their results do not prove panspermia or settle the debate on the origins of life here on Earth. Nevertheless, they provide valuable insight and constraints on the possibility that life came here via objects like ‘Oumuamua. No matter what, these findings are likely to have significant implications for astrobiology, which is becoming an increasingly diverse field:

“We incorporate physics, biology, and chemistry into studying panspermia as the origin of life, and it is rare to have such a diverse range of topics in one research area. I think that astrobiology is trending toward becoming more interdisciplinary, which I believe is a positive trend because it would allow experts of all backgrounds to advance astrobiology. Our research may contribute to this trend. In terms of our findings on panspermia, the probability that panspermia sparked life on Earth is unlikely, but the number of habitable zone planets harboring life in our Galaxy is substantially larger.

“Future astrobiology studies may use these findings to build on our research on panspermia. However, we do not incorporate or even know all factors that may affect the plausibility of panspermia. I believe our findings open up new lines of inquiry for future panspermia studies to build off of by updating our models or incorporating additional factors. One potential area of study if we do find evidence for life on other worlds in the future, whether in our Solar System or via biosignatures in exoplanet atmospheres, is to consider experimental and observational tests to distinguish between life that arrived by the panspermia mechanism or life that evolved and arose independently.”

Further Reading: arXiv

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