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There are Four Ways to Build with Regolith on the Moon

Universe Today Feed - 17 hours 42 min ago

Over the last few years I have been renovating my home. Building on Earth seems to be a fairly well understood process, after all we have many different materials to chose from. But what about future lunar explorers. As we head closer toward a permanent lunar base, astronauts will have very limited cargo carrying capability so will have to use local materials. On the Moon, that means relying upon the dusty lunar regolith that covers the surface. Researchers have now developed 20 different methods for creating building materials out of the stuff. They include solidification, sintering/melting, bonding solidification and confinement formation. But of all these, which is the best?

Apollo astronauts reported the surface of the Moon to be covered in a fine, powdery material, similar in texture to talcum powder. The material, known as the lunar regolith is thought to have formed by the constant bombardment from meteoroids over millions of years. The impacts bombarded the rocks on the Moon’s surface breaking them down into fine grains. The layer varies in depth across the surface from 5 metres to 10 metres and consists mostly of silicon dioxide, iron oxide, aluminium dioxide and a few other minerals. The fine nature of the dust makes it difficult for astronauts and machinery alike to operate on the surface and its sharp contours make it somewhat hazardous.

After taking the first boot print photo, Aldrin moved closer to the little rock and took this second shot. The dusty, sandy pebbly soil is also known as the lunar ‘regolith’. Click to enlarge. Credit: NASA

Any future engineers that visit the Moon to construct habitats will need to somehow employ the use of this material in their work. A paper published in the journal Engineering by Professor Feng from the Tsinghua University has conducted a review of possible techniques. Almost 20 techniques have been employed and these have been categorised into four main processes. 

In what I can only assume to be a process similar to concrete and its reaction with water, reaction solidification takes regolith particles and reacts them with other compounds. These will have to be transported to the Moon and, when mixed with regolith, will solidify. The process would create a solid material where regolith comprises 60% to 95% of the overall mixture. 

An alternative approach involves sintering or melting the regolith by subjecting it to high temperatures. The approach can create solid material composed of entirely regolith however, temperatures in excess of 1,000 degrees are required and this in itself will pose challenges and safety concerns on the lunar surface. 

Bonding solidification is a process that uses other particles to bond regolith together. Similar to the reaction solidification, the result is 65% to 95% regolith in the final product. It requires lower temperatures than melting making it a safer process and it takes less time than solidification. 

Finally a process known as confinement formation is an intriguing approach which uses a fabric to restrict and constrain the regolith, forming what are ultimately, bags of the stuff. This seems to be an advanced form of sand bag where the particles are not connected as they are in other processes, but still confined. 99% of the final product would be regolith and whilst it is a faster, lower temperature process, it may lack the strength of other techniques. 

Based on a series of articles that were recently made available to the public, NASA predicts it could build a base on the Moon by 2022, and for cheaper than expected. Credit: NASA

Finding the best approach requires consideration of cost, performance, safety, energy consumption, and resource requirements. To address the many components, the team identified the 8IMEM quantification method which includes 8 indicators. Working through the processes that have been identified, the team recommend confinement formation as the best, most cost effective and safest approach. 

The confinement formation, whilst the most cost effective and fastest method may not be suitable for all construction needs. It may be suitable for some laboratory needs for example but when it comes to living quarters may not be the best. The research will help to focus and inform future decisions on construction on the Moon. 

Source : Researchers quantify the ideal in situ construction method for lunar habitats

The post There are Four Ways to Build with Regolith on the Moon appeared first on Universe Today.

Categories: Science

Don’t Blame the Patient

Science-based Medicine Feed - 18 hours 5 min ago

When patients are diagnosed with cancer, or a terminal illness of any kind, they report that there are a couple of near universal reactions by the people around them. First, everyone has advice for them. Everyone thinks they know what caused their illness and what will cure it. The floodgates of free advice and misinformation open. Everyone also wants them to stay […]

The post Don’t Blame the Patient first appeared on Science-Based Medicine.
Categories: Science

Your diet may influence how effective vaccines are for you

New Scientist Feed - 18 hours 13 min ago
Obese mice that lost weight on a low-fat diet before getting a flu shot had better immune responses than those that lost weight afterwards, suggesting diet and weight loss influence vaccine efficacy
Categories: Science

Huge dinosaur footprints belonged to one of the largest raptors ever

New Scientist Feed - Tue, 04/23/2024 - 10:00pm
A set of large, distinctive footprints suggest a raptor dinosaur that lived in East Asia 96 million years ago grew to a length of 5 metres
Categories: Science

Exquisite fossils of Cretaceous shark solve mystery of how it hunted

New Scientist Feed - Tue, 04/23/2024 - 5:01pm
Six full-body fossils of Ptychodus sharks have been formally analysed for the first time, revealing that they were fast swimmers that preyed on shelled creatures
Categories: Science

Critical minerals recovery from electronic waste

Matter and energy from Science Daily Feed - Tue, 04/23/2024 - 3:47pm
A nontoxic separation process recovers critical minerals from electronic scrap waste.
Categories: Science

Climate change could make it harder to detect submarines

New Scientist Feed - Tue, 04/23/2024 - 1:30pm
Climate change’s effects on ocean water temperatures and salinity could shrink sonar detection ranges underwater and make it more challenging to spot submarines
Categories: Science

Purple Bacteria — Not Green Plants — Might Be the Strongest Indication of Life

Universe Today Feed - Tue, 04/23/2024 - 1:23pm

Astrobiologists continue to work towards determining which biosignatures might be best to look for when searching for life on other worlds. The most common idea has been to search for evidence of plants that use the green pigment chlorophyll, like we have on Earth. However, a new paper suggests that bacteria with purple pigments could flourish under a broader range of environments than their green cousins. That means current and next-generation telescopes should be looking for the emissions of purple lifeforms.

“Purple bacteria can thrive under a wide range of conditions, making it one of the primary contenders for life that could dominate a variety of worlds,” said Lígia Fonseca Coelho, a postdoctoral associate at the Carl Sagan Institute (CSI) and first author of “Purple is the New Green: Biopigments and Spectra of Earth-like Purple Worlds,” published in the Monthly Notices of the Royal Astronomical Society: Letters.

Artist’s concept of Earth-like exoplanets, which strikes the careful balance between water and landmass. Credit: NASA

According to NASA’s Exoplanet Archive, 5612 extrasolar planets have been found so far, as of this writing, and another 10,000 more are considered planetary candidates, but have not yet been confirmed. Of all those, there are just over 30 potentially Earth-like worlds, planets that lie in their stars’ habitable zones where conditions are conducive to the existence of liquid water on surface.

But Earth-like has a broad meaning, ranging from size, mass, composition, and various chemical makeups. While being within a star’s habitable zone certainly means there’s the potential for life, it doesn’t necessarily mean that life could have emerged there, or even if it did, the life on that world might look very different from Earth.

“While oxygenic photosynthesis gives rise to modern green landscapes, bacteriochlorophyll-based anoxygenic phototrophs can also colour their habitats and could dominate a much wider range of environments on Earth-like exoplanets,” Coelho and team wrote in their paper. “While oxygenic photosynthesis gives rise to modern green landscapes, bacteriochlorophyll-based anoxygenic phototrophs can also colour their habitats and could dominate a much wider range of environments on Earth-like exoplanets.”

The researchers characterized the reflectance spectra of a collection of purple sulfur and purple non-sulfur bacteria from a variety of anoxic and oxic environments found here on Earth in a variety of environments, from shallow waters, coasts and marshes to deep-sea hydrothermal vents. Even though these are collectively referred to as “purple” bacteria, they actually include a range of colors from yellow, orange, brown and red due to pigments  — such as those that make tomatoes red and carrots orange.

These bacteria thrive on low-energy red or infrared light using simpler photosynthesis systems utilizing forms of chlorophyll that absorb infrared and don’t make oxygen. They are likely to have been prevalent on early Earth before the advent of plant-type photosynthesis, the researchers said, and could be particularly well-suited to planets that circle cooler red dwarf stars – the most common type in our galaxy.

A collection of bacteria samples in the Cornell University Space Sciences Building. Ryan Young/Cornell University.

That means this type of bacteria might be more prevalent on more and a wider variety of exo-worlds.

On a world where these bacteria might be dominant, it would produce a distinctive “light fingerprint” detectable by future telescopes.

In their paper, Coelho and team presented models for Earth-like planets where purple bacteria might dominate the surface and show the impact of their signatures on the reflectance spectra of terrestrial exoplanets.

“Our research provides a new resource to guide the detection of purple bacteria and improves our chances of detecting life on exoplanets with upcoming telescopes,” the team wrote.

“We need to create a database for signs of life to make sure our telescopes don’t miss life if it happens not to look exactly like what we encounter around us every day,” said co-author Lisa Kaltenegger, CSI director and associate professor of astronomy at Cornell University, in a press release from Cornell.

The post Purple Bacteria — Not Green Plants — Might Be the Strongest Indication of Life appeared first on Universe Today.

Categories: Science

This tiny chip can safeguard user data while enabling efficient computing on a smartphone

Computers and Math from Science Daily Feed - Tue, 04/23/2024 - 12:58pm
A new chip can efficiently accelerate machine-learning workloads on edge devices like smartphones while protecting sensitive user data from two common types of attacks -- side-channel attacks and bus-probing attacks.
Categories: Science

See the Southern Ring Nebula in 3D

Universe Today Feed - Tue, 04/23/2024 - 12:40pm

Planetary nebula are some of nature’s most stunning visual displays. The name is confusing since they’re the remains of stars, not planets. But that doesn’t detract from their status as objects of captivating beauty and intense scientific study.

Like all planetary nebula, the Southern Ring Nebula is the remnant of a star like our Sun. As these stars age, they will eventually become red giants, expanding and shedding layers of gas out into space. Eventually, the red giant becomes a white dwarf, a stellar remnant bereft of fusion that emanates whatever residual thermal energy it has without ever generating anymore. The white dwarf lights up the shells of gas expelled earlier, and we get to enjoy the show.

When the long-awaited JWST started delivering images, the Southern Ring Nebula (NGC 3132) was one of its first targets. It was one of five objects that made up the telescope’s first science results. The JWST’s images revealed something surprising about NGC 3132: it has two stars. The white dwarf is in the center of NGC 3132 and its companion is between 40 to 60 AU away, about the same distance as Pluto is from the Sun.

Researchers wanted to understand more about the Southern Ring Nebula’s structure. The JWST works in the infrared and can image warm hydrogen in the nebula. But to get a more complete image of the nebula, a team of researchers from the Rochester Institute of Technology (RIT) turned to the Submillimeter Array (SMA). The SMA can sense the cooler CO (carbon monoxide) in the nebula beyond the JWST’s reach. It sensed CO’s presence and measured its velocity and the velocities of other molecules.

The research is published in The Astrophysical Journal titled “The Molecular Exoskeleton of the Ring-like Planetary Nebula NGC 3132.” Professor Joel Kastner from the RIT School of Physics and Astronomy is the lead author.

The new observations showed that most of the nebula’s hydrogen gas is in a large expanding ring and that a second expanding ring lies almost perpendicular to the first.

“JWST showed us the molecules of hydrogen and how they stack up in the sky, while the Submillimeter Array shows us the carbon monoxide that is colder that you can’t see in the JWST image,” explained Kastner.

This figure from the study shows the velocities of three molecules in NGC 3132 as measured by the SMA. From left to right: 12CO, 13CO, and CN (cyanide.) The images clearly show the primary ring in the nebula. Image Credit: Kastner et al. 2024.

“The extra velocity dimension from the array’s radio wavelength observations then effectively allows us to see the nebula in 3-D. When we started to turn the whole nebula around in 3-D, we immediately saw it really was a ring, and then we were amazed to see there was another ring,” Kastner said.

“Surprisingly, the data further reveal that the nebula also appears to harbor a second, dust-rich molecular ring (Ring 2)—detected in (dust) absorption, in low-excitation emission lines, in H2, and (now) in 12CO(2–1)—that appears to lie nearly perpendicular to Ring 1,” the authors explain in their published research.

This figure from the study shows the SMA observations of NGC 3132 in the left column and the JWST infrared image in the right column. The bottom images show the different velocities of molecules in the nebula. The light blue velocity shows the presence of the main ring, but the red and pink high-velocity clumps show the presence of a second ring. Image Credit: Kastner et al. 2024.

The rings are offset from one another, which explains why the 3D view made the second one more visible. The team matched their observations to a geometric model that showed inclinations of 45° for Ring 1 and 78° for Ring 2.

These panels from the published research show the two rings around NGC 3132. The left panel shows the rings with a 45° for Ring 1 and 78° for Ring 2. The right panel shows the two rings with a 15° for Ring 1. Image Credit: Kastner et al. 2024.

Why does the Southern Ring Nebula have two offset rings?

The authors say we have a pole-on view of a bipolar nebula shaped by the presence of a second star. There are many bipolar nebulae, including well-known ones like the Butterfly Nebula.

The Butterfly Nebula as imaged by the Hubble Space Telescope. Image Credit: By NASA, ESA and the Hubble SM4 ERO Team – http://www.hubblesite.org/newscenter/archive/releases/2009/25/image/f/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7777740

However, the presence of a second star has complicated NGC 3132’s shape. “We suggest that this apparent two-ring structure may be the remnant of an ellipsoidal molecular envelope of AGB ejecta that has been mostly dispersed by a series of rapid-fire but misaligned collimated outflows or jets,” the authors explain in their research. “Such a scenario would be consistent with the hypothesis that the mass-losing AGB progenitor of NGC 3132 was a member of an interacting triple star system.”

It would be consistent, but the authors say there’s no way to conclude that a third star was involved with current research. “Detailed simulations of the dynamical effects of such multiple-star toppling jets systems on AGB molecular envelopes are required to test this speculative scenario for the shaping of the molecular exoskeleton of NGC 3132,” the authors explain.

The presence of all that molecular gas in the nebula surprised scientists. The intense UV from the white dwarf should break up the carbon monoxide and the molecular hydrogen. But it hasn’t.

“Where does the carbon and the oxygen and the nitrogen in the universe come from?” said Kastner. “We’re seeing it generated in the sun-like stars that are dying, like the star that’s just died and created the Southern Ring. A lot of that molecular gas could wind up in planetary atmospheres and atmospheres can enable life.”

The post See the Southern Ring Nebula in 3D appeared first on Universe Today.

Categories: Science

Hubble Has Accidentally Discovered Over a Thousand Asteroids

Universe Today Feed - Tue, 04/23/2024 - 12:08pm

The venerable Hubble Space Telescope is like a gift that keeps on giving. Not only is it still making astronomical discoveries after more than thirty years in operation. It is also making discoveries by accident! Thanks to an international team of citizen scientists, with the help of astronomers from the European Space Agency (ESA) and some machine learning algorithms, a new sample of over one thousand asteroids has been identified in Hubble‘s archival data. The methods used represent a new approach for finding objects in decades-old data that could be applied to other datasets as well.

The research team was led by Pablo García-Martín, a researcher with the Department of Theoretical Physics at the Autonomous University of Madrid (UAM). It included members from the ESA, NASA’s Jet Propulsion Laboratory (JPL), the Astronomical Institute of the Romanian Academy, the University of Craiova, the Université Côte d’Azur, and Bastion Technologies. The paper that describes their findings, “Hubble Asteroid Hunter III. Physical properties of newly found asteroids,” recently appeared in Astronomy & Astrophysics.

Ask any astronomers and they will tell you that asteroids are material left over from the formation of the Solar System ca. 4.5 billion years ago. These objects come in many shapes in sizes, ranging from peddle-sized rocks to planetoids. Observing these objects is challenging since they are faint and constantly in motion as they orbit the Sun. Because of its rapid geocentric orbit, Hubble can capture wandering asteroids thanks to the distinct curved trails they leave in Hubble exposures. As Hubble orbits Earth, its point of view changes while observing asteroids following their orbits.

Hubble image of the barred spiral galaxy UGC 12158, with streaks left by photobombing asteroids. Credit: NASA, ESA, P. G. Martín (AUM)/J. DePasquale (STScI)/A. Filippenko (UC Berkeley)

Asteroids have also been known to “photobomb” images acquired by Hubble of distant cosmic objects like UGC 12158 (see image above). By knowing Hubble’s position when it took exposures of asteroids and measuring the curvature of the streaks they leave, scientists can determine the asteroids’ distances and estimate the shapes of their orbits. The ability to do this with large samples allows astronomers to test theories about Main Asteroid Belt formation and evolution. As Martin said in a recent ESA Hubble press release:

“We are getting deeper into seeing the smaller population of main-belt asteroids. We were surprised to see such a large number of candidate objects. There was some hint that this population existed, but now we are confirming it with a random asteroid population sample obtained using the whole Hubble archive. This is important for providing insights into the evolutionary models of our Solar System.”

According to one widely accepted model, small asteroids are fragments of larger asteroids that have been colliding and grinding each other down over billions of years. A competing theory states that small bodies formed as they appear today billions of years ago and have not changed much since. However, astronomers can offer no plausible mechanism for why these smaller asteroids would not accumulate more dust from the circumstellar disk surrounding our Sun billions of years ago (from which the planets formed).

In addition, astronomers have known for some time that collisions would have left a certain signature that could be used to test the current Main Belt population. In 2019, astronomers from the European Science and Technology Centre (ESTEC) and the European Space Astronomy Center’s Science Data Center (ESDC) came together with the world’s largest and most popular citizen-science platform (Zooniverse) and Google to launch the citizen-science project Hubble Asteroid Hunter (HAH) to identify asteroids in archival Hubble data.

This graph is based on Hubble Space Telescope archival data that were used to identify a largely unseen population of very small asteroids. Credit: NASA/ESA/P. G. Martín (AUM)/E. Wheatley (STScI)

The HAH team comprised 11,482 citizen-science volunteers who perused 37,000 Hubble images spanning 19 years. After providing nearly two million identifications, the team was given a training set for an automated algorithm to identify asteroids based on machine learning. This yielded 1,701 asteroid trails, with 1,031 corresponding to previously uncatalogued asteroids – about 400 of which were below 1 km (~1090 ft) in size. Said Martin:

“Asteroid positions change with time, and therefore you cannot find them just by entering coordinates, because they might not be there at different times. As astronomers we don’t have time to go looking through all the asteroid images. So we got the idea to collaborate with more than 10,000 citizen-science volunteers to peruse the huge Hubble archives.”

This pioneering approach may be effectively applied to datasets accumulated by other asteroid-hunting observatories, such as NASA’s Spitzer Space Telescope and Stratospheric Observatory for Infrared Astronomy (SOFIA). Once the James Webb Space Telescope (JWST) has accumulated a large enough dataset, the same method could also be applied to its archival data. As a next step, the HAH project will examine the streaks of previously unknown asteroids to characterize their orbits, rotation periods, and other properties.

Further Reading: ESA Hubble, Astronomy & Astrophysics

The post Hubble Has Accidentally Discovered Over a Thousand Asteroids appeared first on Universe Today.

Categories: Science

Super Mario hackers' tricks could protect software from bugs

Computers and Math from Science Daily Feed - Tue, 04/23/2024 - 10:52am
Video gamers who exploit glitches in games can help experts better understand buggy software, students suggest.
Categories: Science

Researchers create artificial cells that act like living cells

Matter and energy from Science Daily Feed - Tue, 04/23/2024 - 10:52am
Researchers describe the steps they took to manipulate DNA and proteins -- essential building blocks of life -- to create cells that look and act like cells from the body. This accomplishment, a first in the field, has implications for efforts in regenerative medicine, drug delivery systems and diagnostic tools.
Categories: Science

Toward unification of turbulence framework -- weak-to-strong transition discovered in turbulence

Matter and energy from Science Daily Feed - Tue, 04/23/2024 - 10:51am
Astrophysicists have made a significant step toward solving the last puzzle in magnetohydrodynamic turbulence theory by observing the weak to strong transition in the space plasma turbulence surrounding Earth with newly developed multi-spacecraft analysis methods.
Categories: Science

Toward unification of turbulence framework -- weak-to-strong transition discovered in turbulence

Space and time from Science Daily Feed - Tue, 04/23/2024 - 10:51am
Astrophysicists have made a significant step toward solving the last puzzle in magnetohydrodynamic turbulence theory by observing the weak to strong transition in the space plasma turbulence surrounding Earth with newly developed multi-spacecraft analysis methods.
Categories: Science

Will Amazon's robotic revolution spark a new wave of job losses?

New Scientist Feed - Tue, 04/23/2024 - 9:00am
Amazon says it will create new jobs to replace roles taken over by machines, but it isn’t clear whether this will happen quickly enough
Categories: Science

Scientists call for reexamination of animal consciousness

Why Evolution is True Feed - Tue, 04/23/2024 - 9:00am

The Oxford English Dictionary, my go-to source for definitions, has this one for “consciousness”:

But there are other definitions, including sensing “qualia” (subjective conscious experience like pleasure or pain), or “having an inner life” involving self-awareness.  But it’s hard to determine under any of these definitions whether an individual of another species—indeed, even an individual of our own species—is conscious.  We think that other humans are conscious because we’re all built the same way, and we’re pretty sure that other mammals are conscious because they appear to feel pain or pleasure, and are built in a mammalian ground plan. But when an earthworm reacts when you poke it, is it feeling pain and having a subjective experience, or is that an automatic, built-in response to being poked that is adaptive but isn’t mediated through conscious experience?

I’m not going to get into the thorny topic of consciousness here, but I do feel that the more an animal is conscious (whatever that means), the more we should take care of it and avoid hurting it. (This of course is a subjective decision on my part.) It’s probably okay to swat mosquitoes, but not to kill a lizard, a duck, or a cat. (I tend to err on the “assume consciousness” side, and am loath to even swat mosquitoes.)

Researchers themselves have arrived at similar conclusions, for there are increasingly stringent regulations for taking care of lab animals. If you work on primates or rats, you have to ensure your university or granting agency that your research subjects will be properly treated, but those regulations don’t apply to fruit flies. But whether members of another species are conscious in the way that we are (well, the way I am, as I can’t be sure about you!), is something very hard to determine. The “mirror test“, in which you put a mark on an animal’s forehead, put it in front of a mirror and see if it touches its own forehead, is another test used to determine self awareness. The article below describes several other ways scientists have approached the question.

At any rate, according to Nature, a group of scientists have signed short joint declaration (second link below) saying that we need more research on consciousness and that the phenomenon may be present “in all vertebrates (including reptiles, amphibians, and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans, and insects).”  They add that knowing whether an animal is conscious should affect how we consider its welfare, which seems correct. The letter (or petition) doesn’t really define “consciousness”, but the Nature blurb about it does. Click the link below to read that blurb:

An excerpt:

Crowschimps and elephants: these and many other birds and mammals behave in ways that suggest they might be conscious. And the list does not end with vertebrates. Researchers are expanding their investigations of consciousness to a wider range of animals, including octopuses and even bees and flies.

Armed with such research, a coalition of scientists is calling for a rethink in the animal–human relationship. If there’s “a realistic possibility” of “conscious experience in an animal, it is irresponsible to ignore that possibility in decisions affecting that animal”, the researchers write in a document they call The New York Declaration on Animal Consciousness. Issued today during a meeting in New York City, the declaration also says that there is a “realistic possibility of conscious experience” in reptiles, fish, insects and other animals that have not always been considered to have inner lives, and “strong scientific support” for aspects of consciousness in birds and mammals.

As the evidence has accumulated, scientists are “taking the topic seriously, not dismissing it out of hand as a crazy idea in the way they might have in the past,” says Jonathan Birch, a philosopher at the London School of Economics and Political Science and one of the authors of the declaration.

The document, which had around 40 signatories early today, doesn’t state that there are definitive answers about which species are conscious. “What it says is there is sufficient evidence out there such that there’s a realistic possibility of some kinds of conscious experiences in species even quite distinct from humans,” says Anil Seth, director of the Centre for Consciousness Science at the University of Sussex near Brighton, UK, and one of the signatories. The authors hope that others will sign the declaration and that it will stimulate both more research into animal consciousness and more funding for the field.

And Nature says that the group has a definition of consciousness, though I can’t find it in the short declaration:

The definition of consciousness is complex, but the group focuses on an aspect of consciousness called sentience, often defined as the capacity to have subjective experiences, says Birch. For an animal, such experiences would include smelling, tasting, hearing or touching the world around itself, as well as feeling fear, pleasure or pain — in essence, what it is like to be that animal. But subjective experience does not require the capacity to think about one’s experiences.

This is as good a definition as any, I think, but determining whether another animal is even sentient is nearly impossible; all we can do is look for signs of sentience, like a dog howling if you kick it.  But if a protozoan heads for a source of food, is it having a subjective experience of “here’s food”?  Unlikely; protozoans don’t have brains and this is probably an inbuilt adaptive reflex. But there are tons of species intermediate in potential sentience between protozoans and mammals, and how do we decide whether, say, a fish is sentient? (I’ll tell you that scientists have ways of approaching this, but no time to go into it now. But the article has some interesting descriptions of these tests.) And of course most people think that octopuses are sentient.  Some even think that fruit flies are sentient!:

Investigations of fruit flies (Drosophila melanogaster) show that they engage in both deep sleep and ‘active sleep’, in which their brain activity is the same as when they’re awake. “This is perhaps similar to what we call rapid eye movement sleep in humans, which is when we have our most vivid dreams, which we interpret as conscious experiences,” says Bruno van Swinderen, a biologist at the University of Queensland in Brisbane, Australia, who studies fruit flies’ behaviour and who also signed the declaration.

Some suggest that dreams are key components of being conscious, he notes. If flies and other invertebrates have active sleep, “then maybe this is as good a clue as any that they are perhaps conscious”.

Well that’s stretching it a bit, but who knows? And some people weigh in with the caveat I mentioned above: acting as if you’re conscious may not mean that you’re conscious, for consciousness produces adaptive behavior, but so does natural selection, which has the ability produce adaptive reflexes not mediated by consciousness but look like consciousness.

We have a hard problem, then, and that’s reflected in the declaration itself, which is below. You can see the whole thing as well as its signers by clicking on the screenshot:

And the text of the document:

Which animals have the capacity for conscious experience? While much uncertainty remains, some points of wide agreement have emerged.

First, there is strong scientific support for attributions of conscious experience to other mammals and to birds.

Second, the empirical evidence indicates at least a realistic possibility of conscious experience in all vertebrates (including reptiles, amphibians, and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans, and insects).

Third, when there is a realistic possibility of conscious experience in an animal, it is irresponsible to ignore that possibility in decisions affecting that animal. We should consider welfare risks and use the evidence to inform our responses to these risks.

I don’t recognize many of the signers, and I’m surprised that Peter Singer, who surely agrees with the declaration, didn’t sign it. But I think more signers are being added.

At any rate, I can’t disagree with what the document says, but the interesting problems are both philosophical (on the ethical side) and scientific: what do we mean by consciousness, and, once that’s agreed on, how do we determine if a member of another species is conscious? Or, upon rethinking what I just wrote, perhaps we don’t need a definition of consciousness, but simply a set of empirical observations that we think are signs that animals are suffering. But that itself involves some philosophical input. It’s all a mess, but one thing is for sure, we should avoid causing unneeded suffering to animals, and we shouldn’t kill them just because we don’t like them. Even a lowly ant has evolved to preserve its own existence, and to what extent can our selfish desires override that consideration?

As the classic ending of many scientific papers goes, “More work needs to be done.”

h/t: Phil

Categories: Science

How to get the right balance of omega-3s and omega-6s in your diet

New Scientist Feed - Tue, 04/23/2024 - 9:00am
The balance of omega fatty acids in the food we eat affects our health. But what does the evidence say about claims you should be seeking to reduce omega-6 intake as well as boosting omega-3s?
Categories: Science

Major milestone reached for key weapons component

Matter and energy from Science Daily Feed - Tue, 04/23/2024 - 8:31am
Scientists have completed a crucial weapons component development milestone, prior to full rate production.
Categories: Science

Magnetic microcoils unlock targeted single-neuron therapies for neurodegenerative disorders

Matter and energy from Science Daily Feed - Tue, 04/23/2024 - 8:31am
Researchers deploy an array of microscopic coils to create a magnetic field and stimulate individual neurons. The magnetic field can induce an electric field in any nearby neurons, the same effect created by an electrode but much more precise. They used an array of eight coils, which combined can induce electric fields using much less current per coil, and employed soft magnetic materials, which boost the magnetic strength of the coils. The researchers constructed a prototype of their coil array, called MagPatch, and encapsulated it within a biocompatible coating.
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