Tag: The Conversation

Life on other planets

A fascinating article from The Conversation.

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Earth-size stars and alien oceans – an astronomer explains the case for life around white dwarfs

White dwarf stars, like this one shown shrouded by a planetary nebula, are much smaller than stars like our Sun. NASA/R. Ciardullo (PSU)/H. Bond (STScI)

Juliette Becker, University of Wisconsin-Madison

The Sun will someday die. This will happen when it runs out of hydrogen fuel in its core and can no longer produce energy through nuclear fusion as it does now. The death of the Sun is often thought of as the end of the solar system. But in reality, it may be the beginning of a new phase of life for all the objects living in the solar system.

When stars like the Sun die, they go through a phase of rapid expansion called the Red Giant phase: The radius of the star gets bigger, and its color gets redder. Once the gravity on the star’s surface is no longer strong enough for it to hold on to its outer layers, a large fraction – up to about half – of its mass escapes into space, leaving behind a remnant called a white dwarf.

I am a professor of astronomy at the University of Wisconsin-Madison. In 2020, my colleagues and I discovered the first intact planet orbiting around a white dwarf. Since then, I’ve been fascinated by the prospect of life on planets around these, tiny, dense white dwarfs.

Researchers search for signs of life in the universe by waiting until a planet passes between a star and their telescope’s line of sight. With light from the star illuminating the planet from behind, they can use some simple physics principles to determine the types of molecules present in the planet’s atmosphere.

In 2020, researchers realized they could use this technique for planets orbiting white dwarfs. If such a planet had molecules created by living organisms in its atmosphere, the James Webb Space Telescope would probably be able to spot them when the planet passed in front of its star.

In June 2025, I published a paper answering a question that first started bothering me in 2021: Could an ocean – likely needed to sustain life – even survive on a planet orbiting close to a dead star?

An illustration showing a large bright circle, with a very small white dot nearby.
Despite its relatively small size, a white dwarf – shown here as a bright dot to the right of our Sun – is quite dense. Kevin Gill/Flickr, CC BY

A universe full of white dwarfs

A white dwarf has about half the mass of the Sun, but that mass is compressed into a volume roughly the size of Earth, with its electrons pressed as close together as the laws of physics will allow. The Sun has a radius 109 times the size of Earth’s – this size difference means that an Earth-like planet orbiting a white dwarf could be about the same size as the star itself.

White dwarfs are extremely common: An estimated 10 billion of them exist in our galaxy. And since every low-mass star is destined to eventually become a white dwarf, countless more have yet to form. If it turns out that life can exist on planets orbiting white dwarfs, these stellar remnants could become promising and plentiful targets in the search for life beyond Earth.

But can life even exist on a planet orbiting a white dwarf? Astronomers have known since 2011 that the habitable zone is extremely close to the white dwarf. This zone is the location in a planetary system where liquid water could exist on a planet’s surface. It can’t be too close to the star that the water would boil, nor so far away that it would freeze.

A diagram showing a sun, with three planets at varying distances away. The closest one is labeled 'too hot' the next 'just right' and the farthest 'too cold'
Planets in the habitable zone aren’t so close that their surface water would boil, but also not so far that it would freeze. NASA

The habitable zone around a white dwarf would be 10 to 100 times closer to the white dwarf than our own habitable zone is to our Sun, since white dwarfs are so much fainter.

The challenge of tidal heating

Being so close to the surface of the white dwarf would bring new challenges to emerging life that more distant planets, like Earth, do not face. One of these is tidal heating.

Tidal forces – the differences in gravitational forces that objects in space exert on different parts of a nearby second object – deform a planet, and the friction causes the material being deformed to heat up. An example of this can be seen on Jupiter’s moon Io.

The forces of gravity exerted by Jupiter’s other moons tug on Io’s orbit, deforming its interior and heating it up, resulting in hundreds of volcanoes erupting constantly across its surface. As a result, no surface water can exist on Io because its surface is too hot.

A diagram showing Jupiter, with four Moons orbiting around it. Io is the Moon closest to Jupiter, and it has four arrows pointing to the planet and other moons, representing the forces exerted on it.
Of the four major moons of Jupiter, Io is the innermost one. Gravity from Jupiter and the other three moons pulls Io in varying directions, which heats it up. Lsuanli/Wikimedia Commons, CC BY-SA

In contrast, the adjacent moon Europa is also subject to tidal heating, but to a lesser degree, since it’s farther from Jupiter. The heat generated from tidal forces has caused Europa’s ice shell to partially melt, resulting in a subsurface ocean.

Planets in the habitable zone of a white dwarf would have orbits close enough to the star to experience tidal heating, similar to how Io and Europa are heated from their proximity to Jupiter.

This proximity itself can pose a challenge to habitability. If a system has more than one planet, tidal forces from nearby planets could cause the planet’s atmosphere to trap heat until it becomes hotter and hotter, making the planet too hot to have liquid water.

Enduring the red giant phase

Even if there is only one planet in the system, it may not retain its water.

In the process of becoming a white dwarf, a star will expand to 10 to 100 times its original radius during the red giant phase. During that time, anything within that expanded radius will be engulfed and destroyed. In our own solar system, Mercury, Venus and Earth will be destroyed when the Sun eventually becomes a red giant before transitioning into a white dwarf.

For a planet to survive this process, it would have to start out much farther from the star — perhaps at the distance of Jupiter or even beyond.

If a planet starts out that far away, it would need to migrate inward after the white dwarf has formed in order to become habitable. Computer simulations show that this kind of migration is possible, but the process could cause extreme tidal heating that may boil off surface water – similar to how tidal heating causes Io’s volcanism. If the migration generates enough heat, then the planet could lose all its surface water by the time it finally reaches a habitable orbit.

However, if the migration occurs late enough in the white dwarf’s lifetime – after it has cooled and is no longer a hot, bright, newly formed white dwarf – then surface water may not evaporate away.

Under the right conditions, planets orbiting white dwarfs could sustain liquid water and potentially support life.

Search for life on planets orbiting white dwarfs

Astronomers haven’t yet found any Earth-like, habitable exoplanets around white dwarfs. But these planets are difficult to detect.

Traditional detection methods like the transit technique are less effective because white dwarfs are much smaller than typical planet-hosting stars. In the transit technique, astronomers watch for the dips in light that occur when a planet passes in front of its host star from our line of sight. Because white dwarfs are so small, you would have to be very lucky to see a planet passing in front of one.

The transit technique for detecting exoplanets requires watching for the dip in brightness when a planet passes in front of its host star.

Nevertheless, researchers are exploring new strategies to detect and characterize these elusive worlds using advanced telescopes such as the Webb telescope.

If habitable planets are found to exist around white dwarfs, it would significantly broaden the range of environments where life might persist, demonstrating that planetary systems may remain viable hosts for life even long after the death of their host star.

Juliette Becker, Assistant Professor of Astronomy, University of Wisconsin-Madison

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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I take my hats off to the researchers that are looking for life elsewhere.

Staying active!

An interesting article about the benefits of being active.

I try and stay as active as I can mainly by bicycle riding. This article from The Conversation shows the importance of this. It is just a shame that they do not mention being old and active; as in being 80!

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Some pro athletes keep getting better as they age − neuroscience can explain how they stay sharp

Recovery and mental resilience support the development of neuroplasticity, which helps athletes like Allyson Felix stay sharp. AP Photo/Charlie Riedel

Fiddy Davis Jaihind Jothikaran, Hope College

In a world where sports are dominated by youth and speed, some athletes in their late 30s and even 40s are not just keeping up – they are thriving.

Novak Djokovic is still outlasting opponents nearly half his age on tennis’s biggest stages. LeBron James continues to dictate the pace of NBA games, defending centers and orchestrating plays like a point guard. Allyson Felix won her 11th Olympic medal in track and field at age 35. And Tom Brady won a Super Bowl at 43, long after most NFL quarterbacks retire.

The sustained excellence of these athletes is not just due to talent or grit – it’s biology in action. Staying at the top of their game reflects a trainable convergence of brain, body and mindset. I’m a performance scientist and a physical therapist who has spent over two decades studying how athletes train, taper, recover and stay sharp. These insights aren’t just for high-level athletes – they hold true for anyone navigating big life changes or working to stay healthy.

Increasingly, research shows that the systems that support high performance – from motor control to stress regulation, to recovery – are not fixed traits but trainable capacities. In a world of accelerating change and disruption, the ability to adapt to new changes may be the most important skill of all. So, what makes this adaptability possible – biologically, cognitively and emotionally?

The amygdala and prefrontal cortex

Neuroscience research shows that with repeated exposure to high-stakes situations, the brain begins to adapt. The prefrontal cortex – the region most responsible for planning, focus and decision-making – becomes more efficient in managing attention and making decisions, even under pressure.

During stressful situations, such as facing match point in a Grand Slam final, this area of the brain can help an athlete stay composed and make smart choices – but only if it’s well trained.

In contrast, the amygdala, our brain’s threat detector, can hijack performance by triggering panic, freezing motor responses or fueling reckless decisions. With repeated exposure to high-stakes moments, elite athletes gradually reshape this brain circuit.

They learn to tune down amygdala reactivity and keep the prefrontal cortex online, even when the pressure spikes. This refined brain circuitry enables experienced performers to maintain their emotional control.

Creating a brain-body loop

Brain-derived neurotrophic factor, or BDNF, is a molecule that supports adapting to changes quickly. Think of it as fertilizer for the brain. It enhances neuroplasticity: the brain’s ability to rewire itself through experience and repetition. This rewiring helps athletes build and reinforce the patterns of connections between brain cells to control their emotion, manage their attention and move with precision.

BDNF levels increase with intense physical activity, mental focus and deliberate practice, especially when combined with recovery strategies such as sleep and deep breathing.

Elevated BDNF levels are linked to better resilience against stress and may support faster motor learning, which is the process of developing or refining movement patterns.

For example, after losing a set, Djokovic often resets by taking deep, slow breaths – not just to calm his nerves, but to pause and regain control. This conscious breathing helps him restore focus and likely quiets the stress signals in his brain.

In moments like these, higher BDNF availability likely allows him to regulate his emotions and recalibrate his motor response, helping him to return to peak performance faster than his opponent.

Rewiring your brain

In essence, athletes who repeatedly train and compete in pressure-filled environments are rewiring their brain to respond more effectively to those demands. This rewiring, from repeated exposures, helps boost BDNF levels and in turn keeps the prefrontal cortex sharp and dials down the amygdala’s tendency to overreact.

This kind of biological tuning is what scientists call cognitive reserve and allostasis – the process the body uses to make changes in response to stress or environmental demands to remain stable. It helps the brain and body be flexible, not fragile.

Importantly, this adaptation isn’t exclusive to elite athletes. Studies on adults of all ages show that regular physical activity – particularly exercises that challenge both body and mind – can raise BDNF levels, improve the brain’s ability to adapt and respond to new challenges, and reduce stress reactivity.

Programs that combine aerobic movement with coordination tasks, such as dancing, complex drills or even fast-paced walking while problem-solving have been shown to preserve skills such as focus, planning, impulse control and emotional regulation over time.

After an intense training session or a match, you will often see athletes hopping on a bike or spending some time in the pool. These low-impact, gentle movements, known as active recovery, help tone down the nervous system gradually.

Outside of active recovery, sleep is where the real reset and repair happen. Sleep aids in learning and strengthens the neural connections challenged during training and competition.

A tennis player wearing all white hits a forehand
Serbian tennis player Novak Djokovic practices meditation, which strengthens the mental pathways that help with stress regulation. AP Photo/Kin Cheung

Over time, this convergence creates a trainable loop between the brain and body that is better equipped to adapt, recover and perform.

Lessons beyond sport

While the spotlight may shine on sporting arenas, you don’t need to be a pro athlete to train these same skills.

The ability to perform under pressure is a result of continuing adaptation. Whether you’re navigating a career pivot, caring for family members, or simply striving to stay mentally sharp as the world changes, the principles are the same: Expose yourself to challenges, regulate stress and recover deliberately.

While speed, agility and power may decline with age, some sport-specific skills such as anticipation, decision-making and strategic awareness actually improve. Athletes with years of experience develop faster mental models of how a play will unfold, which allows them to make better and faster choices with minimal effort. This efficiency is a result of years of reinforcing neural circuits that doesn’t immediately vanish with age. This is one reason experienced athletes often excel even if they are well past their physical prime.

Physical activity, especially dynamic and coordinated movement, boosts the brain’s capacity to adapt. So does learning new skills, practicing mindfulness and even rehearsing performance under pressure. In daily life, this might be a surgeon practicing a critical procedure in simulation, a teacher preparing for a tricky parent meeting, or a speaker practicing a high-stakes presentation to stay calm and composed when it counts. These aren’t elite rituals – they’re accessible strategies for building resilience, motor efficiency and emotional control.

Humans are built to adapt – with the right strategies, you can sustain excellence at any stage of life.

Fiddy Davis Jaihind Jothikaran, Associate Professor of Kinesiology, Hope College

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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… “you can sustain excellence at any stage of life.” Even at 80 years old? 😉

Logical thinking, in animals!

It is what we share with animals, but it is not as straightforward as one thinks!

The range of thinking, in terms of logical thinking, even in humans, is enormous. And when we watch animals, especially mammals, it is clear that they are operating in a logical manner. By ‘operating’ I am referring to their thought processes.

So a recent article in The Conversation jumped out at me. Here it is:

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Humans and animals can both think logically − but testing what kind of logic they’re using is tricky

For some mental processes, humans and animals likely follow similar lines of thinking. Catherine Falls Commercial/Moment via Getty Images

Olga Lazareva, Drake University

Can a monkey, a pigeon or a fish reason like a person? It’s a question scientists have been testing in increasingly creative ways – and what we’ve found so far paints a more complicated picture than you’d think.

Imagine you’re filling out a March Madness bracket. You hear that Team A beat Team B, and Team B beat Team C – so you assume Team A is probably better than Team C. That’s a kind of logical reasoning known as transitive inference. It’s so automatic that you barely notice you’re doing it.

It turns out humans are not the only ones who can make these kinds of mental leaps. In labs around the world, researchers have tested many animals, from primates to birds to insects, on tasks designed to probe transitive inference, and most pass with flying colors.

As a scientist focused on animal learning and behavior, I work with pigeons to understand how they make sense of relationships, patterns and rules. In other words, I study the minds of animals that will never fill out a March Madness bracket – but might still be able to guess the winner.

Logic test without words

The basic idea is simple: If an animal learns that A is better than B, and B is better than C, can it figure out that A is better than C – even though it’s never seen A and C together?

In the lab, researchers test this by giving animals randomly paired images, one pair at a time, and rewarding them with food for picking the correct one. For example, animals learn that a photo of hands (A) is correct when paired with a classroom (B), a classroom (B) is correct when paired with bushes (C), bushes (C) are correct when paired with a highway (D), and a highway (D) is correct when paired with a sunset (E). We don’t know whether they “understand” what’s in the picture, and it is not particularly important for the experiment that they do.

Comparing four pairs of images labeled a range of A to D in a training column, then one pair of images in the tesitng column
In a transitive inference task, subjects learn a series of rewarded pairs – such as A+ vs. B–, B+ vs. C– – and are later tested on novel pairings, like B vs. D, to see whether they infer an overall ranking. Olga Lazareva, CC BY-ND

One possible explanation is that the animals that learn all the tasks create a mental ranking of these images: A > B > C > D > E. We test this idea by giving them new pairs they’ve never seen before, such as classroom (B) vs. highway (D). If they consistently pick the higher-ranked item, they’ve inferred the underlying order.

What’s fascinating is how many species succeed at this task. Monkeys, rats, pigeons – even fish and wasps – have all demonstrated transitive inference in one form or another.

The twist: Not all tasks are easy

But not all types of reasoning come so easily. There’s another kind of rule called transitivity that is different from transitive inference, despite the similar name. Instead of asking which picture is better, transitivity is about equivalence.

In this task, animals are shown a set of three pictures and asked which one goes with the center image. For example, if white triangle (A1) is shown, choosing red square (B1) earns a reward, while choosing blue square (B2) does not. Later, when red square (B1) is shown, choosing white cross (C1) earns a reward while choosing white circle (C2) does not. Now comes the test: white triangle (A1) is shown with white cross (C1) and white circle (C2) as choices. If they pick white cross (C1), then they’ve demonstrated transitivity.

Comparing two sets of three shapes labeled a range of A to C in a section, then one trio of shapes in the tesitng section
In a transitivity task, subjects learn matching rules across overlapping sets – such as A1 matches B1, B1 matches C1 – and are tested on new combinations, such as A1 with C1 or C2, to assess whether they infer the relationship between A1 and C1. Olga Lazareva, CC BY-ND

The change may seem small, but species that succeed in those first transitive inference tasks often stumble in this task. In fact, they tend to treat the white triangle and the white cross as completely separate things, despite their common relationship with the red square. In my recently published review of research using the two tasks, I concluded that more evidence is needed to determine whether these tests tap into the same cognitive ability.

Small differences, big consequences

Why does the difference between transitive inference and transitivity matter? At first glance, they may seem like two versions of the same ability – logical reasoning. But when animals succeed at one and struggle with the other, it raises an important question: Are these tasks measuring the same kind of thinking?

The apparent difference between the two tasks isn’t just a quirk of animal behavior. Psychology researchers apply these tasks to humans in order to draw conclusions about how people reason.

For example, say you’re trying to pick a new almond milk. You know that Brand A is creamier than Brand B, and your friend told you that Brand C is even waterier than Brand B. Based on that, because you like a thicker milk, you might assume Brand A is better than Brand C, an example of transitive inference.

But now imagine the store labels both Brand A and Brand C as “barista blends.” Even without tasting them, you might treat them as functionally equivalent, because they belong to the same category. That’s more like transitivity, where items are grouped based on shared relationships. In this case, “barista blend” signals the brands share similar quality.

Child looking at colorful toy cars arranged in a line across a table or bed
How researchers define logical reasoning determines how they interpret results. Svetlana Mishchenko/iStock via Getty Images

Researchers often treat these types of reasoning as measuring the same ability. But if they rely on different mental processes, they might not be interchangeable. In other words, the way scientists ask their questions may shape the answer – and that has big implications for how they interpret success in animals and in people.

This difference could affect how researchers interpret decision-making not only in the lab, but also in everyday choices and in clinical settings. Tasks like these are sometimes used in research on autism, brain injury or age-related cognitive decline.

If two tasks look similar on the surface, then choosing the wrong one might lead to inaccurate conclusions about someone’s cognitive abilities. That’s why ongoing work in my lab is exploring whether the same distinction between these logical processes holds true for people.

Just like a March Madness bracket doesn’t always predict the winner, a reasoning task doesn’t always show how someone got to the right answer. That’s the puzzle researchers are still working on – figuring out whether different tasks really tap into the same kind of thinking or just look like they do. It’s what keeps scientists like me in the lab, asking questions, running experiments and trying to understand what it really means to reason – no matter who’s doing the thinking.

Olga Lazareva, Professor of Psychology, Drake University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Fascinating! I quote: “… a reasoning task doesn’t always show how someone got to the right answer.“

Olga finishes her article on reasoning with the statement that scientists are still trying to understand what it means to reason!

Black holes

How black holes challenge our technological world.

I had no idea until reading this recent article that distant black holes are essential for measuring accurately where we are. Have a read.

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Scientists look to black holes to know exactly where we are in the Universe. But phones and wifi are blocking the view

ESA / Hubble / L. Calçada (ESO), CC BY

Lucia McCallum, University of Tasmania

The scientists who precisely measure the position of Earth are in a bit of trouble. Their measurements are essential for the satellites we use for navigation, communication and Earth observation every day.

But you might be surprised to learn that making these measurements – using the science of geodesy – depends on tracking the locations of black holes in distant galaxies.

The problem is, the scientists need to use specific frequency lanes on the radio spectrum highway to track those black holes.

And with the rise of wifi, mobile phones and satellite internet, travel on that highway is starting to look like a traffic jam.

Why we need black holes

Satellites and the services they provide have become essential for modern life. From precision navigation in our pockets to measuring climate change, running global supply chains and making power grids and online banking possible, our civilisation cannot function without its orbiting companions.

To use satellites, we need to know exactly where they are at any given time. Precise satellite positioning relies on the so-called “global geodesy supply chain”.

This supply chain starts by establishing a reliable reference frame as a basis for all other measurements. Because satellites are constantly moving around Earth, Earth is constantly moving around the Sun, and the Sun is constantly moving through the galaxy, this reference frame needs to be carefully calibrated via some relatively fixed external objects.

As it turns out, the best anchor points for the system are the black holes at the hearts of distant galaxies, which spew out streams of radiation as they devour stars and gas.

These black holes are the most distant and stable objects we know. Using a technique called very long baseline interferometry, we can use a network of radio telescopes to lock onto the black hole signals and disentangle Earth’s own rotation and wobble in space from the satellites’ movement.

Different lanes on the radio highway

We use radio telescopes because we want to detect the radio waves coming from the black holes. Radio waves pass cleanly through the atmosphere and we can receive them during day and night and in all weather conditions.

Radio waves are also used for communication on Earth – including things such as wifi and mobile phones. The use of different radio frequencies – different lanes on the radio highway – is closely regulated, and a few narrow lanes are reserved for radio astronomy.

However, in previous decades the radio highway had relatively little traffic. Scientists commonly strayed from the radio astronomy lanes to receive the black hole signals.

To reach the very high precision needed for modern technology, geodesy today relies on more than just the lanes exclusively reserved for astronomy.

Radio traffic on the rise

In recent years, human-made electromagnetic pollution has vastly increased. When wifi and mobile phone services emerged, scientists reacted by moving to higher frequencies.

However, they are running out of lanes. Six generations of mobile phone services (each occupying a new lane) are crowding the spectrum, not to mention internet connections directly sent by a fleet of thousands of satellites.

Today, the multitude of signals are often too strong for geodetic observatories to see through them to the very weak signals emitted by black holes. This puts many satellite services at risk.

What can be done?

To keep working into the future – to maintain the services on which we all depend – geodesy needs some more lanes on the radio highway. When the spectrum is divided up via international treaties at world radio conferences, geodesists need a seat at the table.

Other potential fixes might include radio quiet zones around our essential radio telescopes. Work is also underway with satellite providers to avoid pointing radio emissions directly at radio telescopes.

Any solution has to be global. For our geodetic measurements, we link radio telescopes together from all over the world, allowing us to mimic a telescope the size of Earth. The radio spectrum is primarily regulated by each nation individually, making this a huge challenge.

But perhaps the first step is increasing awareness. If we want satellite navigation to work, our supermarkets to be stocked and our online money transfers arriving safely, we need to make sure we have a clear view of those black holes in distant galaxies – and that means clearing up the radio highway.

Lucia McCallum, Senior Scientist in Geodesy, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The last paragraph of Lucia’s article is key, in my opinion. Hopefully me posting this article will assist in the task of increasing awareness,

What makes us happy?

It is seemingly a simple question but in practice not so.

Listening to danger or telling others of a danger is a very ancient practice. For it is better to share a potential danger than not to. It was easy to look this up:

Modern sense of “risk, peril, exposure to injury, loss, pain, etc.” (from being in the control of someone or something else) evolved first in French and was in English by late 14c. For this, Old English had pleoh; in early Middle English this sense is found in peril. For sound changes, compare dungeon, which is from the same source.

Thus a post on The Conversation that was about happiness caught my eye.

I am delighted to share it with you.

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Philly psychology students map out local landmarks and hidden destinations where they feel happiest

Rittenhouse Square Park in Center City made it onto the Philly Happiness Map. Matthew Lovette/Jumping Rocks/Universal Images Group via Getty Images

Eric Zillmer, Drexel University

What makes you happy? Perhaps a good night’s sleep, or a wonderful meal with friends?

I am the director of the Happiness Lab at Drexel University, where I also teach a course on happiness. The Happiness Lab is a think tank that investigates the ingredients that contribute to people’s happiness.

Often, my students ask me something along the lines of, “Dr. Z, tell us one thing that will make us happier.”

As a first step, I advise them to spend more time outside.

Achieving lasting and sustainable happiness is more complicated. Research on the happiest countries in the world and the places where people live the longest, known as Blue Zones, shows a common thread: Residents feel they are part of something larger than themselves, such as a community or a city.

So if you’re living in a metropolis like Philadelphia, where, incidentally, the iconic pursuit of happiness charge was ratified in the Declaration of Independence, I believe urban citizenship – that is, forming an identity with your urban surroundings – should also be on your list.

A small boat floats in blue-green waters in front of a picturesque village.
The Greek island of Ikaria in the Aegean Sea is a Blue Zone famous for its residents’ longevity. Nicolas Economou/NurPhoto via Getty Images

Safety, social connection, beauty

Carl Jung, the renowned Swiss psychoanalyst, wrote extensively about the relationship between our internal world and our external environment.

He believed that this relationship was crucial to our psychological well-being.

More recent research in neuroscience and functional imaging has revealed a vast, intricate and complex neurological architecture underlying our psychological perception of a place. Numerous neurological pathways and functional loops transform a complex neuropsychological process into a simple realization: I am happy here!

For example, a happy place should feel safe.

The country of Croatia, a tourist haven for its beauty and culinary delights, is also one of the top 20 safest countries globally, according to the 2025 Global Peace Index.

The U.S. ranks 128th.

The availability of good food and drink can also be a significant factor in creating a happy place.

However, according to American psychologist Abraham Maslow, a pioneer in the field of positive psychology, the opportunity for social connectivity, experiencing something meaningful and having a sense of belonging is more crucial.

Furthermore, research on happy places suggests that they are beautiful. It should not come as a surprise that the happiest places in the world are also drop-dead gorgeous, such as the Indian Ocean archipelago of Mauritius, which is the happiest country in Africa, according to the 2025 World Happiness Report from the University of Oxford and others.

Happy places often provide access to nature and promote active lifestyles, which can help relieve stress. The residents of the island of Ikaria in Greece, for example, one of the original Blue Zones, demonstrate high levels of physical activity and social interaction.

A Google map display on right with a list of mapped locations on the left.
A map of 28 happy places in Philadelphia, based on 243 survey responses from Drexel students. The Happiness Lab at Drexel University

Philly Happiness Map

I asked my undergraduate psychology students at Drexel, many of whom come from other cities, states and countries, to pick one place in Philadelphia where they feel happy.

From the 243 student responses, the Happiness Lab curated 28 Philly happy places, based on how frequently the places were endorsed and their accessibility.

Philadelphia’s founder, William Penn, would likely approve that Rittenhouse Square Park and three other public squares – Logan, Franklin and Washington – were included. These squares were vital to Penn’s vision of landscaped public parks to promote the health of the mind and body by providing “salubrious spaces similar to the private garden.” They are beautiful and approachable, serving as “places to rest, take a pause, work, or read a book,” one student told us.

Places such as the Philadelphia Zoo, Penn’s Landing and the Philadelphia Museum of Art are “joyful spots that are fun to explore, and one can also take your parents along if need be,” as another student described.

The Athenaeum of Philadelphia, a historic library with eclectic programming, feels to one student like “coming home, a perfect third place.”

Some students mentioned happy places that are less known. These include tucked-away gardens such as the John F. Collings Park at 1707 Chestnut St., the rooftop Cira Green at 129 S. 30th St. and the James G. Kaskey Memorial Park and BioPond at 433 S. University Ave.

A stone-lined brick path extends through a nicely landscaped outdoor garden area.
The James G. Kaskey Memorial Park and BioPond in West Philadelphia is an urban oasis. M. Fischetti for Visit Philadelphia

My students said these are small, unexpected spots that provide an excellent opportunity for a quiet, peaceful break, to be present, whether enjoyed alone or with a friend. I checked them out and I agree.

The students also mentioned places I had never heard of even though I’ve lived in the city for over 30 years.

The “cat park” at 526 N. Natrona St. in Mantua is a quiet little park with an eclectic personality and lots of friendly cats.

Mango Mango Dessert at 1013 Cherry St. in Chinatown, which is a frequently endorsed happiness spot among the students because of its “bustling streets, lively atmosphere and delicious food,” is a perfect pit stop for mango lovers. And Maison Sweet, at 2930 Chestnut St. in University City, is a casual bakery and cafe “where you may end up staying longer than planned,” one student shared.

I find that Philly’s happy places, as seen through the eyes of college students, tend to offer a space for residents to take time out from their day to pause, reset, relax and feel more connected and in touch with the city.

Happiness principals are universal, yet our own journeys are very personal. Philadelphians across the city may have their own list of happy places. There are really no right or wrong answers. If you don’t have a personal happy space, just start exploring and you may be surprised what you will find, including a new sense of happiness.

See the full Philly Happiness Map list here, and visit the exhibit at the W.W. Hagerty Library at Drexel University to learn more.

Read more of our stories about Philadelphia.

Eric Zillmer, Professor of Neuropsychology, Drexel University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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For me, an Englishman living in Oregon, feeding the wild deer each morning gives me untold joy and happiness. It is my ‘personal happy space’.

So thank you, Prof. Zillmer, for writing this.

The mystery of Dark Matter

This very interesting article is worth a read.

Patrice Ayme published a post on Wednesday, 25th June, 2025 that is deeply conected to the following post from The Conversation.

His post was called: ‘How Does The Universe Expand? The Way Cosmologists Decided That It Does, FLRW Metric! A Causal Loop Is At The Heart Of Modern ΛCDM Cosmology!’

Thus I recommend that you read that article and then the one that is republished by me, with permission, from The Conversation.

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The Vera C. Rubin Observatory will help astronomers investigate dark matter, continuing the legacy of its pioneering namesake

The Rubin Observatory is scheduled to release its first images in 2025. RubinObs/NOIRLab/SLAC/NSF/DOE/AURA/B. Quint

Samantha Thompson, Smithsonian Institution

Everything in space – from the Earth and Sun to black holes – accounts for just 15% of all matter in the universe. The rest of the cosmos seems to be made of an invisible material astronomers call dark matter.

Astronomers know dark matter exists because its gravity affects other things, such as light. But understanding what dark matter is remains an active area of research.

With the release of its first images this month, the Vera C. Rubin Observatory has begun a 10-year mission to help unravel the mystery of dark matter. The observatory will continue the legacy of its namesake, a trailblazing astronomer who advanced our understanding of the other 85% of the universe.

As a historian of astronomy, I’ve studied how Vera Rubin’s contributions have shaped astrophysics. The observatory’s name is fitting, given that its data will soon provide scientists with a way to build on her work and shed more light on dark matter.

Wide view of the universe

From its vantage point in the Chilean Andes mountains, the Rubin Observatory will document everything visible in the southern sky. Every three nights, the observatory and its 3,200 megapixel camera will make a record of the sky.

This camera, about the size of a small car, is the largest digital camera ever built. Images will capture an area of the sky roughly 45 times the size of the full Moon. With a big camera with a wide field of view, Rubin will produce about five petabytes of data every year. That’s roughly 5,000 years’ worth of MP3 songs.

After weeks, months and years of observations, astronomers will have a time-lapse record revealing anything that explodes, flashes or moves – such as supernovas, variable stars or asteroids. They’ll also have the largest survey of galaxies ever made. These galactic views are key to investigating dark matter.

Galaxies are the key

Deep field images from the Hubble Space Telescope, the James Webb Space Telescope and others have visually revealed the abundance of galaxies in the universe. These images are taken with a long exposure time to collect the most light, so that even very faint objects show up.

Researchers now know that those galaxies aren’t randomly distributed. Gravity and dark matter pull and guide them into a structure that resembles a spider’s web or a tub of bubbles. The Rubin Observatory will expand upon these previous galactic surveys, increasing the precision of the data and capturing billions more galaxies.

In addition to helping structure galaxies throughout the universe, dark matter also distorts the appearance of galaxies through an effect referred to as gravitational lensing.

Light travels through space in a straight line − unless it gets close to something massive. Gravity bends light’s path, which distorts the way we see it. This gravitational lensing effect provides clues that could help astronomers locate dark matter. The stronger the gravity, the bigger the bend in light’s path.

Many galaxies, represented as bright dots, some blurred, against a dark background.
The white galaxies seen here are bound in a cluster. The gravity from the galaxies and the dark matter bends the light from the more distant galaxies, creating contorted and magnified images of them. NASA, ESA, CSA and STScI

Discovering dark matter

For centuries, astronomers tracked and measured the motion of planets in the solar system. They found that all the planets followed the path predicted by Newton’s laws of motion, except for Uranus. Astronomers and mathematicians reasoned that if Newton’s laws are true, there must be some missing matter – another massive object – out there tugging on Uranus. From this hypothesis, they discovered Neptune, confirming Newton’s laws.

With the ability to see fainter objects in the 1930s, astronomers began tracking the motions of galaxies.

California Institute of Technology astronomer Fritz Zwicky coined the term dark matter in 1933, after observing galaxies in the Coma Cluster. He calculated the mass of the galaxies based on their speeds, which did not match their mass based on the number of stars he observed.

He suspected that the cluster could contain an invisible, missing matter that kept the galaxies from flying apart. But for several decades he lacked enough observational evidence to support his theory.

A woman adjusting a large piece of equipment.
Vera Rubin operates the Carnegie spectrograph at Kitt Peak National Observatory in Tucson. Carnegie Institution for Science, CC BY

Enter Vera Rubin

In 1965, Vera Rubin became the first women hired onto the scientific staff at the Carnegie Institution’s Department of Terrestrial Magnetism in Washington, D.C.

She worked with Kent Ford, who had built an extremely sensitive spectrograph and was looking to apply it to a scientific research project. Rubin and Ford used the spectrograph to measure how fast stars orbit around the center of their galaxies.

In the solar system, where most of the mass is within the Sun at the center, the closest planet, Mercury, moves faster than the farthest planet, Neptune.

“We had expected that as stars got farther and farther from the center of their galaxy, they would orbit slower and slower,” Rubin said in 1992.

What they found in galaxies surprised them. Stars far from the galaxy’s center were moving just as fast as stars closer in.

“And that really leads to only two possibilities,” Rubin explained. “Either Newton’s laws don’t hold, and physicists and astronomers are woefully afraid of that … (or) stars are responding to the gravitational field of matter which we don’t see.”

Data piled up as Rubin created plot after plot. Her colleagues didn’t doubt her observations, but the interpretation remained a debate. Many people were reluctant to accept that dark matter was necessary to account for the findings in Rubin’s data.

Rubin continued studying galaxies, measuring how fast stars moved within them. She wasn’t interested in investigating dark matter itself, but she carried on with documenting its effects on the motion of galaxies.

A quarter with a woman looking upwards engraved onto it.
A U.S quarter honors Vera Rubin’s contributions to our understanding of dark matter. United States Mint, CC BY

Vera Rubin’s legacy

Today, more people are aware of Rubin’s observations and contributions to our understanding of dark matter. In 2019, a congressional bill was introduced to rename the former Large Synoptic Survey Telescope to the Vera C. Rubin Observatory. In June 2025, the U.S. Mint released a quarter featuring Vera Rubin.

Rubin continued to accumulate data about the motions of galaxies throughout her career. Others picked up where she left off and have helped advance dark matter research over the past 50 years.

In the 1970s, physicist James Peebles and astronomers Jeremiah Ostriker and Amos Yahil created computer simulations of individual galaxies. They concluded, similarly to Zwicky, that there was not enough visible matter in galaxies to keep them from flying apart.

They suggested that whatever dark matter is − be it cold stars, black holes or some unknown particle − there could be as much as 10 times the amount of dark matter than ordinary matter in galaxies.

Throughout its 10-year run, the Rubin Observatory should give even more researchers the opportunity to add to our understanding of dark matter.

Samantha Thompson, Astronomy Curator, National Air and Space Museum, Smithsonian Institution

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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It is difficult to say anything more as my comment will mean practically nothing compared to Patrice Ayme and Samantha Thompson.

I am just grateful that these fine people publish their research with permission for it to be republished elsewhere. Thank you!

The recycling of plastics.

It is not as straightforward as I thought it was.

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How single-stream recycling works − your choices can make it better

Successful recycling requires some care. Alejandra Villa Loarca/Newsday RM via Getty Images

Alex Jordan, University of Wisconsin-Stout

Every week, millions of Americans toss their recyclables into a single bin, trusting that their plastic bottles, aluminum cans and cardboard boxes will be given a new life.

But what really happens after the truck picks them up?

Single-stream recycling makes participating in recycling easy, but behind the scenes, complex sorting systems and contamination mean a large percentage of that material never gets a second life. Reports in recent years have found 15% to 25% of all the materials picked up from recycle bins ends up in landfills instead.

Plastics are among the biggest challenges. Only about 9% of the plastic generated in the U.S. actually gets recycled, according to the Environmental Protection Agency. Some plastic is incinerated to produce energy, but most of the rest ends up in landfills instead.

Photos and arrows show how much of each type of product is recycled.
A breakdown of U.S. recycling by millions of tons shows about two-thirds of all paper and cardboard gets a second life, but only about a third of metal, a quarter of glass and less than 10% of plastics do. Alex Jordan/University of Wisconsin-Stout

So, what makes plastic recycling so difficult? As an engineer whose work focuses on reprocessing plastics, I have been exploring potential solutions.

How does single-stream recycling work?

In cities that use single-stream recycling, consumers put all of their recyclable materials − paper, cardboard, plastic, glass and metal − into a single bin. Once collected, the mixed recyclables are taken to a materials recovery facility, where they are sorted.

First, the mixed recyclables are shredded and crushed into smaller fragments, enabling more effective separation. The mixed fragments pass over rotating screens that remove cardboard and paper, allowing heavier materials, including plastics, metals and glass, to continue along the sorting line.

The basics of a single-stream recycling system in Pennsylvania. Source: Van Dyk Recycling Solutions.

Magnets are used to pick out ferrous metals, such as steel. A magnetic field that produces an electrical current with eddies sends nonferrous metals, such as aluminum, into a separate stream, leaving behind plastics and glass.

The glass fragments are removed from the remaining mix using gravity or vibrating screens.

That leaves plastics as the primary remaining material.

While single-stream recycling is convenient, it has downsides. Contamination, such as food residue, plastic bags and items that can’t be recycled, can degrade the quality of the remaining material, making it more difficult to reuse. That lowers its value.

Having to remove that contamination raises processing costs and can force recovery centers to reject entire batches.

A mound of items send for recycling includes a lot of plastic bags.
Plastic bags, food residue and items that can’t be recycled can contaminate a recycling stream. City of Greenville, N.C./Flickr

Which plastics typically can’t be recycled?

Each recycling program has rules for which items it will and won’t take. You can check which items can and cannot be recycled for your specific program on your municipal page. Often, that means checking the recycling code stamped on the plastic next to the recycling icon.

These are the toughest plastics to recycle and most likely to be excluded in your local recycling program:

  • Symbol 3 – Polyvinyl chloride, or PVC, found in pipes, shower curtains and some food packaging. It may contain harmful additives such as phthalates and heavy metals. PVC also degrades easily, and melting can release toxic fumes during recycling, contaminating other materials and making it unsafe to process in standard recycling facilities.
  • Symbol 4 – Low-density polyethylene, or LDPE, is often used in plastic bags and shrink-wrap. Because it’s flexible and lightweight, it’s prone to getting tangled in sorting machinery at recycling plants.
  • Symbol 6 – Polystyrene, often used in foam cups, takeout containers and packing peanuts. Because it’s lightweight and brittle, it’s difficult to collect and process and easily contaminates recycling streams.

Which plastics to include

That leaves three plastics that can be recycled in many facilities:

However, these aren’t accepted in some facilities for reasons I’ll explain.

Taking apart plastics, bead by bead

Some plastics can be chemically recycled or ground up for reprocessing, but not all plastics play well together.

Simple separation methods, such as placing ground-up plastics in water, can easily remove your soda bottle plastic (PET) from the mixture. The ground-up PET sinks in water due to the plastic’s density. However, HDPE, used in milk jugs, and PP, found in yogurt cups, both float, and they can’t be recycled together. So, more advanced and expensive technology, such as infrared spectroscopy, is often required to separate those two materials.

Once separated, the plastic from your soda bottle can be chemically recycled through a process called solvolysis.

It works like this: Plastic materials are formed from polymers. A polymer is a molecule with many repeating units, called monomers. Picture a pearl necklace. The individual pearls are the repeating monomer units. The string that runs through the pearls is the chemical bond that joins the monomer units together. The entire necklace can then be thought of as a single molecule.

During solvolysis, chemists break down that necklace by cutting the string holding the pearls together until they are individual pearls. Then, they string those pearls together again to create new necklaces.

Other chemical recycling methods, such as pyrolysis and gasification, have drawn environmental and health concerns because the plastic is heated, which can release toxic fumes. But chemical recycling also holds the potential to reduce both plastic waste and the need for new plastics, while generating energy.

The problem of yogurt cups and milk jugs

The other two common types of recycled plastics − items such as yogurt cups (PP) and milk jugs (HDPE) − are like oil and water: Each can be recycled through reprocessing, but they don’t mix.

If polyethylene and polypropylene aren’t completely separated during recycling, the resulting mix can be brittle and generally unusable for creating new products.

Chemists are working on solutions that could increase the quality of recycled plastics through mechanical reprocessing, typically done at separate facilities.

One promising mechanical method for recycling mixed plastics is to incorporate a chemical called a compatibilizer. Compatibilizers contain the chemical structure of multiple different polymers in the same molecule. It’s like how lecithin, commonly found in egg yolks, can help mix oil and water to make mayonnaise − part of the lecithin molecule is in the oil phase and part is in the water phase.

In the case of yogurt cups and milk jugs, recently developed block copolymers are able to produce recycled plastic materials with the flexibility of polyethylene and the strength of polypropylene.

Improving recycling

Research like this can make recycled materials more versatile and valuable and move products closer to a goal of a circular economy without waste.

However, improving recycling also requires better recycling habits.

You can help the recycling process by taking a few minutes to wash off food waste, avoiding putting plastic bags in your recycling bin and, importantly, paying attention to what can and cannot be recycled in your area.

Alex Jordan, Associate Professor of Plastics Engineering, University of Wisconsin-Stout

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Can we all learn to be better at recycling in the face of so much world ‘news’!

Our brains and new memories

A fascinating article!

I may be the wrong side of old but I still enjoy immensely the process of learning new things. Some of these new memories actually stay with me!

That is why it gives me great pleasure in republishing an article from The Conversation about our brains creating new memories.

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How does your brain create new memories? Neuroscientists discover ‘rules’ for how neurons encode new information

Neurons that fire together sometimes wire together. PASIEKA/Science Photo Library via Getty Images

William Wright, University of California, San Diego and Takaki Komiyama, University of California, San Diego

Every day, people are constantly learning and forming new memories. When you pick up a new hobby, try a recipe a friend recommended or read the latest world news, your brain stores many of these memories for years or decades.

But how does your brain achieve this incredible feat?

In our newly published research in the journal Science, we have identified some of the “rules” the brain uses to learn.

Learning in the brain

The human brain is made up of billions of nerve cells. These neurons conduct electrical pulses that carry information, much like how computers use binary code to carry data.

These electrical pulses are communicated with other neurons through connections between them called synapses. Individual neurons have branching extensions known as dendrites that can receive thousands of electrical inputs from other cells. Dendrites transmit these inputs to the main body of the neuron, where it then integrates all these signals to generate its own electrical pulses.

It is the collective activity of these electrical pulses across specific groups of neurons that form the representations of different information and experiences within the brain.

Diagram of neuron, featuring a relatively large cell body with a long branching tail extending from it
Neurons are the basic units of the brain. OpenStax, CC BY-SA

For decades, neuroscientists have thought that the brain learns by changing how neurons are connected to one another. As new information and experiences alter how neurons communicate with each other and change their collective activity patterns, some synaptic connections are made stronger while others are made weaker. This process of synaptic plasticity is what produces representations of new information and experiences within your brain.

In order for your brain to produce the correct representations during learning, however, the right synaptic connections must undergo the right changes at the right time. The “rules” that your brain uses to select which synapses to change during learning – what neuroscientists call the credit assignment problem – have remained largely unclear.

Defining the rules

We decided to monitor the activity of individual synaptic connections within the brain during learning to see whether we could identify activity patterns that determine which connections would get stronger or weaker.

To do this, we genetically encoded biosensors in the neurons of mice that would light up in response to synaptic and neural activity. We monitored this activity in real time as the mice learned a task that involved pressing a lever to a certain position after a sound cue in order to receive water.

We were surprised to find that the synapses on a neuron don’t all follow the same rule. For example, scientists have often thought that neurons follow what are called Hebbian rules, where neurons that consistently fire together, wire together. Instead, we saw that synapses on different locations of dendrites of the same neuron followed different rules to determine whether connections got stronger or weaker. Some synapses adhered to the traditional Hebbian rule where neurons that consistently fire together strengthen their connections. Other synapses did something different and completely independent of the neuron’s activity.

Our findings suggest that neurons, by simultaneously using two different sets of rules for learning across different groups of synapses, rather than a single uniform rule, can more precisely tune the different types of inputs they receive to appropriately represent new information in the brain.

In other words, by following different rules in the process of learning, neurons can multitask and perform multiple functions in parallel.

Future applications

This discovery provides a clearer understanding of how the connections between neurons change during learning. Given that most brain disorders, including degenerative and psychiatric conditions, involve some form of malfunctioning synapses, this has potentially important implications for human health and society.

For example, depression may develop from an excessive weakening of the synaptic connections within certain areas of the brain that make it harder to experience pleasure. By understanding how synaptic plasticity normally operates, scientists may be able to better understand what goes wrong in depression and then develop therapies to more effectively treat it.

Microscopy image of mouse brain cross-section with lower middle-half dusted green
Changes to connections in the amygdala – colored green – are implicated in depression. William J. Giardino/Luis de Lecea Lab/Stanford University via NIH/Flickr, CC BY-NC

These findings may also have implications for artificial intelligence. The artificial neural networks underlying AI have largely been inspired by how the brain works. However, the learning rules researchers use to update the connections within the networks and train the models are usually uniform and also not biologically plausible. Our research may provide insights into how to develop more biologically realistic AI models that are more efficient, have better performance, or both.

There is still a long way to go before we can use this information to develop new therapies for human brain disorders. While we found that synaptic connections on different groups of dendrites use different learning rules, we don’t know exactly why or how. In addition, while the ability of neurons to simultaneously use multiple learning methods increases their capacity to encode information, what other properties this may give them isn’t yet clear.

Future research will hopefully answer these questions and further our understanding of how the brain learns.

William Wright, Postdoctoral Scholar in Neurobiology, University of California, San Diego and Takaki Komiyama, Professor of Neurobiology, University of California, San Diego

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Our human brains are incredible. Billions of nerve cells. Yet we are still getting to know the science of our brains and as that last sentence was written: “Future research will hopefully answer these questions and further our understanding of how the brain learns.”

Roll on this future research.

The US decline in butterflies

The natural world is quite remarkable!

This article was published in The Conversation last Thursday, the 6th March, 2025.

Where we live in rural Southern Oregon is glorious and photos of our locale have been published before. However, I wanted to share this article with you all.

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Butterflies declined by 22% in just 2 decades across the US – there are ways you can help save them

The endangered Karner blue butterfly has struggled with habitat loss. U.S. Fish and Wildlife Service

Eliza Grames, Binghamton University, State University of New York

If the joy of seeing butterflies seems increasingly rare these days, it isn’t your imagination.

From 2000 to 2020, the number of butterflies fell by 22% across the continental United States. That’s 1 in 5 butterflies lost. The findings are from an analysis just published in the journal Science by the U.S. Geological Survey’s Powell Center Status of Butterflies of the United States Working Group, which I am involved in.

We found declines in just about every region of the continental U.S. and across almost all butterfly species.

Overall, nearly one-third of the 342 butterfly species we were able to study declined by more than half. Twenty-two species fell by more than 90%. Only nine actually increased in numbers.

An orange butterfly with black webbing and spots sits on a purple flower.
West Coast lady butterflies range across the western U.S., but their numbers have dropped by 80% in two decades. Renee Las Vegas/Wikimedia Commons, CC BY

Some species’ numbers are dropping faster than others. The West Coast lady, a fairly widespread species across the western U.S., dropped by 80% in 20 years. Given everything we know about its biology, it should be doing fine – it has a wide range and feeds on a variety of plants. Yet, its numbers are absolutely tanking across its range.

Why care about butterflies?

Butterflies are beautiful. They inspire people, from art to literature and poetry. They deserve to exist simply for the sake of existing. They are also important for ecosystem function.

Butterflies are pollinators, picking up pollen on their legs and bodies as they feed on nectar from one flower and carrying it to the next. In their caterpillar stage, they also play an important role as herbivores, keeping plant growth in check.

A closeup of a caterpillar eating a leaf.
A pipevine swallowtail caterpillar munches on leaves at Brookside Gardens in Wheaton, Md. Herbivores help keep plant growth in check. Judy Gallagher/Wikimedia Commons, CC BY

Butterflies can also serve as an indicator species that can warn of threats and trends in other insects. Because humans are fond of butterflies, it’s easy to get volunteers to participate in surveys to count them.

The annual North American Butterfly Association Fourth of July Count is an example and one we used in the analysis. The same kind of nationwide monitoring by amateur naturalists doesn’t exist for less charismatic insects such as walking sticks.

What’s causing butterflies to decline?

Butterfly populations can decline for a number of reasons. Habitat loss, insecticides, rising temperatures and drying landscapes can all harm these fragile insects.

A study published in 2024 found that a change in insecticide use was a major factor in driving butterfly declines in the Midwest over 17 years. The authors, many of whom were also part of the current study, noted that the drop coincided with a shift to using seeds with prophylactic insecticides, rather than only spraying crops after an infestation.

The Southwest saw the greatest drops in butterfly abundance of any region. As that region heats up and dries out, the changing climate may be driving some of the butterfly decline there. Butterflies have a high surface-to-volume ratio – they don’t hold much moisture – so they can easily become desiccated in dry conditions. Drought can also harm the plants that butterflies rely on.

Only the Pacific Northwest didn’t lose butterfly population on average. This trend was largely driven by an irruptive species, meaning one with extremely high abundance in some years – the California tortoiseshell. When this species was excluded from the analyses, trends in the Pacific Northwest were similar to other regions.

A butterfly on a leaf
The California tortoiseshell butterfly can look like wood when its wings are closed, but they’re a soft orange on the other side. Walter Siegmund/Wikimedia Commons, CC BY-SA

When we looked at each species by its historical range, we found something else interesting.

Many species suffered their highest losses at the southern ends of their ranges, while the northern losses generally weren’t as severe. While we could not link drivers to trends directly, the reason for this pattern might involve climate change, or greater exposure to agriculture with insecticides in southern areas, or it may be a combination of many stressors.

There is hope for populations to recover

Some butterfly species can have multiple generations per year, and depending on the environmental conditions, the number of generations can vary between years.

This gives me a bit of hope when it comes to butterfly conservation. Because they have such short generation times, even small conservation steps can make a big difference and we can see populations bounce back.

The Karner blue is an example. It’s a small, endangered butterfly that depends on oak savannas and pine barren ecosystems. These habitats are uncommon and require management, especially prescribed burning, to maintain. With restoration efforts, one Karner blue population in the Albany Pine Bush Preserve in New York rebounded from a few hundred individuals in the early 1990s to thousands of butterflies.

Similar management and restoration efforts could help other rare and declining butterflies to recover.

What you can do to help butterflies recover

The magnitude and rate of biodiversity loss in the world right now can make one feel helpless. But while national and international efforts are needed to address the crisis, you can also take small actions that can have quick benefits, starting in your own backyard.

Butterflies love wildflowers, and planting native wildflowers can benefit many butterfly species. The Xerces Society for Invertebrate Conservation has guides recommending which native species are best to plant in which parts of the country. Letting grass grow can help, even if it’s just a strip of grass and wildflowers a couple of feet wide at the back of the yard.

Butterflies on wildflowers in a small garden.
A patch of wildflowers and grasses can become a butterfly garden, like this one in Townsend, Tenn. Chris Light, CC BY-SA

Supporting policies that benefit conservation can also help. In some states, insects aren’t considered wildlife, so state wildlife agencies have their hands tied when it comes to working on butterfly conservation. But those laws could be changed.

The federal Endangered Species Act can also help. The law mandates that the government maintain habitat for listed species. The U.S. Fish and Wildlife Service in December 2024 recommended listing the monarch butterfly as a threatened species. With the new study, we now have population trends for more than half of all U.S. butterfly species, including many that likely should be considered for listing.

With so many species needing help, it can be difficult to know where to start. But the new data can help concentrate conservation efforts on those species at the highest risk.

I believe this study should be a wake-up call about the need to better protect butterflies and other insects – “the little things that run the world.”

Eliza Grames, Assistant Professor of Biological Sciences, Binghamton University, State University of New York

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Thank you, Eliza, for promoting this article.

If only one person is inspired to make the changes Eliza recommends then republishing this article has been a success.

An article on decluttering

And it isn’t all that one might expect!

Jeannie and I are at opposite ends of the scale, so to speak. The older I get the more I want everything in the same place, primarily because I cannot remember where I previously put something.

Jeannie loves putting stuff anywhere because she can recall where it is!

So an article in The Conversation was fascinating.

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Decluttering can be stressful − a clinical psychologist explains how personal values can make it easier

Asking how discarding an item fits with a person’s goals can help them decide whether to keep it. MoMo Productions via Getty Images

Mary E. Dozier, Mississippi State University

I recently helped my mom sort through boxes she inherited when my grandparents passed away. One box was labeled – either ironically or genuinely – “toothpick holders and other treasures.” Inside were many keepsakes from moments now lost to history – although we found no toothpick holders.

My favorite of the items we sorted through was a solitary puzzle piece, an artifact reflecting my late grandmother’s penchant for hiding the final piece to a jigsaw puzzle just to swoop in at the last moment and finish it.

After several hours of reminiscing, my mom and I threw away 90% of what we had sorted.

“Why did I keep this?” is a question I hear frequently, both from my family and friends and from patients. I am a licensed clinical psychologist whose research focuses on the characterization, assessment and treatment of hoarding disorder, particularly for adults 60 years of age or older. As such, I spend a great deal of my time thinking about this question.

What drives the need to keep stuff?

Hoarding disorder is a psychiatric condition defined by urges to save items and difficulty discarding current possessions. For adults with “clinically severe” hoarding disorder, this leads to a level of household clutter that impairs daily functioning and can even create a fire hazard. In my professional experience, however, many adults struggle with clutter even if they do not meet the clinical criteria for hoarding disorder.

Holding on to things that have sentimental value or could be useful in the future is a natural part of growing older. For some people, though, this tendency to hold on to objects grows over time, to the point that they eventually do meet criteria for hoarding disorder. Age-related changes in executive function may help explain the increase in prevalence of hoarding disorder as we get older; increasing difficulty with decision-making in general also affects decisions around household clutter.

The traditional model behind hoarding disorder suggests that difficulty with discarding comes from distress during decision-making. However, my research shows that this may be less true of older adults.

A room full of piles of papers, stacked shelves and a tricycle.
Time to declutter. Kurt Whitman/Education Images via Getty Images

When I was a graduate student, I conducted a study in which we asked adults with hoarding disorder to spend 15 minutes making decisions about whether to keep or discard various items brought from their home. Participants could sort whatever items they wanted. Most chose to sort paper items such as old mail, cards or notes.

We found that age was associated with lower levels of distress during the task, such that participants who were older tended to feel less stressed when making the decision about what to keep and what to discard. We also found that many participants, particularly those who were older, actually reported positive emotions while sorting their items.

In new research publishing soon, my current team replicated this finding using a home-based version of the task. This suggests that fear of making the wrong decision isn’t a universal driver of our urge to save items.

In fact, a study my team published in August 2024 with adults over 50 with hoarding disorder suggests that altruism, a personality trait of wanting to help others, may explain why some people keep items that others might discard. My colleagues and I compared our participants’ personality profiles with that of adults in the general population of the same gender and age group. Compared with the general population, participants with hoarding disorder scored almost universally high on altruism.

Altruism also comes up frequently in my clinical work with older adults who struggle with clutter. People in our studies often tell me that they have held onto something out of a sense of responsibility, either for the item itself or to the environment.

“I need it to go to a good home” and “my grandmother gave this to me” are sentiments we commonly hear. Thus, people may keep things not out of fear of losing them but because saving them is consistent with their values. https://www.youtube.com/embed/JNVjPM1cIbg?wmode=transparent&start=0 Your values can help guide which possessions should stay in your life and which ones should go.

Leaning into values

In a 2024 study, my team demonstrated that taking a values-based approach to decluttering helps older adults to decrease household clutter and increases their positive affect, a state of mind characterized by feelings such as joy and contentment. Clinicians visited the homes of older adults with hoarding disorder for one hour per week for six weeks. At each visit, the clinicians used a technique called motivational interviewing to help participants talk through their decisions while they sorted household clutter.

We found that having participants start with identifying their values allowed them to maintain focus on their long-term goals. Too often, people focus on the immediate ability of an object to “spark joy” and forget to consider whether an object has greater meaning and purpose. Values are the abstract beliefs that we humans use to create our goals. Values are whatever drives us and can include family, faith or frivolity.

Because values are subjective, what people identify as important to keep is also subjective. For example, the dress I wore to my sister’s wedding reminded me of a wonderful day. However, when it no longer fit I gave it away because doing so was more consistent with my values of utility and helpfulness: I wanted the dress to go to someone who needed it and would use it. Someone who more strongly valued family and beauty might have prioritized keeping the dress because of the aesthetics and its link to a family event.

Additionally, we found that instead of challenging the reasons a person might have for keeping an item, it is helpful to instead focus on eliciting their reasons for discarding it and the goals they have for their home and their life.

Tips for sweeping away the old

My research on using motivational interviewing for decluttering and my observations from a current clinical trial on the approach point to some practical steps people can take to declutter their home. Although my work has been primarily with older adults, these tips should be helpful for people of all ages.

Start with writing out your values. Every object in your home should feel value-consistent for you. For example, if tradition and faith are important values for you, you might be more inclined to hold onto a cookbook that was made by the elders at your church and more able to let go of a cookbook you picked up on a whim at a bookstore.

If, instead, health and creativity are your core values, it might be more important to hold onto a cookbook of novel ways to sneak more vegetables into your diet.

Defining value-consistent goals for using your space can help to maintain motivation as you declutter. Are you clearing off your desk so you can work more efficiently? Making space on kitchen counters to bake cookies with your grandchildren?

Remember that sometimes your values will conflict. At those moments, it may help to reflect on whether keeping or discarding an object will bring you closer to your goals for the space.

Similarly, remember that values are subjective. If you are helping a loved one declutter, maintain a curious, nonjudgmental attitude. Where you might see a box filled with junk, your grandmother might see something filled with “toothpick holders and other treasures.”

For additional resources and information on hoarding disorder, visit the International OCD Foundation website.

Mary E. Dozier, Assistant Professor of Psychology, Mississippi State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

ooOOoo

Prof. Mary Dozier makes some powerful, and cogent, statements in this article. Especially that one’s values are subjective. Nevertheless, I think I should write out my values and see what they tell me.