Category: Writing

This strange and beautiful place

Pondering on space.

Like so many people, I am fascinated by the universe. Just our own universe is staggering. Here are some items published on the NASA website.

Solar System Facts

Our solar system includes the Sun, eight planets, five officially named dwarf planets, hundreds of moons, and thousands of asteroids and comets.

Our solar system is located in the Milky Way, a barred spiral galaxy with two major arms, and two minor arms. Our Sun is in a small, partial arm of the Milky Way called the Orion Arm, or Orion Spur, between the Sagittarius and Perseus arms. Our solar system orbits the center of the galaxy at about 515,000 mph (828,000 kph). It takes about 230 million years to complete one orbit around the galactic center.

Now to the centre of our universe. And it give me pleasure to republish this account.

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Where is the center of the universe?

In space, there are four dimensions: length, width, height and time. scaliger/iStock/NASA via Getty Images Plus

Rob Coyne, University of Rhode Island

About a century ago, scientists were struggling to reconcile what seemed a contradiction in Albert Einstein’s theory of general relativity.

Published in 1915, and already widely accepted worldwide by physicists and mathematicians, the theory assumed the universe was static – unchanging, unmoving and immutable. In short, Einstein believed the size and shape of the universe today was, more or less, the same size and shape it had always been.

But when astronomers looked into the night sky at faraway galaxies with powerful telescopes, they saw hints the universe was anything but that. These new observations suggested the opposite – that it was, instead, expanding.

Scientists soon realized Einstein’s theory didn’t actually say the universe had to be static; the theory could support an expanding universe as well. Indeed, by using the same mathematical tools provided by Einstein’s theory, scientists created new models that showed the universe was, in fact, dynamic and evolving.

I’ve spent decades trying to understand general relativity, including in my current job as a physics professor teaching courses on the subject. I know wrapping your head around the idea of an ever-expanding universe can feel daunting – and part of the challenge is overriding your natural intuition about how things work. For instance, it’s hard to imagine something as big as the universe not having a center at all, but physics says that’s the reality.

The universe gets bigger every day.

The space between galaxies

First, let’s define what’s meant by “expansion.” On Earth, “expanding” means something is getting bigger. And in regard to the universe, that’s true, sort of. Expansion might also mean “everything is getting farther from us,” which is also true with regard to the universe. Point a telescope at distant galaxies and they all do appear to be moving away from us.

What’s more, the farther away they are, the faster they appear to be moving. Those galaxies also seem to be moving away from each other. So it’s more accurate to say that everything in the universe is getting farther away from everything else, all at once.

This idea is subtle but critical. It’s easy to think about the creation of the universe like exploding fireworks: Start with a big bang, and then all the galaxies in the universe fly out in all directions from some central point.

But that analogy isn’t correct. Not only does it falsely imply that the expansion of the universe started from a single spot, which it didn’t, but it also suggests that the galaxies are the things that are moving, which isn’t entirely accurate.

It’s not so much the galaxies that are moving away from each other – it’s the space between galaxies, the fabric of the universe itself, that’s ever-expanding as time goes on. In other words, it’s not really the galaxies themselves that are moving through the universe; it’s more that the universe itself is carrying them farther away as it expands.

A common analogy is to imagine sticking some dots on the surface of a balloon. As you blow air into the balloon, it expands. Because the dots are stuck on the surface of the balloon, they get farther apart. Though they may appear to move, the dots actually stay exactly where you put them, and the distance between them gets bigger simply by virtue of the balloon’s expansion.

split screen of a green balloon with red dots and a squiggle on the surface, lightly inflated and then much more blown up
It’s the space between the dots that’s growing. NASA/JPL-Caltech, CC BY

Now think of the dots as galaxies and the balloon as the fabric of the universe, and you begin to get the picture.

Unfortunately, while this analogy is a good start, it doesn’t get the details quite right either.

The 4th dimension

Important to any analogy is an understanding of its limitations. Some flaws are obvious: A balloon is small enough to fit in your hand – not so the universe. Another flaw is more subtle. The balloon has two parts: its latex surface and its air-filled interior.

These two parts of the balloon are described differently in the language of mathematics. The balloon’s surface is two-dimensional. If you were walking around on it, you could move forward, backward, left, or right, but you couldn’t move up or down without leaving the surface.

Now it might sound like we’re naming four directions here – forward, backward, left and right – but those are just movements along two basic paths: side to side and front to back. That’s what makes the surface two-dimensional – length and width.

The inside of the balloon, on the other hand, is three-dimensional, so you’d be able to move freely in any direction, including up or down – length, width and height.

This is where the confusion lies. The thing we think of as the “center” of the balloon is a point somewhere in its interior, in the air-filled space beneath the surface.

But in this analogy, the universe is more like the latex surface of the balloon. The balloon’s air-filled interior has no counterpart in our universe, so we can’t use that part of the analogy – only the surface matters.

A blown-up purple balloon on a blue background.
Trying to figure out how the universe works? Start by contemplating a balloon. Kristopher_K/iStock via Getty Images Plus

So asking, “Where’s the center of the universe?” is somewhat like asking, “Where’s the center of the balloon’s surface?” There simply isn’t one. You could travel along the surface of the balloon in any direction, for as long as you like, and you’d never once reach a place you could call its center because you’d never actually leave the surface.

In the same way, you could travel in any direction in the universe and would never find its center because, much like the surface of the balloon, it simply doesn’t have one.

Part of the reason this can be so challenging to comprehend is because of the way the universe is described in the language of mathematics. The surface of the balloon has two dimensions, and the balloon’s interior has three, but the universe exists in four dimensions. Because it’s not just about how things move in space, but how they move in time.

Our brains are wired to think about space and time separately. But in the universe, they’re interwoven into a single fabric, called “space-time.” That unification changes the way the universe works relative to what our intuition expects.

And this explanation doesn’t even begin to answer the question of how something can be expanding indefinitely – scientists are still trying to puzzle out what powers this expansion.

So in asking about the center of the universe, we’re confronting the limits of our intuition. The answer we find – everything, expanding everywhere, all at once – is a glimpse of just how strange and beautiful our universe is.

Rob Coyne, Teaching Professor of Physics, University of Rhode Island

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

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That last paragraph says it all: ‘So in asking about the center of the universe, we’re confronting the limits of our intuition.’

Just wonderful!

Breaches of trust.

A riveting article from George Monbiot.

George Monbiot published an article in The Guardian recently that was as hard-hitting as I have ever read from him.

I found it very powerful even though I have not been living in England since 2008. Mr Monbiot has previously given me permission to republish his articles and here it is.

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Four-Year Plan

Posted on 3rd June 2025

Keir Starmer has accidentally given us four years in which to build a new political system. We should seize the chance.

By George Monbiot, published in the Guardian 27th May 2025

This feels terminal. The breaches of trust have been so frequent, so vast and so decisive that the voters Labour has already lost are unlikely to return. In one forum after another, I hear the same sentiments: “I voted for change, not the same or worse.” “I’ve voted Labour all my life, but that’s it for me.” “I feel I’ve been had.”

It’s not dissatisfaction. It’s not disillusionment. It’s revulsion: visceral fury, anger on a level I’ve seldom seen before, even towards Tory cruelties. Why? Because these are Tory cruelties, delivered by a party that claimed to be the only alternative, in our first-past-the-post electoral system.

Everyone can name at least some of the betrayals:

 cutting disability benefits; supplying weapons and, allegedly, intelligence to the Israeli government as it pursues genocide in Gaza; channelling Reform UK and Enoch Powell in maligning immigrants; slashing international aid; trashing wildlife and habitats while insulting and abusing people who want to protect them; announcing yet another draconian anti-protest law; leaving trans people in legal limbo; rigidly adhering to outdated and socially destructive fiscal rules; imposing further austerity on government departments and public services. Once the great hope of the oppressed, Labour has become the oppressor.

Like many people, I was wary of Keir Starmer. I had limited expectations, but I willed Labour to succeed. So I’ve watched aghast as he and his inner circle have squandered one of the greatest opportunities the party has ever been granted. They seem to despise people who voted for them, while courting and flattering those who didn’t and won’t.

The results? Last week, the polling company Thinks Insight & Strategy found that 52% of those who voted Labour in the 2024 general election are considering switching to the Liberal Democrats or the Greens. That’s more than twice as many as might migrate to Reform UK. The research group Persuasion UK estimates that Labour could lose 250 seatsas a result of this flight to more progressive parties (again, more than twice as many as it could lose through voters shifting to Reform). Figures compiled by the progressive thinktank Compass show that Labour would lose its majority on just a 6% swing. Already, while it won a massive majority on a measly 34% vote at the election, it now polls at just 22%.

Labour’s strategy is incomprehensible. Experience from the rest of Europe shows that when centrist parties adopt far-right rhetoric and policies, they empower the far right while shedding their own supporters.

What explains this idiocy? Labour has succumbed, quickly and hard, to the defining sickness of our undemocratic political system: the sofa cabinet system of close advisers. Opaque and unaccountable government favours opaque and unaccountable power. Ever receptive to the demands of rentiers, oligarchs, non-doms and corporations, Labour’s oh-so-clever strategists are moronically giftwrapping the country for Nigel Farage.

Governments don’t start conservative and turn radical. The cruelty will set like concrete. The likely result is annihilation in 2029. On this trajectory, it might not be surprising if Labour were left with seats in only double figures.

Perhaps it’s a blessing that Starmer has shown his hand so soon, as we now have four years in which to prepare. I’m not a party person: for me, it’s a question of what works. And now we can clearly see the shape of it.

The Compass analysis, published in December, reveals extreme electoral volatility. This is caused by a combination of public fury towards austerity, exclusion, rip-off rents and startlingly low rates of wellbeing, and the “democratic mayhem” resulting from a first-past-the-post system in which five parties are now polling at 10% or more. Small vote shifts in this situation can cause wild fluctuations in the allocation of seats.

The report points out that the UK is an overwhelmingly progressive nation: in all but one election since 1979 most voters have supported left or centre-left parties. Of 15 nations surveyed, the UK has the extraordinary distinction of being both the furthest to the left and the most consistent elector of rightwing governments. Why? Because of our first-past-the-post system, which is grossly unfair not by accident but by design. Labour refuses to change it, as it wants to rule alone. The result is that most of the time it doesn’t rule at all.

The thinktank was hoping to mobilise the progressive majority around a revitalised Labour party, but that moment has passed. What the figures show, however, is massive potential for more radical change. A YouGov survey reveals that almost twice as many people want proportional representation in this country as those who wish to preserve the current system. So let’s build a government of parties that will introduce it.

Here’s the strategy. Join the Lib Dems, Greens, SNP or Plaid Cymru. As their numbers rise, other voters will see the tide turning. Encourage troubled Labour MPs to defect. Most importantly, begin the process in each constituency of bringing alienated voters together around a single candidate. This is what we did before the last election in South Devon, where polls had shown the anti-Tory vote evenly split between Labour and the Lib Dems. Through the People’s Primary designed by locals, the constituency decided to back the Lib Dems. The proof of the method can be seen less in the spectacular routing of the Conservatives (as similar upsets occurred elsewhere) than in the collapse in Labour’s numbers, which fell from 17% in 2019, and 26% in a poll before the primary began, to 6% in the 2024 election. The voters took back control, with startling results.

Whether you fully support any of these parties is beside the point. This coalition would break for ever the lesser-of-two-evils choice that Starmer has so cruelly abused, and which has for so long poisoned politics in this country. Game the system once and we’ll never have to game it again.

No longer will we be held hostage, no longer represented by people who hate us. It will be a tragedy if, as seems likely, Keir Starmer has destroyed the Labour party as a major political force. But it will be a blessing if he has also destroyed the two-party system.

http://www.monbiot.com

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Proportional representation is explained in detail here. There is also an explanation on WikiPedia here. From which I quote a small section:

Proportional representation (PR) refers to any electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions (political parties) among voters. The aim of such systems is that all votes cast contribute to the result so that each representative in an assembly is mandated by a roughly equal number of voters, and therefore all votes have equal weight. Under other election systems, a bare plurality or a scant majority in a district are all that are used to elect a member or group of members. PR systems provide balanced representation to different factions, usually defined by parties, reflecting how votes were cast. Where only a choice of parties is allowed, the seats are allocated to parties in proportion to the vote tally or vote share each party receives.

That is a timely and powerful article from George Monbiot.

The building blocks of numbers

We are talking of prime numbers.

Science and mathematics have been a long interest of mine and I regret that I did not go to university to study science. But that was a long time ago!

However, thanks to The Conversation I can write about mathematics, in this case Prime Numbers.

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Prime numbers, the building blocks of mathematics, have fascinated for centuries − now technology is revolutionizing the search for them

Prime numbers are numbers that are not products of smaller whole numbers. Jeremiah Bartz

Jeremiah Bartz, University of North Dakota

A shard of smooth bone etched with irregular marks dating back 20,000 years puzzled archaeologists until they noticed something unique – the etchings, lines like tally marks, may have represented prime numbers. Similarly, a clay tablet from 1800 B.C.E. inscribed with Babylonian numbers describes a number system built on prime numbers.

As the Ishango bone, the Plimpton 322 tablet and other artifacts throughout history display, prime numbers have fascinated and captivated people throughout history. Today, prime numbers and their properties are studied in number theory, a branch of mathematics and active area of research today.

A history of prime numbers

A long, thin shard of bone with small lines scratched into it.
Some scientists guess that the markings on the Ishango bone represent prime numbers. Joeykentin/Wikimedia Commons, CC BY-SA

Informally, a positive counting number larger than one is prime if that number of dots can be arranged only into a rectangular array with one column or one row. For example, 11 is a prime number since 11 dots form only rectangular arrays of sizes 1 by 11 and 11 by 1. Conversely, 12 is not prime since you can use 12 dots to make an array of 3 by 4 dots, with multiple rows and multiple columns. Math textbooks define a prime number as a whole number greater than one whose only positive divisors are only 1 and itself.

Math historian Peter S. Rudman suggests that Greek mathematicians were likely the first to understand the concept of prime numbers, around 500 B.C.E.

Around 300 B.C.E., the Greek mathematician and logician Euler proved that there are infinitely many prime numbers. Euler began by assuming that there is a finite number of primes. Then he came up with a prime that was not on the original list to create a contradiction. Since a fundamental principle of mathematics is being logically consistent with no contradictions, Euler then concluded that his original assumption must be false. So, there are infinitely many primes.

The argument established the existence of infinitely many primes, however it was not particularly constructive. Euler had no efficient method to list all the primes in an ascending list.

a diagram showing prime numbers as dots in rows, with composite numbers as dots arranged in rectangles of at least two rows of dots, with the same number of dots in each row.
Prime numbers, when expressed as that number of dots, can be arranged only in a single row or column, rather than a square or rectangle. David Eppstein/Wikimedia Commons

In the middle ages, Arab mathematicians advanced the Greeks’ theory of prime numbers, referred to as hasam numbers during this time. The Persian mathematician Kamal al-Din al-Farisi formulated the fundamental theorem of arithmetic, which states that any positive integer larger than one can be expressed uniquely as a product of primes.

From this view, prime numbers are the basic building blocks for constructing any positive whole number using multiplication – akin to atoms combining to make molecules in chemistry.

Prime numbers can be sorted into different types. In 1202, Leonardo Fibonacci introduced in his book “Liber Abaci: Book of Calculation” prime numbers of the form (2p – 1) where p is also prime.

Today, primes in this form are called Mersenne primes after the French monk Marin Mersenne. Many of the largest known primes follow this format.

Several early mathematicians believed that a number of the form (2p – 1) is prime whenever p is prime. But in 1536, mathematician Hudalricus Regius noticed that 11 is prime but not (211 – 1), which equals 2047. The number 2047 can be expressed as 11 times 89, disproving the conjecture.

While not always true, number theorists realized that the (2p – 1) shortcut often produces primes and gives a systematic way to search for large primes.

The search for large primes

The number (2p – 1) is much larger relative to the value of p and provides opportunities to identify large primes.

When the number (2p – 1) becomes sufficiently large, it is much harder to check whether (2p – 1) is prime – that is, if (2p – 1) dots can be arranged only into a rectangular array with one column or one row.

Fortunately, Édouard Lucas developed a prime number test in 1878, later proved by Derrick Henry Lehmer in 1930. Their work resulted in an efficient algorithm for evaluating potential Mersenne primes. Using this algorithm with hand computations on paper, Lucas showed in 1876 that the 39-digit number (2127 – 1) equals 170,141,183,460,469,231,731,687,303,715,884,105,727, and that value is prime.

Also known as M127, this number remains the largest prime verified by hand computations. It held the record for largest known prime for 75 years.

Researchers began using computers in the 1950s, and the pace of discovering new large primes increased. In 1952, Raphael M. Robinson identified five new Mersenne primes using a Standard Western Automatic Computer to carry out the Lucas-Lehmer prime number tests.

As computers improved, the list of Mersenne primes grew, especially with the Cray supercomputer’s arrival in 1964. Although there are infinitely many primes, researchers are unsure how many fit the type (2p – 1) and are Mersenne primes.

By the early 1980s, researchers had accumulated enough data to confidently believe that infinitely many Mersenne primes exist. They could even guess how often these prime numbers appear, on average. Mathematicians have not found proof so far, but new data continues to support these guesses.

George Woltman, a computer scientist, founded the Great Internet Mersenne Prime Search, or GIMPS, in 1996. Through this collaborative program, anyone can download freely available software from the GIMPS website to search for Mersenne prime numbers on their personal computers. The website contains specific instructions on how to participate.

GIMPS has now identified 18 Mersenne primes, primarily on personal computers using Intel chips. The program averages a new discovery about every one to two years.

The largest known prime

Luke Durant, a retired programmer, discovered the current record for the largest known prime, (2136,279,841 – 1), in October 2024.

Referred to as M136279841, this 41,024,320-digit number was the 52nd Mersenne prime identified and was found by running GIMPS on a publicly available cloud-based computing network.

This network used Nvidia chips and ran across 17 countries and 24 data centers. These advanced chips provide faster computing by handling thousands of calculations simultaneously. The result is shorter run times for algorithms such as prime number testing.

A small rectangle metal chip reading 'nVIDIA'
New and increasingly powerful computer chips have allowed prime-number hunters to find increasingly larger primes. Fritzchens Fritz/Flickr

The Electronic Frontier Foundation is a civil liberty group that offers cash prizes for identifying large primes. It awarded prizes in 2000 and 2009 for the first verified 1 million-digit and 10 million-digit prime numbers.

Large prime number enthusiasts’ next two challenges are to identify the first 100 million-digit and 1 billion-digit primes. EFF prizes of US$150,000 and $250,000, respectively, await the first successful individual or group.

Eight of the 10 largest known prime numbers are Mersenne primes, so GIMPS and cloud computing are poised to play a prominent role in the search for record-breaking large prime numbers.

Large prime numbers have a vital role in many encryption methods in cybersecurity, so every internet user stands to benefit from the search for large prime numbers. These searches help keep digital communications and sensitive information safe.

Jeremiah Bartz, Associate Professor of Mathematics, University of North Dakota

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

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I find it unbelievable that there are prizes for the first 100 million-digit prime number and also the first 1 billion-digit prime number. It is so far away from my understanding of these numbers that all I can say is: I find it unbelievable!

Your start in a vet business

Penny Martin regularly sends me content that I can publish as a post for you kind people.

And so it is with this one.

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Going Green with Fur and Grit: How to Launch an Eco-Friendly Pet Care Business That Actually Work

You’ve been sitting on the idea for a while now. Maybe it started with that pile of single-use plastic baggies after your dog’s walk, or the ingredient list on your cat’s kibble that read more like a chemistry project than actual food. Maybe you just got tired of feeling like you had to choose between loving your pet and loving the planet. Whatever the reason, you’re here now, staring down the reality of launching a business that’s not only built for animals—but built for good. You want to make something that matters. And you can. But you need to know exactly what you’re walking into.

Anchor Yourself in a Real Way
 
You can’t build this kind of business on good vibes and a cool logo. Before anything else—before the business plan, the branding, or the Instagram account—you’ve got to know exactly why you’re doing this. If your reason isn’t rooted in something deeply personal, something that makes your chest tighten when you think about it, you’ll burn out fast. Maybe it’s watching your senior dog react to over-processed treats, or maybe it’s the garbage island growing in the ocean—whatever it is, let that be your compass.

Streamline the Chaos with the Right Tools

When you’re building a mission-driven business from scratch, the backend can get messy fast. That’s where using an all-in-one business platform becomes a game-changer—it keeps your focus on your values instead of your paperwork. Whether you’re forming an LLC, managing compliance, creating a website, or handling finances, this type of platform can provide comprehensive services and expert support to ensure business success. Platforms like ZenBusiness are built for entrepreneurs like you, giving you the structure to stay organized while you pour your energy into the work that really matters.

Get Ruthlessly Local with Sourcing
 
If you’re serious about sustainability, you’ve got to look hard at where your products come from. Local sourcing doesn’t just reduce your carbon footprint—it tells your community that you care about it. Reach out to nearby farms, independent makers, and ethical manufacturers who align with your mission. Not only will this lower your shipping emissions, it’ll also create real relationships with partners who have skin in the game—and people can feel that authenticity the moment they walk through your door.

Know That Packaging Will Be a Battle
 
You’re going to lose sleep over packaging. You’ll try compostable options that fall apart in humid weather. You’ll learn that “recyclable” doesn’t mean the same thing in every city. And somewhere along the way, you’ll realize that the most sustainable solution might be the least convenient one. This is the part where you have to experiment, ask questions, and stay transparent with your customers. No one expects perfection—but they’ll appreciate your effort to figure it out.

Make the Community Your Co-Founders
 
You’re not building this business for yourself. You’re building it for every person who loves their animal and wants to do better by the planet. So bring them in early. Host small events, set up “ask me anything” nights, partner with local shelters, and turn your customer base into a real community. These people won’t just buy your products—they’ll give you feedback, advocate for your brand, and make you feel less alone when the grind gets real.

Ditch the Guilt, Offer Solutions
 
You’re not here to shame anyone. The pet parent buying big-box kibble isn’t your enemy—they’re someone who probably hasn’t been offered a better option yet. So don’t lecture. Instead, educate through action. Make eco-friendly choices feel fun, feel doable, and feel worth it. When you center your messaging on empowerment instead of guilt, people are way more likely to stick around—and tell their friends.

Teach Through Curiosity, Not Preaching
 
People want to learn, but they don’t want to be condescended to. Your job is to become the kind of brand that shares knowledge without turning it into a TED Talk. Drop bite-sized facts on your packaging, start conversations in-store, and use your social platforms to casually open people’s eyes. Think of it like planting seeds—not every customer will bloom overnight, but the ones who do will remember how you made them feel when they were just getting started.

Hire with Heart, Not Just Skill
 
You can train someone to trim nails or restock shelves, but you can’t teach them to care. The team you build needs to believe in the mission as much as you do. They’re the ones explaining the difference between corn-based and petroleum-based bags to a frazzled pet parent who’s late for pickup. If your staff is just collecting paychecks, your message won’t land. But if they’re aligned with your values? That’s when your business becomes a movement.

Don’t Let Perfect Be the Point
 
You will mess up. You’ll stock a “sustainable” product that turns out to be greenwashed. You’ll order packaging that gets held up in customs. You’ll have days where you wonder if any of this actually matters. That’s normal. Progress in this space is messy, nonlinear, and full of trade-offs. The key is to keep going, stay honest, and let your customers come along for the ride. They don’t need you to be flawless—they just need to believe you’re trying.

Starting an eco-conscious pet care business means doing things the hard way on purpose. It means waking up early to answer emails from suppliers and staying up late comparing compostable labels. It means showing up for your customers, your team, your animals—and the planet. But if your heart’s in the right place and your feet stay on the ground, you’ll build something that matters. And really, that’s the kind of work worth doing.

Discover the wisdom of our loyal companions and explore the journey of life with Learning from Dogs, where every post is a step towards understanding and fulfillment.

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As a very ex-entrepreneur, I can tell you that there is much in Penny’s article that applies to starting any business.

And as an ex-salesman, everything starts with the customer. The persons who are attracted to what you are selling. It is hard work but pleasing work. Before I started Dataview I worked for IBM UK in their office products division, as a salesman. I loved the job!

Artificial Intelligence and Mars

NASA hasn’t landed humans on Mars yet. But thanks to robotic missions, scientists now know more about the planet’s surface than they did when the movie, The Martian, was released.

Our human knowledge is constantly growing. In many, many directions. Here is a fascinating (well it is to me!) article from The Conversation.

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A decade after the release of ‘The Martian’ and a decade out from the world it envisions, a planetary scientist checks in on real-life Mars exploration

‘The Martian’ protagonist Mark Watney contemplates his ordeal. 20th Century Fox

Ari Koeppel, Dartmouth College

Andy Weir’s bestselling story “The Martian” predicts that by 2035 NASA will have landed humans on Mars three times, perfected return-to-Earth flight systems and collaborated with the China National Space Administration. We are now 10 years past the Hollywood adaptation’s 2015 release and 10 years shy of its fictional timeline. At this midpoint, Mars exploration looks a bit different than how it was portrayed in “The Martian,” with both more discoveries and more controversy.

As a planetary geologist who works with NASA missions to study Mars, I follow exploration science and policy closely. In 2010, the U.S. National Space Policy set goals for human missions to Mars in the 2030s. But in 2017, the White House Space Policy Directive 1 shifted NASA’s focus toward returning first to the Moon under what would become the Artemis program.

Although concepts for crewed missions to Mars have gained popularity, NASA’s actual plans for landing humans on Mars remain fragile. Notably, over the last 10 years, it has been robotic, rather than crewed, missions that have propelled discovery and the human imagination forward.

A diagram showing the steps from lunar missions to Mars missions. The steps in the current scope are labeled 'Human presence on Moon,' 'Practice for Mars Exploration Demo' and 'Demo exploration framework on Mars.' The partial scope step is labeled 'Human presence on Mars.'
NASA’s 2023 Moon to Mars Strategy and Objectives Development document lays out the steps the agency was shooting for at the time, to go first to the Moon, and from there to Mars. NASA

Robotic discoveries

Since 2015, satellites and rovers have reshaped scientists’ understanding of Mars. They have revealed countless insights into how its climate has changed over time.

As Earth’s neighbor, climate shifts on Mars also reflect solar system processes affecting Earth at a time when life was first taking hold. Thus, Mars has become a focal point for investigating the age old questions of “where do we come from?” and “are we alone?”

The Opportunity, Curiosity and Perseverance rovers have driven dozens of miles studying layered rock formations that serve as a record of Mars’ past. By studying sedimentary layers – rock formations stacked like layers of a cake – planetary geologists have pieced together a vivid tale of environmental change that dwarfs what Earth is currently experiencing.

Mars was once a world of erupting volcanoes, glaciers, lakes and flowing rivers – an environment not unlike early Earth. Then its core cooled, its magnetic field faltered and its atmosphere drifted away. The planet’s exposed surface has retained signs of those processes ever since in the form of landscape patterns, sequences of layered sediment and mineral mixtures.

Rock shelves layered on top of each other, shown from above.
Layered sedimentary rocks exposed within the craters of Arabia Terra, Mars, recording ancient surface processes. Photo from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment. NASA/JPL/University of Arizona

Arabia Terra

One focus of scientific investigation over the last 10 years is particularly relevant to the setting of “The Martian” but fails to receive mention in the story. To reach his best chance of survival, protagonist Mark Watney, played by Matt Damon, must cross a vast, dusty and crater-pocked region of Mars known as Arabia Terra.

In 2022 and 2023, I, along with colleagues at Northern Arizona University and Johns Hopkins University, published detailed analyses of the layered materials there using imagery from the Mars Reconnaissance Orbiter and Mars Odyssey satellites.

By using infrared imagery and measuring the dimensions of surface features, we linked multiple layered deposits to the same episodes of formation and learned more about the widespread crumbling nature of the terrain seen there today. Because water tends to cement rock tightly together, that loose material indicates that around 3.5 billion years ago, that area had a drying climate.

To make the discussions about this area easier, we even worked with the International Astronomical Union to name a few previously unnamed craters that were mentioned in the story. For example, one that Watney would have driven right by is now named Kozova Crater, after a town in Ukraine.

More to explore

Despite rapid advances in Mars science, many unknowns remain. Scientists still aren’t sure of the precise ages, atmospheric conditions and possible signatures of life associated with each of the different rock types observed on the surface.

For instance, the Perseverance rover recently drilled into and analyzed a unique set of rocks hosting organic – that is, carbon-based – compounds. Organic compounds serve as the building blocks of life, but more detailed analysis is required to determine whether these specific rocks once hosted microbial life.

The in-development Mars Sample Return mission aims to address these basic outstanding questions by delivering the first-ever unaltered fragments of another world to Earth. The Perseverance rover is already caching rock and soil samples, including ones hosting organic compounds, in sealed tubes. A future lander will then need to pick up and launch the caches back to Earth.

Sampling Mars rocks could tell scientists more about the red planet’s past, and whether it could have hosted life.

Once home, researchers can examine these materials with instruments orders of magnitude more sensitive than anything that could be flown on a spacecraft. Scientists stand to learn far more about the habitability, geologic history and presence of any signs of life on Mars through the sample return campaign than by sending humans to the surface.

This perspective is why NASA, the European Space Agency and others have invested some US$30 billion in robotic Mars exploration since the 1960s. The payoff has been staggering: That work has triggered rapid technological advances in robotics, telecommunications and materials science. For example, Mars mission technology has led to better sutures for heart surgery and cars that can drive themselves.

It has also bolstered the status of NASA and the U.S. as bastions of modern exploration and technology; and it has inspired millions of students to take an interest in scientific fields.

The Perseverance rover and the Ingenuity helicopter on the Martian surface, with the rover's camera moving to look down at Ingenuity.
A selfie from NASA’s Perseverance Mars rover with the Ingenuity helicopter, taken with the rover’s extendable arm on April 6, 2021. NASA/JPL-Caltech/MSSS

Calling the red planet home?

Colonizing Mars has a seductive appeal. It’s hard not to cheer for the indomitable human spirit while watching Watney battle dust storms, oxygen shortages and food scarcity over 140 million miles from rescue.

Much of the momentum toward colonizing Mars is now tied to SpaceX and its CEO Elon Musk, whose stated mission to make humanity a “multi-planetary species” has become a sort of rallying cry. But while Mars colonization is romantic on paper, it is extremely difficult to actually carry out, and many critics have questioned the viability of a Mars habitation as a refuge far from Earth.

Now, with NASA potentially facing a nearly 50% reduction to its science budget, the U.S. risks dissolving its planetary science and robotic operations portfolio altogether, including sample return.

Nonetheless, President Donald Trump and Musk have pushed for human space exploration to somehow continue to progress, despite those proposed cuts – effectively sidelining the robotic, science-driven programs that have underpinned all of Mars exploration to date.

Yet, it is these programs that have yielded humanity’s richest insights into the red planet and given both scientists and storytellers like Andy Weir the foundation to imagine what it must be like to stand on Mars’ surface at all.

Ari Koeppel, Postdoctoral Scientist in Earth and Planetary Science, Dartmouth College

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

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Nothing to add from yours truly except to say that this quote is highly relevant: “Challenges are what make life interesting and overcoming them is what makes life meaningful.” – Joshua J. Marine

(And this was the result of me looking online for quotes and coming across 50 quotes from USA Today.)

Light speed

There is more to this topic that many of us do not know.

Photons are massless. They travel at a speed that 99% of us do not really comprehend. But over to Prof. Jarred Roberts who does comprehend the subject.

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Do photons wear out? An astrophysicist explains light’s ability to travel vast cosmic distances without losing energy

Light, whether from a star or your flashlight, travels at 186,000 miles per second. Artur Debat/Moment via Getty Images

Jarred Roberts, University of California, San Diego

My telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, walked up just as the first space photo streamed to my tablet. It sparkled on the screen in front of us.

“That’s the Pinwheel galaxy,” I said. The name is derived from its shape – albeit this pinwheel contains about a trillion stars.

The light from the Pinwheel traveled for 25 million years across the universe – about 150 quintillion miles – to get to my telescope.

My wife wondered: “Doesn’t light get tired during such a long journey?”

Her curiosity triggered a thought-provoking conversation about light. Ultimately, why doesn’t light wear out and lose energy over time?

Let’s talk about light

I am an astrophysicist, and one of the first things I learned in my studies is how light often behaves in ways that defy our intuitions.

A photo of outer space that shows a galaxy shaped like a pinwheel.
The author’s photo of the Pinwheel galaxy. Jarred Roberts

Light is electromagnetic radiation: basically, an electric wave and a magnetic wave coupled together and traveling through space-time. It has no mass. That point is critical because the mass of an object, whether a speck of dust or a spaceship, limits the top speed it can travel through space.

But because light is massless, it’s able to reach the maximum speed limit in a vacuum – about 186,000 miles (300,000 kilometers) per second, or almost 6 trillion miles per year (9.6 trillion kilometers). Nothing traveling through space is faster. To put that into perspective: In the time it takes you to blink your eyes, a particle of light travels around the circumference of the Earth more than twice.

As incredibly fast as that is, space is incredibly spread out. Light from the Sun, which is 93 million miles (about 150 million kilometers) from Earth, takes just over eight minutes to reach us. In other words, the sunlight you see is eight minutes old.

Alpha Centauri, the nearest star to us after the Sun, is 26 trillion miles away (about 41 trillion kilometers). So by the time you see it in the night sky, its light is just over four years old. Or, as astronomers say, it’s four light years away. Imagine – a trip around the world at the speed of light.

With those enormous distances in mind, consider Cristina’s question: How can light travel across the universe and not slowly lose energy?

Actually, some light does lose energy. This happens when it bounces off something, such as interstellar dust, and is scattered about.

But most light just goes and goes, without colliding with anything. This is almost always the case because space is mostly empty – nothingness. So there’s nothing in the way.

When light travels unimpeded, it loses no energy. It can maintain that 186,000-mile-per-second speed forever.

It’s about time

Here’s another concept: Picture yourself as an astronaut on board the International Space Station. You’re orbiting at 17,000 miles (about 27,000 kilometers) per hour. Compared with someone on Earth, your wristwatch will tick 0.01 seconds slower over one year.

That’s an example of time dilation – time moving at different speeds under different conditions. If you’re moving really fast, or close to a large gravitational field, your clock will tick more slowly than someone moving slower than you, or who is further from a large gravitational field. To say it succinctly, time is relative.

An astronaut floats weightless aboard the International Space Station.
Even astronauts aboard the International Space Station experience time dilation, although the effect is extremely small. NASA

Now consider that light is inextricably connected to time. Picture sitting on a photon, a fundamental particle of light; here, you’d experience maximum time dilation. Everyone on Earth would clock you at the speed of light, but from your reference frame, time would completely stop.

That’s because the “clocks” measuring time are in two different places going vastly different speeds: the photon moving at the speed of light, and the comparatively slowpoke speed of Earth going around the Sun.

What’s more, when you’re traveling at or close to the speed of light, the distance between where you are and where you’re going gets shorter. That is, space itself becomes more compact in the direction of motion – so the faster you can go, the shorter your journey has to be. In other words, for the photon, space gets squished.

Which brings us back to my picture of the Pinwheel galaxy. From the photon’s perspective, a star within the galaxy emitted it, and then a single pixel in my backyard camera absorbed it, at exactly the same time. Because space is squished, to the photon the journey was infinitely fast and infinitely short, a tiny fraction of a second.

But from our perspective on Earth, the photon left the galaxy 25 million years ago and traveled 25 million light years across space until it landed on my tablet in my backyard.

And there, on a cool spring night, its stunning image inspired a delightful conversation between a nerdy scientist and his curious wife.

Jarred Roberts, Project Scientist, 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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This remark jumped out at me when I first read the article: ‘In the time it takes you to blink your eyes, a particle of light travels around the circumference of the Earth more than twice.’

The following photograph is the Milky Way.

The image is from Geography Realm.

Despite the fact that the article is far from me understanding it, it doesn’t reduce the wonder and the awe for me of outer space.

Starting a Veterinary Clinic

A guest post.

This post, and the next one, are submitted by Penny Martin.

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Image: Freepik

Vision to Reality: Building a Profitable Vet Clinic

Launching a veterinary clinic is a significant endeavor that requires meticulous planning and strategic decision-making. This venture combines a passion for animal care with the intricacies of managing a successful business. Aspiring clinic owners must navigate several critical steps to lay a strong foundation and ensure operational excellence. Starting your own clinic promises not only to fulfill a dream of helping animals but also to establish a thriving enterprise in the community.

Build a Strong Foundation with an Effective Marketing Strategy

A robust marketing strategy is essential to attract potential clients in the digital era. Establishing a professional online presence through a user-friendly website that details your services, team, and location builds trust among pet owners. Engage actively on social media with regular updates and client testimonials to showcase your expertise and commitment to animal care. Forge partnerships with local pet-related businesses to increase visibility and drive traffic to your clinic, enhancing both your and your partners’ customer bases.

Craft a Clear and Detailed Business Plan

A well-constructed business plan acts as your clinic’s roadmap, detailing your mission, services offered, and the specific target market. Identify your niche early—whether it’s specializing in certain animals or treatments—to attract the appropriate clientele. Include comprehensive financial projections and a marketing budget in your plan to ensure financial preparedness and support your clinic’s promotional activities.

Enhance Your Business Knowledge by Pursuing an MBA

Running a veterinary clinic demands a blend of clinical and business expertise. Pursuing a master’s of business administration online can boost your proficiency in key business areas such as strategy, management, and finance. An MBA not only deepens your understanding of business operations but also enhances leadership skills and self-assessment capabilities. These competencies are essential for balancing the medical and business demands of your clinic, ensuring its long-term success.

Safeguard Your Business with Proper Insurance

Operating a veterinary clinic comes with inherent risks, making comprehensive insurance coverage essential. Essential policies include malpractice insurance to handle legal issues and general liability insurance for accidents on your premises. Property insurance is crucial to protect your clinic’s infrastructure and equipment against unexpected events. Consulting with an insurance expert can ensure that you have thorough coverage to protect against potential financial setbacks.

Invest in High-Quality Veterinary Equipment

Providing top-tier care necessitates investing in high-quality veterinary equipment. Essential tools like X-ray machines, surgical instruments, and lab equipment should be of the highest standard to ensure accurate diagnoses and treatments. Modern technologies, such as digital imaging systems, not only enhance patient care but also improve operational efficiency. While the initial cost may be higher, investing in quality equipment pays off in the long run by boosting efficiency and minimizing errors.

Secure the Necessary Funding for Your Clinic

Securing sufficient funding is critical when starting a veterinary clinic. Estimate your startup costs accurately to understand your financial needs, including equipment, premises, staffing, and marketing. Explore diverse financing options, such as bank loans, private investors, and specialty medical practice loans that might offer favorable terms. Adequate initial funding prevents cash flow problems and supports your clinic’s growth trajectory.

Choose the Right Location for Your Clinic

The location of your clinic is pivotal to its success, necessitating a spot with a high demand for veterinary services. Conduct thorough market research to choose a community rich in pet owners who need your services. Select a location that is accessible, visible, and has ample parking to ensure convenience for your clients. Proximity to complementary services like pet groomers or dog trainers can further enhance client traffic and provide expansion opportunities.

Opening a veterinary clinic is both challenging and rewarding, demanding a careful blend of dedication and strategic foresight. Success in this field not only enhances the well-being of pets but also contributes positively to the local community. It requires ongoing commitment to adapt and grow in a dynamic environment. Ultimately, the fulfillment of running a successful veterinary clinic comes from both the impact on animal health and the achievement of entrepreneurial goals.

Discover the timeless wisdom that dogs offer at Learning from Dogs, where integrity and living in the present are celebrated. Dive into our content and embrace the lessons from our four-legged friends.

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Opening a vet clinic is well beyond me even though many years ago I was an entrepreneur.

However, one hopes that somewhere a person or two find this very useful.

The magic of gratitude

A fascinating article!

Nothing more to add from me!

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Gratitude comes with benefits − a social psychologist explains how to practice it when times are stressful

If the concept of journaling feels daunting, perhaps just call it a gratitude list. Karl Tapales/Moment via Getty Images

Monica Y. Bartlett, Gonzaga University

A lot has been written about gratitude over the past two decades and how we ought to be feeling it. There is advice for journaling and a plethora of purchasing options for gratitude notebooks and diaries. And research has consistently pointed to the health and relationship benefits of the fairly simple and cost-effective practice of cultivating gratitude.

Yet, Americans are living in a very stressful time, worried about their financial situation and the current political upheaval.

How then do we practice gratitude during such times?

I am a social psychologist who runs the Positive Emotion and Social Behavior Lab at Gonzaga University. I teach courses focused on resilience and human flourishing. I have researched and taught about gratitude for 18 years.

At the best of times, awareness of the positive may require more effort than noticing the negative, let alone in times of heightened distress. There are, however, two simple ways to work on this.

A team of soccer players lift their coach into the air, as she smiles and high fives the air.
Expressions of gratitude can take many different forms. Lighthouse Films/DigitalVision via Getty Images

Gratitude doesn’t always come easily

Generally, negative information captures attention more readily than the positive. This disparity is so potent that it’s called the negativity bias. Researchers argue that this is an evolutionary adaptation: Being vigilant for life’s harms was essential for survival.

Yet, this means that noticing the kindnesses of others or the beauty the world has to offer may go unnoticed or forgotten by the end of the day. That is to our detriment.

Gratitude is experienced as a positive emotion. It results from noticing that others − including friends and family certainly, but also strangers, a higher power or the planet − have provided assistance or given something of value such as friendship or financial support. By definition, gratitude is focused on others’ care or on entities outside of oneself. It is not about one’s own accomplishments or luck.

When we feel gratitude toward something or someone, it can increase well-being and happiness and relationship satisfaction, as well as lower depression.

Thus, it may assist in counteracting the negativity bias by helping us find and remember the good that others are doing for us every day − the good that we may lose sight of in the best of times, let alone in times when Americans are deeply stressed.

A middle-aged woman sits at a kitchen table between two older women, all of whom are laughing joyously.
We feel gratitude more easily when we notice the good that others have brought into our lives. Catherine Falls Commercial/Moment via Getty Images

How to practice gratitude

Research has shown that some people are naturally more grateful than others.

But it’s also clear that gratitude can be cultivated through practice. People can improve their ability to notice and feel this positive emotion.

One way to do this is to try a gratitude journal. Or, if the idea of journaling is daunting or annoying, perhaps call it a daily list instead. If you have given this a try and dislike it, skip to the second method below.

Gratitude lists are designed to create a habit in which you scan your day looking for the positive outcomes that others have brought into your life, no matter how small. Writing down several experiences each day that went well because of others may make these positive events more visible to you and more memorable by the end of the day − thus, boosting gratitude and its accompanying benefits.

While the negative news − “The stock market is down again!” “How are tariffs going to affect my financial security?” − is clearly drawing attention, a gratitude list is meant to help highlight the positive so that it doesn’t go overlooked.

The negative doesn’t need help gaining attention, but the positive might.

A second method for practicing gratitude is expressing that gratitude to others. This can look like writing a letter of gratitude and delivering it to someone who has made a positive impact in your life.

When my students do this exercise, it often results in touching interactions. For instance, my college students often write to high school mentors, and those adults are regularly moved to tears to learn of the positive impact they had. Expressing gratitude in work settings can boost employees’ sense of social worth.

In a world that may currently feel bleak, a letter of gratitude may not only help the writer recognize the good of others but also let others know that they are making a beautiful difference in the world.

Monica Y. Bartlett, Professor of Psychology, Gonzaga University

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

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I like the suggestions for practicing gratitude and I am going to reproduce that last sentence from Monica, namely: ‘In a world that may currently feel bleak, a letter of gratitude may not only help the writer recognize the good of others but also let others know that they are making a beautiful difference in the world.

I would add sending an email to that person as well is a good move.

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.