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The largest sample of galaxy groups ever detected has been presented by a team of international astronomers using data from the James Webb Space telescope (JWST) in an area of the sky called COSMOS Web. The study marks a major milestone in extragalactic astronomy, providing unprecedented insights into the formation and evolution of galaxies and the large-scale structure of the universe.

Researchers analyzed a global database of 500,000 strange streaks that occur on steep Martian slopes, concluding that they're most likely caused by dry processes rather than liquid flow.

We need to learn our letters before we can learn to read and our numbers before we can learn how to add and subtract. The same principles are true with AI, a team of scientists has shown through laboratory experiments and computational modeling. In their work, researchers found that when recurrent neural networks (RNNs) are first trained on simple cognitive tasks, they are better equipped to handle more difficult and complex ones later on.

A new discovery could mean more donor hearts are available for heart transplant, giving more people a second chance at life.

Underwater or aerial vehicles with dimples like golf balls could be more efficient and maneuverable, a new prototype has demonstrated.

An unprecedented international effort to decode how cells manage the transport of chemical substances has culminated in four groundbreaking studies This decade-long project provides the first comprehensive functional blueprint of chemical transport pathways in human cells.

A team was able to show that swimming movements are possible even without a central control unit. This not only explains the behavior of microorganisms, it could also enable nanobots to move in a targeted manner, for example to transport drugs to the right place in the body.

A new AI chip works without the cloud server or internet connections needed by existing chips. The AI Pro, designed by Prof Hussam Amrouch, is modelled on the human brain. Its innovative neuromorphic architecture enables it to perform calculations on the spot, ensuring full cyber security. It is also up to ten times more energy efficient.

A new AI chip works without the cloud server or internet connections needed by existing chips. The AI Pro, designed by Prof Hussam Amrouch, is modelled on the human brain. Its innovative neuromorphic architecture enables it to perform calculations on the spot, ensuring full cyber security. It is also up to ten times more energy efficient.

A new AI decision making tool effectively balances various complex trade-offs to recommend ways of maximizing carbon storage, minimizing economic disruptions and helping improve the environment and people's everyday lives. It uses evolutionary AI, a kind of digital version of biological natural selection, to optimize policies in the face of competing priorities.

If you've ever watched a flock of birds move in perfect unison or seen ripples travel across a pond, you've witnessed nature's remarkable ability to coordinate motion. Recently, a team of scientists and engineers has discovered a similar phenomenon on a microscopic scale, where tiny magnetic particles driven by rotating fields spontaneously move along the edges of clusters driven by invisible 'edge currents' that follow the rules of an unexpected branch of physics.

Researchers have developed a 3D micro-printed sensor for highly sensitive on-chip biosensing, opening new opportunities for developing high-performance, cost-effective lab-on-a-chip devices for early disease diagnosis.

Researchers have developed a 3D micro-printed sensor for highly sensitive on-chip biosensing, opening new opportunities for developing high-performance, cost-effective lab-on-a-chip devices for early disease diagnosis.

There are a range of competing views on whether smartphones and social media are harmful to adolescents, and an attempt to settle the debate has instead sparked more disagreement

The AI Con by Emily Bender and Alex Hanna wants to expose the hype generated by large artificial intelligence companies, but it is a frustrating read

A group of white-faced capuchins on a remote island have started stealing infants from another primate species, and researchers don’t know why

A declining ability to detect scents is linked to conditions including Parkinson’s and Alzheimer’s. But restoring our most neglected sense might not only reduce cognitive decline – studies also show it could even reverse it

Today we have a lighthearted change of pace: reader Athayde Tonhasca Júnior is writing not about pollination, but about aging.  His captions are indented, and you can enlarge the photos by clicking on them.

In banana years, we are bread

I think it’s safe to assume that a good many WEIT readers, like me, have already accrued many miles on their personal odometers. Or, as Brazilians say it, dobraram o Cabo da Boa Esperança (have rounded the Cape of Good Hope): our odyssey  is almost completed, the distance to the end is much shorter than to the starting point. We can fall into anguish about it, despair, deny, ignore, fight back to slow the rate of decrepitude, or be philosophical regarding the inevitable outcome. Because, as Maurice Chevalier quipped, old age isn’t so bad when you consider the alternative.

Here are some thoughts about ageing and some assorted images lifted from Private Eye magazine (hopelessly lefty but unbeatable with their cartoons), or sent by fellow old codgers.

Some quotes:

There are three deaths: the first is when the body ceases to function. The second is when the body is consigned to the grave. The third is that moment, sometime in the future, when your name is spoken for the last time. David Eagleman

Death does not make us equal. There are skulls with all their teeth. Mário Quintana

At my age, I don’t even buy green bananas. Often credited to Claude Pepper

First you forget names, then you forget faces. Next you forget to pull your zipper up and finally, you forget to pull it down. George Burns

Nothing is more responsible for the good old days than a bad memory. Franklin P. Adams

Tom Smith is dead, and here he lies, / Nobody laughs and nobody cries; / Where his soul’s gone, or how it fares, / Nobody knows, and nobody cares. Grave epitaph, Newbury, England, 1742

You start off irresistible. And, then you become resistible. And then you become transparent – not exactly invisible but as if you are seen through old plastic. Then you actually do become invisible. And then — and this is the most amazing transformation — you become repulsive. But that’s not the end of the story. After repulsive then you become cute – and that’s where I am. Leonard Cohen

I refuse to spend my life worrying about what I eat. There is no pleasure worth forgoing just for an extra three years in the geriatric ward. John Mortimer

There is still no cure for the common birthday. John Glenn

She said she was approaching forty, and I couldn’t help wondering from what direction. Bob Hope

Happiness is good health and bad memory. Ingrid Bergman

Older people shouldn’t eat health food: they need all the preservatives they can get. Robert Orben

An autobiography is an obituary in serial form with the last instalment missing. Quentin Crisp

About the only thing that comes to us without effort is old age. Gloria Pitzer

Time is a great teacher, but unfortunately it kills all its pupils. Hector Berlioz

Inside every old person is a young person wondering what happened. Terry Pratchett

In the long run, we’re all dead. John Maynard Keynes

The best time to plant a tree is twenty years ago. The second best time is now. Anon

The time you enjoy wasting is not wasted. Bertrand Russell 

The fluffy newborn chick of hope tumbles from the eggshell of life and splashes into the hot frying pan of doom. Humprey Lyttleton

A doctor is seeing an old millionaire who had started using a revolutionary hearing aid:

– So, Mr Humphrey, are you enjoying the new device?

– Very much so.

– Did your family like it?

– I don’t know, I haven’t told anyone yet. But I’ve already changed my will three times.

And for the final image: my wife suggested that I should hang a sign like this by my desk. I declined because it is not truthful: I am not on a diet.

Let’s talk about climate change and life on Earth. Not anthropogenic climate change – but long term natural changes in the Earth’s environment due to stellar evolution. Eventually, as our sun burns through its fuel, it will go through changes. It will begin to grow, becoming a red giant that will engulf and incinerate the Earth. But long before Earth is a cinder, it will become uninhabitable, a dry hot wasteland. When and how will this happen, and is there anything we or future occupants of Earth can do about it?

Our sun is a main sequence yellow star. The “main sequence” refers to the Hertzsprung-Russell diagram (HR diagram), which maps all stars based on mass, luminosity, temperature, and color. Most stars fall within a band called the main sequence, which is where stars will fall when they are burning hydrogen into helium as their source of energy. More massive stars are brighter and have a color more towards the blue end of the spectrum. They also have a shorter lifespan, because they burn through their fuel faster than lighter stars. Blue stars can burn through their fuel in mere millions of years. Yellow stars, like our own, can last 10 billion years, while red dwarfs can last for hundreds of billions of year or longer.

Which stars are the best for life? We categorize main sequence stars as blue, white, yellow, orange, and red (this is a continuum, but that is how we humans categorize the colors we see). Interestingly, there are no green stars, which has more to do with human color perception than anything else. Stars at an otherwise “green” temperature have enough blue and red mixed in to appear white to our color perception. The hotter the star the farther away a planet would have to be to be in its habitable zone, and that zone can be quite wide. But hotter stars are short-lived. Colder stars last for a long time but have a small and close-in habitable zone, so close they may be tidally locked to their star. Red dwarfs are also relatively unstable and put out a lot of solar wind which is unfriendly to atmospheres.

So the ideal color for a star, if you want to evolve some life, is probably in the middle – yellow, right where we are. However, some astronomers argue that the optimal temperature may be orange, which can last for 15-45 or more billion years, but with a comfortably distant habitable zone. If we are looking for life in our galaxy than orange stars are probably the way to go.

What about our humble yellow sun? Our sun is about 4.6 billion years old, with a total lifespan of about 10 billion years. So it might seem as if we have another 5 billion years to go, which is a comfortable chunk of time. While main sequence stars are relatively stable, they do subtly change, and can significantly change toward the end of their life. So the question is – when will our sun change enough to threaten the habitability of the Earth? The 5 billion years figure is how much longer our sun can burn hydrogen. After that it will start burning its helium at the core, and that is when it will start expanding into a red giant. However, we will run into problems long before then. As the sun burns hydrogen and collects helium at its core, it heats up, by about 10% every billion years. When will this slow heating spell doom for life on Earth?

There are two other variables to consider. The environment of the Earth depends on three main things – the sun, the orbit of the Earth (and anything else in the solar system that might affect Earth), and conditions on Earth itself (the atmosphere, the biosphere, geologically, our magnetic field). When you think about it, having a stable environment for billions of years is pretty amazing.

A recent paper considers the interaction between the slowly warming sun and the biosphere. Using a supercomputer to model what may happen, they conclude:

Our results suggest that the planetary carbonate–silicate cycle will tend to lead to terminally CO2-limited biospheres and rapid atmospheric deoxygenation, emphasizing the need for robust atmospheric biosignatures applicable to weakly oxygenated and anoxic exoplanet atmospheres and highlighting the potential importance of atmospheric organic haze during the terminal stages of planetary habitability.

In other words, the increasing heat will lead to chemical reactions that will reduce atmosphere CO2, this in turn will limit oxygen production through photosynthesis. Oxygen levels will crash, making the Earth uninhabitable to anything dependent on CO2 or oxygen. This will happen in about 1 billion years – 4 billion year sooner than our red giant phase. Eventually the Earth will continue to heat anyway, burning away all our water and resulting in a dry lifeless desert.

Is there anything we can or should do about this? I will leave a deep discussion of “should” to philosophers, and only say keeping Earth habitable to life for as long as possible seems like a good idea to me. Assuming we want this, what can we do? First let me say that I think the question is irrelevant from a practical perspective. Even in a million years, humanity will have changed significantly, definitely technologically, but also probably biologically. In 20 million years or 100 million years, still long before the Earth becomes uninhabitable, other technological species may evolve on Earth. Many things can happen. It’s massively premature to worry about things on that timescale.

I also think its very likely that long before this becomes an issue humanity will either be extinct, or (hopefully) we will be a multi-planet species. We will likely settle many parts of our own solar system, and eventually travel to the nearest stars. Even still, the future technological inhabitants of Earth may want to preserve its ecosystem for as long as possible.

Assuming we cannot change the sun (barring some ridiculously advanced stellar engineering) we could try to manipulate the other variables. We could, for example, put objects into orbit that will reflect away part of the sun’s light and heat to compensate for its increased output. Another option seems more radical but may be easier, and even necessary – we could slowly move the Earth further from the sun to precisely compensate for the sun’s increased temperature. We could use spacecraft flybys to take some angular momentum from Jupiter and give it to the Earth, pushing it a tiny bit further from the sun.  By one calculation, such a flyby would only need to occur once every 6,000 years in order to compensate for the warming of the sun (hat tip to Warwick for sending me this link).

But it seems likely that if we have a robust space presence within our solar system over the next billion years (seems likely), there will be countless Earth flybys by spacecraft. What we will need to do is track all the flybys, and/or their effects, and then calculate a compensatory flyby schedule, which can include moving the Earth slowly further from the sun.

It’s interesting, and daunting, to think about such long time scales. It reminds me of a science-fiction story (I forget which one) in which a tourist planet started to run into the problem of tourists carrying away net mass. Over hundreds and thousands of years, the planet was losing mass. So they had to pass and strictly enforce rules that no visitor could leave with more mass than they came with. If you wanted souvenirs (or even gain a little weight, which people on vacation often do) you had to pack your suitcase with some rocks to leave behind.

It seems like it will not be overly difficult for future Earth inhabitants (whether humans or something else) to keep Earth habitable for the full 5 billion years left in our sun’s main sequence life. So we have that going for us. But seriously, while all this is a fun thought experiment informed by our current scientific knowledge, it is also a reminder of how fragile our ecosystem is, especially when you think long term. We should respect our current stability, and we shouldn’t mess with it casually.

The post End of Life on Earth first appeared on NeuroLogica Blog.

Using human cells, researchers were able to create a novel cervix-on-a-chip model to study how the vaginal microbiome affects pregnancy