Category: Science

Hollywood movie to reality?

Where is the global climate going?

The challenge with writing posts, albeit not so often, about the global environment, especially when I am a non-scientist, is that one relies entirely on the words of others. In the case of a recent article, published by The Conversation, the authors are claimed to be specialists, and I do not doubt their credentials.

The three authors are René van Westen who is a Postdoctoral Researcher in Climate Physics, at Utrecht University, Henk A. Dijkstra who is a Professor of Physics, also at Utrecht University, and Michael Kliphuis, a Climate Model Specialist, again at Utrecht University.

So, here is their article:

ooOOoo

Atlantic Ocean is headed for a tipping point − once melting glaciers shut down the Gulf Stream, we would see extreme climate change within decades, study shows

Too much fresh water from Greenland’s ice sheet can slow the Atlantic Ocean’s circulation. Paul Souders/Stone via Getty Images

René van Westen, Utrecht University; Henk A. Dijkstra, Utrecht University, and Michael Kliphuis, Utrecht University

Superstorms, abrupt climate shifts and New York City frozen in ice. That’s how the blockbuster Hollywood movie “The Day After Tomorrow” depicted an abrupt shutdown of the Atlantic Ocean’s circulation and the catastrophic consequences.

While Hollywood’s vision was over the top, the 2004 movie raised a serious question: If global warming shuts down the Atlantic Meridional Overturning Circulation, which is crucial for carrying heat from the tropics to the northern latitudes, how abrupt and severe would the climate changes be?

Twenty years after the movie’s release, we know a lot more about the Atlantic Ocean’s circulation. Instruments deployed in the ocean starting in 2004 show that the Atlantic Ocean circulation has observably slowed over the past two decades, possibly to its weakest state in almost a millennium. Studies also suggest that the circulation has reached a dangerous tipping point in the past that sent it into a precipitous, unstoppable decline, and that it could hit that tipping point again as the planet warms and glaciers and ice sheets melt.

In a new study using the latest generation of Earth’s climate models, we simulated the flow of fresh water until the ocean circulation reached that tipping point.

The results showed that the circulation could fully shut down within a century of hitting the tipping point, and that it’s headed in that direction. If that happened, average temperatures would drop by several degrees in North America, parts of Asia and Europe, and people would see severe and cascading consequences around the world.

We also discovered a physics-based early warning signal that can alert the world when the Atlantic Ocean circulation is nearing its tipping point.

The ocean’s conveyor belt

Ocean currents are driven by winds, tides and water density differences.

In the Atlantic Ocean circulation, the relatively warm and salty surface water near the equator flows toward Greenland. During its journey it crosses the Caribbean Sea, loops up into the Gulf of Mexico, and then flows along the U.S. East Coast before crossing the Atlantic.

Two illustrations show how the AMOC looks today and its weaker state in the future
How the Atlantic Ocean circulation changes as it slows. IPCC 6th Assessment Report

This current, also known as the Gulf Stream, brings heat to Europe. As it flows northward and cools, the water mass becomes heavier. By the time it reaches Greenland, it starts to sink and flow southward. The sinking of water near Greenland pulls water from elsewhere in the Atlantic Ocean and the cycle repeats, like a conveyor belt.

Too much fresh water from melting glaciers and the Greenland ice sheet can dilute the saltiness of the water, preventing it from sinking, and weaken this ocean conveyor belt. A weaker conveyor belt transports less heat northward and also enables less heavy water to reach Greenland, which further weakens the conveyor belt’s strength. Once it reaches the tipping point, it shuts down quickly.

What happens to the climate at the tipping point?

The existence of a tipping point was first noticed in an overly simplified model of the Atlantic Ocean circulation in the early 1960s. Today’s more detailed climate models indicate a continued slowing of the conveyor belt’s strength under climate change. However, an abrupt shutdown of the Atlantic Ocean circulation appeared to be absent in these climate models. https://www.youtube.com/embed/p4pWafuvdrY?wmode=transparent&start=0 How the ocean conveyor belt works.

This is where our study comes in. We performed an experiment with a detailed climate model to find the tipping point for an abrupt shutdown by slowly increasing the input of fresh water.

We found that once it reaches the tipping point, the conveyor belt shuts down within 100 years. The heat transport toward the north is strongly reduced, leading to abrupt climate shifts.

The result: Dangerous cold in the North

Regions that are influenced by the Gulf Stream receive substantially less heat when the circulation stops. This cools the North American and European continents by a few degrees.

The European climate is much more influenced by the Gulf Stream than other regions. In our experiment, that meant parts of the continent changed at more than 5 degrees Fahrenheit (3 degrees Celsius) per decade – far faster than today’s global warming of about 0.36 F (0.2 C) per decade. We found that parts of Norway would experience temperature drops of more than 36 F (20 C). On the other hand, regions in the Southern Hemisphere would warm by a few degrees.

Two maps show US and Europe both cooling by several degrees if the AMOC stops.
The annual mean temperature changes after the conveyor belt stops reflect an extreme temperature drop in northern Europe in particular. René M. van Westen

These temperature changes develop over about 100 years. That might seem like a long time, but on typical climate time scales, it is abrupt.

The conveyor belt shutting down would also affect sea level and precipitation patterns, which can push other ecosystems closer to their tipping points. For example, the Amazon rainforest is vulnerable to declining precipitation. If its forest ecosystem turned to grassland, the transition would release carbon to the atmosphere and result in the loss of a valuable carbon sink, further accelerating climate change.

The Atlantic circulation has slowed significantly in the distant past. During glacial periods when ice sheets that covered large parts of the planet were melting, the influx of fresh water slowed the Atlantic circulation, triggering huge climate fluctuations.

So, when will we see this tipping point?

The big question – when will the Atlantic circulation reach a tipping point – remains unanswered. Observations don’t go back far enough to provide a clear result. While a recent study suggested that the conveyor belt is rapidly approaching its tipping point, possibly within a few years, these statistical analyses made several assumptions that give rise to uncertainty.

Instead, we were able to develop a physics-based and observable early warning signal involving the salinity transport at the southern boundary of the Atlantic Ocean. Once a threshold is reached, the tipping point is likely to follow in one to four decades.

A line chart of circulation strength shows a quick drop-off after the amount of freshwater in the ocean hits a tipping point.
A climate model experiment shows how quickly the AMOC slows once it reaches a tipping point with a threshold of fresh water entering the ocean. How soon that will happen remains an open question. René M. van Westen

The climate impacts from our study underline the severity of such an abrupt conveyor belt collapse. The temperature, sea level and precipitation changes will severely affect society, and the climate shifts are unstoppable on human time scales.

It might seem counterintuitive to worry about extreme cold as the planet warms, but if the main Atlantic Ocean circulation shuts down from too much meltwater pouring in, that’s the risk ahead.

This article was updated to Feb. 11, 2024, to fix a typo: The experiment found temperatures in parts of Europe changed by more than 5 F per decade.

René van Westen, Postdoctoral Researcher in Climate Physics, Utrecht University; Henk A. Dijkstra, Professor of Physics, Utrecht University, and Michael Kliphuis, Climate Model Specialist, Utrecht University

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

ooOOoo

I am 79! I like to think that whatever is coming down the wires, so to speak, will be after my death. But that is a cop out for a) I have a son and a daughter who are in their early fifties, b) I have a grandson, my daughter and son-in-law’s young man, who is a teenager, with his birthday next month, and c) I could possibly live for another twenty years.

The challenge is how to bring this imminent catastrophic global change in temperature to the fore. We need a global solution now enforced by a globally respected group of scientists and leaders, and, frankly, I do not see that happening.

All one can do is to hope. Hope that the global community will eschew the present-day extremes of warring behaviour and see the need for change. That is NOW!

So that the Hollywood movie, The Day After Tomorrow, remains a fictional story. And for those that have forgotten the film or who have never seen it, here is a small slice of a Wikipedia report:

The Day After Tomorrow is a 2004 American science fiction disaster film conceived, co-written, directed, co-produced by Roland Emmerich, based on the 1999 book The Coming Global Superstorm by Art Bell and Whitley Strieber, and starring Dennis Quaid, Jake Gyllenhaal, Sela Ward, Emmy Rossum, and Ian Holm. The film depicts catastrophic climatic effects following the disruption of the North Atlantic Ocean circulation, in which a series of extreme weather events usher in climate change and lead to a new ice age.

Wikipedia

And here is a YouTube video:

There we go, folks!

Atmospheric river hitting us in Merlin

The atmospheric river in California is reaching up to Southern Oregon

After we had the thick end of twelve inches of rain in January, February has kept up the downpours; as of yesterday morning we had had 0.52 inches (1.32 cm) for the month and it was still raining. (And 0.8 in at 08:00 this morning.)

Here’s an item from yesterday about the situation in California.

Plus the BBC News had an item on the California flood.

So it seemed opportune to present this article on atmospheric rivers.

ooOOoo

What is an atmospheric river? A hydrologist explains the good and bad of these flood-prone storms and how they’re changing

A satellite image shows a powerful atmospheric river hitting the Pacific Northwest in December 2023. Darker greens are more water vapor. Lauren Dauphin/NASA Earth Observatory

By Qian Cao, University of California, San Diego

A series of atmospheric rivers is bringing the threat of heavy downpours, flooding, mudslides and avalanches to the Pacific Northwest and California this week. While these storms are dreaded for the damage they can cause, they are also essential to the region’s water supply, particularly in California, as Qian Cao, a hydrologist at the University of California, San Diego, explains.

What are atmospheric rivers?

An atmospheric river is a narrow corridor or filament of concentrated water vapor transported in the atmosphere. It’s like a river in the sky that can be 1,000 miles long. On average, atmospheric rivers have about twice the regular flow of the Amazon River.

When atmospheric rivers run up against mountains or run into local atmospheric dynamics and are forced to ascend, the moisture they carry cools and condenses, so they can produce intense rainfall or snowfall. https://www.youtube.com/embed/w3rtYM0HtIM?wmode=transparent&start=0 A satellite view of atmospheric rivers.

Atmospheric rivers occur all over the world, most commonly in the mid-latitudes. They form when large-scale weather patterns align to create narrow channels, or filaments, of intense moisture transport. These start over warm water, typically tropical oceans, and are guided toward the coast by low-level jet streams ahead of cold fronts of extratropical cyclones.

Along the U.S. West Coast, the Pacific Ocean serves as the reservoir of moisture for the storm, and the mountain ranges act as barriers, which is why the western sides of the coastal ranges and Sierra Nevada see so much rain and snow.

Why are back-to-back atmospheric rivers a high flood risk?

Consecutive atmospheric rivers, known as AR families, can cause significant flooding.

The first heavy downpours saturate the ground. As consecutive storms arrive, their precipitation falls on soil that can’t absorb more water. That contributes to more runoff. Rivers and streams fill up. In the meantime, there may be snowmelt due to warm temperatures, further adding to the runoff and flood risk.

California experienced a historic run of nine consecutive atmospheric rivers in the span of three weeks in December 2022 and January 2023. The storms helped bring most reservoirs back to historical averages in 2023 after several drought years, but they also produced damaging floods and debris flows.

An animation shows filaments of water heading toward the coast.
Atmospheric rivers forming over the tropical Pacific Ocean head for the U.S. West Coast. NOAA

The cause of AR families is an active area of research. Compared with single atmospheric river events, AR families tend to be associated with lower atmospheric pressure heights across the North Pacific, higher pressure heights over the subtropics, a stronger and more zonally elongated jet stream and warmer tropical air temperatures.

Large-scale weather patterns and climate phenomena such as the Madden-Julian Oscillation, or MJO, also play an important role in the generation of AR families. An active MJO shift occurred during the early 2023 events, tilting the odds toward increased atmospheric river activity over California.

A truck drives through muddy streets that fill a large section of town. People stand on one small patch of pavement not flooded.
An aerial view shows a flooded neighborhood in the community of Pajaro in central California on March 11, 2023, after a series of atmospheric rivers. Josh Edelson/AFP via Getty Images

A recent study by scientists at Stanford and the University of Florida found that storms within AR families cause three to four times more economic damage when the storms arrive back to back than they would have caused by themselves.

How important are atmospheric rivers to the West Coast’s water supply?

I’m a research hydrologist, so I focus on hydrological impacts of atmospheric rivers. Although they can lead to flood hazards, atmospheric rivers are also essential to the Western water supply. Atmospheric rivers have been responsible for ending more than a third of the region’s major droughts, including the severe California drought of 2012-16.

Atmospheric rivers provide an average of 30% to 50% of the West Coast’s annual precipitation.

They also contribute to the snowpack, which provides a significant portion of California’s year-round water supply.

In an average year, one to two extreme atmospheric rivers with snow will be the dominant contributors to the snowpack in the Sierra Nevada. Together, atmospheric rivers will contribute about 30% to 40% of an average season’s total snow accumulation there.

A dam spillway with a full reservoir behind it.
After several winter storms brought record snowfall to California’s Sierra Nevada in early 2023, Lake Oroville, California’s second-largest reservoir, was at 100% capacity. The previous year, much of the state had faced water restrictions. Justin Sullivan/Getty Images

That’s why my colleagues at the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography, part of the University of California, San Diego, work on improving atmospheric river forecasts and predictions. Water managers need to be able to regulate reservoirs and figure out how much water they can save for the dry season while still leaving room in the reservoirs to manage flood risk from future storms.

How is global warming affecting atmospheric rivers?

As global temperatures rise in the future, we can expect more intense atmospheric rivers, leading to an increase in heavy and extreme precipitation events.

My research also shows that more atmospheric rivers are likely to occur concurrently during already wet conditions. So, the chance of extreme flooding also increases. Another study, by scientists from the University of Washington, suggests that there will be a seasonal shift to more atmospheric rivers earlier in the rainy season.

There will likely also be more year-to-year variability in the total annual precipitation, particularly in California, as a study by my colleagues at the Center for Western Weather and Water Extremes projects.

Qian Cao, Hydrologist, Center For Western Weather and Water Extremes, University of California, San Diego

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

ooOOoo

PBS have also presented an item on what is an atmospheric river. Their article starts:

Forecasters warned of dangerous flooding, heavy mountain snow and a heightened risk of mudslides and avalanches Feb. 4-6, 2024, as a powerful atmospheric river took aim at California. It’s the latest in a series of atmospheric rivers to bring extreme rainfall to the West Coast.

Qian Cao

I sense many things are changing and the challenge is not to let one’s imagination go into overdrive.

A study on dog aging

It is very likely to lose funding.

I am reading the latest issue of Science, the magazine put out by AAAS – the American Academy for the Advancement of Science. One of the news items in that issue is entitled Massive study of dog aging likely to lose funding.

One reads, in part, a remark by biogerontologist, Steve Austed of the University of Alabama at Birmingham: “It was going to be the most informative study of aging that was not done in humans.“

The project has a website, Dog Aging Project, from which one finds, under Project Details:

Science’s Best Friend

DOGS & HUMANS

Studying aging in humans is challenging and expensive, but dogs truly are science’s best friends. Even though they age more rapidly than humans, they experience the same diseases of aging, they are genetically diverse, and they share our environment. By studying aging in dogs, we can more quickly expand our knowledge of the aging process not just in dogs but in humans too!

It is a great shame that the likelihood is that the project will cease.

Photo by Hannah Lim on Unsplash

Artificial intelligence to the rescue

The colonisation of space.

Patrice Ayme is a writer who lives in France and is a person of extreme breadth of knowledge, and very clever to boot.

He writes blog posts on a variety of topics. His latest post is breathtakingly powerful and could be the way we all go over the future years. Read it for yourself online or as follows:

ooOOoo

How Solar System Colonization Will Save Earth

By Patrice Ayme

Saving Earth and colonizing the Solar System are basically the same problem and have the same solution: much more advanced technology [1]. There is no contradiction, far from it. There is complementarity, as technology that will have to be developed for space will be found to be useful for Earth. For psycho-political reasons those technologies won’t be developed directly for Earth. So those who complain about space, while claiming we should focus on Earth, get it only half right.

Colonizing Mars with present technology is not going to happen anymore than the technology of the 1960s enabled to colonize the Moon. A visit from a human crew on Mars with the technology SpaceX wants to develop is imaginable… Barely.  And those will just be visits, multi-year commitments full of lethal radiation and worse living accommodations than the highest maximum security prison: basically what was done on the Moon in the 1960s, but much more daunting.

It’s much more feasible to establish bases on the Moon. First, there is plenty of oxygen and hydrogen (so water) on the Moon, imprisoned in rocks: one only needs energy to extract them, and the Moon has plenty of that (solar panels!) Second, the gravity well of the Moon is also half that of Mars. Third, the Moon is close by and one can go there all the time (whereas Mars can be visited with present fossil fuel tech only every two years, when the planets align; serious commuting of goods and people between Earth and Mars will require nuclear propulsion).Monitoring robots on the Moon is possible, whereas on Mars, with up to twenty minutes delay, one will have to use advanced, autonomous AI. Fixing problems caused by dust in robots on the Moon with roaming human crews… A solution that won’t exist on Mars, for decades. 

Thus AI is the first order solution: AI just needs energy, not shelter, air, water and food. AI colonies on the Moon, and then, later, Mars could build environments that humans could then inhabit. Say pressurized lava tubes… 

Skeptics could object that I didn’t roll out specific techs. But space colonization, especially if robot and AI driven, will require much higher tech. For example solar energy, which works wonderfully, was led by its usage in space… where it has long worked splendidly. The solar cells used in space have an efficiency more than twice that of the ones used on the ground… from using more advanced (but expensive) materials, like Gallium… That has invited researchers and companies to boost the efficiency of the silicon and now perovskites cells used on the ground. SpaceX uses Reliable Reusable Rockets (RRR), lowering the cost of space access… That is revolutionary, but actually follows the tech used to land on the Moon in the first place. But the first landing rockets, the LEMS, were Lunar Exploration Modules… They showed the way…

Technology is impossible without wisdom, and wisdom impossible without technology. One can’t grow without the other. The quest for tech is a quest for wisdom.

We don’t need AI on Earth, at least so many “leaders” will think (and they would be very wrong)… However, for space colonization, clearly, we need AI. Space AI will then bring in the Earth AI we need to solve countless problems, including the ones we didn’t think we had. 

NASA picture from Curiosity rover on a rather barren, poisonous, irradiated, dusty and dry Mars

P/S: Scifi novels are an old genre: The Birds of Aristophanes, making fun of the colonies Athens established everywhere, by establishing one in the sky, preceded the space colonization of Lucian by seven centuries… 

***

[1] The European solution to the Earth Crisis has been Mathusianism: use less energy. This weakens Europe and encourages its dictatorial enemies. Actually the best solution is rather the opposite: to use more ABSOLUTE WORTH ENERGY. Use, much more EFFICIENT energy. In particular, we have to leverage fossil fuels to get out of them… using the energy they provide to invent new science and tech….

ooOOoo

Yet another masterpiece from Mr. Ayme. I cannot add anything to this post except to applaud it.

Another guest post from Penny

Concerning addiction recovery.

Penny Martin is a regular contributor to these pages and I am delighted with that.

So without any more todo, here is Penny’s post.

ooOOoo

Fur-Ever Friends: The Therapeutic Bonds of Pets in Addiction Rehab

By Penny Martin

Image via Pexels

Recovery from addiction is a complex and emotionally taxing process that involves much more than simply abstaining from substance use. It necessitates a holistic approach to healing, which often includes medical treatment, psychotherapy, lifestyle changes, and, for many people, the support of loved ones. 

Another source of support that is increasingly recognized for its therapeutic benefits is the companionship of pets. Whether it’s a dog, a cat, or even a bird, pets offer emotional sustenance, non-judgmental companionship, and numerous practical advantages. In this article from Learning from Dogs, we delve into how the presence of a pet can be a transformative experience.

It’s All About a Good Routine

Establishing a stable routine is a cornerstone of addiction recovery. A routine not only provides structure to the day but also instills a sense of responsibility and purpose. Owning a pet naturally requires a routine for feeding, exercise, and care. 

This routine can help an individual in recovery stay focused and reduce the void or emptiness often cited as a relapse trigger. Technologies like automated pet feeders can further support this routine, ensuring that your responsibilities are met even when you’re dealing with emotional ups and downs.

Pets Just Make You Feel Better

PsychCentral notes that interacting with pets has been scientifically shown to improve emotional health. Simple actions such as petting a dog or cat trigger the release of “feel-good” hormones like oxytocin, reducing stress and elevating mood. 

These emotional benefits are invaluable, especially during the psychologically taxing phases of withdrawal and detoxification. Mental health tracking apps can provide real-time data on your emotional state, often reflecting an improvement correlated with increased time spent with your pet.

Pet-Friendliness and Rehab

Selecting the appropriate rehab facility is an essential step toward a successful recovery journey. An important criterion to consider is the availability of pet-friendly options or the incorporation of pet therapy in the facility’s treatment approach. 

Many centers, including local resources for treatment and recovery, are increasingly acknowledging the multifaceted therapeutic advantages that pets can offer and are thus integrating them into their treatment regimens. Specialized online platforms provide comprehensive data about such pet-amicable facilities, empowering individuals to make a well-informed decision.

Diverting from Destructive Urges

Engaging with pets can provide a crucial distraction from cravings and negative thoughts. Whether it’s going for a walk, playing fetch, or simply cuddling on the sofa, these activities require engagement that diverts attention away from destructive patterns. There are even interactive pet toys available now, controlled via smartphone apps, that can keep both the pet and the owner engaged, further reducing idle time that might otherwise lead to cravings.

Pets Make You Social

HABRI points out that owning a pet often encourages social interaction, which can be particularly beneficial during recovery. Whether it’s through meeting other dog owners during walks or engaging in community pet events, these interactions foster a sense of community and belonging. These newly formed social connections can be a significant supportive element in staying sober. Social platforms and apps for pet owners offer a virtual space to connect, share experiences, and seek advice, contributing to a broader support system.

Enhancing Self-Image

Successfully caring for a pet significantly boosts self-esteem and self-worth. Taking responsibility for the well-being of another life generates a sense of accomplishment and purpose, which are foundational in rebuilding one’s life after addiction. Virtual training modules and online courses offer valuable insights into pet care, further increasing competence and confidence in this area.

The journey through addiction recovery is seldom straightforward. It’s a path fraught with challenges, emotional turbulence, and setbacks. However, the simple act of caring for a pet offers an unmatched emotional and practical support system that aids significantly in the recovery process. From establishing routine and boosting emotional well-being to providing a sense of purpose, the benefits are multi-layered and profound. As you navigate through the trials of addiction recovery, the companionship of a pet can become one of your most significant sources of comfort, strength, and hope.

Learning from Dogs serves as a reminder of the values of life and the power of unconditional love – as so many, many dogs prove each and every day. Read more informative articles today!

ooOOoo

HABRI stands for The Human Animal Bond Research Institute and their website is available if you click on the title. I am going to see if I can republish some of HABRI’s articles.

Anyway, thanks to Penny for another great guest post.

It just goes to show the importance of loving an animal, especially a cat or a dog.

An inspiring TED Talk

Hannah Ritchie raises a very important question.

I was born in London before the end of World War II and to a great extent my upbringing was in the times of yesterday. But the world has moved on in many, many ways. It is too easy to say that we live in very strange times.

Thus it was enlightening to come across this talk, under the TED Talks banner, quite recently. I have great pleasure in sharing it with you. Plus, Hannah’s website is here. (From which I have taken the following words!)

(P.S. The YouTube video is just over thirteen minutes long. It automatically runs into the next video so you will have to stop it yourself.)

ooOOoo

The word “sustainability” gets thrown around a lot these days. But what does it actually mean for humanity to be sustainable? Environmental data scientist Hannah Ritchie digs into the numbers behind human progress across centuries, unpacking why the conventional understanding of sustainability is misleading and showing how we can be the first generation of humans to actually achieve it.

Why you should listen

Hannah Ritchie is deputy editor and research lead at Our World in Data, an online publication making data and research on the world’s largest problems accessible and understandable for non-experts. She is a senior researcher at the University of Oxford, where she studies how environmental issues intersect with others like poverty, global health and education. She has also done extensive research into the question of how to feed everyone in the world a nutritious diet without wrecking the planet. Her work has appeared in The New York Times, The Washington Post, Vox, Wired, BBC, Al Jazeera, The Economist and New Scientist.

In 2022, Ritchie was named Scotland’s Youth Climate Champion. She is also an honorary fellow at the University of Edinburgh and Edinburgh Centre for Carbon Innovation, and a fellow at the Energy for Growth Hub, focused on ending global energy poverty. Her forthcoming book, The First Generation, makes an evidence-based case for why we have a meaningful chance to solve global environmental problems for the first time in human history.

ooOOoo

It is a very inspiring talk; please watch it!

The expansion of the Universe

I am reproducing a recent article published by The Conversation.

It is a reflection of the latest research undertaken by NASA, it is beyond fascinating!

ooOOoo

The universe is expanding faster than theory predicts – physicists are searching for new ideas that might explain the mismatch

The James Webb Space Telescope’s deep field image shows a universe full of sparkling galaxies. NASA/STScI

Ryan Keeley, University of California, Merced

Astronomers have known for decades that the universe is expanding. When they use telescopes to observe faraway galaxies, they see that these galaxies are moving away from Earth.

To astronomers, the wavelength of light a galaxy emits is longer the faster the galaxy is moving away from us. The farther away the galaxy is, the more its light has shifted toward the longer wavelengths on the red side of the spectrum – so the higher the “redshift.”

Because the speed of light is finite, fast, but not infinitely fast, seeing something far away means we’re looking at the thing how it looked in the past. With distant, high-redshift galaxies, we’re seeing the galaxy when the universe was in a younger state. So “high redshift” corresponds to the early times in the universe, and “low redshift” corresponds to the late times in the universe.

But as astronomers have studied these distances, they’ve learned that the universe is not just expanding – its rate of expansion is accelerating. And that expansion rate is even faster than the leading theory predicts it should be, leaving cosmologists like me puzzled and looking for new explanations.

Dark energy and a cosmological constant

Scientists call the source of this acceleration dark energy. We’re not quite sure what drives dark energy or how it works, but we think its behavior could be explained by a cosmological constant, which is a property of spacetime that contributes to the expansion of the universe.

Albert Einstein originally came up with this constant – he marked it with a lambda in his theory of general relativity. With a cosmological constant, as the universe expands, the energy density of the cosmological constant stays the same.

Imagine a box full of particles. If the volume of the box increases, the density of particles would decrease as they spread out to take up all the space in the box. Now imagine the same box, but as the volume increases, the density of the particles stays the same.

It doesn’t seem intuitive, right? That the energy density of the cosmological constant does not decrease as the universe expands is, of course, very weird, but this property helps explain the accelerating universe.

A standard model of cosmology

Right now, the leading theory, or standard model, of cosmology is called “Lambda CDM.” Lambda denotes the cosmological constant describing dark energy, and CDM stands for cold dark matter. This model describes both the acceleration of the universe in its late stages as well as the expansion rate in its early days.

Specifically, the Lambda CDM explains observations of the cosmic microwave background, which is the afterglow of microwave radiation from when the universe was in a “hot, dense state” about 300,000 years after the Big Bang. Observations using the Planck satellite, which measures the cosmic microwave background, led scientists to create the Lambda CDM model.

Fitting the Lambda CDM model to the cosmic microwave background allows physicists to predict the value of the Hubble constant, which isn’t actually a constant but a measurement describing the universe’s current expansion rate.

But the Lambda CDM model isn’t perfect. The expansion rate scientists have calculated by measuring distances to galaxies, and the expansion rate as described in Lambda CDM using observations of the cosmic microwave background, don’t line up. Astrophysicists call that disagreement the Hubble tension.

An illustration showing the progression of the Universe's expansion after the Big Bang. The Universe is depicted as a cylindrical funnel with labels along the bottom showing the first stars, the development of planets, and now the dark energy acceleration
The universe is expanding faster than predicted by popular models in cosmology. NASA

The Hubble tension

Over the past few years, I’ve been researching ways to explain this Hubble tension. The tension may be indicating that the Lambda CDM model is incomplete and physicists should modify their model, or it could indicate that it’s time for researchers to come up with new ideas about how the universe works. And new ideas are always the most exciting things for a physicist.

One way to explain the Hubble tension is to modify the Lambda CDM model by changing the expansion rate at low redshift, at late times in the universe. Modifying the model like this can help physicists predict what sort of physical phenomena might be causing the Hubble tension.

For instance, maybe dark energy is not a cosmological constant but instead the result of gravity working in new ways. If this is the case, dark energy would evolve as the universe expands – and the cosmic microwave background, which shows what the universe looked like only a few years after its creation, would have a different prediction for the Hubble constant.

But, my team’s latest research has found that physicists can’t explain the Hubble tension just by changing the expansion rate in the late universe – this whole class of solutions falls short.

Developing new models

To study what types of solutions could explain the Hubble tension, we developed statistical tools that enabled us to test the viability of the entire class of models that change the expansion rate in the late universe. These statistical tools are very flexible, and we used them to match or mimic different models that could potentially fit observations of the universe’s expansion rate and might offer a solution to the Hubble tension.

The models we tested include evolving dark energy models, where dark energy acts differently at different times in the universe. We also tested interacting dark energy-dark matter models, where dark energy interacts with dark matter, and modified gravity models, where gravity acts differently at different times in the universe.

But none of these could fully explain the Hubble tension. These results suggest that physicists should study the early universe to understand the source of the tension.

Ryan Keeley, Postdoctoral Scholar in Physics, University of California, Merced

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

ooOOoo

Ryan Keeley explains it above. Hopefully most of you who read this understand the physics involved. Ryan has a website here.

As I said at the start it is beyond fascinating! In the truest sense, out of this world!

The history of Oxygen!

A fascinating subject.

We take it for granted! Of that I am sure. But the question of how oxygen first came to be built up in our atmosphere is fascinating. There was a recent article written by Elizabeth Swanner, who is Associate Professor of Geology, Iowa State University that was published in The Conversation. It makes for a very interesting read.

ooOOoo

A layered lake is a little like Earth’s early oceans − and lets researchers explore how oxygen built up in our atmosphere billions of years ago

Researchers sample water from various layers to analyze back in the lab. Elizabeth Swanner, CC BY-ND

Elizabeth Swanner, Iowa State University

Little Deming Lake doesn’t get much notice from visitors to Itasca State Park in Minnesota. There’s better boating on nearby Lake Itasca, the headwaters of the Mississippi River. My colleagues and I need to maneuver hundreds of pounds of equipment down a hidden path made narrow by late-summer poison ivy to launch our rowboats.

But modest Deming Lake offers more than meets the eye for me, a geochemist interested in how oxygen built up in the atmosphere 2.4 billion years ago. The absence of oxygen in the deep layers of Deming Lake is something this small body of water has in common with early Earth’s oceans.

On each of our several expeditions here each year, we row our boats out into the deepest part of the lake – over 60 feet (18 meters), despite the lake’s surface area being only 13 acres. We drop an anchor and connect our boats in a flotilla, readying ourselves for the work ahead.

Smooth lake with boats in the distance against woodsy shoreline
Researchers’ boats on Deming Lake. Elizabeth Swanner, CC BY-ND

Deming Lake is meromictic, a term from Greek that means only partially mixing. In most lakes, at least once a year, the water at the top sinks while the water at the bottom rises because of wind and seasonal temperature changes that affect water’s density. But the deepest waters of Deming Lake never reach the surface. This prevents oxygen in its top layer of water from ever mixing into its deep layer.

Less than 1% of lakes are meromictic, and most that are have dense, salty bottom waters. Deming Lake’s deep waters are not very salty, but of the salts in its bottom waters, iron is one of the most abundant. This makes Deming Lake one of the rarest types of meromictic lakes.

man seated in small boat wearing gloves injecting water into a collection tube
Postdoc researcher Sajjad Akam collects a water sample for chemical analysis back in the lab. Elizabeth Swanner, CC BY-ND

The lake surface is calm, and the still air is glorious on this cool, cloudless August morning. We lower a 2-foot-long water pump zip-tied to a cable attached to four sensors. The sensors measure the temperature, amount of oxygen, pH and amount of chlorophyll in the water at each layer we encounter. We pump water from the most intriguing layers up to the boat and fill a myriad of bottles and tubes, each destined for a different chemical or biological analysis.

My colleagues and I have homed in on Deming Lake to explore questions about how microbial life adapted to and changed the environmental conditions on early Earth. Our planet was inhabited only by microbes for most of its history. The atmosphere and the oceans’ depths didn’t have much oxygen, but they did have a lot of iron, just like Deming Lake does. By investigating what Deming Lake’s microbes are doing, we can better understand how billions of years ago they helped to transform the Earth’s atmosphere and oceans into what they’re like now.

Layer by layer, into the lake

Two and a half billion years ago, ocean waters had enough iron to form today’s globally distributed rusty iron deposits called banded iron formations that supply iron for the modern global steel industry. Nowadays, oceans have only trace amounts of iron but abundant oxygen. In most waters, iron and oxygen are antithetical. Rapid chemical and biological reactions between iron and oxygen mean you can’t have much of one while the other is present.

The rise of oxygen in the early atmosphere and ocean was due to cyanobacteria. These single-celled organisms emerged at least 2.5 billion years ago. But it took roughly 2 billion years for the oxygen they produce via photosynthesis to build up to levels that allowed for the first animals to appear on Earth.

water concentrated on a filter looks pale green
Chlorophyll colors water from the lake slightly green. Elizabeth Swanner, CC BY-ND

At Deming Lake, my colleagues and I pay special attention to the water layer where the chlorophyll readings jump. Chlorophyll is the pigment that makes plants green. It harnesses sunlight energy to turn water and carbon dioxide into oxygen and sugars. Nearly 20 feet (6 meters) below Deming’s surface, the chlorophyll is in cyanobacteria and photosynthetic algae, not plants.

But the curious thing about this layer is that we don’t detect oxygen, despite the abundance of these oxygen-producing organisms. This is the depth where iron concentrations start to climb to the high levels present at the lake’s bottom.

This high-chlorophyll, high-iron and low-oxygen layer is of special interest to us because it might help us understand where cyanobacteria lived in the ancient ocean, how well they were growing and how much oxygen they produced.

We suspect the reason cyanobacteria gather at this depth in Deming Lake is that there is more iron there than at the top of the lake. Just like humans need iron for red blood cells, cyanobacteria need lots of iron to help catalyze the reactions of photosynthesis.

A likely reason we can’t measure any oxygen in this layer is that in addition to cyanobacteria, there are a lot of other bacteria here. After a good long life of a few days, the cyanobacteria die, and the other bacteria feed on their remains. These bacteria rapidly use up any oxygen produced by still photosynthesizing cyanobacteria the way a fire does as it burns through wood.

We know there are lots of bacteria here based on how cloudy the water is, and we see them when we inspect a drop of this water under a microscope. But we need another way to measure photosynthesis besides measuring oxygen levels.

Long-running lakeside laboratory

The other important function of photosynthesis is converting carbon dioxide into sugars, which eventually are used to make more cells. We need a way to track whether new sugars are being made, and if they are, whether it’s by photosynthetic cyanobacteria. So we fill glass bottles with samples of water from this lake layer and seal them tight with rubber stoppers.

We drive the 3 miles back to the Itasca Biological Station and Laboratories where we will set up our experiments. The station opened in 1909 and is home base for us this week, providing comfy cabins, warm meals and this laboratory space.

In the lab, we inject our glass bottle with carbon dioxide that carries an isotopic tracer. If cyanobacteria grow, their cells will incorporate this isotopic marker.

We had a little help to formulate our questions and experiments. University of Minnesota students attending summer field courses collected decades worth of data in Itasca State Park. A diligent university librarian digitized thousands of those students’ final papers.

My students and I pored over the papers concerning Deming Lake, many of which tried to determine whether the cyanobacteria in the chlorophyll-rich layer are doing photosynthesis. While most indicated yes, those students were measuring only oxygen and got ambiguous results. Our use of the isotopic tracer is trickier to implement but will give clearer results.

woman holds a clear plastic bag aloft, she and man are seated in boat
Graduate students Michelle Chamberlain and Zackry Stevenson about to sink the bottles for incubation in Deming Lake. Elizabeth Swanner, CC BY-ND

That afternoon, we’re back on the lake. We toss an anchor; attached to its rope is a clear plastic bag holding the sealed bottles of lake water now amended with the isotopic tracer. They’ll spend the night in the chlorophyll-rich layer, and we’ll retrieve them after 24 hours. Any longer than that and the isotopic label might end up in the bacteria that eat the dying cyanobacteria instead of the cyanobacteria themselves. We tie off the rope to a floating buoy and head back to the station’s dining hall for our evening meal.

Iron, chlorophyll, oxygen

The next morning, as we wait for the bottles to finish their incubation, we collect water from the different layers of the lake and add some chemicals that kill the cells but preserve their bodies. We’ll look at these samples under the microscope to figure out how many cyanobacteria are in the water, and we’ll measure how much iron is inside the cyanobacteria.

That’s easier said than done, because we have to first separate all the “needles” (cyanobacteria) from the “hay” (other cells) and then clean any iron off the outside of the cyanobacteria. Back at Iowa State University, we’ll shoot the individual cells one by one into a flame that incinerates them, which liberates all the iron they contain so we can measure it.

rowboat with one woman in it on a lake with woodsy shoreline
Biogeochemist Katy Sparrow rows a research vessel to shore. Elizabeth Swanner, CC BY-ND

Our scientific hunch, or hypothesis, is that the cyanobacteria that live in the chlorophyll- and iron-rich layer will contain more iron than cyanobacteria that live in the top lake layer. If they do, it will help us establish that greater access to iron is a motive for living in that deeper and dimmer layer.

These experiments won’t tell the whole story of why it took so long for Earth to build up oxygen, but they will help us to understand a piece of it – where oxygen might have been produced and why, and what happened to oxygen in that environment.

Deming Lake is quickly becoming its own attraction for those with a curiosity about what goes on beneath its tranquil surface – and what that might be able to tell us about how new forms of life took hold long ago on Earth.

Elizabeth Swanner, Associate Professor of Geology, Iowa State University

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

ooOOoo

Nothing I can add to this very erudite article. Please read it and be fascinated by the findings.

Just a rainbow!

Well, just two rainbows!

I just ran out of time yesterday to publish a proper blog post so I am sharing this photograph with you. It shows Mount Sexton in the distance, just to the right of the fir tree, and two rainbows, it being a rainy afternoon. The camera is facing North-East and the picture was taken at the north end of our rear deck.

Keeping healthy in old age.

One has to work at it!

For most of us these days old age is part of the scene (and I am classifying old age as being over 70 years). Here are a few facts from the website of the World Health Organization.

Key facts

  • Worldwide obesity has nearly tripled since 1975.
  • In 2016, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 650 million were obese.
  • 39% of adults aged 18 years and over were overweight in 2016, and 13% were obese.
  • Most of the world’s population live in countries where overweight and obesity kills more people than underweight.
  • 39 million children under the age of 5 were overweight or obese in 2020.
  • Over 340 million children and adolescents aged 5-19 were overweight or obese in 2016.
  • Obesity is preventable.

What are obesity and overweight Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2).

Adults

For adults, WHO defines overweight and obesity as follows:

  • overweight is a BMI greater than or equal to 25; and
  • obesity is a BMI greater than or equal to 30.

BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.

World Health Organisation

This is the link for anyone who wants to use the BMI Calculator.

Now this is not a post about obesity or being overweight. It is a post taken from The Conversation about staying as healthy as one can in one’s older years.

ooOOoo

Steep physical decline with age is not inevitable – here’s how strength training can change the trajectory

Resistance training can take many forms and can be individualized to suit a person’s needs as they age. Jamie Grill/Tetra Images via Getty Images

Zachary Gillen, Mississippi State University

Raise your hand if you regularly find yourself walking up a flight of stairs. What about carrying heavy bags of groceries? How about picking up your child or grandchild? Most of us would raise our hands to doing at least one of those weekly, or even daily.

As people age, it can become more and more difficult to perform some physical tasks, even those that are normal activities of daily living. However, prioritizing physical fitness and health as you get older can help you go through your normal day-to-day routine without feeling physically exhausted at the end of the day.

It can also help you continue to have special memories with your family and loved ones that you might not have been able to have if you weren’t physically active. For example, I ran two half-marathons with my dad when he was in his 60s!

I am an exercise physiologist who studies how people can use resistance training to improve human performance, whether it be in sports and other recreational settings, in everyday life, or both. I am also a certified strength and conditioning specialist. My career has given me the opportunity to design exercise programs for kids, college athletes and elderly adults.

Staying physically active as you get older doesn’t need to include running a half-marathon or trying to be a bodybuilder; it could be as simple as trying to get through the day without feeling winded after you go up a flight of stairs. Although our muscles naturally get weaker as we age, there are ways we can combat that to help improve quality of life as we get older.

Man in his 60s, a middle-aged woman and a middle-aged man, all wearing race medals and running gear.
From left are the author’s father, who was age 61 at the time, the author’s wife and the author after completing the Lincoln Half Marathon. Zachary Gillen, CC BY-NC-ND

Muscle loss and chronic disease

One of the most important parts of exercise programming, no matter who I am working with, is proper resistance training to build muscle strength. Some amount of age-related loss of muscle function is normal and inevitable. But by incorporating resistance training that is appropriate and safe at any ability level, you can slow down the rate of decline and even prevent some loss of muscle function.

The medical term for a condition that involves age-related loss of muscle function and mass is sarcopenia. Sarcopenia can begin as early as age 40, but it tends to be more common in adults age 60 and older. Sarcopenia is associated with a number of health issues such as increased risk of falling, cardiovascular disease and metabolic disease, among others.

In one of our team’s previous studies, we saw that otherwise healthy individuals with sarcopenia had issues delivering vital nutrients to muscle. This could lead to greater likelihood of various diseases, such as Type 2 diabetes, and slow down recovery from exercise.

Recent estimates suggest that sarcopenia affects 10% to 16% of the elderly population worldwide. But even if a person doesn’t have clinically diagnosed sarcopenia, they may still have some of the underlying symptoms that, if not dealt with, could lead to sarcopenia.

Strength training is key

So the question is, what can be done to reverse this decline?

Recent evidence suggests that one of the key factors leading to sarcopenia is low muscle strength. In other words, combating or reversing sarcopenia, or both, may be best done with a proper resistance-training program that prioritizes improving strength. In fact, the decline in muscle strength seems to occur at a much faster rate than the decline in muscle size, underscoring the importance of proper strength training as people age.

Chart showing the general pattern for changes in muscle strength and size across stage of life.
Typical age-related changes in muscle strength and size with and without strength training. Zachary Gillen

Continuing to regularly strength train with moderate to heavy weights has been shown to be not only effective at combating the symptoms of sarcopenia but also very safe when done properly. The best way to make sure you are strength training properly is to seek out guidance from a qualified individual such as a personal trainer or strength and conditioning specialist.

Despite the clear benefits of strength training, it’s been shown that only about 13% of Americans age 50 and older do some form of strength training at least twice a week.

Finding what works for you

So how does a person properly strength train as they age?

The National Strength and Conditioning Association, a leading organization in advancing strength and conditioning around the world, states that for older adults, two to three days per week of strength training can be incredibly helpful for maintaining healthy muscle and bone and combating a number of chronic conditions.

The organization recommends that these workouts involve one to two exercises involving multiple joints per major muscle group, with six to 12 repetitions per set. These are done at an intensity of 50% to 85% of what’s known as one-repetition maximum – the most weight you could handle for a single repetition – with the exception of body weight exercises that use one’s own body weight as the resistance, such as pushups.

I would also recommend resting for about two to three minutes between sets, or even up to five minutes if the set was challenging. For older adults, particularly those age 60 and older, the National Strength and Conditioning Association guidelines suggest that a program like this be performed two to three days per week, with 24 to 48 hours between sessions.

An example of a strength training routine for older adults based on the National Strength and Conditioning Association guidelines

There are a great variety of exercises that could be done interchangeably in a strength training program like this.

ExerciseNumber of setsRepetitions per setIntensity
Barbell squat3670-85%
Barbell bench press3670-85%
Dumbbell lunges38 per leg50-70%
Dumbbell bent over row31050-70%
Double-leg hops212Body weight
Pushups212Body weight

Table: The Conversation Source: Zachary Gillen Get the data Created with Datawrapper

Making life’s tasks lighter

The guidelines above are only one example out of many options, but they provide a framework that you can use to build your own program. However, I would highly recommend seeking out a professional in the field to give specific exercise programming advice that can be tailored to your own needs and goals as you age.

Following such a program would give your muscles an excellent stimulus to enhance strength, while also allowing enough recovery, a very important consideration as people age. You might think it looks like a huge time commitment, but an exercise routine like this can be done in less than an hour. This means that in less than three hours of strength training per week you can help improve your muscle health and reduce the risk of getting sarcopenia and associated health issues.

It’s also important to note that there is no one right way to do resistance training, and it needn’t involve traditional weight equipment. Group classes like Pilates and yoga or those that involve circuit training and work with resistance bands can all produce similar results. The key is to get out and exercise regularly, whatever that entails.

Zachary Gillen, Assistant Professor of Exercise Physiology, Mississippi State University

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

ooOOoo

My wife, Jean, was diagnosed with Parkinson’s Disease (PD) in December, 2015. Many of you know that.

Fortunately at our local Club Northwest there was a group of PD sufferers who twice a week held a ‘Rock Steady Class’ under the instruction of a professional coach; Jean joined the group. It was a brilliant move for Jean and she gets a huge amount of care from being with them.

Luckily for me having to drive Jean into Club Northwest it made sense for me to sign up to a fitness class at the same time so I am put through a regular fitness routine under the coaching of Bruce. Plus I try and go bike riding three times a week.

In other words, we both try and stay as fit as we can.