Category: Science

Critical thinking!

Thinking it through thanks to a recent issue of Skeptical Inquirer.

Melanie Trecer-King is the creator of Thinking is Power and the associate professor of biology at the Massasoit Community College, where she teaches a science course designed to equip her students with essential critical thinking, information literacy, and science literacy skills.

The article was published in the November/December, 2024 issue of the magazine. I believe it is free to share.

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Most people agree that critical thinking is an important skill that should be taught in schools. And most educators think they teach critical thinking. I know I did. After all, I was a science educator, and science is critical thinking. Isn’t it?

For years, I taught general-education biology, a course commonly taken by undergraduates who aren’t science majors. And while I love biology, I grew more and more frustrated with the content. I asked myself: If I had one semester to teach the average student what they need to know about the process of science and critical thinking, what would it look like?

Thankfully, my college allowed me to replace my traditional introductory biology course with a course titled Science for Life, designed to teach critical thinking, information literacy, and science literacy skills (Trecek-King 2022). Since my conversion, I’ve been sharing my new path with anyone who will listen about the value of teaching critical thinking.

Yet conversations with Bertha Vazquez, director of education for the Center for Inquiry, gave me pause. In a recent podcast conversation with the two of us and Daniel Reed (of the West Virginia Skeptics Society), Vazquez was adamant. Educators do teach critical thinking: the Next Generation Science Standards (NGSS) require students to ask questions, plan and carry out investigations, analyze and interpret data, construct explanations, and engage in arguments from evidence.

As a science communicator, I constantly fight misconceptions around certain terms. Theory and skepticism are prime examples. So imagine my surprise (and embarrassment) when I realized that, as a critical thinking educator, I had overlooked an important first step in critical thinking: defining terms. The irony.

What Is Critical Thinking?

While we can all agree that it’s important to teach critical thinking, there’s not always agreement on what we mean by the term.

In his book Critical Thinking, Jonathan Haber (2020) explains how the concept emerged and some of the ways it’s currently defined. John Dewey, in his 1910 work How We Think, proposed one of the first modern definitions of reflective thinking, describing it as an “active, persistent, and careful consideration of any belief” (Dewey 1910, 6).

In his 1941 dissertation, Edward Glaser identified three components of critical thinking: “(1) an attitude of being disposed to consider in a thoughtful way the problems and subjects that come within the range of one’s experiences, (2) knowledge of the methods of logical inquiry and reasoning, and (3) some skill in applying those methods” (Glaser 1941, 5–6). That same year, Glaser and Goodwin Watson published the Watson-Glaser Tests of Critical Thinking (now the Watson-Glaser Critical Thinking Appraisal), a widely used standardized test for assessing critical thinking skills.

Critical thinking’s “big bang” moment, according to Haber, came in the early 1980s when the state of California (Harmon 1980, 3) mandated that all students in its university system complete a course that teaches “an understanding of the relationship of language to logic, leading to the ability to analyze, criticize and advocate ideas, reason inductively and deductively, and reach factual or judgmental conclusions based on sound inferences drawn from unambiguous statements of knowledge or belief.”

And the Delphi Report (Facione 1990, 2), in which Peter Facione worked with critical thinking experts to create a consensus definition, concludes that critical thinking is a “purposeful, self-regulatory judgment which results in interpretation, analysis, evaluation, and inference, as well as explanation of the evidential, conceptual, methodological, criteriological, or contextual considerations upon which that judgment is based.”

From these (and many other) definitions, Haber identifies three interconnected parts of critical thinking: knowledge of critical thinking components, such as logic and argumentation; the skills to put the knowledge to use in real-world situations; and the dispositions needed to prioritize critical thinking honestly and ethically.

This problem-solving view of critical thinking forms the basis of many of the current educational standards, including the NGSS and Common Core, which ask students to think deeply within a specific domain. And it is one scientists themselves use when trying to understand issues.

These are worthy educational goals to be sure. However, in my experience teaching general-education biology, I’ve come to realize that this approach is incomplete.

If critical thinking requires deep knowledge, then our ability to analyze topics is limited to areas in which we possess sufficient expertise. Pedagogy that encourages “independent” thinking outside these areas can have the unintended consequence of teaching students to overestimate their abilities. The best minds know they can’t know everything. Even experts rely on other experts and sources.

Additionally, in the classroom, students are provided with reliable content from which to critically analyze. In the “real world,” these guardrails are nonexistent. Not only is misinformation ubiquitous, disinformation purveyors exploit our biases and emotions to manipulate our reasoning.

And finally, we can’t address science misinformation, from evolution to vaccines to climate change, by giving students more content knowledge. We don’t fall for science denial and pseudoscience because we don’t have the facts but because of our emotions, desires, identities, and biases.

I now have a better understanding of what my colleague and friend Andy Norman means when he says that critical thinking suffers from a branding problem.

Yes, And …?

Using the above definition(s), I was teaching my biology students how to think critically. For example, I didn’t just ask them to memorize the stages of mitosis but to explore the mutations that could disrupt the cell cycle and lead to cancer. But to what end? If (or when) my former students are touched by cancer, will they remember how proto-oncogenes and tumor suppressor genes can lead to unregulated cell growth? Is that even what they need to know? I argue that, especially for students who aren’t going to be scientists, it’s far more important to teach students how and why the process of science results in reliable knowledge … and how to find it.

My Science for Life course and my Thinking Is Power resource are both based on the same premise. Knowledge may be power, but there’s too much to know. Even more, knowledge is a process; it’s not just what we know but how we know. It’s not just a noun but a verb. When we need reliable knowledge, can we find it and use it to make wiser decisions? And how do we know what information to ignore?

As a science educator, I want my students to understand how the process of science produces knowledge and why it’s reliable. Why aren’t comments such as “it worked for me” or “I know what I saw” sufficient evidence? I’ve come to realize that an essential—and often overlooked—ingredient is why we need science in the first place.

Richard Feynman famously said, “The first principle is that you must not fool yourself, and you are the easiest person to fool.” Science is how we correct for this tendency toward self-deception. That’s why I spend the first third of the semester exploring how we come to our beliefs, the limits of our perception and memory, the importance of skepticism, the cognitive biases that can lead our thinking astray, and the logical fallacies we use to convince ourselves (and others) that our conclusions are justified.

Influential voices in the skeptical community played a crucial role in shaping the ingredients of critical thinking I use in Science for Life and Thinking Is Power, which include the following:

  • Being aware of our limitations: Understanding that our perception and memory are flawed, and the biases and heuristics our brains rely on to make fast and easy decisions can lead us astray.
  • Arguing with evidence and logic: Using arguments that are well-structured and supported by evidence. This includes understanding how the different types of arguments work (i.e., deductive, inductive, and abductive) and avoiding logical fallacies.
  • Thinking about our thinking (metacognition): Actively examining and questioning our own thought processes—including the source of our knowledge, assumptions, intuitions, motivations, emotions, and biases—and how they might influence our judgments.
  • Embracing nuance and uncertainty: Avoiding the black-or-white thinking that can lead to oversimplified conclusions and accepting that our knowledge is never perfect or complete.
  • Seeking objectivity: Actively working to counter the limitations that prevent us from accurately understanding the world. This includes seeking diverse perspectives, separating our identity from our beliefs, and prioritizing accuracy over ego.
  • Having curiosity and open-mindedness: Possessing a desire to learn and understand by asking questions and seeking out information, even if it contradicts what we want to believe.
  • Maintaining healthy skepticism: Balancing gullibility and doubt and proportioning our beliefs to the available evidence. And remembering that claims made without evidence can be dismissed without evidence and extraordinary claims require extraordinary evidence.
  • Exhibiting intellectual humility: Recognizing the limitations of our knowledge, being open to the expertise of others, and being willing to change our minds with evidence.

In my experience, giving students this foundation is essential for helping them become better consumers of information and science. Without an awareness that our emotions and existing beliefs can drive our reasoning, search engines and low-quality sources become tools to confirm our biases. And without an understanding of how our identities and worldviews can alter our standards of evidence, pseudoscience and science denial provide cover for what we want or don’t want to believe.

The logic of science’s practices, from carefully controlling experimental variables to making the findings available to other experts for scrutiny and replication, falls into place once students understand the problems it’s addressing. Simply put, science is our shield against self-deception.

Now instead of asking students to think critically about the biology of cancer, I teach them how to evaluate sources to find reliable information, how to recognize pseudoscientific “treatments,” and how their need for hope and answers makes them vulnerable to misinformation.

The Take-Home Message

I have no doubt that most educators teach critical thinking. But for pedagogical and communication purposes, it would be beneficial to clarify what we mean—and just as importantly to ask ourselves what we want our students to learn.

The dominant view of critical thinking in education is problem-solving in specific domains, which is absolutely a valuable skill. However, many skeptics view critical thinking as good thinking in a broader sense. My own teaching shifted toward this latter framework after I realized that problem-solving skills are insufficient without a foundation in better thinking. We may be born with the ability to think, but we must be taught to think well, and our primate brains aren’t adapted to today’s tidal wave of misinformation.

I’m grateful to the skeptical community for challenging my assumptions about critical thinking and my friend Bertha Vazquez for encouraging me to think more deeply about the good work science educators do in their classrooms every day. This article is the result of my attempt to reconcile what critical thinking means to educators and what it means to skeptics, and my hope is that it opens a conversation about how we can better serve our students. Maybe it will even start a critical thinking revolution, especially in science education.

Let the critical thinking revolution begin!

Acknowledgments

My thanks go to those on this brief list of skeptical thinkers/authors who’ve influenced my understanding of critical thinking: James Alcock, Timothy Caulfield, John Cook, Brian Dunning, Julia Galef, Adam Grant, David Robert Grimes, Jon Guy, Harriet Hall, Guy Harrison, Daniel Kahneman, David McRaney, Steven Novella, Carl Sagan, Michael Shermer, and Carol Tavris.

Special thanks to Bertha Vazquez, Daniel Pimentel, Andy Norman, Daniel Reed, and Jon Guy for their helpful feedback on this article.

References

Dewey, John. 1910. How We Think. Lexington, MA: D.C. Heath and Company.

Facione, Peter A. 1990. Critical Thinking: A Statement of Expert Consensus for Purposes of Educational Assessment and Instruction—The Delphi Report. Millbrae, CA: California Academic Press.

Glaser, Edward M. 1941. An Experiment in the Development of Critical Thinking. New York, NY: Teachers College, Columbia University.

Haber, Jonathan. 2020. Critical Thinking. Cambridge, MA: The MIT Press.

Harmon, Harry. 1980. Executive Order No. 338: General Education-Breadth Requirements. The California State University and Colleges.

Trecek-King, Melanie. 2022. Teach skills, not facts. Skeptical Inquirer 46(1): 39–42.

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I hope others have read this fascinating article and repeat the statement: ‘While we can all agree that it’s important to teach critical thinking, there’s not always agreement on what we mean by the term.’

Whatever, the article was superb.

The geological history of Planet Earth

We live on a profoundly ancient and beautiful planet.

I follow the photographic website Ugly Hedgehog and have been doing for some time. There has been a post recently from the section Photo Gallery and ‘greymule’ from Colorado called his entry ‘A Couple of Desert Scenes’ and I will display just one of his images from that post.

It makes a wonderful connection to today’s post which is from The Conversation.

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Evidence from Snowball Earth found in ancient rocks on Colorado’s Pikes Peak – it’s a missing link

Rocks can hold clues to history dating back hundreds of millions of years. Christine S. Siddoway

Liam Courtney-Davies, University of Colorado Boulder; Christine Siddoway, Colorado College, and Rebecca Flowers, University of Colorado Boulder

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years.

Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today.

The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists – until now.

In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado’s Pikes Peak.

An illustration of an icy earth viewed from space
Earth iced over during the Cryogenian Period, but life on the planet survived. NASA illustration

Solving a Snowball Earth mystery on a mountain

Pikes Peak, originally named Tavá Kaa-vi by the Ute people, lends its ancestral name, Tava, to these notable rocks. They are composed of solidified sand injectites, which formed in a similar manner to a medical injection when sand-rich fluid was forced into underlying rock.

A possible explanation for what created these enigmatic sandstones is the immense pressure of an overlying Snowball Earth ice sheet forcing sediment mixed with meltwater into weakened rock below.

A hand holds a rock with dark seams through it and other colors.
Dark red to purple bands of Tava sandstone dissect pink and white granite. The Tava is also cross-cut by silvery-gray veins of iron oxide. Liam Courtney-Davies

An obstacle for testing this idea, however, has been the lack of an age for the rocks to reveal when the right geological circumstances existed for sand injection.

We found a way to solve that mystery, using veins of iron found alongside the Tava injectites, near Pikes Peak and elsewhere in Colorado.

A cliff side showing a long strip of lighter color Tava cutting through Pikes Peak Granite. The injectite here is 5 meters tall
A 5-meter-tall, almost vertical Tava dike is evident in this section of Pikes Peak granite. Liam Courtney-Davies

Iron minerals contain very low amounts of naturally occurring radioactive elements, including uranium, which slowly decays to the element lead at a known rate. Recent advancements in laser-based radiometric dating allowed us to measure the ratio of uranium to lead isotopes in the iron oxide mineral hematite to reveal how long ago the individual crystals formed.

The iron veins appear to have formed both before and after the sand was injected into the Colorado bedrock: We found veins of hematite and quartz that both cut through Tava dikes and were crosscut by Tava dikes. That allowed us to figure out an age bracket for the sand injectites, which must have formed between 690 million and 660 million years ago.

So, what happened?

The time frame means these sandstones formed during the Cryogenian Period, from 720 million to 635 million years ago. The name is derived from “cold birth” in ancient Greek and is synonymous with climate upheaval and disruption of life on our planet – including Snowball Earth.

While the triggers for the extreme cold at that time are debated, prevailing theories involve changes in tectonic plate activity, including the release of particles into the atmosphere that reflected sunlight away from Earth. Eventually, a buildup of carbon dioxide from volcanic outgassing may have warmed the planet again.

University of Exeter professor Timothy Lenton explains why the Earth was able to freeze over.

The Tava found on Pikes Peak would have formed close to the equator within the heart of an ancient continent named Laurentia, which gradually over time and long tectonic cycles moved into its current northerly position in North America today.

The origin of Tava rocks has been debated for over 125 years, but the new technology allowed us to conclusively link them to the Cryogenian Snowball Earth period for the first time.

The scenario we envision for how the sand injection happened looks something like this:

A giant ice sheet with areas of geothermal heating at its base produced meltwater, which mixed with quartz-rich sediment below. The weight of the ice sheet created immense pressures that forced this sandy fluid into bedrock that had already been weakened over millions of years. Similar to fracking for natural gas or oil today, the pressure cracked the rocks and pushed the sandy meltwater in, eventually creating the injectites we see today.

Clues to another geologic puzzle

Not only do the new findings further cement the global Snowball Earth hypothesis, but the presence of Tava injectites within weak, fractured rocks once overridden by ice sheets provides clues about other geologic phenomena.

Time gaps in the rock record created through erosion and referred to as unconformities can be seen today across the United States, most famously at the Grand Canyon, where in places, over a billion years of time is missing. Unconformities occur when a sustained period of erosion removes and prevents newer layers of rock from forming, leaving an unconformable contact.

Unconformity in the Grand Canyon is evident here where horizontal layers of 500-million-year-old rock sit on top of a mass of 1,800-million-year-old rocks. The unconformity, or ‘time gap,’ demonstrates that years of history are missing. Mike Norton via Wikimedia, CC BY-SA

Our results support that a Great Unconformity near Pikes Peak must have been formed prior to Cryogenian Snowball Earth. That’s at odds with hypotheses that attribute the formation of the Great Unconformity to large-scale erosion by Snowball Earth ice sheets themselves.

We hope the secrets of these elusive Cryogenian rocks in Colorado will lead to the discovery of further terrestrial records of Snowball Earth. Such findings can help develop a clearer picture of our planet during climate extremes and the processes that led to the habitable planet we live on today.

Liam Courtney-Davies, Postdoctoral Research Associate in Geological Sciences, University of Colorado Boulder; Christine Siddoway, Professor of Geology, Colorado College, and Rebecca Flowers, Professor of Geological Sciences, University of Colorado Boulder

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

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All I can add is fascinating.

The summer of 2024 in the Northern Hemisphere.

Once more, an article on the changing climate.

Recently, the BBC News reported that:

Global efforts to tackle climate change are wildly off track, says the UN, as new data shows that warming gases are accumulating faster than at any time in human existence.

Current national plans to limit carbon emissions would barely cut pollution by 2030, the UN analysis shows, leaving efforts to keep warming under 1.5C this century in tatters.

The update comes as a separate report shows that greenhouse gases have risen by over 11% in the last two decades, with atmospheric concentrations surging in 2023.

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What the jet stream and climate change had to do with the hottest summer on record − remember all those heat domes?

Shuang-Ye Wu, University of Dayton

Summer 2024 was officially the Northern Hemisphere’s hottest on record. In the United States, fierce heat waves seemed to hit somewhere almost every day.

Phoenix reached 100 degrees for more than 100 days straight. The 2024 Olympic Games started in the midst of a long-running heat wave in Europe that included the three hottest days on record globally, July 21-23. August was Earth’s hottest month in the National Oceanic and Atmospheric Administration’s 175-year record.

Overall, the global average temperature was 2.74 degrees Fahrenheit (1.52 degrees Celsius) above the 20th-century average.

That might seem small, but temperature increases associated with human-induced climate change do not manifest as small, even increases everywhere on the planet. Rather, they result in more frequent and severe episodes of heat waves, as the world saw in 2024.

The most severe and persistent heat waves are often associated with an atmospheric pattern called a heat dome. As an atmospheric scientist, I study weather patterns and the changing climate. Here’s how heat domes, the jet stream and climate change influence summer heat waves and the record-hot summer of 2024.

What the jet stream has to do with heat domes

If you listened to weather forecasts during the summer of 2024, you probably heard the term “heat dome” a lot.

A heat dome is a persistent high-pressure system over a large area. A high-pressure system is created by sinking air. As air sinks, it warms up, decreasing relative humidity and leaving sunny weather. The high pressure also serves as a lid that keeps hot air on the surface from rising and dissipating. The resulting heat dome can persist for days or even weeks.

The longer a heat dome lingers, the more heat will build up, creating sweltering conditions for the people on the ground.

A 3D image of the US showing a heat dome above it.
High pressure in the middle layers of the atmosphere acts as a dome or cap, allowing heat to build up at the Earth’s surface. NOAA

How long these heat domes stick around has a lot to do with the jet stream.

The jet stream is a narrow band of strong winds in the upper atmosphere, about 30,000 feet above sea level. It moves from west to east due to the Earth’s rotation. The strong winds are a result of the sharp temperature difference where the warm tropical air meets the cold polar air from the north in the mid-latitudes.

The jet stream does not flow along a straight path. Rather, it meanders to the north and south in a wavy pattern. These giant meanders are known as the Rossby waves, and they have a major influence on weather.

An illustration shows how ridges create high pressure to the south of them and troughs create low pressure to the north of them.
Ridges and troughs created as the jet stream meanders through the mid-latitudes create high (H) and low (L) pressure systems. Reds indicate the fastest winds. NASA/Goddard Space Flight Center Scientific Visualization Studio

Where the jet stream arcs northward, forming a ridge, it creates a high-pressure system south of the wave. Where the jet stream dips southward, forming a trough, it creates a low-pressure system north of the jet stream. A low-pressure system contains rising air in the center, which cools and tends to generate precipitation and storms.

Most of our weather is modulated by the position and characteristics of the jet stream.

How climate change affects the jet stream

The jet stream, or any wind, is the result of differences in surface temperature.

In simple terms, warm air rises, creating low pressure, and cold air sinks, creating high pressure. Wind is the movement of the air from high to low pressure. Greater differences in temperature produce stronger winds.

For the Earth as a whole, warm air rises near the equator, and cold air sinks near the poles. The temperature difference between the equator and the pole determines the strength of the jet stream in each hemisphere.

However, that temperature difference has been changing, particularly in the Northern Hemisphere. The Arctic region has been warming about three times faster than the global average. This phenomenon, known as Arctic amplification, is largely caused by the melting of Arctic sea ice, which allows the exposed dark water to absorb more of the Sun’s radiation and heat up faster.

Because the Arctic is warming faster than the tropics, the temperature difference between the two regions is lessened. And that slows the jet stream.

As the jet stream slows, it tends to meander more, causing bigger waves. The bigger waves create larger high-pressure systems. These can often be blocked by the deep low-pressure systems on both sides, causing the high-pressure system to sit over a large area for a long period of time.

A stagnant polar jet stream can trapped heat over parts of North America, Europe and Asia at the same time. This example happened in July 2023. UK Met Office

Typically, waves in the jet stream pass through the continental United States in around three to five days. When blocking occurs, however, the high-pressure system could stagnate for days to weeks. This allows the heat to build up underneath, leading to blistering heat waves.

Since the jet stream circles around the globe, stagnating waves could occur in multiple places, leading to simultaneous heat waves at the mid-latitude around the world. That happened in 2024, with long-lasting heat waves in Europe, North America, Central Asia and China.

Jet stream behavior affects winter, too

The same meandering behavior of the jet stream also plays a role in extreme winter weather. That includes the southward intrusion of frigid polar air from the polar vortex and conditions for severe winter storms.

Many of these atmospheric changes, driven by human-caused global warming, have significant impacts on people’s health, property and ecosystems around the world.

Shuang-Ye Wu, Professor of Geology and Environmental Geosciences, University of Dayton

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

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I maybe approaching my own end of life but millions of others are younger than me. When I see a woman with a young baby in her arms I cannot stop myself from wondering what that generation is going to do.

The changing climate

Here is one explanation.

There is no question the world’s weather systems are changing. However, for folk who are not trained in this science it is all a bit mysterious. So thank goodness that The Conversation have not only got a scientist who does know what he is talking about but also they are very happy for it to be republished.

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Atmospheric rivers are shifting poleward, reshaping global weather patterns

Atmospheric rivers are long filaments of moisture that curve poleward. Several are visible in this satellite image. Bin Guan, NASA/JPL-Caltech and UCLA

Zhe Li, University Corporation for Atmospheric Research

Atmospheric rivers – those long, narrow bands of water vapor in the sky that bring heavy rain and storms to the U.S. West Coast and many other regions – are shifting toward higher latitudes, and that’s changing weather patterns around the world.

The shift is worsening droughts in some regions, intensifying flooding in others, and putting water resources that many communities rely on at risk. When atmospheric rivers reach far northward into the Arctic, they can also melt sea ice, affecting the global climate.

In a new study published in Science Advances, University of California, Santa Barbara, climate scientist Qinghua Ding and I show that atmospheric rivers have shifted about 6 to 10 degrees toward the two poles over the past four decades.

Atmospheric rivers on the move

Atmospheric rivers aren’t just a U.S West Coast thing. They form in many parts of the world and provide over half of the mean annual runoff in these regions, including the U.S. Southeast coasts and West Coast, Southeast Asia, New Zealand, northern Spain, Portugal, the United Kingdom and south-central Chile.

California relies on atmospheric rivers for up to 50% of its yearly rainfall. A series of winter atmospheric rivers there can bring enough rain and snow to end a drought, as parts of the region saw in 2023.

Atmospheric rivers occur all over the world, as this animation of global satellite data from February 2017 shows. NASA/Goddard Space Flight Center Scientific Visualization Studio

While atmospheric rivers share a similar origin – moisture supply from the tropics – atmospheric instability of the jet stream allows them to curve poleward in different ways. No two atmospheric rivers are exactly alike.

What particularly interests climate scientists, including us, is the collective behavior of atmospheric rivers. Atmospheric rivers are commonly seen in the extratropics, a region between the latitudes of 30 and 50 degrees in both hemispheres that includes most of the continental U.S., southern Australia and Chile.

Our study shows that atmospheric rivers have been shifting poleward over the past four decades. In both hemispheres, activity has increased along 50 degrees north and 50 degrees south, while it has decreased along 30 degrees north and 30 degrees south since 1979. In North America, that means more atmospheric rivers drenching British Columbia and Alaska.

A global chain reaction

One main reason for this shift is changes in sea surface temperatures in the eastern tropical Pacific. Since 2000, waters in the eastern tropical Pacific have had a cooling tendency, which affects atmospheric circulation worldwide. This cooling, often associated with La Niña conditions, pushes atmospheric rivers toward the poles.

The poleward movement of atmospheric rivers can be explained as a chain of interconnected processes.

During La Niña conditions, when sea surface temperatures cool in the eastern tropical Pacific, the Walker circulation – giant loops of air that affect precipitation as they rise and fall over different parts of the tropics – strengthens over the western Pacific. This stronger circulation causes the tropical rainfall belt to expand. The expanded tropical rainfall, combined with changes in atmospheric eddy patterns, results in high-pressure anomalies and wind patterns that steer atmospheric rivers farther poleward.

An animation of satellite data shows sea surface temperatures changing over months along the equator in the eastern Pacific Ocean. When they're warmer than normal, that indicates El Niño forming. Cooler than normal indicates La Nina.
La Niña, with cooler water in the eastern Pacific, fades, and El Niño, with warmer water, starts to form in the tropical Pacific Ocean in 2023. NOAA Climate.gov

Conversely, during El Niño conditions, with warmer sea surface temperatures, the mechanism operates in the opposite direction, shifting atmospheric rivers so they don’t travel as far from the equator.

The shifts raise important questions about how climate models predict future changes in atmospheric rivers. Current models might underestimate natural variability, such as changes in the tropical Pacific, which can significantly affect atmospheric rivers. Understanding this connection can help forecasters make better predictions about future rainfall patterns and water availability.

Why does this poleward shift matter?

A shift in atmospheric rivers can have big effects on local climates.

In the subtropics, where atmospheric rivers are becoming less common, the result could be longer droughts and less water. Many areas, such as California and southern Brazil, depend on atmospheric rivers for rainfall to fill reservoirs and support farming. Without this moisture, these areas could face more water shortages, putting stress on communities, farms and ecosystems.

In higher latitudes, atmospheric rivers moving poleward could lead to more extreme rainfall, flooding and landslides in places such as the U.S. Pacific Northwest, Europe, and even in polar regions.

A long narrow band of moisture sweeps up toward California, crossing hundreds of miles of Pacific Ocean.
A satellite image on Feb. 20, 2017, shows an atmospheric river stretching from Hawaii to California, where it brought drenching rain. NASA/Earth Observatory/Jesse Allen

In the Arctic, more atmospheric rivers could speed up sea ice melting, adding to global warming and affecting animals that rely on the ice. An earlier study I was involved in found that the trend in summertime atmospheric river activity may contribute 36% of the increasing trend in summer moisture over the entire Arctic since 1979.

What it means for the future

So far, the shifts we have seen still mainly reflect changes due to natural processes, but human-induced global warming also plays a role. Global warming is expected to increase the overall frequency and intensity of atmospheric rivers because a warmer atmosphere can hold more moisture.

How that might change as the planet continues to warm is less clear. Predicting future changes remains uncertain due largely to the difficulty in predicting the natural swings between El Niño and La Niña, which play an important role in atmospheric river shifts.

As the world gets warmer, atmospheric rivers – and the critical rains they bring – will keep changing course. We need to understand and adapt to these changes so communities can keep thriving in a changing climate.

Zhe Li, Postdoctoral Researcher in Earth System Science, University Corporation for Atmospheric Research

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

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Those last two paragraphs of the above article show the difficulty in coming up with clear predictions of the future. As was said: ‘How that might change as the planet continues to warm is less clear. Predicting future changes remains uncertain due largely to the difficulty in predicting the natural swings between El Niño and La Niña, which play an important role in atmospheric river shifts.‘

Ancient times

This attracted me very much, and I wanted to share it with you.

The opening paragraph of this article caught my eye so I read it fully. As it was published in The Conversation then that meant I could republish it.

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Centuries ago, the Maya storm god Huracán taught that when we damage nature, we damage ourselves

An illustration of K’awiil, the Maya god of storm, on pottery. K2970 from the Justin Kerr Maya archive, Dumbarton Oaks, Trustees for Harvard University, Washington, D.C.

James L. Fitzsimmons, Middlebury

The ancient Maya believed that everything in the universe, from the natural world to everyday experiences, was part of a single, powerful spiritual force. They were not polytheists who worshipped distinct gods but pantheists who believed that various gods were just manifestations of that force.

Some of the best evidence for this comes from the behavior of two of the most powerful beings of the Maya world: The first is a creator god whose name is still spoken by millions of people every fall – Huracán, or “Hurricane.” The second is a god of lightning, K’awiil, from the early first millennium C.E.

As a scholar of the Indigenous religions of the Americas, I recognize that these beings, though separated by over 1,000 years, are related and can teach us something about our relationship to the natural world.

Huracán, the ‘Heart of Sky’

Huracán was once a god of the K’iche’, one of the Maya peoples who today live in the southern highlands of Guatemala. He was one of the main characters of the Popol Vuh, a religious text from the 16th century. His name probably originated in the Caribbean, where other cultures used it to describe the destructive power of storms.

The K’iche’ associated Huracán, which means “one leg” in the K’iche’ language, with weather. He was also their primary god of creation and was responsible for all life on earth, including humans.

Because of this, he was sometimes known as U K’ux K’aj, or “Heart of Sky.” In the K’iche’ language, k’ux was not only the heart but also the spark of life, the source of all thought and imagination.

Yet, Huracán was not perfect. He made mistakes and occasionally destroyed his creations. He was also a jealous god who damaged humans so they would not be his equal. In one such episode, he is believed to have clouded their vision, thus preventing them from being able to see the universe as he saw it.

Huracán was one being who existed as three distinct persons: Thunderbolt Huracán, Youngest Thunderbolt and Sudden Thunderbolt. Each of them embodied different types of lightning, ranging from enormous bolts to small or sudden flashes of light.

Despite the fact that he was a god of lightning, there were no strict boundaries between his powers and the powers of other gods. Any of them might wield lightning, or create humanity, or destroy the Earth.

Another storm god

The Popol Vuh implies that gods could mix and match their powers at will, but other religious texts are more explicit. One thousand years before the Popol Vuh was written, there was a different version of Huracán called K’awiil. During the first millennium, people from southern Mexico to western Honduras venerated him as a god of agriculture, lightning and royalty.

A drawing showing a reclining god-like figure with a large snake around him.
The ancient Maya god K’awiil, left, had an ax or torch in his forehead as well as a snake in place of his right leg. K5164 from the Justin Kerr Maya archive, Dumbarton Oaks, Trustees for Harvard University, Washington, D.C.

Illustrations of K’awiil can be found everywhere on Maya pottery and sculpture. He is almost human in many depictions: He has two arms, two legs and a head. But his forehead is the spark of life – and so it usually has something that produces sparks sticking out of it, such as a flint ax or a flaming torch. And one of his legs does not end in a foot. In its place is a snake with an open mouth, from which another being often emerges.

Indeed, rulers, and even gods, once performed ceremonies to K’awiil in order to try and summon other supernatural beings. As personified lightning, he was believed to create portals to other worlds, through which ancestors and gods might travel.

Representation of power

For the ancient Maya, lightning was raw power. It was basic to all creation and destruction. Because of this, the ancient Maya carved and painted many images of K’awiil. Scribes wrote about him as a kind of energy – as a god with “many faces,” or even as part of a triad similar to Huracán.

He was everywhere in ancient Maya art. But he was also never the focus. As raw power, he was used by others to achieve their ends.

Rain gods, for example, wielded him like an ax, creating sparks in seeds for agriculture. Conjurers summoned him, but mostly because they believed he could help them communicate with other creatures from other worlds. Rulers even carried scepters fashioned in his image during dances and processions.

Moreover, Maya artists always had K’awiil doing something or being used to make something happen. They believed that power was something you did, not something you had. Like a bolt of lightning, power was always shifting, always in motion.

An interdependent world

Because of this, the ancient Maya thought that reality was not static but ever-changing. There were no strict boundaries between space and time, the forces of nature or the animate and inanimate worlds.

People walking through knee-deep water on a flooded street with building on either side and electric wires overhead.
Residents wade through a street flooded by Hurricane Helene, in Batabano, Mayabeque province, Cuba, on Sept. 26, 2024. AP Photo/Ramon Espinosa

Everything was malleable and interdependent. Theoretically, anything could become anything else – and everything was potentially a living being. Rulers could ritually turn themselves into gods. Sculptures could be hacked to death. Even natural features such as mountains were believed to be alive.

These ideas – common in pantheist societies – persist today in some communities in the Americas.

They were once mainstream, however, and were a part of K’iche’ religion 1,000 years later, in the time of Huracán. One of the lessons of the Popol Vuh, told during the episode where Huracán clouds human vision, is that the human perception of reality is an illusion.

The illusion is not that different things exist. Rather it is that they exist independent from one another. Huracán, in this sense, damaged himself by damaging his creations.

Hurricane season every year should remind us that human beings are not independent from nature but part of it. And like Hurácan, when we damage nature, we damage ourselves.

James L. Fitzsimmons, Professor of Anthropology, Middlebury

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

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It is such a powerful message, that when we damage nature, we damage ourselves.

But I am unaware, no we are both unaware of a solution, and there doesn’t appear to be a government desire to make this the number one topic.

Please, if there is anyone who reads this post and has a more positive message then we would be very keen to hear from you.

Picture Parade Four Hundred and Fifty

Today is the Autumn Equinox.

At the equinoxes, the ecliptic and the celestial equator intersect. See the intersection point on this imaginary great circle, representing the dome of Earth’s sky? The celestial equator is directly above Earth’s equator. The ecliptic is the sun’s apparent path across our sky. And the celestial equator intersects your horizon at points due east and due west. That’s why – at every equinox, no matter where you are on the globe – the sun, on the celestial equator, rises due east and sets due west. Image via NASA.

This September equinox happens at 12:44 UTC or 04:44 Pacific Daylight Time today, September 22, 2024.

The equinox sun rises due east and sets due west

It’s not true that day and night are precisely equal on the day of an equinox. But here’s an equinox fact that is true. The sun rises due east and sets due west at the equinox. It might seem counterintuitive. But it’s true no matter where you live on Earth (except at the North and South Poles). Here’s how to visualize it.

To understand the nearly due-east and due-west rising and setting of an equinox sun, you have to think of the reality of Earth in space. First think about why the sun’s path across our sky shifts from season to season. That’s because our world is tilted on its axis with respect to its orbit around the sun.

Read the rest of this article here: https://earthsky.org/tonight/equinox-sun-rises-due-east-and-sets-due-west/

Fantastic advice re dogs for seniors

A great post on WebMD.

Now I appreciate that many who come to this place are not seniors but as I approach 80 that makes me most definitely a senior.

So this article was highly relevant.

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Best Dogs for Seniors

Medically Reviewed by Poonam Sachdev on October 12, 2023

Written by WebMD Editorial Contributors

Any dog owner can tell you there’s nothing like having a loyal companion. Dogs are good pets for people of any age, as long as you choose the right dog for your lifestyle.

If you’re an older adult looking to find a furry, four-legged friend, here are a few things you should consider. 

Why Get a Dog?

It’s a big responsibility, but the benefits are worth the work. Dogs can give you joy, companionship, and unconditional love. They can bring warmth and comfort into your life.

Better health. Decades of studies have shown the health benefits of spending time with dogs. Dog owners tend to have better heart and blood vessel health, including lower blood pressure, than those who don’t have a pet pup. That’s because dogs get people moving. Walking a dog regularly can help you boost how much exercise you get each day.

Less lonely. Dogs offer companionship just by being around. They might also help you be more social. Taking your dog on walks gives you a chance to meet neighbors or other canine owners at the local dog park.

Much happier. Looking at your dog can release a hormone that makes you feel happier. Science shows that gazing into your dog’s eye releases oxytocin. Known as the love hormone, oxytocin quickly boosts your mood.

Caring for a Dog

Before you get a furry pal, you should think about what you can offer the dog, as well as what they can offer you. You want to make sure to choose a dog that will be happy with the kind of life you lead. Consider these things when you start looking for a new pet.

Space. How much room do you have indoors and outdoors? You need to pick a dog that will be happy with the space you have to offer. 

Exercise. Some dogs need a lot of exercise, while others are happy hanging out on the couch all day. Think about how much exercise time you can give your pup. Also, think about how fit you are. You may not want a large, strong dog that could tug hard on the leash and cause you to get hurt on a walk.

Cost. All dogs need vet care, food, and toys. If they need a lot of grooming, you need to consider paying a professional groomer.

Age. Puppies are cute, but they’re also a lot of work. Older dogs may already have some training, but they might be set in their ways. Spend some time thinking about what you’re willing to accept in dog behavior.

Best Breeds for Seniors

Here are a few breeds that are natural choices for older adults.

Bichon Frise. These dogs are very small and cute. Their fluffy coats need regular grooming. They’re happy in small homes and apartments, and they only need moderate exercise.

Cocker spaniels. These dogs are known for their beautiful, soft coats, which need regular grooming. They’re gentle and friendly, and usually weigh under 30 pounds. They need regular walks to stay fit, but they aren’t highly energetic.

Beagles. They’re small, smart, and make wonderful companions. Their short coats are easy to groom. Beagles are energetic and need a lot of exercise every day.

Greyhounds. They can run fast, but they don’t always want to. They’re happiest lounging around indoors, but they need walks to stay fit. They’re large, usually weighing around 60 pounds, but they have short coats that don’t require a lot of grooming.

Pugs. These happy little dogs make great companions. They’re usually around 15 pounds and have short, easy-to-groom coats. They need more exercise than they want because they’re prone to be overweight. Regular walks can take care of that.

If you’re an older adult looking for a four-legged companion, you can speak to a veterinarian or a dog trainer in your area for more information. They can help you choose the perfect pet.

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I am certain there are many people who will find this a practical help in deciding what dog to get.

In my own case we currently have two dogs, Cleo and Oliver, and I frequently ponder on what Jean and I do when the last of them dies.

This article reminds me and Jean that at whatever age we are it is better to have a dog than not!

There is no-one else

We are speaking of the universe.

I follow Patrice Ayme and have done for many years. Some of his posts are super-intellectual and those I struggle to understand.

But a post published on September 8th, 2024 was very easy for me, and countless others no doubt, to understand and I have pleasure in republishing it on Learning from Dogs today.

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No Civilizations Out There, We Are It. We Must Rise To The Occasion

September 8, 2024

I doubt that there are civilizations around. We are facing a galaxy devoid of intelligent aliens: little green mats out there, not little green men.

First, we don’t see them. With foreseeable technology (hibernation, nuclear propulsion, compact thermonuclear reactors, bioengineering, AI, quantum computers) we should be able to send very large interstellar spaceships at 1,000 kilometers per second… Thus it would take a millennium to colonize the Centaur tri-star system…. 25,000 years to colonize a 200 light years across ball… And the entire galaxy in ten million years… Wars would only accelerate the expansion. So if there was a galactic civilization, within ten million years it would have spanned the entire galaxy and its presence should be in sight.

Second, life took nearly four billion years to evolve animals. Bacterial life could have been nearly extinguished on Earth many times…. Be it only during the Snowball Earths episodes. A star whizzing by could have launched a thousand large comets. The large planets could have fallen inward.

Third, ultra intelligent life may not be able to have hands or tentacles and thus develop industry. Once intelligent life forms have evolved, say sea lions or parrots, let alone wolves, they may just be sitting ducks for the next disaster which would revert life to the bacterial level, erasing billions of years of evolution.

Fourth, when civilization is launched, it can fail… And not get a second chance (from lack of availability of mines after easy picking during the initial civilization).

Fifth, nuclear powered Earth is special. Earth has plate tectonics, probably from a nuclear reactor at the core, keeps the CO2 just so for a temperate temperature… Water, but not too much. Her large Moon stabilizes her. Earth doesn’t have a weird rotation like Venus (retrograde and slow) or Mars (spectacularly tilting axis). Ian Miller has aluminosilicates considerations on top of that.

So I don’t expect little green men… Besides those sent by the perverse Putin…

Just when we thought we knew of all the stress, here is another one: if we go extinct, the universe loses its soul! We have thus found a new Superior Moral Directive: SUS, Save Unique Soul!

Expect little green mats, not little green men.

Patrice Ayme

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A couple of weeks ago I gave a talk to our local Freethinkers group and called it The Next Ten Years. It began, thus:

This presentation is about the world of the future; of the near future. And the biggest issue, most agree, is the change in the climate. 

The Global Temperature anomaly, as of last year, 2023, is 1.17 Centigrade, 2.11 Fahrenheit, above the long-term average from 1951 to 1980. The 10 most recent years are the warmest years on record.

Antoine de Saint-Exupéry is quoted as saying that ‘a goal without a plan is just a wish.’ So my plan is to show you how we can change, no let me put that more strongly, how we must change in the next ten years. Because our present habits are ruining the world.

The weather conundrum!

We are in an era of unknown weather, across the world!

Niccolò Ubalducci Photographer
Photo by Niccolò Ubalducci

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The climate is changing so fast that we haven’t seen how bad extreme weather could get

Simon H. Lee, University of St Andrews; Hayley J. Fowler, Newcastle University, and Paul Davies, Newcastle University

Published: July 30, 2024

Extreme weather is by definition rare on our planet. Ferocious storms, searing heatwaves and biting cold snaps illustrate what the climate is capable of at its worst. However, since Earth’s climate is rapidly warming, predominantly due to fossil fuel burning, the range of possible weather conditions, including extremes, is changing.

Scientists define “climate” as the distribution of possible weather events observed over a length of time, such as the range of temperatures, rainfall totals or hours of sunshine. From this they construct statistical measures, such as the average (or normal) temperature. Weather varies on several timescales – from seconds to decades – so the longer the period over which the climate is analysed, the more accurately these analyses capture the infinite range of possible configurations of the atmosphere.

Typically, meteorologists and climate scientists use a 30-year period to represent the climate, which is updated every ten years. The most recent climate period is 1991-2020. The difference between each successive 30-year climate period serves as a very literal record of climate change.

This way of thinking about the climate falls short when the climate itself is rapidly changing. Global average temperatures have increased at around 0.2°C per decade over the past 30 years, meaning that the global climate of 1991 was around 0.6°C cooler than that in 2020 (when accounting for other year-to-year fluctuations), and even more so than the present day.

A moving target for climate modellers

If the climate is a range of possible weather events, then this rapid change has two implications. First, it means that part of the distribution of weather events comprising a 30-year climate period occurred in a very different background global climate: for example, northerly winds in the 1990s were much colder than those in the 2020s in north-west Europe, thanks to the Arctic warming nearly four times faster than the global average. Statistics from three decades ago no longer represent what is possible in the present day.

Second, the rapidly changing climate means we have not necessarily experienced the extremes that modern-day atmospheric and oceanic warmth can produce. In a stable climate, scientists would have multiple decades for the atmosphere to get into its various configurations and drive extreme events, such as heatwaves, floods or droughts. We could then use these observations to build up an understanding of what the climate is capable of. But in our rapidly changing climate, we effectively have only a few years – not enough to experience everything the climate has to offer.

Extreme weather events require what meteorologists might call a “perfect storm”. For example, extreme heat in the UK typically requires the northward movement of an air mass from Africa combined with clear skies, dry soils and a stable atmosphere to prevent thunderstorms forming which tend to dissipate heat.

Such “perfect” conditions are intrinsically unlikely, and many years can pass without them occurring – all while the climate continues to change in the background. Based on an understanding of observations alone, this can leave us woefully underprepared for what the climate can now do, should the right weather conditions all come together at once.

Startling recent examples include the extreme heatwave in the Pacific north-west of North America in 2021, in which temperatures exceeded the previous Canadian record maximum by 4.6°C. Another is the occurrence of 40°C in the UK in summer 2022, which exceeded the previous UK record maximum set only three years earlier by 1.6°C. This is part of the reason why the true impact of a fixed amount of global warming is only evident after several decades, but of course – since the climate is changing rapidly – we cannot use this method anymore.

Playing with fire

To better understand these extremes, scientists can use ensembles: many runs of the same weather or climate model that each slightly differ to show a range of plausible outcomes. Ensembles are routinely used in weather prediction, but can also be used to assess extreme events which could happen even if they do not actually happen at the time.

When 40°C first appeared in ensemble forecasts for the UK before the July 2022 heatwave, it revealed the kind of extreme weather that is possible in the current climate. Even if it had not come to fruition, its mere appearance in the models showed that the previously unthinkable was now possible. In the event, several naturally occurring atmospheric factors combined with background climate warming to generate the record-shattering heat on July 19 that year.

The highest observed temperature each year in the UK, from 1900 to 2023

A graph showing the highest observed temperature in the UK between 1900 and 2023.
The hottest days are getting hotter in the UK. Met Office/Kendon et al. 2024

Later in summer 2022, after the first occurrence of 40°C, some ensemble weather forecasts for the UK showed a situation in which 40°C could be reached on multiple consecutive days. This would have posed an unprecedented threat to public health and infrastructure in the UK. Unlike the previous month, this event did not come to pass, and was quickly forgotten – but it shouldn’t have been.

It is not certain whether these model simulations correctly represent the processes involved in producing extreme heat. Even so, we must heed the warning signs.

Despite a record-warm planet, summer 2024 in the UK has been relatively cool so far. The past two years have seen global temperatures far above anything previously observed, and so potential extremes have probably shifted even further from what we have so far experienced.

Just as was the case in August 2022, we’ve got away with it for now – but we might not be so lucky next time.

Simon H. Lee, Lecturer in Atmospheric Science, University of St Andrews; Hayley J. Fowler, Professor of Climate Change Impacts, Newcastle University, and Paul Davies, Chief Meteorologist, Met Office and Visiting Professor, Newcastle University

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

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That last sentence says it all: “Just as was the case in August 2022, we’ve got away with it for now – but we might not be so lucky next time.”

I am giving a talk, The Next Ten Years, next Saturday to our local Freethinkers group in Grants Pass. Close to the start of the presentation I say: “The Global Temperature anomaly, as of last year, 2023, is 1.17 C, 2.11 F, above the long-term average from 1951 to 1980. The 10 most recent years are the warmest years on record.“

Finally, I am getting on in age and part of me wants to die, hopefully naturally, before more climate extremes are reached, but then another part of me would like to experience it!

Essentially, life is about play

We take our decision from watching the animal kingdom.

A recent post in The Conversation provides the article for today’s blog post.

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At its core, life is all about play − just look at the animal kingdom

Throw it to me! Mike Linnane / 500px via Getty Images

David Toomey, UMass Amherst

At Cambridge University Library, along with all the books, maps and manuscripts, there’s a child’s drawing that curators have titled “The Battle of the Fruit and Vegetable Soldiers.”

The drawing depicts a turbaned cavalry soldier facing off against an English dragoon. It’s a bit trippy: The British soldier sits astride a carrot, and the turbaned soldier rides a grape. Both carrot and grape are fitted with horses’ heads and stick appendages.

A child's drawing of two soldiers ridind a grape and a carrot
‘The Battle of the Fruit and Vegetable Soldiers,’ a drawing on the back of a manuscript page from Charles Darwin’s ‘On the Origin of Species,’ attributed to Darwin’s young son Francis. Cambridge University Library, CC BY-ND

It’s thought to be the work of Francis Darwin, the seventh child of British naturalist Charles Darwin and his wife, Emma, and appears to have been made in 1857, when Frank would have been 10 or 11. And it’s drawn on the back of a page of a draft of “On the Origin of Species,” Darwin’s masterwork and the foundational text of evolutionary biology. The few sheets of the draft that survive are pages Darwin gave to his children to use for drawing paper.

Darwin’s biographers have long recognized that play was important in his personal and familial life. The Georgian manor in which he and Emma raised their 10 children was furnished with a rope swing hung over the first-floor landing and a portable wooden slide that could be laid over the main stairway. The gardens and surrounding countryside served as an open-air laboratory and playground.

Play also has a role in Darwin’s theory of natural selection. As I explain in my new book, “Kingdom of Play: What Ball-bouncing Octopuses, Belly-flopping Monkeys, and Mud-sliding Elephants Reveal about Life Itself,” there are many similarities – so many that if you could distill the processes of natural selection into a single behavior, that behavior would be play.

No goal, no direction

Natural selection is the process by which organisms that are best adapted to their environments are more likely to survive, and so able to pass on the characteristics that helped them thrive to their offspring. It is undirected: In Darwin’s words, it “includes no necessary and universal law of advancement or development.”

Through natural selection, the rock pocket mouse has evolved a coat color that hides it from predators in the desert Southwest.

In contrast to foraging and hunting – behaviors with clearly defined goals – play is likewise undirected. When a pony frolics in a field, a dog wrestles with a stick or chimpanzees chase each other, they act with no goal in mind.

Natural selection is utterly provisional: The evolution of any organism responds to whatever conditions are present at a given place and time. Likewise, animals at play are acting provisionally. They constantly adjust their movements in response to changes in circumstances. Playing squirrels, faced with obstacles such as falling branches or other squirrels, nimbly alter their tactics and routes.

Natural selection is open-ended. The forms of life are not fixed, but continually evolving. Play, too, is open-ended. Animals begin a play session with no plan of when to end it. Two dogs play-fighting, for instance, cease playing only when one is injured, exhausted or simply loses interest.

Natural selection also is wasteful, as Darwin acknowledged. “Many more individuals of each species are born than can possibly survive,” he wrote. But in the long term, he allowed, such profligacy could produce adaptations that enable an evolutionary line to become “more fit.”

Keepers noticed that Shanthi, a 36-year-old elephant at the Smithsonian national zoo, liked to make noise with objects, so they gave her horns, harmonicas and other noisemakers.

Play is likewise profligate. It requires an animal to expend time and energy that perhaps would be better devoted to behaviors such as foraging and hunting that could aid survival.

And that profligacy is also advantageous. Animals forage and hunt in specific ways that don’t typically change. But an animal at play is far more likely to innovate – and some of its innovations may in time be adapted into new ways to forage and hunt.

Competing and cooperating

As Darwin first framed it, the “struggle for existence” was by and large a competition. But in the 1860s, Russian naturalist Pyotr Kropotkin’s observations of birds and fallow deer led him to conclude that many species were “the most numerous and the most prosperous” because natural selection also selects for cooperation.

Scientists confirmed Kroptokin’s hypothesis in the 20th century, discovering all manner of cooperation, not only between members of the same species but between members of different species. For example, clown fish are immune to anemone stings; they nestle in anemone tentacles for protection and, in return, keep the anemones free of parasites, provide nutrients and drive away predators.

Play likewise utilizes both competition and cooperation. Two dogs play-fighting are certainly competing, yet to sustain their play, they must cooperate. They often reverse roles: A dog with the advantage of position might suddenly surrender that advantage and roll over on its back. If one bites harder than intended, it is likely to retreat and perform a play bow – saying, in effect, “My bad. I hope we can keep playing.”

River otters at the Oregon Zoo repeatedly separate and reunite while playing in a tub of ice.

Natural selection and play also may both employ deception. From butterflies colored to resemble toxic species to wild cats that squeal like distressed baby monkeys, many organisms use mimicry to deceive their prey, predators and rivals. Play – specifically, play-fighting – similarly offers animals opportunities to learn about and practice deception.

To live is to play

Darwin wrote that natural selection creates “endless forms most beautiful and most wonderful.” Play also creates beauty in countless ways, from the aerial acrobatics of birds of prey to the arcing, twisting leaps of dolphins.

In 1973, Ukrainian-American geneticist Theodosius Dobzhansky published an essay with the take-no-prisoners title “Nothing in Biology Makes Sense Except in the Light of Evolution.” Many biologists would agree. Perhaps the most satisfying definition of life attends not to what it is but to what it does – which is to say, life is what evolves by natural selection.

And since natural selection shares so many features with play, we may with some justification maintain that life, in a most fundamental sense, is playful.

David Toomey, Professor of English, UMass Amherst

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

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Prof. Toomey’s analysis is spot-on.

All of life involves some form of play.