Why Are Basalt Columns Mostly Hexagonal “Bestagons”
The Giant’s Causeway is a rock formation that is so otherworldly that it seems like it was made by supernatural beings. But these incredible hexagonal columns of rock aren’t the result of giant masons. They formed through a quirk of volcanic activity that shows that hexagons really are the bestagons! Cooling lava naturally creates hexagonal cracks to evenly relieve stress When lava cools and turns into rock, it contracts and builds up tension, particularly when held in place by the surrounding landscape. Just as drying mud cracks, initial cracks in the rock are random, but quickly organize into a hexagonal pattern, which scientists consider the most space-efficient shape. Note: the presentation talks about lava cooling from the top down, but it also cools upward from the bottom where it flowed onto a cooler land surface. In our area we typically see columns underlying a more chaotically fractured “entablature”. It is generally thought that because the entablature section is exposed to the air and precipitation, that results in rapid cooling that produces chaotic fracturing. The columnar section which is cooling upward from the base, would experience a much slower and more even rate of cooling, allowing it to better organize into an optimal, space-efficient “bestagonal” shape. Found via SciShow, hosted by: Niba @NotesbyNiba
There IS such a thing as ‘settled science’
How bad-faith arguments sow doubt by weaponizing scientific humility Good advice to consider when either claiming or questioning scientific (and geologic) theories and hypotheses “Science is never settled” has become a go-to slogan for populists seeking to legitimize fringe scientific positions. In 2020, Representative Nancy Mace was asked whether she agreed that climate change is the result of humanmade greenhouse emissions. She responded: “My opponent has said that the science is settled on this. Well, the science is never settled. Scientists will tell you that.” In February, Senator Roger Marshall argued more money should be spent on investigating widely debunked links between autism and vaccines, saying “I’m a physician. Science is never settled. That’s what makes us scientists.” When U.K. Reform party leader Nigel Farage was pressed on whether he would “side with medical experts who say ‘a link between Tylenol use in pregnancy and autism’ is dangerous nonsense,” he responded, “When it comes to science, I don’t side with anybody… because science is never settled.” The issue is, of course, that in many areas, from the theory of evolution to the theory of gravity, science is very much settled. To pretend otherwise is to misrepresent the position of the scientific community. That doesn’t mean that scientific positions are eternally fixed and can’t be updated in light of new evidence. It means that our current best explanations have been tested enough for us to be confident that they are good descriptions of the way things work. Myth of overturned consensus A favorite trope of climate denialists is that scientists in the 1970s predicted “global cooling” — an imminent ice age. It’s a smart argument, because if you can suggest that the exact opposite of global warming was once the prevailing view, surely you throw the current consensus on climate science into doubt? Despite media attention and much discussion of the idea, global cooling was never a consensus scientific position. Reviews of the literature at the time show that even 50 years ago, global warming dominated scientific thinking about the Earth’s short-term climate future. That climate change is the result of greenhouse gas emissions is now very much the consensus scientific position. There are, however, examples in science where consensus positions have been modified or updated. Gravity is a classic case. Galileo established that acceleration due to gravity is the same for all objects near Earth’s surface. But it wasn’t until Newton that we had a universal theory of gravitation. Newton’s theory unified the behavior of objects falling on earth with the motions of planets. For years, every measurement seemed to confirm it, and the theory became known as a “law” that nature was thought to obey without exception. But as experiments expanded and instruments improved, the edges of Newton’s “law” began to fray. When dealing with strong gravitational fields like those near a black hole, or when calculating to high precision or over short astronomical distances, Newton’s law wasn’t sufficient. In the 20th century, Einstein’s general relativity filled many gaps — resolving a range of seeming astronomical anomalies and describing how light bends near a black hole. Yet even the relativistic interpretation of gravity is not perfect. We know, for example, that it must break down inside a black hole. First Galileo’s and then Newton’s theories were superseded, and we know Einstein’s isn’t correct in every situation. Does that mean these earlier theories are useless and not examples of settled science? Definitely not. In contexts where these theories have been rigorously tested and shown to give the correct answers (to a given degree of precision), they remain valid. They aren’t wrong — just special cases of the more general theories, valid within a given domain of legitimacy in which they were originally postulated and tested. In the same way, whatever supersedes Einstein’s theory will have to include it as a special case. The example of gravity shows that scientific knowledge can evolve yet still be considered settled within its domain of legitimacy. We can point to other consensuses, like evolution or germ theory, as settled science that has been expanded and generalized over time. Scientific ‘facts’ There are also questions that most would call definitively settled. That Earth is round, not flat, is perhaps the most obvious. But whether we choose to call this a “fact” or not depends on how we define the word. If we demand 100% certainty, science can’t provide it. If you want certainty, you need to look to mathematics, where knowledge is built through deduction from axioms (a fundamental set of premises), independent of the world. Science, in contrast, built on evidence and induction, can only ever offer increasing confidence. A key premise of the scientific method is openness to new evidence. If you consider yourself 100% certain, then no new evidence, however convincing, can change your mind. That is not good science. However, if you accept that science provides evidence for hypotheses, it can offer what we might call indisputable evidence — so robust that disputing it isn’t a tenable position. Overturning the not-flat worldview would require such a massive reconsideration of what we understand about reality as to make it practically impossible. So, “settled science” does not mean we know something with absolute certainty, but that the weight of evidence is heavily in favor of this interpretation. Perhaps more importantly, if someone wants to change the currently held conception, the burden of proof is on them. All scientific knowledge comes with uncertainty. That is the hallmark of good science. But uncertainty doesn’t mean we cannot confidently assert that entropy always increases (the second law of thermodynamics) or that Earth orbits the sun. Science embraces uncertainty and is open to revision when new information appears, but that does not mean we shouldn’t take a position when the evidence stacks up on one side of the balance. Issues that have been rigorously tested can still be considered settled. Not being 100% certain isn’t the same as being 50-50. Admitting doubt isn’t the same as both-siding a one-sided issue. The fact that scientists acknowledge uncertainty isn’t a reason for championing false balance. But these are the fallacious positions populists are taking when
The first people in the Americas
The first people to arrive in the Western Hemisphere were Indigenous Americans, who were descended from an ancestral group of Ancient North Siberians and East Asians. They likely traveled along the Bering Land Bridge by land or sea. When the first Americans arrived is a source of ongoing debate. Several studies suggest that a series of fossilized human footprints found at White Sands National Park in New Mexico date to sometime between 21,000 and 23,000 years ago. That dates them to the coldest part of the last ice age, the last glacial maximum (which lasted from around 26,500 to 19,000 years ago), when the northern part of the continent was covered in glaciers and ice sheets. Other controversial studies suggest even earlier dates. For example, dated stone artifacts in Chiquihuite Cave, in Mexico, to more than 30,000 years ago. However, it’s unclear if humans actually crafted these rocks or if they formed naturally that way, making the finding uncertain. Other studies go back much further. In 2017, a controversial study in the journal Nature reported mastodon bones in California that may have been modified by humans around 130,000 years ago. However, other archaeologists have expressed concerns about the excavation of this finding and noted that other natural events or animals could have modified the bones. To put the 130,000-year-old date into context, the earliest evidence for Homo sapiens dates to around 300,000 years ago in Morocco, while the earliest evidence for a successful migration of humans into Asia was more than 100,000 years ago and the earliest evidence of successful human migration into Europe was around 55,000 years ago. Excerpted from Who discovered America? By Owen Jarus in LiveScience
Amazing Forensics Solve 150-Million-Year Pterosaur Mystery
Two tiny pterosaur fossils, each smaller than a mouse, have finally solved a puzzle that has mystified paleontologists for decades. The perfectly preserved hatchlings, nicknamed “Lucky I” and “Lucky II,” were discovered in Germany’s famous Solnhofen limestone formations and reveal both how they died and why juvenile flying reptiles dominate this fossil record. The Tragic Discovery Both Pterodactylus hatchlings, just one to two weeks old when they perished, share a telling characteristic: broken wing bones with identical fracture patterns. The clean, slanted breaks to their humerus bones suggest the same type of twisting force killed them both 150 million years ago. University of Leicester paleontologist Rab Smyth and his team reconstructed their final moments through careful forensic analysis. The evidence points to a violent Late Jurassic storm that battered the tiny pterosaurs with winds so powerful their fragile wing bones snapped under pressure. The same storm then hurled their bodies into a saltwater lagoon, where churning waters quickly carried them to the bottom for rapid burial and exceptional preservation. Solving the Solnhofen Paradox The discovery resolves a long-standing mystery about the Solnhofen formations, which contain hundreds of pterosaur specimens but are dominated by juveniles. This seemed counterintuitive since young pterosaurs had more fragile bones and should be less likely to fossilize than adults. The research reveals this apparent contradiction actually makes perfect sense. The same catastrophic storms that killed vulnerable hatchlings created ideal conditions for their preservation. Adult pterosaurs, being stronger and more experienced, could survive the violent weather that proved fatal to their offspring. When adults eventually died under calm conditions, their remains would float and decompose before sinking, making fossilization unlikely. “For centuries, scientists believed that the Solnhofen lagoon ecosystems were dominated by small pterosaurs,” Smyth explains. “But we now know this view is deeply biased. Many of these pterosaurs weren’t native to the lagoon at all – they were inexperienced juveniles caught up in powerful storms.” Broader Implications This discovery transforms our understanding of pterosaur ecology and fossil preservation. Rather than reflecting true population dynamics, the juvenile-heavy fossil record represents a preservation bias created by extreme weather events. The findings also provide rare insight into Late Jurassic climate patterns, suggesting violent storms regularly impacted ancient ecosystems. The research exemplifies how modern paleontology combines traditional fossil analysis with environmental reconstruction. By examining preservation circumstances alongside the bones themselves, scientists can extract far more information from specimens and avoid misinterpreting ancient ecosystems. Published in Current Biology, this work offers a new framework for understanding how environmental factors influence fossil records – reminding us that every preserved specimen tells a story not just about the creature’s life, but about the dramatic events that led to its preservation across deep time. AI adapted from Original reporting by Michelle Starr, ScienceAlert about research by Rab Smyth and colleagues, University of Leicester..
DNR Releases Stunning Dry Falls Visualization
DNR’s Daniel Coe collaborating with Joel Gombiner has produced a stunning arial oblique visualization and poster showing incredible detail of the Dry Falls geologic complex. The DNR webpage announcing the release also shows additional materials like sliders illustrating differences in image capture resolution and grayscale vs. color representation, as well as Bretz’s scaled line drawing sketch comparing the Dry Falls Complex to Niagara Falls.
“The Next Big One” – NOVA|PBS Short Video
NOVA|PBS is sharing a short 5:16 min) video, THE NEXT “BIG ONE” – The Next Big Earthquake Could Sink Parts of the Pacific Northwest. It contains a brief explanation of the potential timing, causes, and some effects of the impending and widely-feared next Cascadia Earthquake Zone rupture. It’s worth a watch for most anyone in the PacNW.
Greenland’s Subglacial Surprises: How Subglacial Breakouts Might Have Shaped Ice Age Landscapes
Recent discoveries in Greenland are reshaping our understanding of massive flood events beneath ice sheets, offering compelling new perspectives on the formation of some Ice Age Floods-related features. Two recent studies highlight an unprecedented sub-glacial flood in 2014, where a staggering 90 billion liters of meltwater unexpectedly burst through nearly 91 meters (300 feet) of solid ice. This previously undocumented phenomenon in Greenland involved a massive volume of water punching upwards, fracturing the surface, and creating a 2-square-kilometer (0.77 square-mile) crater 85 meters (279 feet) deep. Satellite data revealed that the ice surface dropped dramatically after having bulged from water pressure. Evidence downstream showed a heavily fractured area with large ice boulders and a scoured ice surface, indicative of immense erosive power. This event challenges previous assumptions that the base of ice sheets is always frozen solid and provides critical insights into the destructive potential of sub-glacial meltwater. While the iconic Missoula Floods are well-established as a result of glacial lake outbursts, this Greenland discovery suggests that other, perhaps more localized or intermittent, sub-glacial flood breakouts could have played a significant role in shaping the landscape during past ice ages. Such events could explain certain geomorphological features that don’t neatly fit the Missoula Flood narrative, such as Moses Coulee and possibly much of the Upper Grand Coulee, opening new avenues for research into the diverse origins of Ice Age Floods-related landforms. AI-condensed from articles in LiveScience by Ben Turner and ScienceAlert by Michelle Starr
Hells Canyon Caves Reveal When it was Cut
The origin story of Hells Canyon, North America’s deepest river gorge, has long been unclear to scientists. But new research estimates it formed about 2.1 million years ago when a dramatic flood event likely created a river over the deep gorge. The researchers made the finding after studying clues hidden in the landscape and river deposits preserved in caves. They described their findings in a study published May 19 in the journal PNAS>. Hells Canyon borders Oregon, Idaho and Washington. It’s cut through by the Snake River and is North America’s deepest river gorge, at 10 miles (16 kilometers) wide and about 1.5 miles (2.4 km) deep — almost 2,000 feet deeper than the Grand Canyon. Canyons are inherently difficult to understand and date, said study lead author Matthew Morriss, a geologist at the Utah Geological Survey. “As a river erodes and carves a canyon, it sort of destroys the evidence of its own history,” Morriss told Live Science. But because Hells Canyon is so steep, he guessed it was carved quickly. To find out how the gorge formed, the team examined caves along the side of the canyon. When floods cause rivers to swell, they can deposit sediment into caves where it’s then preserved, Morriss said. The researchers analyzed gravel deposited by the Snake River in three caves along the sides of Hells Canyon, and estimated the age of the deposited material using isotope dating. This enabled the researchers to determine when the river was higher than its current level, which would have been when it was shaping the canyon. The team combined this information with the locations of knickpoints — drastic changes in river steepness where the rivers connect to the gorge — to piece together Hells Canyon’s history. These clues suggest that Hells Canyon formed when water diverted from Lake Idaho into the current route of the gorge to form what’s now the Snake River. The lake may have spilled over because of higher precipitation, or changes to the continental divide, Morriss said. This caused a river to form a path over the area that’s now Hells Canyon, and the water slowly began eroding rock about 5 million years ago, then carved the gorge much more quickly from about 2.1 million years ago. The canyon’s age was unexpected. “The age of the canyon was so much younger than I thought it would be,” Morriss said. “I had no idea it could be as young as 2 million years old — that’s younger than the Grand Canyon, which most people think could be about 5 million years old.” Hells Canyon has a lot in common with the Grand Canyon, according to Karl Karlstrom, geologist at the University of New Mexico whose work focuses on the Grand Canyon, and who was not involved with the new research. “The Grand Canyon and Hells Canyon always get compared to each other,” said Karlstrom. “They’re both big canyons with big rivers at the bottom, they’re about the same length and the same width,” Karlstrom told Live Science, but this study gives a clear picture of Hells Canyon’s distinct history. “To me this paper is a good hypothesis, and it paves the way for next generations of work,” Karlstrom said. Dating more caves in the canyon, and integrating other dating methodologies, could refine the findings and make the dates more precise, Karlstrom added. The findings can inform research on other canyons that may have been carved quickly by rivers, Morriss said. Understanding the history of Hells Canyon also gives insight into how the canyon’s formation shaped the surrounding ecosystem, as some animal species are divided by the canyon and others connected across it. Many landscape features of the southwestern U.S., like Hells Canyon and the Grand Canyon, are younger than previously expected. “[The] Western U.S. has a young and ever changing landscape that has been reshaped in the past few million years and is currently still adjusting,” Karlstrom said. This shows just how quickly — on the scale of geological time — a landscape can dramatically change, he noted. LiveScience article by Olivia Ferrari
Anthropoclastite – Rock Formed in 35 Years or Less
New research reveals industrial waste can turn into rock in as little as 35 years, instead of the thousands or millions of years previously assumed. The finding challenges what scientists know about rock formation, revealing an entirely new “anthropoclastic rock cycle.” The scientists found that waste from seaside industrial plants turns into rock especially rapidly due to the ocean water and air, which activate minerals such as calcium and magnesium in the waste, or slag, cementing it together faster than natural sediments. For a couple of hundred years, we’ve understood the rock cycle as a natural process that takes thousands to millions of years but these human-made materials are being incorporated into natural systems and becoming lithified — essentially turning into rock — over the course of decades instead. Researchers dubbed this newly discovered process the “rapid anthropoclastic rock cycle.” The findings challenge long-standing theories about how rocks form and suggest industries have far less time to dispose of their waste properly than previously thought, Owen said in the statement. The research was published April 10 in the journal Geology. Researchers discovered the first clues of turbo slag-to-rock transformation on Derwent Howe, a giant pile of waste from now-closed iron and steelmaking plants on the northwest coast of England. The scientists noticed irregular formations in these slag “cliffs,” prompting them to take a closer look. One sample contained an aluminum can tab, with a design that couldn’t have been manufactured before 1989, embedded in the material that helped the researchers estimate how long it takes for slag to lithify. For the can tab to become encased in rock, the slag must have solidified and lithified in the past 35 years. It’s possible that these processes finished earlier, so 35 years is the maximum time it takes to turn slag into rock. Scientists have previously made similar observations on the coast of Spain in the Gorrondatxe area, the researchers noted in the study, but those observations didn’t come with a time frame. Excerpted from a LiveScience article by Sascha Pare
The Earth – A Brief Overview
Background The 4.5 billion-year-old Earth is the only known astronomical object to harbor life, giving rise to billions of species of stunning diversity, including ours, Homo sapiens. It has formed the backdrop of an estimated 110 billion human lives. At 13.1 septillion pounds and 25,000 miles in circumference, the third planet from the sun long formed the horizon of all human experience and knowledge (watch overview). Recent discoveries have revealed our home planet’s relative size and location in the universe: a pale blue dot within the Orion Spur, located 26,000 light-years from the center of the Milky Way Galaxy, one of 100,000 galaxies within the Laniakea Supercluster. Formation Early Earth is theorized to have formed alongside the other planets within a solar nebula, where a massive cloud of spinning, interstellar gas and dust contracted under its own gravity and flattened into a hot disk (watch visualization). The core of the disk became dense with lighter elements like hydrogen, eventually heating up and triggering nuclear fusion, forming the sun. Solar wind pushed lighter elements farther out into the system, while heavier metals like iron gathered into increasingly larger masses known as planetismals in a process called accretion to form the Earth and other inner rocky planets. As the protoplanet grew, heat from the colliding material and radioactive decay differentiated Earth’s heavier iron-rich core from its lighter rocky mantle, giving rise to Earth’s magnetic field and long-term stability. Various models suggest Earth’s formation took tens of millions of years. Two billion years later, Earth changed dramatically when cyanobacteria, a microbe, evolved to generate energy from sunlight (i.e., photosynthesis) and release oxygen as a byproduct into the atmosphere during the Great Oxidation Event. Structure and Composition Earth is the densest planet in the solar system and the most massive of the four rocky terrestrials. Shaped into a sphere by gravity, Earth is flattened at its poles and bulges at its equator due to its roughly 1,000-mile-per-hour eastward spin (Jupiter spins 28 times faster). By analyzing seismic waves, researchers theorize that a solid, 9,800-degree Fahrenheit inner core is surrounded by an outer core of liquid iron and nickel—common elements that consolidate into solids at high pressures. Above the core, a slow-moving rocky mantle moves the crust’s tectonic plates, causing volcanoes and earthquakes (see overview). Earth’s spin combines with the core’s electrical conductivity and extreme heat to produce a magnetic field that protects its surface from damaging solar winds, cosmic rays, and deep space radiation. This so-called geodynamo process is expected to last for billions of years. Surface and Climate Situated within the solar system’s “Goldilocks zone,” Earth is the only planet with conditions able to sustain liquid surface water, key to the formation of life. Roughly 71% of its surface is water; the rest is land. An estimated 300 million planets in our galaxy are located in similar zones. The Earth’s five-layer atmosphere traps solar energy and maintains an average global surface temperature of 59 degrees Fahrenheit. Roughly 21% is oxygen, crucial for respiration but highly flammable. Nitrogen (78%) dilutes the oxygen and prevents rapid combustion. Seasons result from the Earth’s 23.4-degree tilt in relation to the orbital plane. Ice ages last millions of years and result from shifting climatic conditions—like ocean currents and the position of tectonic plates—that drop average temperatures by double digits. We live amid the fifth major ice age, though we are in the middle of a warmer interglacial period that began 11,000 years ago.