Science & TechnologyS


Boat

Ancient tree resin artifacts provide earliest-known evidence of humans dispersing through the Pacific

Sandee Oster
Phys Org
Tue, 20 Aug 2024 15:12 UTC
tree resin human migration pacific evidence
© Gaffney et al. 2024Image of the tree resin artefact from lateral (A), dorsal (B), ventral (C) and other ventral (D) side.
Exactly when and how humans dispersed into and through the Pacific remains an intensely debated topic. Previous studies have been hampered by imprecise chronometric dating, making the exact timing and movement of people into the Pacific difficult to ascertain.

One of the earliest sites humans have occupied in northern Australia is the Madjedbebe rock shelter, dated to about 65-60 thousand years ago (ka). In order to reach this area, Homo sapiens would have had to travel through the Wallacea Islands to reach Sahul, the Pleistocene continent that connected New Guinea and Australia. However, sites along this southern route only have evidence of human occupation dating to around 44ka.

These discrepancies in the data have led to some archaeologists arguing that the northern Australian dates are erroneous and that humans likely only arrived in Sahul much later, after 50 ka.
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Microscope 2

Divide and conquer: Bacterial cell division hints at self-healing materials

Srishti Gupta
Interesting Engineering
Mon, 12 Aug 2024 21:30 UTC
cell division ring
© Nicola de MitriComputer simulation of filaments assembling into a division ring in the middle of the cell.
But how do molecules know when and where to come together, and when to fall apart?

Scientists have discovered a new way bacteria organize themselves during cell division, which they describe as "dying to align." In this process, misaligned filaments in the cell naturally break down, allowing a ring structure to form at the center, which is crucial for the cell to divide properly.

This discovery might help in creating synthetic materials that can repair themselves.

The big question is how non-living matter organizes itself in ways that lead to life. Self-organization, a key feature of life, involves the natural formation and breakdown of active biological matter. But how do these molecules know when and where to come together and when to fall apart?
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Better Earth

'Catastrophic' climate shifts 4,200 years ago may have been smaller and more regional than initially thought, new study reveals

Northern Arizona University
Phys.org
Mon, 19 Aug 2024 15:34 UTC
4,200 year climate
© Nature Communications (2024). DOI: 10.1038/s41467-024-50886-wSpatial expression of the 8.2 ka and 4.2 ka climate excursions.
A megadrought that occurred 4,200 years ago had catastrophic impacts, potentially wiping out early empires and leading to large-scale changes worldwide. It was so significant it marked a turning point in the Earth's geologic history.

Or was it?

New research out of Northern Arizona University shows that while the 4.2 ka event did happen, its impacts may not have been globally catastrophic as previously thought. In fact, it may simply have been one of many events in the varied climate of the Holocene Era, which began about 11,700 years ago.

The study, published in Nature Communications, is unique not just for its surprising findings but for the way it was produced. Faced with more than 1,000 datasets, faculty at NAU created a graduate class that allowed students to participate in the research. The paper's dozen co-authors range from NAU faculty to students to alumni who participated over several years.

Comment: As we can see in our own time, depending on the society and location, the impact of these many smaller, regional shifts varies. It may be that some fare better than others, perhaps because of the structure and health of their society, or because their regional climate is tempered in some way, such as an increase increase in rainfall where before it was lacking - that indeed seems to be the case at certain periods: It's also becoming apparent that whilst it may appear that a region is relatively unaffected, everything is connected in one way or another. In the same way that space weather is known to effect Earth's climate, the global climate will undoubtedly effect regional weather. Moreover, with humanity often being connected, and even reliant, on each other, what effects one culture can indeed effect others in profound ways:

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Cassiopaea

Lightning energy is transferred to Earth's magnetosphere by newly discovered 'whistler' wave, study reveals

Rod Boyce, University of Alaska Fairbanks
Phys.org
Sat, 17 Aug 2024 12:00 UTC
earth whistler wave
This graphic shows a cutaway model of Earth's radiation belts with the two Van Allen Probes satellites flying through them. Credit: NASA illustration

Two University of Alaska Fairbanks scientists have discovered a new type of "whistler," an electromagnetic wave that carries a substantial amount of lightning energy to the Earth's magnetosphere.

The research is published today in Science Advances.

Vikas Sonwalkar, a professor emeritus, and Amani Reddy, an assistant professor, discovered the new type of wave. The wave carries lightning energy, which enters the ionosphere at low latitudes, to the magnetosphere. The energy is reflected upward by the ionosphere's lower boundary, at about 55 miles altitude, in the opposite hemisphere.

Comment: A variety of research seems to be revealing that Earth is far from a closed system, and it seems that it may be that it's not just a recipient of energy, but also an emitter.

Earth's relationships with the other bodies in our solar system are proving to be of significance, too: And check out SOTT radio's:

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Better Earth

Increased volcanic activity significantly reduced wine production at various times in last millennia, new study finds

Hannah Bird
Phys.org
Wed, 31 Jul 2024 17:44 UTC
volcanoes wine
Climate has an important role to play in viticulture (wine production) due to the impacts on grape harvest from variability in parameters such as temperature, precipitation and aridity. Warmer and drier climates with long growing seasons benefit grapevine growth, although beyond a tipping point, it can be damaging in climates akin to the Mediterranean. The Moselle Valley, spanning north-eastern France, south-western Germany, and eastern Luxembourg, has historically been and continues to be a major source of wine production in climatically-sensitive central and southern Europe.

New research, published in Climate of the Past, has investigated the impact volcanic eruptions have had on viticulture due to climate cooling. Such colder temperatures result from the aerosols released in the eruption reflecting incoming solar radiation, as well as acting as condensation nuclei for cloud formation to further this process, therefore reducing the temperature of Earth's surface and triggering a negative feedback loop.

Comment: Whilst this study focused on grapes, one can presume that a great many other crops, and cattle, will have been effected, too. And with the seeming increase in volcanic activity in our own time, this may provide insight into the kinds of issues we'll encounter - although judging by the increase in extreme weather events, erratic seasons, crop failures, and shortages, already being reported across the planet, there are signs that we're already in the midst of it: Volcanoes, Earthquakes And The 3,600 Year Comet Cycle

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Mars

NASA made a world-shaking discovery: Compelling evidence of past life on Mars

Darren Orf
Yahoo News
Mon, 05 Aug 2024 00:00 UTC
marsearth
© Lifeburadaki Getty ImagesNASA finds evidence of past Martian Microbial
  • In its ancient past, Mars likely contained many of the necessarily ingredients for microbial life to flourish on its surface.
  • Now, a new discovery by NASA's Perseverance rover shows a trifecta of compelling evidence — including the presence of water, organic compounds, and a chemical energy source — all on one rock located in the Jezero Crater.
  • Although this is the best clue yet that microbial life existed on Mars, there are still other explanations that could explain this geologic display without the existence of microbes.
"Is there life on Mars" is a question that has vexed astrobiologists and David Bowie alike. While the latter imagined some macabre collection of arachnids on the Red Planet, NASA scientists are fixated on finding evidence that microbial life once flourished on the fourth rock from the Sun. So fixated, in fact, that the space agency has spent more than $5 billion getting two immensely complicated robotic rovers — Curiosity and Perseverance — onto the Martian surface with this specific microbial mission in mind.

Now, one of those rovers might've discovered one of the most compelling pieces of evidence for Martian microbial life. Located on an arrowhead-shaped, three-foot-long rock nicknamed "Cheyava Falls" in the Jezero Crater (the 28-mile-wide crater that Perseverance has called home for the past three years), this "piece of evidence" is actually a trifecta of data points that suggest the presence of past microbial life. The rock in question features two vertical veins of calcium sulfate that likely formed from past water, and these stripes both flank a red band of rock filled with "leopard spots."

Comment: Further Mars discoveries in the hunt for water:
A study released Monday using data from NASA's Mars InSight lander shows evidence of liquid water far below the surface of the fourth planet, advancing the search for life there and showing what might have happened to Mars' ancient oceans.

The lander, which has been on the red planet since 2018, measured seismic data over four years, examining how quakes shook the ground and determining what materials or substances were beneath the surface.

Based on that data, the researchers found liquid water was most likely present deep beneath the lander. Water is considered essential for life, and geological studies show the planet's surface had lakes, rivers and oceans more than 3 billion years ago.

Vashan Wright of the University of California San Diego's Scripps Institution of Oceanography, said:
"On Earth what we know is where it is wet enough and there are enough sources of energy, there is microbial life very deep in Earth's subsurface. The ingredients for life as we know it exist in the Martian subsurface if these interpretations are correct."
The study found that large reservoirs of liquid water in fractures 11.5 kilometres (7.15 miles) to 20km (12.43 miles) beneath the surface best explained the InSight measurements.

It notes that the volume of liquid water predicted beneath the surface is "more than the water volumes proposed to have filled hypothesized ancient Martian oceans."
"On Earth, groundwater infiltrated from the surface" to deep underground. We expect this process to have occurred on Mars as well when the upper crust was warmer than it is today."
There is no way to directly study water that deep beneath the surface of Mars, but the authors said:
"The results have implications for understanding Mars' water cycle, determining the fates of past surface water, searching for past or extant life, and assessing in situ resource utilization for future missions."
The study, whose other authors are Matthias Morzfeld of the Scripps Institution of Oceanography and Michael Manga of the University of California Berkeley, was published the week of Aug. 12 in the journal Proceedings of the National Academy of Sciences.


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Eye 2

Evolution of snakes takes surprise twist — cobras didn't come from where we thought they did

Richard Pallardy
Live Science
Fri, 09 Aug 2024 00:00 UTC
snake
© Image credit: dikkyoesin1 /Getty Images
"When the cobra runs for her life, she goes like a whiplash flicked across a horse's neck," Rudyard Kipling wrote of the villainous cobra Nagaina in his story of the heroic mongoose Rikki-Tiki-Tavi. And this whiplash motion may have helped real-life cobras and their relatives spread from Asia, where they originated, to the rest of the world.

Scientists once believed that Elapoidea, the superfamily containing cobras, coral snakes and mambas, originated in Africa. A fossil of a file snake found in Tanzania and dated to the Oligocene Epoch (33.9 million to 23 million years ago) supported this hypothesis — it is the oldest relative of this group discovered in the fossil record.

But in new research, published Aug. 7 in the journal Royal Society Open Science, researchers used genetic analysis and fossils from other regions to conclude that these snakes, as well as snakes in the related superfamily Colubroidea, actually originated in Asia.
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Bacon

Salt taste is surprisingly mysterious

Amber Dance
Knowable Magazine
Wed, 13 Sep 2023 20:48 UTC
salt pretzel child
© Istock.com/NYCShooterOur bodies need sodium to survive and function. The good-salt taste detects moderate levels of sodium and signals the brain that this is desirable. The second, bad-salt taste, which detects potentially harmful salt levels, works differently — perhaps by detecting sodium's molecular partner, chloride.
Too much sodium is bad, but so is too little — no wonder the body has two sensing mechanisms

We've all heard of the five tastes our tongues can detect — sweet, sour, bitter, savory-umami and salty. But the real number is actually six, because we have two separate salt-taste systems. One of them detects the attractive, relatively low levels of salt that make potato chips taste delicious. The other one registers high levels of salt — enough to make overly salted food offensive and deter overconsumption.

Exactly how our taste buds sense the two kinds of saltiness is a mystery that's taken some 40 years of scientific inquiry to unravel, and researchers haven't solved all the details yet. In fact, the more they look at salt sensation, the weirder it gets.

Many other details of taste have been worked out over the past 25 years. For sweet, bitter and umami, it's known that molecular receptors on certain taste bud cells recognize the food molecules and, when activated, kick off a series of events that ultimately sends signals to the brain.
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Blue Planet

Trees 'hold their breath' to protect themselves from wildfire smoke

Mj Riches
The Conversation
Tue, 30 Jul 2024 19:19 UTC
trees smoke wildfire
© Dan Jesperson/StoryBlock
When wildfire smoke is in the air, doctors urge people to stay indoors to avoid breathing in harmful particles and gases. But what happens to trees and other plants that can't escape from the smoke?

They respond a bit like us, it turns out: Some trees essentially shut their windows and doors and hold their breath.

As atmospheric and chemical scientists, we study the air quality and ecological effects of wildfire smoke and other pollutants. In a study that started quite by accident when smoke overwhelmed our research site in Colorado, we were able to watch in real time how the leaves of living pine trees responded.
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Moon

Scientists find new and potentially renewable source of water on the moon

Matthew Lodge
The Daily Mail
Thu, 08 Aug 2024 20:07 UTC
China Chang-e 5 spacecraft moon mission
© ReutersPeople look at a screen showing footage of the Chang-e 5 spacecraft on its mission to the moon
The findings came from samples recovered by China's Chang'e 5 moon mission

A new and renewable source of water has been found on the moon which could make it easier for future explorers to live there, Chinese scientists say.

Water embedded in tiny glass beads in the lunar dirt where meteorite impacts had take place was found in samples brought back from the moon by China in 2020. It was found that the water in these shiny, multicoloured beads would be relatively easy to extract, with suggestions they could even be used for fuel or for astronauts to drink.

Experts have known there is water on moon for years in the form of ice in shaded regions at its poles - but the new findings could be evidence of a continuous water cycle, scientists say.

The samples were recovered by Beijing's Chang'e 5 moon mission, with the findings published on Monday in the journal Nature Geoscience.
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