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Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 6:52am

Archaeological finds are dated using both relative and absolute dating methods, with common techniques including stratigraphy (analyzing the layers of soil and artifacts), radiocarbon dating (measuring carbon-14 decay in organic materials), and dendrochronology (analyzing tree-ring patterns).
Here's a more detailed breakdown of these methods:
Relative Dating:
Stratigraphy:
This method examines the layers of earth or strata where artifacts are found, to understand the chronological order of past human activities. The Law of Superposition states that in undisturbed layers, the deeper a layer is, the older it is.
Seriation:
This method involves arranging artifacts in a chronological sequence based on their similarities, helping to establish a relative timeline.
Cross-dating:
This method compares artifacts from different locations with known dates to establish a timeline.
Absolute Dating:
Radiocarbon Dating:
This method measures the decay of radioactive carbon-14 (C-14) in organic materials like wood, bone, and charcoal, to determine the age of the sample.
Dendrochronology:
This method uses the annual growth rings in trees to create a precise timeline and date wooden artifacts and structures.
Thermoluminescence:
This method dates materials that were heated in the past by measuring the light emitted from mineral crystals.
Archaeomagnetism:
This method analyzes the direction and intensity of Earth's magnetic field as recorded in baked earth or clay to establish the last time the material was heated.
Potassium-Argon Dating:
This method is used to date rocks and minerals and is often used in conjunction with archaeology, especially when dealing with volcanic or igneous materials.
Fission Track Dating:
This method is used to date minerals and rocks by measuring the trails left by radioactive decay of Uranium in the past.

https://crowcanyon.org/education/learn-about-archaeology/archaeolog...

Part 1.

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 6:51am

Plastic trash dating of bird nests!

Plastic trash in bird nests documents the Anthropocene epoch

We have heard about radio carbon dating (measuring carbon-14 decay in organic materials), dendrochronology (analyzing tree-ring patterns), stratigraphy (analyzing the layers of soil and artifacts), Thermoluminescence (this method dates materials that were heated in the past by measuring the light emitted from mineral crystals), Archaeomagnetism (this method analyzes the direction and intensity of Earth's magnetic field as recorded in baked earth or clay to establish the last time the material was heated),  Potassium-Argon Dating:
This method is used to date rocks and minerals and is often used in conjunction with archaeology, especially when dealing with volcanic or igneous materials, Fission Track Dating (this method is used to date minerals and rocks by measuring the trails left by radioactive decay of Uranium in the past).

But have you ever heard about plastic trash dating?

Expiration dates could tell us more than when something goes bad! Scientists have found that dates on plastic food and beverage packaging can serve as markers of the Anthropocene, a period in Earth's history marked by the widespread impact of human activities on nature. That is what is happening now!

Here is the story:

The Eurasian coot, a round and black waterbird with a white beak, is a common sight in the Netherlands, along the canals of Amsterdam. In the wild, coots usually avoid reusing their nests, as their preferred building materials are typically fast-decaying plant matter.

The urban population, however, have started supplementing their nesting material with something much more long-lasting—plastic trash created by humans. Since plastic never truly disappears, every bit of old nesting material remains as the birds stack new layers of material, one breeding season after another.

In a study published in Ecology, a team of researchers from the Netherlands revealed that plastic waste in bird nests can serve as a time capsule, allowing biologists to determine when the nests were built by examining expiration dates on the plastic food packaging. In one case, the team traced nest materials back to 1991. 

Part 2

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 2:49pm

No evidence for 'wind turbine syndrome' claims

A team of cognitive neuroscientists and acoustic engineers at Adam Mickiewicz University, in Poland, has found no evidence that wind turbine noise causes mental impairment. In their study, published in the journal Humanities and Social Sciences Communication, the group conducted experiments exposing human volunteers to various noises and measured a range of impacts.

Over the past several years, several groups and individuals around the world, most particularly in the U.S., have conceived of the idea of something called "wind turbine syndrome"—a theory that suggests noise from windmills can cause mental illness, or other health problems such as cancer. To date, such claims have not been backed up by research or any other type of proof. In this new effort, the research team in Poland sought to find out if there is any merit to the theory.

The researchers recruited 45 students at a local university who listened to various noises while wearing devices that measured their brainwaves. The researchers intentionally chose young volunteers because prior research has shown they are more sensitive to noise than older people.

None of the volunteers were told the purpose of the study. They were also kept in the dark regarding the source of the noises they heard. Each was exposed to normal traffic noise, silence and windmill noise. None of the volunteers could identify the source of the windmill noise; most described it as some sort of white noise.

Additionally, none of them reported the noise from the windmills as any more bothersome or stressful than the traffic noise. No evidence of mental health issues was found during testing. The researchers were also unable to detect any measurable difference in brain waves as the volunteers listened to the two types of sounds.

The research team says that listening to windmill noise in the short term does not appear to pose a mental health threat. 

 Agnieszka Rosciszewska et al, Cognitive neuroscience approach to explore the impact of wind turbine noise on various mental functions, Humanities and Social Sciences Communications (2025). DOI: 10.1057/s41599-025-04645-x

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 2:44pm

Mice help other mice when they are hurt

Humans may not be the only ones who aid their friends when they're hurt. Mice may do it, too, as shown by a new research study  by scientists published recently in Science.

Scientists have been trying to understand why social mammals appear to help injured members of their species. There are numerous factors that determine empathetic behavior and social bonding in mammals. But this study is the first time we're seeing a first responder-like behavior in mice.

The study shows that mice tend to help other mice they know are unconscious. Their response ranges from gentle sniffing and grooming to more forceful actions such as mouth or tongue biting, before finally escalating to pulling the tongue out of the unconscious mouse.

The behavior was especially unique due to its similarity to how humans behave in emergency responses. The urgency with which "helper mice" target the mouth and tongue of their unconscious peers appears to improve the airway of their peer and lead to a faster recovery.

 What the scientists learned the act of tongue-pulling between mice in this study cannot not be interpreted as an aggressive gesture. The social behaviors in the study were significantly more pronounced among familiar pairs of mice and were rarely seen when one of the paired mice was simply sleeping or active. Furthermore, after the unconscious mice regained consciousness, they had regular use of their tongue.

The study utilized advanced neural imaging and optogenetics to investigate the neural mechanisms behind the social behaviors of the helper mice.

 The research team's neural observations was the discovery of the activation of oxytocin neuropeptides. Oxytocin is widely known as a hormone that plays a crucial role in social bonding.

Wenjian Sun et al, Reviving-like prosocial behavior in response to unconscious or dead conspecifics in rodents, Science (2025). DOI: 10.1126/science.adq2677

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 8:12am

If we are going to tackle climate change, we have to think about both cultural and technical solutions."

The study also underscored an important wrinkle in the emissions due to clothes drying: They vary greatly from region to region in the U.S. In areas powered primarily by coal, for example, dryers are going to lead to more emissions than areas relying more heavily on sustainable options, like hydroelectric power.

So the fact that there is variation makes sense, but the size of it is staggering. Depending on where the change is made, switching from a gas dryer to an electric dryer can reduce emissions by more than 90% or increase them by more than 220%.

Thus, moving toward a cleaner energy grid is another technical solution to reduce the impact of dryers

When you can simply dry the clothes for free in your backyard, why spend money on it and increase your carbon foot print as well?

Zhu Zhu et al, The relative benefits of electrification, energy efficiency, and line drying clothes in the United States, Resources, Conservation and Recycling (2025). DOI: 10.1016/j.resconrec.2025.108212

Part 2

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Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 8:12am

Clothes dryers and the bottom line: Switching to air drying can save hundreds

Researchers are hoping their new study will inspire some people to rethink their relationship with laundry. Because, no matter how you spin it, clothes dryers use a lot of comparatively costly energy when air works for free.

Household dryers in the U.S. consume about 3% of our residential energy budget, about six times that used by washing machines. Collectively, dryers cost more than $7 billion to power each year in this country, and generating that energy emits the equivalent of more than 27 million tons of carbon dioxide.

The U.S. also leads the world in dryer ownership, with more than 80% of homes having one, compared with less than 30% in South Korea, just over 40% in Germany and just under 60% in the United Kingdom.

That got researchers in the U-M School for Environment and Sustainability, or SEAS, wondering what it would mean for the average American household if we warmed up to air drying.

In most other places in the world, it's hard to find a clothes dryer. 

 Dryers consume a lot of energy, so what if you used line drying instead? How much could you save? How many CO₂ emissions could you avoid?

Researchers   investigated the costs and emissions associated with different drying technology behaviors in the U.S.

Over the lifetime of a dryer, 100% line drying could save a household upwards of $2,100. That would also cut back CO₂ emissions by more than 3 tons per household over the same time. Though the contrast between dryers and line drying is stark, it's not surprising, the researchers said.

The researchers did find some striking results in its analysis, published in the journal Resources, Conservation and Recycling.

For example, a mixture of line drying and dryer use proved to be the second most economical and eco-friendly option, over changes like upgrading to more efficient dryers. And, in some cases, households that invested in more energy-efficient dryers wouldn't end up saving money in the long run.

"We tend to focus on technological improvements, but a lot of the time, behavioral changes can have larger impacts.
Part 1

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 7:18am

Frame dragging 

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 7:12am

Climate change may reduce the number of satellites that can safely orbit in space

Aerospace engineers have found that greenhouse gas emissions are changing the environment of near-Earth space in ways that, over time, will reduce the number of satellites that can sustainably operate there.

In a study appearing in Nature Sustainability, the researchers report that carbon dioxide and other greenhouse gases can cause the upper atmosphere to shrink. An atmospheric layer of special interest is the thermosphere, where the International Space Station and most satellites orbit today.

When the thermosphere contracts, the decreasing density reduces atmospheric drag— a force that pulls old satellites and other debris down to altitudes where they will encounter air molecules and burn up.

Less drag therefore means extended lifetimes for space junk, which will litter sought-after regions for decades and increase the potential for collisions in orbit.

The team carried out simulations of how carbon emissions affect the upper atmosphere and orbital dynamics, in order to estimate the "satellite carrying capacity" of low-Earth orbit. These simulations predict that by the year 2100, the carrying capacity of the most popular regions could be reduced by 50–66% due to the effects of greenhouse gases.

There's been a massive increase in the number of satellites launched, especially for delivering broadband internet from space. If we don't manage this activity carefully and work to reduce our emissions, space could become too crowded, leading to more collisions and debris, the experts warn.

William Parker, Greenhouse gases reduce the satellite carrying capacity of low Earth orbit, Nature Sustainability (2025). DOI: 10.1038/s41893-025-01512-0. www.nature.com/articles/s41893-025-01512-0

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 7:01am

This finding may simultaneously explain wider mysteries of our galaxy, such as a specific type of X-ray observation found at the center of the Milky Way—known as the "511-keV emission line." This specific energy signature could also be due to the same low-mass dark matter colliding and producing charged particles.

Pedro De la Torre Luque et al, Anomalous Ionization in the Central Molecular Zone by Sub-GeV Dark Matter, Physical Review Letters (2025). DOI: 10.1103/PhysRevLett.134.101001

Part 2

Comment by Dr. Krishna Kumari Challa on March 11, 2025 at 7:00am

Mysterious phenomenon at center of galaxy could reveal new kind of dark matter

A mysterious phenomenon at the center of our galaxy could be the result of a different type of dark matter.

Dark matter, the mysterious form of unobserved matter which could make up 85% of the mass of the known universe, is one of science's biggest manhunts.

In this first of its kind study, scientists have taken a step closer to understanding the elusive mystery matter. They think a reimagined candidate for dark matter could be behind unexplained chemical reactions taking place in the Milky Way.

At the center of our galaxy sit huge clouds of positively charged hydrogen, a mystery to scientists for decades because normally the gas is neutral. So, what is supplying enough energy to knock the negatively charged electrons out of them?

The energy signatures radiating from this part of our galaxy suggest that there is a constant, roiling source of energy doing just that, and our data says it might come from a much lighter form of dark matter than current models consider.

The most established theory for dark matter is that it is likely a group of particles known as Weakly Interacting Massive Particles (WIMPs), which pass through regular matter without much interaction—making them extremely hard to detect.

However, this study, published recently in Physical Review Letters, has potentially revived another type of dark matter with much lower mass than a WIMP.

The researchers think that these tiny dark matter particles are crashing into each other and producing new charged particles in a process called "annihilation." These newly produced charged particles can subsequently ionize the hydrogen gas.
Previous attempts to explain this ionization process had relied on cosmic rays, fast and energetic particles that travel throughout the universe. However, this explanation has faced some difficulties, as energy signatures recorded from observations of the Central Molecular Zone (CMZ) where this is happening, don't seem to be large enough to be attributed to cosmic rays. Such a process doesn't seem to be possible with WIMPs either.

The research team were left with the explanation that the energy source causing the annihilation is slower than a cosmic ray and less massive than a WIMP.

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