Many people experience unusual bad dreams. If you often wake up feeling anxious and sweaty, you might be concerned whether it’s simply stress or if there’s a deeper issue at play.
Recent research has indicated a link between frequent nightmares and a heightened risk of dementia.
A 2022 study published in Lancet eClinicalMedicine revealed that individuals in middle age who have weekly nightmares are more prone to cognitive decline.
Furthermore, older adults with recurrent nightmares showed an increased likelihood of developing dementia. While this may seem alarming, should it genuinely be a cause for concern?
Individuals with mental health conditions, such as anxiety and depression, are more prone to experiencing bad dreams – Image courtesy of Getty Images
Not necessarily. The study suggests a correlation but does not establish causation. It remains uncertain whether nightmares are early indicators of existing changes in the brain or if sleep disturbances contribute to disease progression.
Other factors could also be at play—individuals suffering from anxiety, depression, and poor sleep (which themselves have ties to elevated dementia risk) are more likely to encounter bad dreams.
What we do know is that sleep is vital for brain health. Regardless of the underlying cause, there’s evidence that chronic sleep disruption or low-quality sleep may elevate the long-term risk of cognitive decline.
The takeaway? Experiencing regular nightmares alone does not serve as a dependable early warning of Alzheimer’s disease.
For now, practicing good sleep hygiene is the most effective initial step—not just for pleasant dreams, but for a healthy brain. Aim for a consistent bedtime, minimize caffeine and alcohol intake, and limit screen time before sleeping.
This article addresses the query (from Aaron Martin of Stoke-on-Trent): “I keep having nightmares.” Should I be worried?”
If you have any inquiries, feel free to email us at:questions@sciencefocus.com or message usfacebook,×orInstagrampage (make sure to include your name and location).
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Researchers have crafted an environmentally friendly substitute for palm oil, potentially available by the end of 2025.
Palm oil, alongside other tropical oils like shea, coconut oil, cocoa butter, and soybeans, presents significant environmental challenges.
These oils encroach upon rainforests, contributing to deforestation, biodiversity decline, greenhouse gas emissions, as well as air and water pollution in regions such as Southeast Asia, South America, and Africa.
However, palm oil is prevalent in our foods and cosmetics. It is estimated that nearly half of all packaged goods in supermarkets contain palm oil, disguised under various ingredient names including glycerin and stearic acid.
This dilemma prompted a team of scientists at Bath University, led by chemical engineer Professor Chris Chuck, to seek alternatives for over a decade. Their research has led to a promising solution: a yeast called Metschnikowia pulcherrima.
“It thrives on grapes,” Chuck mentioned in BBC Science Focus. “It’s already applied in the organic wine sector. When you enjoy the blackcurrant notes in red wines from South Africa, that’s thanks to Metschnikowia.”
This yeast naturally comprises about 20% fat; however, Chuck’s team employed a method termed “directional evolution,” which promotes a rise in fat proportions, akin to selective breeding, by utilizing environmental pressures.
“Currently, about half of it is pure fat,” Chuck explained. “We didn’t just increase the yeast’s mass; it’s impressively fatty. Plus, we managed to accelerate its growth.”
The cultivation of this oil requires minimal space and uncomplicated equipment—just a large vat. The yeast feeds on food waste, such as discarded bread and potato byproducts, which are converted into sugar.
Once the yeast becomes densely populated, the cells burst and release oil, which is processed similarly to traditional cooking oils.
After this process, half of the non-oil yeast can be repurposed into other food ingredients, such as natural emulsifiers and beta-glucans, a heart-healthy fiber also found in oats.
By adjusting temperature, acidity, and sugar, yeast can produce a range of fats. The oil on the right is engineered to resemble more saturated, semi-solid palm oil, while the oil on the left is a less saturated liquid – Credit: Clean Food Group
Adjusting the yeast’s growing environment allows scientists to modify its flavor, texture, and nutritional properties, balancing saturation levels to mimic various fats.
“If executed correctly, we can prevent the destruction of tropical forests,” Chuck stated. “Currently, we’re using land equivalent to Argentina to cultivate cooking oil, making it one of the largest agricultural footprints globally.”
Demand for palm oil continues to rise. The current palm oil market is valued at $50.6 billion and is projected to increase to $65.5 billion (£48.3 billion) by 2027.
“We need forests to act as the planet’s lungs,” Chuck explained. “We cannot afford to clear everything.”
Moreover, substituting some tropical oils with yeast-based alternatives can lead to reduced greenhouse gas emissions.
“These tropical crops emit more CO2 than oil they produce,” Chuck added, noting that yeast-derived oils emit 95% less carbon dioxide and can be cultivated in nearly any location.
“These cutting-edge fermentation techniques enable us to establish local production,” he elucidated. “We’ve implemented this model on the outskirts of Birmingham, utilizing waste from our nearby factory to create oil and reintegrate it into our local ecosystem.”
This yeast-based oil is on the horizon; Chuck indicated it could debut in cosmetics by late 2025 or early 2026, with food applications to follow shortly thereafter.
read more:
About our experts
Professor Chris Chuck is a chemical engineer at the University of Bath, UK, and co-founder of the food technology startup Clean Food Group. He also contributes to the Reaction and Catalytic Engineering Research Unit (Racial), Center for Sustainable Chemical Technology (CSCT), Center for Water Innovation Research (WIRC), Center for Bioengineering and Biomedical Technology (CBIO), and the Institute for Sustainability and Climate Change.
Warming oceans might elevate storm intensity, exemplified by Hurricane Milton in 2024
NOAA
Scientists have cautioned that the extreme ocean temperatures observed since 2023 could indicate the onset of drastic changes in global marine conditions, posing a severe risk to life on our planet.
Historic ocean heat waves unfolded in the North Atlantic and Pacific in 2023, marked by their unprecedented severity, duration, and geographical spread, many persisting for over a year.
These heat waves have led to record-high sea surface temperatures globally in 2023 and 2024, contributing to severe weather patterns on land and resulting in back-to-back years being declared the hottest on record.
“While there’s been a gradual increase in ocean temperatures over the past 40-50 years, 2023 stands out as a pivotal year, with significant ocean heat waves impacting numerous regions,” stated Matthew England from the University of New South Wales, Australia.
Sea surface temperatures worldwide remain at alarming heights, with the Mediterranean currently experiencing marine heat waves, as water temperatures exceed 5°C (9°F) during this time.
Researchers are concerned that the oceans may be shifting to new, hotter states, endangering their predictions for both short-term weather phenomena like hurricanes and long-term climate change trends.
To understand the situation, Zhenzhong Zeng from China’s Southern University of Science and Technology is collaborating with colleagues to pinpoint the causes of the 2023 global ocean heat wave by analyzing heat movement within the ocean, wind patterns, and ocean currents. They found that reduced cloud cover significantly increases solar radiation reaching the water, compounded by weak winds and the influence of the warming El Niño pattern in the Pacific Ocean.
Considering the heat wave that began in earnest in 2023 and continues in various regions, Zeng suggests this could be the start of a “new normal” for the world’s oceans. He notes that new data reveals an exponential rise in ocean heat, contradicting previous climate model forecasts.
Persistently elevated water temperatures severely impact marine ecosystems, heightening the risk of coral reef collapse, causing mass die-offs, and leading to shifts in marine species distributions. This also exacerbates heating on land, resulting in intensified droughts, heatwaves, wildfires, and storms.
Zeng expressed that he is “very alarmed” by this potential sea regime change, adding, “I believe nearly all predictions made by Earth System models are incorrect.”
Conversely, some experts argue that it may be premature to declare fundamental shifts in ocean dynamics. Neil Holbrook from the University of Tasmania in Australia points out that there is currently no “clear evidence” to indicate we have reached a critical turning point, given the limited years of data to assess. “I cannot predict what will happen next year; [ocean temperatures] could return to more typical patterns,” he remarked.
However, Holbrook stressed that without substantial reductions in greenhouse gas emissions, “marine heat waves will likely continue to gain intensity and duration, potentially escalating faster than various marine species can adapt.”
Fast Radio Bursts (FRBs) represent one of the greatest mysteries of the universe in our time. Initially identified in 2007, these transient radio wave phenomena have perplexed astronomers ever since.
Although we have detected thousands of them, the precise causes, origins, and unpredictable behaviors of FRBs remain elusive.
Just when scientists thought they were starting to unravel the mysteries, two new studies published in January 2025 added twists to the ongoing FRB enigma, challenging earlier theories.
“The FRB is one of those cosmic mysteries that deserves to be solved,” states Dr. Tarraneh Eftekhari, a radio astronomer at Northwestern University, in reference to the first new paper published in Astrophysics Letter.
Though the solution may be a long way off, the universe continues to guard its secrets.
What Makes the FRB Mysterious?
While it may not be entirely accurate to say that FRBs were discovered purely by chance, their initial detection happened within data collected for an entirely different purpose.
Pulsars, or “pulsating radio sources,” are far better understood cosmic phenomena, having been discovered in 1967 by Professor Jocelyn Bell Burnell, arising from neutron stars. These are incredibly dense remnants of giant stars boasting magnetic fields far stronger than Earth’s.
These rapidly spinning stellar remnants emit regular pulses of radio waves akin to cosmic beacons.
The consistency of these pulses and their emissions at specific frequencies initially led to the hypothesis that they could be of natural origin, which earned the first pulsar the nickname “Little Green Man 1.”
While pulsars quickly found their rightful place in astrophysics, FRBs tell a different story.
Jump forward to 2007 when they emerged unexpectedly from data gathered by the Parkes Multibeam Pulsar Survey, an international collaboration involving Jodrell Bank Observatory, Massachusetts Institute of Technology, Bologna Astronomical Observatory, and Australia’s National Facilities.
The emission from this event was so powerful that it overshadowed all other known sources at the time by a substantial margin.
“In terms of energy output, a 1-millisecond-long FRB can emit as much energy as the Sun produces over three days,” says Dr. Fabian Djankowski, an astrophysicist at the French National Centre for Science and Technology specializing in FRBs.
However, for over five years after the initial detection, no similar events were recorded. Skepticism faded as more FRBs began to emerge.
Thousands have been detected since then, and astronomers estimate that two or three FRBs may blaze across the sky every minute.
These enigmatic signals release immense energy from deep space, illuminating the sky with their mysterious nature. And the strangeness does not end there.
Initially, FRBs were believed to be one-off occurrences, cosmic anomalies. This assumption seemed valid, as follow-up observations failed to reveal any repeating sources.
That changed in 2016 when FRB 121102 was found to emit repeated bursts. Currently, between 3% and 10% of FRBs are classified as “repeaters.”
Why do some FRBs remain silent after a single burst, while others emit multiple bursts? This is yet another mystery awaiting resolution.
read more:
What Causes FRBs?
Numerous hypotheses have been proposed regarding the cause of FRBs, ranging from chaotic black hole collisions to extraterrestrial signals. Many explanations have emerged, including the unlikely scenario of a microwave being accidentally detected. However, one candidate seems to rise above the rest.
“When massive stars collapse and go supernova, they leave behind highly magnetized neutron stars, or ‘magnetars,'” notes Eftekhari. “The reason magnetars are a compelling candidate for FRBs is that we have observed similar events emanating from known magnetars within our Milky Way.”
Neutron stars already possess strong magnetic fields, but magnetars are in a category of their own, with magnetic fields thousands of times stronger than those of typical neutron stars.
Furthermore, a higher frequency of FRBs has been detected in galaxies with rapid star formation. As Eftekhari explains, “To produce a supernova that results in a magnetar, a massive star is required, and these giant stars are found in star-forming galaxies.”
So, is the case settled? Not quite.
The Canadian CHIME radio telescope detected FRB 20240209A, potentially originating from a globular cluster. – Photo Credit: CHIME Experiment
This is where the two new studies published in January 2025 come into play, both examining the recurring FRB known as 20240209A.
“The first exciting aspect of this FRB is that it originates outside our galaxy,” says Vishwangi Shah, a doctoral student at McGill University, referencing the second study.
“There is only one other FRB detected outside our galaxy. In terms of its repeaters, I believe it originates from a globular cluster.”
Both Eftekhari and Shah suggest that 20240209A is also associated with globular clusters (dense groups of ancient stars existing on the outskirts of galaxies).
“This is remarkable,” Eftekhari comments. “The notion of magnetar progenitors poses a challenge since they typically require a group of young stars to form magnetars.”
So what does this mean for FRBs? One possibility is that magnetars are still the culprits, but they may be generated through entirely different mechanisms.
For instance, within these stellar graveyards, two normal neutron stars might combine to form magnetars. Alternatively, a white dwarf—a stellar remnant too small to evolve into a neutron star—could gather material from a nearby companion, culminating in a massive explosion that results in a magnetar.
Ultimately, the exact origin of these outlier events remains unknown. “It’s thrilling to contemplate that we might be dealing with a subpopulation of FRBs,” Eftekhari remarks. “This case isn’t as clear as it appears.”
Can We Determine the Origins of FRBs?
Despite nearly two decades of research, many questions regarding FRBs linger. Which objects are responsible? What processes drive these phenomena? And why do some FRBs repeat while others do not?
Thanks to advances in FRB detection technology, answers may be nearer than anticipated.
CHIME is currently undergoing enhancements aimed at pinpointing bursts with unprecedented precision.
This advancement in FRB detection represents great progress in unraveling their mysteries. While many FRBs have been observed, accurately identifying their environments has left several key questions regarding their origins unanswered.
Jankowski believes that in the near future, many cases like 20240209A could be unlocked, revealing their underlying mechanisms. “I anticipate significant progress in the coming years,” he adds.
The Square Kilometer Array (SKA), a massive observatory spanning Australia and South Africa, aims to join the search for FRBs shortly.
Eftekhari and Shah have also proposed utilizing the James Webb Space Telescope to explore the region where 20240209A was detected.
“It’s an incredibly exciting time for FRB research,” highlights Jankowski. “We are poised to make remarkable discoveries in the next few years.”
Meet Our Experts
Dr. Tarraneh Eftekhari is a radio astronomer at Northwestern University, USA, with contributions to various scientific journals including Astrophysics Letter, Nature Astronomy, and Astrophysical Journal.
Dr. Fabian Djankowski is an astrophysicist at the French National Centre for Science and Technology who specializes in FRBs. His work has appeared in Monthly Notices of the Royal Astronomical Society, Astrophysics Letter, and Astronomy and Astrophysics.
Vishwangi Shah is a doctoral student at McGill University in the USA and a researcher focusing on radio astronomy and FRBs. She has been published in Astrophysics Letter and Astronomy Journal.
The White House spent a week trying to downplay the revelation that national security authorities discussed plans for our strike in Yemen over Signal, a commercial messaging app.
In a spectacular violation of national security, Defense Secretary Pete Hegses revealed details of certain operations prior to the attack on group chat. National security adviser Michael Waltz, who added Goldberg to the chat, said he took “full responsibility” for the leak.
Several Democrats urged Hegses to step down. However, the Trump administration has tried to bypass or avoid the issue. (Trump said the scandal was a “witch hunt.”
As part of a regular check-in during Trump’s first 100-day inauguration, the New York Times asked five voters what they thought of the administration’s response.
Dave Abdallah wasn’t happy with the way Trump and those around him continued to play signal chat breaches downplay.
They are “completely wrong,” Adbola said.
He added, the violation could have cost us their lives. “This is a serious and serious mistake,” he said of the whole.
Abdallah, a real estate broker who moved to the US from Lebanon as a child, voted for Green Party candidate Jill Stein in the 2024 election. It was a protest against the Biden administration’s handling of the war in Gaza, and concerns that Trump would not help the situation. Still, Abdallah hoped that Trump’s foreign policy could bring peace and stability to the region.
So far, he’s disappointed.
The fighting recently resumed between Israel and Hamas. Now Abdallah believes Trump, his administration and supporters are proving hypocritical in the face of a backlash on signal issues.
He recalls watching a recent video of Tiktok showing old clips of Republicans criticizing Hillary Clinton for using private computer servers while he was Secretary of State during the Obama administration. The video then showed images of the same critic. He is now a Trump supporter and makes excuses for signal chat, not a big deal.
Such excuses struck Abdallah as dishonest. “I can’t understand that,” he said of the signal chat. “So you definitely should be on the table to get rid of someone.”
– Kurt Streeter
“I don’t think anyone should be fired for this because it’s not as serious as many people think.”
Hey, do you want to send it to your group chat? Likewise, are you sure about 1,000%?
Just check it. It was a strange week in the history of group chats, so it’s a seemingly intimate textual conversation that goes back and forth between friends, family and apparently national security officials.
On Monday, Atlantic Editor-in-Chief Jeffrey Goldberg. I wrote it That he was accidentally added to group chat with encrypted messaging app signals. He announced plans for the attack on the base of Houthi in Yemen, followed when other national security officials came up with plans for the attack after the celebration emoji.
Just as lawmakers on both sides of the aisle condemned the security breaches, Americans were seen as perceived and distrustful with their own unruly group chat.
“It’s clearly a very relevant screw-in,” Goldberg said. Interview With Tim Miller of Bluwork on Tuesday. “We all texted the wrong people,” he added.
However, these careless texts do not contain high-stakes national security information that is usually shared outside of secure government channels.
The incident could be “the most shocking stupid group chat error in history,” said Tommy Beiotter, a liberal podcaster and former National Security Council spokesman. X’s Video. In the same post, he confessed that he was in an email thread that once mistakenly included singer Lyle Lovett in place of his colleague John Lovett. Approximately 30 emails had been sent before anyone noticed.
Group chat has quietly become a staple of modern communication since 2008, when Apple enabled text messaging with multiple recipients. Private group chats award a kind of juicy intimacy to a book club member, a neighbor’s mom, work friends, or a large family who exchanges hundreds of messages per day.
Feeds tend to be less self-conscious than posts on social media. In 2022, a guest essay from the New York Times declared the group chat “leave the last place online for real conversations.”
Even people with no security clearance are aware of what they share with the pleasant familiarity of group chats. Clayton Fletcher, 48, is part of the WhatsApp group, where he and about 35 other comedians roast each other and tackle new ingredients. He is wary high when a new phone number appears. It didn’t appear to happen when Goldberg was added to the signal chat.
“The wisdom of a comedian’s age is to know your audience,” Fletcher said. “In the modern world, I think it’s like knowing who’s in group chat.”
The intimacy of group chats is often elaborate when it spills into the public eye. In 2021, an anonymous leaker shared a group message from Sen. Ted Cruz’s wife, Heidi Cruz, where she planned a trip to Cancun, but millions of members of the senators had no electricity. (Heidi Cruz clearly didn’t understand that group chats didn’t know loyalty,” Jezebel said. read. )
In 2023, the New York Times published a text between the Fox News hosts, which were completely different from the official statement on the 2020 election results. And last year, Daily Beast reported Former House member George Santos texted the humiliation to a group chat that includes members of a New York Republican delegation.
“Sorry, new phone, who’s diss?” Representative Andrew Garbarino I responded.
Our group chats may include people who extend to our professionals and personal lives and who have strong and loose social connections to which we have. It could make them a “minefield” for error, said LM Chilton, author of the upcoming thriller “Everyone in the Group Chat Dies.”
The signal group chat incident was colloquial and especially uncomfortable due to just the tone of Amon Friends (including emojis). And while it may be easy to blame the technology for violations, it was a mistake by national security adviser Michael Waltz to make it accessible to journalists to group chats.
“At the end of the day, it was an artificial mistake and it was with us from the dawn of time,” Chilton said.
New York writer Matt Buquere, 35, found a bit of a dark humor in the way that members of the Signal Group introduced themselves one by one.
Everyone has been added to a group chat where they do not belong to completely. However, he suggested not to stand out unless he was certain he could trust the rest of the group.
“If you have a lot of numbers you don’t know, you should limit group chat participation to thumbs up or ‘haha’ reactions. There’s nothing else,” he said.
Signal, a popular messaging app, has recently come under scrutiny for reports that senior Trump administration officials used the platform to plan wars and inadvertently included journalists in messaging groups.
Launched in 2014 and boasting hundreds of millions of users, the app is favored by journalists, activists, privacy experts, and politicians.
The use of the app by government officials led to intelligence report violations occurring outside of the secure government channels typically used for classified, highly sensitive war plans. This incident raises concerns about the security of Signal and the reasons behind government officials using it. (In general, federal officials are not authorized to install Signal on government-issued devices.)
Here’s what you need to know.
What is Signal used for?
Signal is an encrypted messaging application used for secure communication. It encrypts messages end-to-end, ensuring that the content remains encrypted until it reaches the intended recipient. This method protects users from interception and ensures message confidentiality.
Users can set Signal messages to disappear after a set period of time. They can also enable a feature to auto-delete messages in individual chats.
Who owns Signal?
Signal is owned by an independent nonprofit organization in the U.S. called the Signal Foundation. It is funded through user contributions and grants.
Founded in 2018 with a $50 million donation from Brian Acton, co-founder of WhatsApp, the Signal Foundation was established after Acton left WhatsApp due to a dispute with Facebook. Acton teamed up with Moxie Marlinspike, the cryptographer behind Signal’s security system, to create the Signal Foundation, which is structured to prevent data selling incentives.
“There are numerous reasons why Signal is crucial,” wrote Marlinspike, who resigned from the foundation’s board in 2022. “One important reason is to avoid mistakenly adding the Vice President of the U.S. to group chats for coordinating sensitive military operations. This must not be overlooked.”
Is Signal secure?
Yes, Signal is widely regarded as the most secure messaging app due to its encryption technology and other privacy features.
The encryption technology used by Signal is open source, allowing external experts to review and identify any vulnerabilities. This technology is also utilized by services like WhatsApp.
When Signal was targeted by foreign hackers, its encryption technology proved effective. Although there were attempts to compromise user accounts, the encryption remained intact.
In case of a security breach, Signal minimizes user data retention to protect user privacy. Unlike other messaging platforms, Signal does not store user contacts or unnecessary information.
While Signal is secure, it may not be suitable for discussing sensitive military operations if a user’s device is compromised, potentially exposing message content. Government officials should use authorized communication systems to prevent inadvertent disclosures.
Signal representatives have not responded to requests for comment.
Are Signal text messages secure?
Generally, Signal text messages are secure, but users should exercise caution when adding new contacts, similar to other social platforms.
When creating group chats, users should verify that they are including the correct contacts to ensure message confidentiality.
in New paper Published in Astrophysical JournalDr. Ravi Kopparapu of NASA’s Goddard Space Flight Center and colleagues assessed the detectability of silicon solar panels on Earth-like exoplanets as potential technological signatures.
Conceptual illustration of an exoplanet with an advanced extraterrestrial civilization. The structure on the right is an orbiting solar panel array that collects light from the parent star, converts it into electricity and transmits it via microwaves to the surface. The exoplanet on the left shows other potential technological features: on the night side there are city lights (the glowing circular structures), and on the day side there are multi-colored clouds representing various forms of pollution, such as nitrogen dioxide gas from the burning of fossil fuels and chlorofluorocarbons used in refrigeration. Image credit: NASA/Jay Freidlander.
“The search for extraterrestrial life has primarily focused on detecting biosignatures – remote observations of atmospheric or ground-based spectral properties that indicate signs of life on exoplanets,” said Dr Kopparapu and his co-authors.
“Recently, there has been a rise in interest in technosignatures, which refer to observational signs of extraterrestrial technology that can be detected or inferred through astronomical surveys.”
“While the search for extraterrestrial intelligence through radio observations has been popular for decades, recent studies have proposed an alternative: searching for technological signatures in the ultraviolet to mid-infrared spectral range.”
Astronomers speculate that extraterrestrials might build solar panels out of silicon because it is relatively abundant compared to other elements used in solar power generation, such as germanium, gallium, and arsenic.
Silicon is also excellent at converting light emitted by stars like the Sun into electricity, and it is cost-effective to mine and manufacture into solar cells.
The researchers also assume that a hypothetical extraterrestrial civilization would rely solely on solar energy.
However, if other energy sources, such as nuclear fusion, were used, the technological signature of silicon would be diminished, making the civilization even more difficult to detect.
Furthermore, they assume that the population of the civilization will stabilize at some point, and if for some reason this does not happen, they may end up expanding the Eternal Father into deep space.
For the study, scientists used computer models and NASA satellite data to simulate Earth-like planets with different degrees of silicon solar panel coverage.
They then modeled an advanced telescope, like NASA’s proposed Habitable Worlds Observatory, to see if it could detect the solar panels of a planet about 30 light-years away, a relatively close galaxy that is more than 100,000 light-years across.
The researchers found that hundreds of hours of observation time would be required with this type of telescope to detect signals from solar panels covering about 23% of the land area of an Earth-like exoplanet.
However, the solar panel coverage needed to support 30 billion people with a high standard of living was only around 8.9%.
“We find that even if the current population of around 8 billion were to stabilise to a high standard of living of 30 billion and run solely on solar energy for power, it would still use far less energy than the total amount of sunlight illuminating the Earth,” Dr Kopparap said.
The research has implications on the Fermi Paradox, proposed by physicist Enrico Fermi, which asks why extraterrestrial civilizations have not spread across the galaxy by now, given that our own Milky Way galaxy is ancient and vast, making interstellar travel difficult but possible.
“This suggests that if a civilisation chooses a very high standard of living, it may not feel the need to expand across the galaxy because it can achieve sustainable population and energy use levels,” Dr Kopparap said.
“They may expand within their own star system, or neighboring star systems, but there may not be a galaxy-wide civilization.”
“Furthermore, our own technological expertise may not yet be able to predict what more advanced civilizations will be able to achieve.”
_____
Ravi Kopparap others2024. Detectability of Solar Panels as a Technology Signature. ApJ 967, 119; doi: 10.3847/1538-4357/ad43d7
This article is based on a press release provided by NASA.
This hat looks normal, but you can sense it when the traffic light changes color
Wang Zhihun
Flexible, wear-resistant strands of conductive fibers are used to make smart clothing with embedded computers and sensors, such as hats that can sense changes in signals.
Previous efforts to create fibers with wear-resistant coatings and conductive cores have encountered problems. When materials cool and shrink at different rates during manufacturing, or are twisted and cleaned once in the final product, small stress cracks can develop and often cause smart devices to stop working.
now, Rayway Researchers at Singapore's Nanyang Technological University have discovered a conductive material that shrinks on cooling and does not develop stress cracks, similar to the aluminosilicate glass used in smartphone screens. The material borrows techniques from fiber-optic cable manufacturing, and the process is cheap and “industry-ready,” Wei said.
The technique involves placing a semiconductor wire made of silicon or germanium into molten glass at a temperature of about 1000 degrees Celsius and drawing it into thin strands. The glass is later etched away with hydrofluoric acid and replaced with a polymer coating that allows for a more flexible material. Fibers can stretch up to 10 kilometers.
A small amount of this fiber is then woven into fabric using a standard loom and regular cotton. Wei says the new material alone feels like “fishing line” on the skin, so cotton is needed to make the clothes comfortable.
The researchers used the fibers to create several prototypes, including electronic sensors and chips that communicate through conductive materials, such as a hat that detects changes in the color of traffic lights.It then passes that information to a smartphone app, a jumper that can receive and decode images sent by pulses of light rather than radio waves, and a watch strap that measures the wearer's heart rate.
In a six-month test where the garment was worn, washed and dried, the fibers were durable and continued to conduct electricity.
However, there are still weaknesses. The link between the flexible material and the rigid circuit board that holds computer chips and other components tends to fail after a few months, causing smart features to stop working.
“The only part that consistently leads to test failures is the connection between the fiber and the external circuitry,” Wei says. “The challenge now is to find a stable connection method.”
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