A new unpublished study is making waves on the internet by claiming that one of the brightest stars in the night sky might die in a spectacular explosion within our lifetime.

The study, currently available on the online pre-print serverarXiv, conjectures that the red giant star Betelgeuse, the left shoulder of the constellation Orion also known as Alpha Orionis, may have less than three hundred years’ worth of fuel left in its core. When the star burns through those last drops, its core will collapse into a black hole and in the process blast out the star’s outer layers at enormous speeds of up to 25,000 miles (40,000 kilometers) per second. This fiery demise is what astronomers call a supernova explosion, and in the case of Betelgeuse, it will be a spectacular sight for observers on Earth. Since the star is only 650 light-years from Earth, those layers of gas and dust will shine as bright as the full moon in our sky for several weeks.

The problem is that most astronomers don’t think that Betelgeuse is ready to go bang just yet. So what makes the researchers behind the new paper think otherwise?

Betelgeuse is undoubtedly a red giant star that has already burned through its primary fuel hydrogen and is now fusing helium in its core into heavier elements. The point at which a star runs out of hydrogen in its lifetime is unmissable. Stars short on hydrogen need to put extra energy into igniting the helium produced during the fusion of hydrogen, which forces them to expand dozens of times beyond their original size. In the process, they also become cooler and redder.

Astronomers know that Betelgeuse is huge. If it were to sit at the center of our solar system, the scorching gas in its outer atmosphere would reach far enough to engulf even the planet Jupiter. However, the exact width of Betelgeuse is hard to measure. That’s because instead of being one rather smooth ball of plasma, Betelgeuse is a lumpy clump of boiling gas bubbles shrouded in burped out dust clouds. To measure its diameter is therefore not easy, yet, the case for determining Betelgeuse’s remaining lifetime rests on the star’s size.

In the new controversial study, a team of astronomers led by Hideyuki Saio from the Tohoku University in Japan suggests that Betelgeuse is larger than what most researchers believe. This could be possible as Betelgeuse is known to pulsate — expand and shrink, dim and brighten up — at regular intervals. Most obviously, Betelgeuse’s brightness swings up and down every 420 days. Astronomers attribute this brightening to the periodical expansion of the star’s envelope, or roughly spherical outer region, in a phenomenon known as the fundamental mode.

A smattering of stars numbers in the thousands across the image, a deep purple background fades to black inconsistently throughout. A small number of exceptionally bright stars shine evident in the bottom corners and just above right center.

There are other quirks in Betelgeuse’s behavior, also appearing on a regular basis, which astronomers attribute to additional turbulent processes taking place inside the dying star. One of those additional variations takes place on a 2,200-day cycle, and astronomers have no explanation for it. The team led by Saio therefore proposed that this 2,200-day oscillation could, in fact, represent Betelgeuse’s main pulsation mode while the 420-day brightness variation could be a secondary quirk.

Such a scenario, however, requires Betelgeuse to be up to one third wider for these models of its evolution to work, Saio told Space.com in an email.

"To explain the 2,200-day period as fundamental mode requires a much larger radius than the case of fitting the 420-day [period] with fundamental mode," Saio wrote in an email. "A larger radius with a range of observed surface temperature means the intrinsic brightness of Betelgeuse to be higher than previously thought."

But for Betelgeuse to be as wide as the models require, it would also have to be in a later stage of its life, already done burning helium and instead running on carbon, which arose from the previous fusion of helium atoms. Whether a red giant star is burning helium or carbon makes a big difference in terms of how much life it has left. The helium-burning phase of a red giant star’s life lasts tens of thousands of years. When carbon-burning switches on, the end is nigh, at least in cosmic terms, and might come within a few thousand years.

"Although we cannot determine exactly how much carbon remains right now, our evolution models suggest that the carbon exhaustion would occur in less than 300 years," Saio wrote. "After the carbon exhaustion, fusions of further heavier elements would occur in probably a few tens of years, and after that the central part would collapse and a supernova explosion would occur."

That would certainly be exciting for skywatchers. The last time a nearby star went supernova was in 1604. Although stars explode somewhere in the universe on a daily basis, most of them are too far away to be visible without powerful telescopes.

But the question remains: What else is there but models to make Saio and his colleagues think that Betelgeuse is larger than what other astronomers think?

An asymmetrical, blurry sphere sits in the center of a black background. Its face is smeared with dull shades of yellow and pale brown.

In their paper, the researchers point out two measurements of Betelgeuse’s size to support their theory. But this is exactly where the paper has drawn criticism from other astronomers.

Miguel Montargès, a postdoctoral fellow at the Laboratory of Space Studies and Instrumentation in Astrophysics at the Paris Observatory who published papers on Betelgeuse based on observations by the Very Large Telescope in Chile, told Space.com in an earlier interview that "of the tens of measurements of Betelgeuse, [Saio and his colleagues] have selected only two."

László Molnár, an astronomy research fellow at the Konkoly Observatory in Budapest, Hungary, who also published several papers on Betelgeuse said that the measurements picked by Saio and his colleagues to support their theory were likely influenced by clouds of dust and gas around the star that make Betelgeuse appear bigger.

"If we look at the sun, we see a well-defined surface with a very crisp edge," Molnár told Space.com in an email. "But Betelgeuse being a red supergiant, is extremely fluffy and puffy, and the photosphere, what we would call its ‘surface,’ is hidden beneath multiple layers of molecular gas and clouds of dust."

Violent expulsions of these materials are typical for red giant stars. In the case of Betelgeuse, astronomers observed one such massive cloud emerge from within the star in 2019, causing the star to temporarily dim.

Molnár and his team made their own measurements of Betelgeuse’s size, which are more aligned with what most scientists think.

The release of Saio’s paper coincides with an unusual brightening of Betelgeuse that led some enthusiasts to speculate that the star might be about to explode. But neither Molnár nor Montargès are convinced. Betelgeuse, Montargès said, is actually too bright to be in its death throes due to the fact that expulsions of material typically make older red giants gradually dim. Betelgeuse, on the contrary, despite its regular pulsations, has been a fixture in the top ten brightest stars of our sky for at least the past 100 years.

The paper has not yet been peer-reviewed and published, so some of its shortcomings might get addressed before it gets officially released.

Source: https://www.space.com/betelgeuse-supernova-in-our-lifetime-study-unsure

[I've known about neutrinos for a very long time. They are totally amazing and weird. And they are passing through your body all the time. Even more bizarre, neutrinos pass through the ENTIRE EARTH. Neutrinos can come at you from above, but also from BELOW! Yes, they can pass through the entire Earth and come out the other side!! As always, these are wonderful European Race discoveries. Jan]

Neutrino map of the galaxy is 1st view of the Milky Way in ‘anything other than light’

By Ben Turner
published 4 days ago

Scientists at the IceCube Neutrino Observatory have used 60,000 neutrinos to create the first map of the Milky Way made with matter and not light.

Scientists have traced the galactic origins of thousands of "ghost particles" known as neutrinos to create the first-ever portrait of the Milky Way made from matter and not light — and it’s given them a brand-new way to study the universe.

The groundbreaking image was snapped by capturing the neutrinos as they fell through the IceCube Neutrino Observatory, a gigantic detector buried deep inside the South Pole’s ice.

Neutrinos earn their spooky nickname because their nonexistent electrical charge and almost-zero mass mean they barely interact with other types of matter. As such, neutrinos fly straight through regular matter at close to the speed of light.

Yet by slowing these neutrinos, physicists have finally traced the particles’ origins billions of light-years away to ancient, cataclysmic stellar explosions and cosmic-ray collisions. The researchers published their findings June 29 in the journal Science.

"The capabilities provided by the highly sensitive IceCube detector, coupled with new data analysis tools, have given us an entirely new view of our galaxy — one that had only been hinted at before," Denise Caldwell, director of the National Science Foundation’s physics division, which funded the research, said in a statement. "As these capabilities continue to be refined, we can look forward to watching this picture emerge with ever-increasing resolution, potentially revealing hidden features of our galaxy never before seen by humanity."

Every second, about 100 billion neutrinos pass through each square centimeter of your body. The tiny particles are everywhere — produced in the nuclear fire of stars, in enormous supernova explosions, by cosmic rays and radioactive decay, and in particle accelerators and nuclear reactors on Earth. In fact, neutrinos, which were first discovered zipping out of a nuclear reactor in 1956, are second only to photons as the most abundant subatomic particles in the universe.

Despite their ubiquity, the chargeless and near-massless particles’ minimal interactions with other matter make neutrinos incredibly difficult to detect. Many famous neutrino-detection experiments have spotted the steady bombardment of neutrinos sent to us from the sun, but this cascade also masks neutrinos from more unusual sources, such as gigantic star explosions called supernovas and particle showers produced by cosmic rays.

To capture the neutrinos, particle physicists turned to IceCube, located at the Amundsen-Scott South Pole Station in Antarctica. The gigantic detector consists of more than 5,000 optical sensors beaded across 86 strings that dangle into holes drilled up to 1.56 miles (2.5 kilometers) into the Antarctic ice.

While many neutrinos pass completely unimpeded through the Earth, they do occasionally interact with water molecules, creating particle byproducts called muons that can be witnessed as flashes of light inside the detector’s sensors. From the patterns these flashes make, scientists can reconstruct the energy, and sometimes the sources, of the neutrinos.

Finding a neutrino’s starting point depends on how clear its direction is recorded in the detector; some have very obvious initial directions, whereas others produce cascading "fuzz balls of light" that obscure their origins, lead author Naoko Kurahashi Neilson, a physicist at Drexel University in Philadelphia, said in the statement.

By feeding more than 60,000 detected neutrino cascades collected over 10 years into a machine-learning algorithm, the physicists built up a stunning picture: an ethereal, blue-tinged image showing the neutrinos’ sources all across our galaxy.

The map showed that the neutrinos were being overwhelmingly produced in regions with previously detected high gamma-ray counts, confirming past suspicions that many ghost particles are summoned as byproducts of cosmic rays smashing into interstellar gas. It also left the physicists awestruck.

"I remember saying, ‘At this point in human history, we’re the first ones to see our galaxy in anything other than light,’" Neilson said.

Just like previous revolutionary advances such as radio astronomy, infrared astronomy and gravitational wave detection, neutrino mapping has given us a completely new way to peer out into the universe. Now, it’s time to see what we find.

Source: https://www.livescience.com/physics-mathematics/particle-physics/ghost-particle-image-is-the-1st-view-of-our-galaxy-in-anything-other-than-light?utm_term=23709803-D360-4259-9C73-BE4FF46B5C71&utm_campaign=368B3745-DDE0-4A69-A2E8-62503D85375D&utm_medium=email&utm_content=2D5C159E-DF3C-4887-B039-4BED38DE05F5&utm_source=SmartBrief

[There are images and even a video at the source link below. Jan]

A runaway supermassive black hole ejected from its own galaxy, possibly in a tussle with two other black holes, is being trailed by a 200,000 light-year-long chain of infant stars, a new study reports.

The incredible sight, which is like nothing astronomers have spotted before, was identified by the Hubble Space Telescope in a happy accident.

The supermassive black hole, with a mass equivalent to 20 million suns, is traveling so fast that it would cover the distance between Earth and the moon in just 14 minutes.

An illustration of a runaway black hole ejected from its host galaxy and followed by a trail of infant stars.
An illustration of a runaway black hole ejected from its host galaxy and followed by a trail of infant stars. (Image credit: NASA, ESA, Leah Hustak (STScI))

As it travels, the cosmic runaway is piling up gas in front of it. When dense regions of gas like those left in the wake of this rogue black hole collapse, new stars are born. A supermassive black hole cruising through clouds of gas would normally feed on it, a process called accretion. But this runaway cosmic monster is moving too fast to grab a bite.

As a result, the rogue black hole is actively creating a corridor of infant stars, and these are forming a tail that tracks right back to the supermassive black hole’s galaxy of origin, researchers said. And this tail is half as bright as that galaxy, meaning it must be absolutely brimming with stars.

"We think we’re seeing a wake behind the black hole where the gas cools and is able to form stars. So, we’re looking at star formation trailing the black hole," study lead author Pieter van Dokkum, of Yale University, said in a statement. "What we’re seeing is the aftermath. Like the wake behind a ship, we’re seeing the wake behind the black hole. It didn’t look like anything we’ve seen before."

At the outermost tip of the column of stars in a knot of ionized oxygen that is incredibly bright. The team believes that this is the result of the black hole striking gas, shocking it and heating it.

"Gas in front of it gets shocked because of this supersonic, very-high-velocity impact of the black hole moving through the gas," said van Dokkum. "How it works exactly is not really known."

Something else that isn’t totally clear yet is how the supermassive black hole came to be launched out of its host galaxy.
Click here for more Space.com videos…
Kicked out by a cosmic cuckoo

The team thinks that the ejected black hole could have escaped its host galaxy as the result of multiple collisions of supermassive black holes, the first occurring when two galaxies merged 50 million years ago, bringing two cosmic titans close together.

As these supermassive black holes circled around each other, another galaxy entered the mix, carrying with it another supermassive black hole. Following the old adage "two’s company and three’s a crowd," the interaction between the three black holes was chaotic and led to one black hole stealing momentum from the others and hurtling off into space.

That means there’s a good chance that the interloper black hole introduced itself to the system and eventually replaced one of the original black holes, like a cosmic cuckoo.

As the runaway black hole blasted away from its former companions, the new pairing would have moved in the opposite direction. And there are hints at a runaway black-hole binary on the opposite side of the host galaxy to the black hole racing through space with its stellar tail.

The next step for this research will be to search for evidence of these binary black holes with NASA’s James Webb Space Telescope (JWST) and the Chandra X-ray Observatory, study team members aid.
Related stories:

Scientists will be hoping for the same good fortune experienced by van Dokkum and his team when they initially made the extraordinary observation of this massive cosmic runaway.

"This is pure serendipity that we stumbled across it," van Dokkum concluded. "I was just scanning through the Hubble image, and then I noticed that we have a little streak. I immediately thought, ‘Oh, a cosmic ray hitting the camera detector and causing a linear imaging artifact.’ When we eliminated cosmic rays, we realized it was still there."

The team’s research was published on April 6 in The Astrophysical Journal Letters.

Source: https://www.space.com/runaway-supermassive-black-hole-hubble-telescope?utm_term=AF536F6D-055D-443A-91F7-FD448D0CCA73&utm_campaign=58E4DE65-C57F-4CD3-9

[Just read this and be amazed at what this British technology can do. It's just insane! But as always, Western Civilization does the impossible. This is very important because near Earth space is getting filled with tiny pieces of debris that will destroy spacecraft and endanger lives. Jan]

The technology will be able to extrapolate the trajectory of the smallest pieces of space junk.

A new method of tracking tiny pieces of space junk has passed its first demonstration test in orbit, according to its builders ODIN Space of London.

Over the past two years, ODIN has been developing and qualifying technology to detect and track space junk that is too small to register using existing methods. The company’s first demonstration sensor was integrated into the D-Orbit ION satellite, which hitched a ride to orbit as part of SpaceX’s Transporter-8 mission that launched June 12.

Now, after more than a week on orbit, ODIN has confirmed with D-Orbit that their onboard sensor is operational, and picked up faint acoustic vibrations from its host satellite. For this demo flight, ODIN’s debris sensor was set to an exceptionally high sensitivity, to ensure even the smallest of readings from the ION satellite could be detected.

There are tens of thousands of pieces of trackable debris in orbit around Earth, with that number expected to increase exponentially into the 2030s and beyond with the continuing growth of the space economy. Using current technology, only pieces of debris larger than around 4 inches (10 centimeters) are able to be tracked. ODIN hopes its technology will help track sub-centimeter debris, which travel in near invisibility, at bullet speeds, and pose threats to satellites, space stations and other on-orbit infrastructure.

"We’ll now focus on providing our customers with the next generation of space data and sending many more sensors to every orbit," said ODIN CEO and co-founder James New in an ODIN press release, adding, "by understanding how lethal, sub-centimeter debris behaves, we can protect space assets, maximize growth and drive sustainability in space."

Now, ODIN plans to scale up the technology in order to bring the technology to the commercial market. Once operational, ODIN’s sub-centimeter sensor will be able to track the size, location and, for the first time, the speed and trajectory of debris measuring as small as 1/250th of an inch (0.1 millimeters).

With this trajectory mapping, ODIN strives to build complex models of sub-centimeter debris to improve situational awareness for thousands of satellites in Earth orbit.

Source: https://www.space.com/odin-space-completes-debris-tracking-demo?utm_term=AF536F6D-055D-443A-91F7-FD448D0CCA73&utm_campaign=58E4DE65-C57F-4CD3-9A5A-609994E2C5A9&utm_medium=email&utm_content=E5039B48-7782-41C2-91B9-8DC8DA3B43A5&utm_source=SmartBrief

[This German lady scientist is interesting. Jan]

Here’s the video: https://www.youtube.com/watch?v=9-jIplX6Wjw

[There were a LOT of nuclear tests in America, on American soil, mostly in Nevada. There have been all kinds of nuclear tests, in the air, at sea, in space, underground, etc. Scientists, especially American scientists, tested and measured nuclear explosions under every conceivable kind of condition. In the final years, underground nuclear testing was the most common and safe way to do it. Atmospheric tests were the most dangerous because of winds. Jan]

Here’s the video: https://www.youtube.com/watch?v=FCf_yEoLj9o

[This topic is nasty but belongs in the field of human science. I have been following, out of pure curiosity the nightmare problem of the 5 people in the tiny submarine that went down to the Titanic and they are now lost on the sea bed. I had just pondered their fate. I thought at first that the most likely scenario is that maybe the submarine imploded and they all just died. From every angle, human survival in this case is IMPOSSIBLE. I looked at this as done and dusted, these people died. Regardless of what happened, they are DEAD. The thing that piqued my interest was that sonars were picking up tapping noises every 30 minutes which sounded like people trapped in the submarine knocking on it so that they could be found. There are many safety issues with the submarine like: Why didn't they have some cheap transponders on it which send out messages that are easy to find. That, for example, is a very simple, and very effective solution. But, that clearly was not done. The tapping noises were heard yesterday and last night. So it seems as if these people are genuinely alive. The temperature down there is extremely cold. So I thought that between the cold and oxygen deprivation they WILL DIE. There is ZERO HOPE. Then I wondered if some would not die before others? What if some die and others can then continue breathing oxygen? I must say, I had thought that the final outcome of this is that it may take them days, weeks or months, or longer to eventually find the submarine and they'll open it and it will be a forensic coffin and a year or more from now we'll find out how long they lived and when they died. But check out what a doctor and an admiral have to say. This is quite bizarre and it is how the human body adapts! Jan]

It is a claustrophobic, terrifying prospect – being trapped in a 22ft submersible, potentially thousands of feet underwater, with oxygen running out.

The exact whereabouts of the Titanic submersible and the condition of the five crew onboard are unknown. It is thought that, if the vessel is still intact, it may have just a few hours of oxygen remaining, creating a race against time to find the sub before it is too late.

However, that timeline is not necessarily rigid. Dr Ken LeDez, a hyperbaric medicine expert at Memorial University in St John’s, Newfoundland, has told BBC News that, depending on conditions, some of those aboard could survive longer than expected.

"It depends on how cold they get and how effective they are at conserving oxygen," he said, adding that shivering will use up a lot of oxygen, while wrapping up in a huddle can help to conserve heat.

He said running out of oxygen is a gradual process. "It’s not like switching off a light, it’s like climbing a mountain – as the temperature gets colder and metabolism falls [it depends] how fast you ascend that mountain," he said.

While admitting that we do not know the full situation inside the submersible, Dr LeDez said conditions could be different person-to-person, and that although it is a "disturbing conversation", some could survive longer than others.

On Wednesday, Rear Admiral John Mauger from the US Coast Guard said there were a number of unknowns in the search and rescue mission.

"We do not know the rate of consumption of oxygen per occupant on the sub," Rear Adm Mauger told the BBC.

Dr LeDez also said that running out of oxygen is not the only danger those on board face.

The vessel may have lost electrical power, which is likely to have a role in controlling the amount of oxygen and carbon dioxide inside the vessel.

As the oxygen level falls, the proportion of carbon dioxide being breathed out by the crew will be rising, with potentially fatal consequences.

"As levels of carbon dioxide build up, then it becomes sedative, it becomes like an anaesthetic gas, and you will go to sleep."

Too much of the gas in a person’s bloodstream, known as hypercapnia, can kill them if not treated.

Former Royal Navy submarine captain Ryan Ramsey says he looked at videos online of the inside of Titan and could not see a carbon dioxide removal system, known as scrubbers.

"That for me is the greatest problem of all of them," he says.
line

At the same time, the crew are at risk from hypothermia, where the body gets too cold.

According to Capt Ramsey, if the sub is on the seabed, the water temperature will be about 0C. If it has also lost electricity, it will not be generating any power and therefore cannot generate heat.

But hypothermia "could be their friend", said Dr LeDez.

"There is a possibility if they cool down enough and lose consciousness they could live through it – rescuers know this," he said, adding that the body will automatically try to adapt to survive.

However on the flip side, hypothermia, the lack of oxygen and the build-up of carbon dioxide within the sub mean the crew’s ability to make contact with the search and rescue mission, such as by banging on the hull at regular intervals to try and attract attention, will dwindle.

"If they’re unconscious, they’re not going to be able to do much to help themselves," says Dr LeDez.

While the Coast Guard has warned there is probably little oxygen left, the crew may be able to conserve their supplies – at least for a while.

Mr Ramsey says slowing their breathing would also help but admits this could be difficult considering the stress they would be under.

Dr LeDez says they could also spread out carbon dioxide-absorbing granules or reduce their power use if they still have electricity.

In terms of food and water, the Coast Guard said the crew had some "limited rations" on board but couldn’t say how much.

Despite all these challenges, Dr LeDez urges against cancelling the search-and-rescue operation too soon, saying they might be able to survive even when oxygen levels are very low.

"If anybody can survive in it, you know, it’s these individuals," he says. "It just depends on them having power and depends on them having light to be able to find things and make these controls, but absolutely, they could still be alive."

Source: https://www.bbc.com/news/world-us-canada-65981277

[This makes sense. I did look into the effects of the mass of ice accumulating at the poles in the past, and how that could cause the Earth to tilt. So this is not surprising. We live on a very fragile planet and our biology is very soft. Whites are the only race who can actually help to keep this planet going and who could survive anything. Jan]

Earth’s tilt has changed by 31.5 inches (80 centimeters) between 1993 and 2010 because of the amount of groundwater humans have pumped from the planet’s interior.

In that period, humans removed 2,150 gigatons of water from natural reservoirs in the planet’s crust. If such an amount was poured into the global ocean, its surface would rise by 0.24 inches (6 millimeters). A new study has now revealed that displacing such an enormous amount of water has had an effect on the axis around which the planet spins.

Scientists arrived at this conclusion by modeling the changes in the position of Earth’s rotational pole, the point at which the planet’s imaginary axis would stick out of the surface if it were a physical object. The position of the rotational pole is not identical with the geographical north and south poles and actually changes over time, so the rotational axis cuts through different spots on the planet’s crust at various points in time.

Since 2016, scientists have known that the rotational pole is affected by climate-related processes, such as the thawing of icebergs and the redistribution of the mass of the water locked in them. But until the researchers added the pumped-out water into their models, the results hadn’t perfectly matched observations. Without the pumped-out groundwater, the model was off by 31 inches (78.5 centimeters).

"Earth’s rotational pole actually changes a lot," Ki-Weon Seo, a geophysicist at Seoul National University who led the study, said in a statement. "Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole."

Since the tilt of Earth’s axis can have an effect on seasonal weather on the planet’s surface, scientists now wonder whether the shifts of the rotational pole could contribute to climate change in the long-term.

"Observing changes in Earth’s rotational pole is useful for understanding continent-scale water storage variations," Seo said. "Polar motion data are available from as early as the late 19th century. So, we can potentially use those data to understand continental water storage variations during the last 100 years. Were there any hydrological regime changes resulting from the warming climate? Polar motion could hold the answer."

Overall, the Earth’s rotational pole shifts by several meters a year. How much drained groundwater reservoirs contribute to this shift depends on where on the planet they are located. The study showed that water removed from mid-latitudes has the largest effect on the planet’s tilt.

Managing how groundwater moves around the globe could therefore help limit the shifts of the rotational pole and thus the potential climate effects that come with them.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community.

Source: https://www.space.com/earth-tilt-changed-by-groundwater-pumping

[This is the nastiest event that has taken place in a long time. It is the worst thing that has happened on the planet in HUNDREDS of years. It happened in Russia in 1908. Jan]

Here’s the video: https://www.youtube.com/watch?v=qhVvihYJBEs

[What is really interesting in this article is that these scientists studied the growth of CITIES and that cities WILL COLLAPSE! This is something I did not know about. I would otherwise not take this idea too seriously. I have been looking into this topic about life in the universe, and the answer is actually much scarier. As bizarre as it sounds, we might be alone – and that might be a very good thing! I will discuss this later. Jan]

Why has humanity never been visited by aliens (that we know of)? The question has confounded scientists for decades, but two researchers have come up with a possible — and disturbing — explanation: Advanced civilizations could be doomed to either stagnate or die before they get the chance.

The new hypothesis suggests that, as space-faring civilizations grow in scale and technological development, they eventually reach a crisis point where innovation no longer keeps up with the demand for energy. What comes next is collapse. The only alternative path is to reject a model of "unyielding growth" in favor of maintaining equilibrium, but at the cost of a civilization’s ability to expand across the stars, the researchers said.

The argument, published on May 4 in the journal Royal Society Open Science, attempts to find a resolution to the Fermi Paradox. Taking its name from the casual lunchtime musings of Nobel Prize-winning physicist Enrico Fermi, the paradox draws attention to the contradiction between the immense scope and age of the universe — two things that suggest the universe should be teeming with advanced alien life — and the lack of evidence that extraterrestrials exist anywhere in sight. "So where is everybody?" Fermi is thought to have remarked.

The researchers of the new study say they may have the answer.

"Civilizations either collapse from burnout or redirect themselves to prioritizing homeostasis, a state where cosmic expansion is no longer a goal, making them difficult to detect remotely," astrobiologists Michael Wong, of the Carnegie Institution for Science, and Stuart Bartlett, of the California Institute of Technology, wrote in the study. "Either outcome — homeostatic awakening or civilization collapse — would be consistent with the observed absence of [galactic-wide] civilizations."

The pair came to their hypothesis by researching studies of the "’superlinear"’ growth of cities. These studies suggested that cities increase in size and energy consumption at an exponential rate as their populations grow, inevitably leading to crisis points — or singularities — that cause rapid crashes in growth, followed by an even more precipitous, potentially civilization-ending, collapse.

"We hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an ‘asymptotic burnout,’ an ultimate crisis where the singularity-interval time scale becomes smaller than the time scale of innovation," they wrote.

These close-to-collapse civilizations would be the easiest for humanity to detect, the researchers suggest, as they would be dissipating large amounts of energy in a "wildly unsustainable" way. "This presents the possibility that a good many of humanity’s initial detections of extraterrestrial life may be of the intelligent, though not yet wise, kind," the researchers wrote.

To avert their doom, civilizations could undergo a "homeostatic awakening," redirecting their production away from unbounded growth across the stars to one that prioritizes societal wellbeing, sustainable and equitable development and harmony with their environment, the researchers suggest. While such civilizations may not completely abandon space exploration, they would not expand on scales great enough to make contact with Earth likely.

The researchers point to a few of humanity’s "mini-awakenings" that addressed global crises on Earth, such as the reduction of global nuclear arms stockpiles from 70,000 warheads to below 14,000; the halting of the once-growing hole in Earth’s ozone layer by banning chlorofluorocarbon emissions; and the 1982 international whaling moratorium.

The scientists stress, however, that their suggestion is simply a hypothesis, taken from the observation of laws that seem to govern life on Earth, and is designed to "provoke discussion, introspection and future work."

Their proposal joins a bountiful crop of other scientific and popular suggestions as to why we’ve never made direct contact with celestial visitors. These include the numerous practical challenges presented by interstellar travel; that aliens may actually be visiting in secret; or that aliens arrived to Earth too soon (or humans too early) in the life of the universe for direct contact.

Another hypothesis, published April 4 in The Astrophysics Journal, suggests that the sheer scale of the universe means it could take as long as 400,000 years for a signal sent by one advanced species to be received by another — a timescale that’s far greater than the brief period humans have been able to scan the skies.

Source: https://www.livescience.com/alien-civilizations-doomed-to-collapse