NASA’s picture features a detailed portrait of the distant galaxy NGC 4380. The spiral body sits nearly 63 million light-years from Earth in the constellation Virgo. The European Space Agency (ESA), which operates Hubble together with NASA, likened the image to a special effect in a Hollywood blockbuster.
ESA said: “In this image taken by Hubble Space Telescope, the galaxy NGC 4380 looks like a special effect straight out of a science fiction or fantasy film, swirling like a gaping portal to another dimension.
“In the grand scheme of things, though, the galaxy is actually quite ordinary.
“Spiral galaxies like NGC 4380 are common in the universe.
“These colossal collections of stars, often numbering in the hundreds of billions, are shaped like a flat disc, sometimes with a rounded bulge in the center.
Picture this. You’re camping with your family and it’s a clear night. As you look up into the night sky, it feels like there are a thousand stars, and they’re bright enough to touch. You feel the impact of how small you are in the grand scheme of things. And then your mind wanders as you try to wrap your head around how big the universe is. If this question has been keeping you up at night, we have the answer.
So, how big is the universe?
There was a time when we couldn’t give you a hard figure. But as far back as 1920, astronomers have been sharing estimates on the size of the known universe. Before we dig into hard figures, best guesses, and even erroneous ones, we need to set some ground rules.
First, the universe is constantly expanding. Any measurements given today won’t be accurate in the future. Likewise, scientists and astronomers can give only measurements based on the observable or known universe. This references what can be seen through their telescope, whether on the ground or with a satellite. Much like the expanding universe factor, dimensions based on the observable universe can be limited.
In other words, based on current research, observations and mathematical equations, the experts can estimate the universe’s size within a fair degree of certainty. But the caveat will always apply that these figures are impacted by the universe’s growth rate and the limitation of the observable universe.
What’s the number?
Slow down there! Another important note is that we aren’t measuring in miles or kilometers like we would the distance between New York and London. Instead, we use light-years when we’re discussing the distance between two bodies in space. Standard forms of measurement would be too impractical because, in space, celestial bodies are very far apart.
Speaking literally, a light-year describes the distance a beam of light can travel in one year. To help you quantify that and realize why light years are better than traditional Earth-distance measurements, one light0year is the equivalent of 6 trillion miles. If you got dizzy just hearing that, now you know why astronomers prefer light-years over miles or kilometers.
Is there an estimate?
Initial size estimates of our universe began with measuring our galaxy, the Milky Way. In 1920 the American astronomer Harlow Shapley was one of the first experts who attempted to measure the Milky Way and came up with a diameter of 300,000 light-years. It turns out he was very wrong, as today most astronomers believe our Milky Way is somewhere between 100,000 and 150,000 light years in diameter.
For perspective, we know that the Milky Way isn’t the only galaxy in our universe — nor is it the biggest. Current counts estimate that there are at least 100 billion galaxies in the known universe and the largest discovered galaxy to date is IC 1101 with a diameter of 6 million light-years (although this figure is contested). So if our little corner of the universe is 100,000 light-years wide, and the biggest galaxy is around 6 million light-years in diameter, that can give you a hint that the known universe is quite large.
Just say how big the universe is!
Current measurements place the observable universe at roughly 93 billion light-years in diameter. There are a variety of methods used to reach this figure, but popular options include measuring radio wavelengths, parallax measurements, main sequence fitting, and cepheid variables. Radio wavelengths are a great option within our solar system because astronomers can measure the time it takes for a radio wave to bounce off the surface of a planet or asteroid and translate that into an actual light-year reading. But for celestial bodies farther out in the universe, it’s not practical.
Beyond our solar system, parallax measurement is preferred as it relies on comparing distances to an object based on measurements from multiple angles. This method relies on telescopes and satellites to compute various distance readings over time and scientists to extrapolate accurate positions from the data. But beyond 100 light-years, even parallax measurement is inefficient.
At great distances, main sequence fitting and cepheid variables are the preferred measurement tools. Main sequence fitting relies on a basic understanding of a star’s brightness and color compared to its age to determine distance. Cepheid variables focus on the actual “twinkle” or pulsating factor to determine age and position.
So what does this all mean?
If we haven’t given you a headache yet, it means that even though astronomers and experts have a great grasp on the general size of the universe, figures can change as our methods for analyzing data improve. And for the average Joe, just know that the universe is huge, and we’re in one little corner of it!
Astronomers have discovered the oldest cluster of galaxies ever seen, which dates to the early universe.
The discovery, which could help explain the shape of the modern cosmos, reveals 12 galaxies that existed in a clump 13 billion years ago — just about 700 million years after the Big Bang. We can see them now because they’re so far away in the expanding universe (13 billion light-years) that their starlight is only now reaching Earth. One of the galaxies, a mammoth named Himiko after a mythological Japanese queen, was discovered a decade ago by the same team.
Surprisingly, the other 11 galaxies aren’t clustered around the giant Himiko, the researchers wrote in a paper that will be published on Sept. 30 in The Astrophysical Journal and is available as a draft on the website arXiv. Instead, Himiko sits at the edge of the system, which the researchers call a “protocluster” because it’s so small and ancient compared to most of the clusters we can see in the universe..
“It is reasonable to find a protocluster near a massive object, such as Himiko. However, we’re surprised to see that Himiko was located not in the center of the protocluster but on the edge, 500 million light-years away from the center,” Masami Ouchi, a co-author of the paper and an astronomer at the National Astronomical Observatory of Japan and the University of Tokyo, said in a statement.
Understanding how galaxy clusters came to be turns out to be important for understanding the galaxies they contain. Most galaxies, including the Milky Way, show up in clumps with other galaxies, so the galaxies aren’t evenly distributed throughout the universe. And that clumping seems to affect their behavior, astronomers have said. Galaxies in high-density, clumped environments full of galaxies form stars in different ways than do galaxies in low-density environments empty of galaxies. And the impact of clumping seems to have changed over time, the researchers said.
In more recent times, the researchers wrote in the paper, “there is a clear trend that the star-formation activity of galaxies tends to be lower in high-density environment than low-density environment.”
So, clumped-up galaxies these days form stars less often than their more independent cousins do. It’s as if they’re aging faster in their clusters, the researchers wrote, becoming geriatric and giving up on making new stars.
But in the ancient universe, the trend seems to have been reversed. Galaxies in highly packed clusters formed stars faster, not slower, remaining young and spry compared with their cousins not in dense clusters.
Still, “protoclusters” like this one from the early eons of the universe are rarely found and are poorly understood, the researchers wrote. These clumps tend to be much smaller than modern examples, which can contain hundreds of galaxies.
The further back telescopes peer into time, the fewer proto-clusters turn up. It’s possible many of them are simply obscured by intergalactic dust. The astronomers hope, they wrote, that the new discovery will help flesh out the picture and explain how the state of things 13 billion years ago changed over time to produce that clustered universe we see today.
So there you are, about to leap into a black hole. What could possibly await should — against all odds — you somehow survive? Where would you end up and what tantalizing tales would you be able to regale if you managed to clamor your way back?
The simple answer to all of these questions is, as Professor Richard Massey explains, “Who knows?” As a Royal Society research fellow at the Institute for Computational Cosmology at Durham University, Massey is fully aware that the mysteries of black holes run deep. “Falling through an event horizon is literally passing beyond the veil — once someone falls past it, nobody could ever send a message back,” he said. “They’d be ripped to pieces by the enormous gravity, so I doubt anyone falling through would get anywhere.”
If that sounds like a disappointing — and painful — answer, then it is to be expected. Ever since Albert Einstein’s general theory of relativity was considered to have predicted black holes by linking space-time with the action of gravity, it has been known that black holes result from the death of a massive star leaving behind a small, dense remnant core. Assuming this core has more than roughly three-times the mass of the sun, gravity would overwhelm to such a degree that it would fall in on itself into a single point, or singularity, understood to be the black hole’s infinitely dense core.
The resulting uninhabitable black hole would have such a powerful gravitational pull that not even light could avoid it. So, should you then find yourself at the event horizon — the point at which light and matter can only pass inward, as proposed by the German astronomer Karl Schwarzschild — there is no escape. According to Massey, tidal forces would reduce your body into strands of atoms (or ‘spaghettification’, as it is also known) and the object would eventually end up crushed at the singularity. The idea that you could pop out somewhere — perhaps at the other side — seems utterly fantastical.
What about a wormhole?
Or is it? Over the years scientists have looked into the possibility that black holes could be wormholes to other galaxies. They may even be, as some have suggested, a path to another universe.
Such an idea has been floating around for some time: Einstein teamed up with Nathan Rosen to theorize bridges that connect two different points in space-time in 1935. But it gained some fresh ground in the 1980’s when physicist Kip Thorne — one of the world’s leading experts on the astrophysical implications of Einstein’s general theory of relativity — raised a discussion about whether objects could physically travel through them.
“Reading Kip Thorne’s popular book about wormholes is what first got me excited about physics as a child,” Massey said. But it doesn’t seem likely that wormholes exist.
Indeed, Thorne, who lent his expert advice to the production team for the Hollywood movie Interstellar, wrote: “We see no objects in our universe that could become wormholes as they age,” in his book “The Science of Interstellar” (W.W. Norton and Company, 2014). Thorne told Space.com that journeys through these theoretical tunnels would most likely remain science fiction, and there is certainly no firm evidence that a black hole could allow for such a passage.
Artist’s concept of a wormhole. If wormholes exist, they might lead to another universe. But, there’s no evidence that wormholes are real or that a black hole would act like one.
(Image credit: Shutterstock)
But, the problem is that we can’t get up close to see for ourselves. Why, we can’t even take photographs of anything that takes place inside a black hole — if light cannot escape their immense gravity, then nothing can be snapped by a camera. As it stands, theory suggests that anything which goes beyond the event horizon is simply added to the black hole and, what’s more, because time distorts close to this boundary, this will appear to take place incredibly slowly, so answers won’t be quickly forthcoming.
“I think the standard story is that they lead to the end of time,” said Douglas Finkbeiner, professor of astronomy and physics at Harvard University. “An observer far away will not see their astronaut friend fall into the black hole. They’ll just get redder and fainter as they approach the event horizon [as a result of gravitational red shift]. But the friend falls right in, to a place beyond ‘forever.’ Whatever that means.”
Maybe a black hole leads to a white hole
Certainly, if black holes do lead to another part of a galaxy or another universe, there would need to be something opposite to them on the other side. Could this be a white hole — a theory put forward by Russian cosmologist Igor Novikov in 1964? Novikov proposed that a black hole links to a white hole that exists in the past. Unlike a black hole, a white hole will allow light and matter to leave, but light and matter will not be able to enter.
Scientists have continued to explore the potential connection between black and white holes. In their 2014 study published in the journal Physical Review D, physicists Carlo Rovelli and Hal M. Haggard claimed that “there is a classic metric satisfying the Einstein equations outside a finite space-time region where matter collapses into a black hole and then emerges from a while hole.” In other words, all of the material black holes have swallowed could be spewed out, and black holes may become white holes when they die.
Far from destroying the information that it absorbs, the collapse of a black hole would be halted. It would instead experience a quantum bounce, allowing information to escape. Should this be the case, it would shed some light on a proposal by former Cambridge University cosmologist and theoretical physicist Stephen Hawking who, in the 1970’s, explored the possibility that black holes emit particles and radiation — thermal heat — as a result of quantum fluctuations.
Red shifting Star Orbiting Super massive Black Hole Demonstrates Einstein Prediction
“Hawking said a black hole doesn’t last forever,” Finkbeiner said. Hawking calculated that the radiation would cause a black hole to lose energy, shrink and disappear, as described in his 1976 paper published in Physical Review D. Given his claims that the radiation emitted would be random and contain no information about what had fallen in, the black hole, upon its explosion, would erase loads of information.
This meant Hawking’s idea was at odds with quantum theory, which says information can’t be destroyed. Physics states information just becomes more difficult to find because, should it become lost, it becomes impossible to know the past or the future. Hawking’s idea led to the ‘black hole information paradox’ and it has long puzzled scientists. Some have said Hawking was simply wrong, and the man himself even declared he had made an error during a scientific conference in Dublin in 2004.
So, do we go back to the concept of black holes emitting preserved information and throwing it back out via a white hole? Maybe. In their 2013 study published in Physical Review Letters, Jorge Pullin at Louisiana State University and Rodolfo Gambini at the University of the Republic in Montevideo, Uruguay, applied loop quantum gravity to a black hole and found that gravity increased towards the core but reduced and plonked whatever was entering into another region of the universe. The results gave extra credence to the idea of black holes serving as a portal. In this study, singularity does not exist, and so it doesn’t form an impenetrable barrier that ends up crushing whatever it encounters. It also means that information doesn’t disappear.
Maybe black holes go nowhere
Yet physicists Ahmed Almheiri, Donald Marolf, Joseph Polchinski and James Sully still believed Hawking could have been on to something. They worked on a theory that became known as the AMPS firewall, or the black hole firewall hypothesis. By their calculations, quantum mechanics could feasibly turn the event horizon into a giant wall of fire and anything coming into contact would burn in an instant. In that sense, black holes lead nowhere because nothing could ever get inside.
This, however, violates Einstein’s general theory of relativity. Someone crossing the event horizon shouldn’t actually feel any great hardship because an object would be in free fall and, based on the equivalence principle, that object — or person — would not feel the extreme effects of gravity. It could follow the laws of physics present elsewhere in the universe, but even if it didn’t go against Einstein’s principle it would undermine quantum field theory or suggest information can be lost.
Artist’s impression of a tidal disruption event which occurs when a star passes too close to a super massive black hole.
(Image credit: All About Space magazine)
A black hole of uncertainty
Step forward Hawking once more. In 2014, he published a study in which he eschewed the existence of an event horizon — meaning there is nothing there to burn — saying gravitational collapse would produce an ‘apparent horizon’ instead.
This horizon would suspend light rays trying to move away from the core of the black hole, and would persist for a “period of time.” In his rethinking, apparent horizons temporarily retain matter and energy before dissolving and releasing them later down the line. This explanation best fits with quantum theory — which says information can’t be destroyed — and, if it was ever proven, it suggests that anything could escape from a black hole.
Hawking went as far as saying black holes may not even exist. “Black holes should be redefined as metastable bound states of the gravitational field,” he wrote. There would be no singularity, and while the apparent field would move inwards due to gravity, it would never reach the center and be consolidated within a dense mass.
And yet anything which is emitted will not be in the form of the information swallowed. It would be impossible to figure out what went in by looking at what is coming out, which causes problems of its own — not least for, say, a human who found themselves in such an alarming position. They’d never feel the same again!
One thing’s for sure, this particular mystery is going to swallow up many more scientific hours for a long time to come. Rovelli and Francesca Vidotto recently suggested that a component of dark matter could be formed by remnants of evaporated black holes, and Hawking’s paper on black holes and ‘soft hair’ was released in 2018, and describes how zero-energy particles are left around the point of no return, the event horizon — an idea that suggests information is not lost but captured.
This flew in the face of the no-hair theorem which was expressed by physicist John Archibald Wheeler and worked on the basis that two black holes would be indistinguishable to an observer because none of the special particle physics pseudo-charges would be conserved. It’s an idea that has got scientists talking, but there is some way to go before it’s seen as the answer for where black holes lead. If only we could find a way to leap into one.
ByCHALMERS UNIVERSITY OF TECHNOLOGYSEPTEMBER 22, 2019
For DNA to be read, replicated or repaired, DNA molecules must open themselves. This happens when the cells use a catalytic protein to create a hydrophobic environment around the molecule. Illustration Credit: Yen Strandqvist/Chalmers University of Technology
Researchers at Chalmers University of Technology, Sweden, disprove the prevailing theory of how DNA binds itself. It is not, as is generally believed, hydrogen bonds which bind together the two sides of the DNA structure. Instead, water is the key. The discovery opens doors for new understanding in research in medicine and life sciences. The researchers’ findings are presented in the journal PNAS.
DNA is constructed of two strands, consisting of sugar molecules and phosphate groups. Between these two strands are nitrogen bases, the compounds which make up organisms’ genes, with hydrogen bonds between them. Until now, it was commonly thought that those hydrogen bonds were what held the two strands together.
But now, researchers from Chalmers University of Technology show that the secret to DNA’s helical structure may be that the molecules have a hydrophobic interior, in an environment consisting mainly of water. The environment is therefore hydrophilic, while the DNA molecules’ nitrogen bases are hydrophobic, pushing away the surrounding water. When hydrophobic units are in a hydrophilic environment, they group together, to minimize their exposure to the water.
The role of the hydrogen bonds, which were previously seen as crucial to holding DNA helixes together, appear to be more to do with sorting the base pairs, so that they link together in the correct sequence.
The discovery is crucial for understanding DNA’s relationship with its environment.
Bobo Feng, Postdoc, Chemistry and Chemical Engineering, Chalmers University of Technology. Credit: Johan Bodell/Chalmers University of Technology
“Cells want to protect their DNA, and not expose it to hydrophobic environments, which can sometimes contain harmful molecules,” says Bobo Feng, one of the researchers behind the study. “But at the same time, the cells’ DNA needs to open up in order to be used.”
“We believe that the cell keeps its DNA in a water solution most of the time, but as soon as a cell wants to do something with its DNA, like read, copy or repair it, it exposes the DNA to a hydrophobic environment.”
Reproduction, for example, involves the base pairs dissolving from one another and opening up. Enzymes then copy both sides of the helix to create new DNA. When it comes to repairing damaged DNA, the damaged areas are subjected to a hydrophobic environment, to be replaced. A catalytic protein creates the hydrophobic environment. This type of protein is central to all DNA repairs, meaning it could be the key to fighting many serious sicknesses.
Understanding these proteins could yield many new insights into how we could, for example, fight resistant bacteria, or potentially even cure cancer. Bacteria use a protein called RecA to repair their DNA, and the researchers believe their results could provide new insight into how this process works – potentially offering methods for stopping it and thereby killing the bacteria.Rad51
In human cells, the protein Rad51 repairs DNA and fixes mutated DNA sequences, which otherwise could lead to cancer.
“To understand cancer, we need to understand how DNA repairs. To understand that, we first need to understand DNA itself,” says Bobo Feng. “So far, we have not, because we believed that hydrogen bonds were what held it together. Now, we have shown that instead it is the hydrophobic forces which lie behind it. We have also shown that DNA behaves totally differently in a hydrophobic environment. This could help us to understand DNA, and how it repairs. Nobody has previously placed DNA in a hydrophobic environment like this and studied how it behaves, so it’s not surprising that nobody has discovered this until now.”
More information on the methods the researchers used to show how DNA binds together:
The researchers studied how DNA behaves in an environment which is more hydrophobic than normal, a method they were the first to experiment with.
They used the hydrophobic solution polyethylene glycol, and step-by-step changed the DNA’s surroundings from the naturally hydrophilic environment to a hydrophobic one. They aimed to discover if there is a limit where DNA starts to lose its structure, when the DNA does not have a reason to bind, because the environment is no longer hydrophilic. The researchers observed that when the solution reached the borderline between hydrophilic and hydrophobic, the DNA molecules’ characteristic spiral form started to unravel.
Upon closer inspection, they observed that when the base pairs split from one another (due to external influence, or simply from random movements), holes are formed in the structure, allowing water to leak in. Because DNA wants to keep its interior dry, it presses together, with the base pairs coming together again to squeeze out the water. In a hydrophobic environment, this water is missing, so the holes stay in place.
Reference: “Hydrophobic catalysis and a potential biological role of DNA unstacking induced by environment effects” by Bobo Feng, Robert P. Sosa, Anna K. F. Mårtensson, Kai Jiang, Alex Tong, Kevin D. Dorfman, Masayuki Takahashi, Per Lincoln, Carlos J. Bustamante, Fredrik Westerlund and Bengt Nordén, 27 August 2019, Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1909122116
A single grain of rock lodged in a diamond contains a never-before-found mineral.
And that newfound substance could reveal unusual chemical reactions unfolding in the depths of the mantle, the layer of Earth that lies between the planet’s crust and outer core.
Scientists unearthed the mineral from a volcanic site in South Africa known as the Koffiefontein pipe. Shining diamonds speckle the dark, igneous rock that lines the pipe, and the diamonds themselves contain tiny bits of other minerals from hundreds of miles beneath Earth’s surface. Within one of these sparkling stones, scientists found a dark green, opaque mineral that they estimated was forged about 105 miles (170 kilometers) underground.
They named the newfound mineral “goldschmidtite” in honor of acclaimed geochemist Victor Moritz Goldschmidt, according to the study, published Sept. 1 in the journal American Mineralogist.
A newfound mineral, called goldschmidtite, was extracted from a South African diamond.
(Image credit: Nicole Meyer/University of Alberta)
The entire mantle is about 1,802 miles (2,900 km) thick, according to National Geographic, which makes the layer’s lowermost regions difficult for scientists to study. The intense pressure and heat in the upper mantle transform humble carbon deposits into sparkling diamonds; the rocks trap other mantle minerals in their structures and can be pushed to the planet surface by underground volcanic eruptions. By analyzing mineral inclusions in the diamonds, scientists can take a peek at chemical processes that occur far beneath the crust.
The study authors noted that, for a mantle mineral, goldschmidtite has a peculiar chemical composition.
“Goldschmidtite has high concentrations of niobium, potassium and the rare-earth elements lanthanum and cerium, whereas the rest of the mantle is dominated by other elements, such as magnesium and iron,” study co-author Nicole Meyer, a doctoral student at the University of Alberta in Canada, said in a statement. Potassium and niobium make up most of the mineral, meaning the relatively rare elements were brought together and concentrated to form the unusual substance, despite other nearby elements being more abundant, she said.
“Goldschmidtite is highly unusual for an inclusion captured by diamond and gives us a snapshot of fluid processes that affect the deep roots of continents during diamond formation,” mantle geochemist Graham Pearson, Meyer’s co-supervisor, said in the statement. The odd mineral now lies in the Royal Ontario Museum in Toronto, Meyer told Live Science in an email.
Two of the planet’s leading astrophysicists, Columbia University’s Caleb Scharf and Harvard’s Lisa Randall speculate about the possibility of the dominant dark side of our universe harboring advanced life.
“It’s a thought-provoking idea,” said Scharf, about the possibility that perhaps some advanced life five billion years ago figured out how to activate dark energy via the symmetron field, which is said to pervade space much like the Higgs field, speculates Columbia University’s Caleb Scharf in Nautil.us. Scharf’s speculative conjecture is an idea for the mechanism of an accelerating cosmic expansion called quintessence, a relative of the Higgs field that permeates the cosmos.
One of the great known unknowns of the universe is the nature of dark energy, a force field making the universe expand faster. Current theories range from end-of-the universe scenarios to dark energy as the manifestation of advanced alien life.
On March 2, 2019, The Galaxy posted “Dark Energy –“New Exotic Matter or ET Force Field?” describing a new, controversial theory that suggests that dark energy might be getting stronger and denser, leading to a future in which atoms are torn asunder and time ends.
“Long, long ago, when the universe was only about 100,000 years old — a buzzing, expanding mass of particles and radiation — a strange new energy field switched on,” writes Dennis Overbye for New York Times Science. “That energy suffused space with a kind of cosmic antigravity, delivering a not-so-gentle boost to the expansion of the universe.”
Then, after another 100,000 years or so, the new field simply switched off, leaving no trace other than a sped-up universe says a team of astronomers from Johns Hopkins University led by Adam Riess, a Bloomberg Distinguished Professor and Nobel laureate. In a bold and speculative leap into the past, the team has posited the existence of this field to explain a baffling astronomical puzzle: the universe seems to be expanding faster than it should be.
“What we think might be the effects of mysterious forces such as dark energy and dark matter in the Universe, could actually be the influence of alien intelligence – or maybe even aliens themselves,” suggests Scharf in “Mind-Bending” –‘Hyper-Advanced ET May Be What We Perceive to Be Physics’ posted on The Galaxy on Mar 1, 2019.
“If machines continue to grow exponentially in speed and sophistication, they will one day be able to decode the staggering complexity of the living world, from its atoms and molecules all the way up to entire planetary biomes,” continues Scharf, author of The Copernicus Complex: Our Cosmic Significance in a Universe of Planets and Probabilities, in Nautil.us. “Presumably life doesn’t have to be made of atoms and molecules, but could be assembled from any set of building blocks with the requisite complexity. If so, a civilization could then transcribe itself and its entire physical realm into new forms. Indeed, perhaps our universe is one of the new forms into which some other civilization transcribed its world.”
After all, with our universe 13.5 billion years old, the cosmos may hold other life, and if some of that life has evolved beyond ours in terms of complexity and technology, adds Scharf. “We should be considering some very extreme possibilities. Today’s futurists and believers in a machine “singularity” predict that life and its technological baggage might end up so beyond our ken that we wouldn’t even realize we were staring at it. That’s quite a claim, yet it would neatly explain why we have yet to see advanced intelligence in the cosmos around us, despite the sheer number of planets it could have arisen on—the so-called Fermi Paradox.”
“Perhaps hyper-advanced life isn’t just external. Perhaps it’s already all around. It is embedded in what we perceive to be physics itself, from the root behavior of particles and fields to the phenomena of complexity and emergence,” says Scharf, a research scientist at Columbia University and director of the Columbia Astrobiology Center. “What we think might be the effects of mysterious forces such as dark energy and dark matter in the Universe, could actually be the influence of alien intelligence – or maybe even aliens themselves.”
Once we start proposing that life could be part of the solution to cosmic mysteries, Scharf concludes, “Although dark-matter life is a pretty exotic idea, it’s still conceivable that we might recognize what it is, even capturing it in our labs one day (or being captured by it). We can take a tumble down a different rabbit hole by considering that we don’t recognize advanced life because it forms an integral and unsuspicious part of what we’ve considered to be the natural world.”
Scharf points out that Arthur C. Clarke suggested that any sufficiently advanced technology is going to be indistinguishable from magic. “If you dropped in on a bunch of Paleolithic farmers with your iPhone and a pair of sneakers,” Scharf says, “you’d undoubtedly seem pretty magical. But the contrast is only middling: The farmers would still recognize you as basically like them, and before long they’d be taking selfies. But what if life has moved so far on that it doesn’t just appear magical, but appears like physics?”
If the universe harbors other life, and if some of that life has evolved beyond our own waypoints of complexity an technology, Scharf proposes that we should be considering some very extreme positions.
Meanwhile up at Harvard, theoretical physicist Lisa Randall, speculates that an invisible civilization could be living right under your nose. In Does Dark Matter Harbor Life she observes that dark matter is the “glue” that holds together galaxies and galaxy clusters, but resides only in amorphous clouds around them. “But what.” asks Randall, “if this assumption isn’t true and it is only our prejudice—and ignorance, which is after all the root of most prejudice—that led us down this potentially misleading path?”
The Standard Model, Randall points out, contains six types of quarks, three types of charged leptons (including the electron), three species of neutrinos, all the particles responsible for forces, as well as the newly discovered Higgs boson. What if the world of dark matter, which matter interacts only negligibly with matter, harbors “a small component of dark matter would interact under forces reminiscent of those in ordinary matter. The rich and complex structure of the Standard Model’s particles and forces gives rise to many of the world’s interesting phenomena. If dark matter has an interacting component, this fraction might be influential too.”
No one had allowed, Randall asserts, for the very simple possibility that although most dark matter doesn’t interact, a small fraction of it might.
Shadow life,” exciting as that would be, won’t necessarily have any visible consequences that we would notice, making it a tantalizing possibility but one immune to observations. In fairness, dark life is a tall order. Science-fiction writers may have no problem creating it, but the universe has a lot more obstacles to overcome. Out of all possible chemistries, it’s very unclear how many could sustain life, and even among those that could, we don’t know the type of environments that would be necessary.
Nonetheless, dark life could in principle be present—even right under our noses. But without stronger interactions with the matter of our world, it can be partying or fighting or active or inert and we would never know. But the interesting thing is that if there are interactions in the dark world—whether or not they are associated with life—the effects on structure might ultimately be measured. And then we will learn a great deal more about the dark world.
Randall suggests that “if we were creatures made of dark matter, we would be very wrong to assume that the particles in our ordinary matter sector were all of the same type. Perhaps we ordinary matter people are making a similar mistake.
“Given the complexity of the Standard Model of particle physics, she observes, which describes the basic components of matter we know of, it seems very odd to assume that all of dark matter is composed of only one type of particle. Why not suppose instead that some fraction of the dark matter experiences its own forces?”
The image at the top of the page shows dark matter filaments bridge the space between galaxies in this false colour map. The locations of bright galaxies are shown by the white regions and the presence of a dark matter filament bridging the galaxies is shown in red. ( S. Epps & M. Hudson / University of Waterloo)
Io is about the same size as Earth’s moon. Because it’s so far away, in the Jovian sky Io appears about four times the size as the sun – so its shadow is large and relatively sharp, compared to eclipses here on Earth, Universe Today reports.
This image shows the divisions between Earth’s layers. The ancient, continent-sized rock regions encircle the liquid outer core. Credit: Lawrence Livermore National Laboratory
Ancient, distinct, continent-sized regions of rocks, isolated since before the collision that created the Moon 4.5 billion years ago, exist hundreds of miles below the Earth’s crust, offering a window into the building blocks of our planet, according to new research.
The new study in the AGU Journal Geochemistry, Geophysics, Geosystems used models to trace the location and origin of volcanic rock samples found throughout the world back to two solid continents in the deep mantle. The new research suggests the specific giant rock regions have existed for 4.5 billion years, since Earth’s beginning.
Previously, scientists theorized that separated continents in the deep mantle came from subducted oceanic plates. But the new study indicates these distinct regions may have been formed from an ancient magma ocean that solidified during the beginning of Earth’s formation and may have survived the massive Moon-creating impact.
Determining the masses’ origin reveals more details about their evolution and composition, as well as clues about primordial Earth’s history in the early Solar System, according to the study’s authors.
It’s amazing that these regions have survived most of Earth’s volcanic history relatively untouched, said Curtis Williams, a geologist at the University of California, Davis, in Davis, California and lead author of the study.
The mantle is a layer of rock, stretching 2,900 kilometers (1,802 miles) down inside the Earth. Earth’s molten, liquid, metallic core lies beneath the mantle. The core-mantle boundary is where the solid mantle meets the metallic liquid core.
Scientists knew from past seismic imaging studies that two individual rock bodies existed near the core-mantle boundary. One solid rock body is under Africa and the other is under the Pacific Ocean.
Seismic waves, the vibrations produced by earthquakes, move differently through these masses than the rest of the mantle, suggesting they have distinct physical properties from the surrounding mantle. But geologists couldn’t determine whether seismic waves moved differently through the core-mantle continents because of differences in their temperature, mineral composition or density, or some combination of these properties. That meant they could only hypothesize about the separate rocky masses’ origin and history.
“We had all of these geochemical measurements from Earth’s surface, but we didn’t know how to relate these geochemical measurements to regions of Earth’s interior. We had all of these geophysical images of the Earth’s interior, but we didn’t know how to relate that to the geochemistry at Earth’s surface,” Williams said.
Primitive material and plumes
Williams and his colleagues wanted to determine the distinct masses’ origin and evolution to learn more about Earth’s composition and past. To do this, they needed to be able to identify samples at Earth’s surface with higher concentrations of primitive material and then trace those samples back to their origins.
Scientists often take rock samples from volcanic regions like Hawaii and Iceland, where deep mantle plumes, or columns of extremely hot rock, rise from the areas near the core, melt in the shallow mantle and emerge far from tectonic fault lines. These samples are made of igneous rock created from cooling lava. The study’s authors used an existing database of samples and also collected new samples from volcanically active areas like the Balleny Islands in Antarctica.
Geologists can measure specific isotopes in igneous rocks to learn more about the origin and evolution of the Earth. Some isotopes, like Helium-3, are primordial, meaning they were created during the Big Bang. Rocks closer to Earth’s crust have less of the isotope than rocks deeper underground that were never exposed to air. Samples with more Helium-3 are thought to come from more primitive rocks in the mantle.
The researchers found some of the samples they studied had more Helium-3, indicating they may have come from primitive rocks deep in the Earth’s mantle.
The researchers then used a new model to trace how these primitive samples could have gotten to the Earth’s surface from the mantle. Geological models assume plumes rise vertically from deep within the mantle to the Earth’s surface. But plumes can move off course, deflected, due to various reasons. The new model took into account this plume deflection, allowing the study’s authors to trace the samples back to the two giant masses near the core-mantle boundary.
The combination of the isotope information and the new model allowed the researchers to determine the composition of the two giant masses and theorize how they may have formed.
Understanding the composition of specific rock masses near the core-mantle boundary helps geologists conceptualize ancient Earth-shaping processes that led to the modern-day mantle, according to the study’s authors.
“It’s a more robust framework to try and answer these questions in terms of not making these assumptions of vertically rising material but rather to take into account how much deflection these plumes have seen,” Williams said.
Reference: “Primitive Helium Is Sourced From Seismically Slow Regions in the Lowermost Mantle” by C. D. Williams, S. Mukhopadhyay, M. L. Rudolph and B. Romanowicz, 31 July 2019, Journal Geochemistry, Geophysics, Geosystems.
But NASA Administrator Jim Bridenstine wants answers.
Russia’s Soyuz MS-09 crew spacecraft is is shown docked to the International Space Station (ISS). The MS-09 carried NASA astronaut Serena M. Auñón-Chancellor, the European Space Agency’s Alexander Gerst and cosmonaut Sergey Prokopyev to the ISS in June 2018.
“They have not told me anything,” Bridenstine said during a Houston energy conference question session Thursday (Sept. 19), according to the Houston Chronicle. But he emphasized that he wants to keep good relations with the Russians, one of the two chief partners on the orbiting complex.
“I don’t want to let one item set [the relationship] back, but it is clearly not acceptable that there are holes in the International Space Station,” he said, referring to the 2-millimeter (0.08 inches) hole that the Expedition 56 crew found in the Soyuz MS-09 spacecraft, a crew vehicle that was docked to the station.
Bridenstine’s comments came in the wake of a report by Russia’s state-run international news agency RIA Novosti, in which Dmitry Rogozin, head of Roscosmos (the Russian space agency), suggested his agency found what created the hole last year, but would not disclose the results outside of Roscosmos.
Space Station’s Cabin Pressure Loss Explained by NASA
“What happened is clear to us, but we won’t tell you anything,” Rogozin said at a meeting with participants at a science conference, according to a computer-translated page from RIA Novosti’s Russian-language report on Wednesday (Sept. 18).
After NASA reported a slow drop in cabin pressure at the station on Aug. 29, 2018, the crew of Expedition 56 located the cause of the air leak in the orbital compartment of the Soyuz MS-09 spacecraft, nearly three months after the vessel arrived at the International Space Station with three new crewmembers on board.
Roscosmos is currently the only agency capable of launching crew members to space since NASA retired the space shuttle in 2011. NASA is readying American commercial crew vehicles from Boeing and SpaceX and expects to start running crewed test flights as early as this year. But for now, the Soyuz is the only way astronauts can fly to and from the International Space Station.
The two agencies are the chief partners on the space station, and have been working together to build and maintain the 21-year-old orbiting complex since the early 1990s. Bridenstine and other NASA officials have thus repeatedly emphasized the level of trust between their agency and Roscosmos, which includes several missions before ISS. NASA and the Soviet Union ran a joint mission in 1975 called Apollo-Soyuz, and the new Russian nation partnered with NASA for shuttle flights to the space station Mir between 1994 and 1998.