Science

In Iceland, scientists are planning to drill two boreholes to a reservoir of liquid rock. One will give us our first direct measurements of magma – the other could supercharge geothermal power

What medical breakthrough are likely in the near future?

The post Medical Science in 2024 first appeared on Science-Based Medicine.

A non-lethal method of catching great white sharks and releasing them 500 metres further out to sea can make the predators steer clear of beaches where people swim

The first ever soap films with chemically distinct sides are a step towards cheap soap-based devices that could create useful chemicals through artificial photosynthesis

People with severe covid-19 infections are more than 4 times as likely to later be diagnosed with schizophrenia than people who have not been infected, though the risk of developing the condition is relatively low

In 1950, during a lunchtime conversation with colleagues at the Los Alamos National Laboratory, famed physicist Enrico Fermi asked the question that launched a hundred (or more) proposed resolutions. “Where is Everybody?” In short, given the age of the Universe (13.8 billion years), the fact that the Solar System has only existed for the past 4.5 billion years, and the fact that the ingredients for life are everywhere in abundance, why haven’t we found evidence of extraterrestrial intelligence by now? This came to be the basis of Fermi’s Paradox, which remains unresolved to this day.

Interest in Fermi’s question has been piqued in recent years thanks to the sheer number of “potentially habitable” exoplanets discovered in distant star systems. Despite that, all attempts to find signs of technological activity (“technosignatures”) have come up empty. In a recent study, a team of astrobiologists considered the possible resolutions and concluded that only two possibilities exist. Either extraterrestrial civilizations (ETCs) are incredibly rare (or non-existent), or they are deliberately avoiding contact with us (aka. the “Zoo Hypothesis“).

The paper, which was recently published in Nature Astronomy, was the work of Ian A. Crawford and Dirk Schulze-Makuch. Crawford is a Professor of Planetary Science and Astrobiology at the School of Natural Sciences and the Center for Planetary Sciences at UCL/Birbeck College, while Schulze-Makuch is a Professor of Planetary Habitability and Astrobiology at the Technical University of Berlin, the GFZ German Research Center for Geosciences, the Leibniz-Institute of Freshwater Ecology and Inland Fisheries, and Washington State University.

The Big Question

As we addressed in our series, “Beyond Fermi’s Paradox,” the paradox itself actually began with astronomer (and white nationalist) Michael Hart in 1975. In a paper titled “Explanation for the Absence of Extraterrestrials on Earth,” Hart argued that given the age of the Universe and the relatively short time it would take for an advanced civilization to spread across the Milky Way Galaxy (650,000 years, by Hart’s estimate), Earth should have been visited by an extraterrestrial civilization (ETC) by now.

In 1980, mathematical physicist and cosmologist Frank J. Tipler built on and refined Hart’s arguments with his paper, “Extraterrestrial Intelligent Beings do not Exist.” Based on the Copernican Principle, which states that neither humanity nor Earth are in a privileged position to observe the Universe. Accordingly, Tipler theorized that an ETC would be assisted by self-replicating robotic explorers (von Neumann probes) that would spread from system to system, facilitating the arrival of settlers later. By Tipler’s refined estimate, an ETC would be able to explore the entire galaxy in “less than 300 million years.”

This came to be known as the Hart-Tipler Conjecture, which essentially states that the absence of evidence can only be explained by the absence of ETCs. In 1983, Carl Sagan and William Newman produced a rebuttal paper titled “The Solipsist Approach to Extraterrestrial Intelligence” (aka. “Sagan’s Response”) where they argued that “the absence of evidence is not the evidence of absence” and took the Hart-Tipler Conjecture to account for the many assumptions it made. They and countless other scientists have proposed potential resolutions for why we haven’t seen any ETCs yet.

The Great Silence Persists

Nevertheless, despite decades of observation and SETI surveys, there is still no definitive evidence that advanced extraterrestrial civilizations are out there. For the most part, these have consisted of radio SETI experiments that have observed distant stars and galaxies for indications of radio transmissions. However, other SETI experiments have focused on anomalous infrared (heat) signatures that could indicate the presence of a megastructure designed to enclose an entire star system – otherwise known as a Dyson Sphere (or Dyson Structure).

Alas, these searches have found no compelling evidence of technosignatures within our galaxy or beyond. According to Crawford and Schulze-Makuch, the “Great Silence” we perceive when we look out into the Universe can only mean one of two things. First, there’s the possibility that the Hart-Tipler Conjecture is correct, and there are no advanced ETC out there. Similarly, it may be that intelligent life (or life in general) is rare in the Universe due to the odds being stacked against its emergence or evolution (aka. the Great Filter).

If neither of these scenarios is true, we are left with only one answer: the Zoo Hypothesis is correct and advanced civilizations are keeping their distance to avoid being detected. As Crawford told Universe Today via email:

“There are only two possibilities; either ETI exists, or it does not. As several people have noted over the years, either answer would be astonishing, yet one must be true. All we know is that we see no evidence for ETI, despite the number of planets and the great age of the Universe which would, naively, seem to imply that ETI should exist and perhaps be common. This is the FP. However, if ETI exists there are only two possibilities consistent with the fact that we don’t observe them. Either:

1. We would never expect to observe them because space is so big, etc.
2. We don’t observe them because they have taken steps to ensure that we don’t ( this is the ZH).”

Are we in a Zoo?

The term was coined in 1973 by John A. Ball, a Harvard astrophysicist and scientist with MIT’s Haystack Observatory. In a study of the same name, Ball addressed various proposed resolutions to the Fermi Paradox and some common assumptions made by SETI researchers. Among them is the belief that intelligent species exist in our galaxy, that they are older and more advanced than we are, and that they want to make contact with other intelligent species (including us). In contrast, Ball argued that advanced species are “deliberately avoiding interaction and that they have set aside the area in which we live as a zoo.”

In summary, the Zoo Hypothesis predicts that we shall never find them because they do not want to be found, and they have the technological ability to ensure this. This theory is similar to the Planetarium Hypothesis, which also posits that advanced civilizations have the means to elude detection from our instruments. Unlike the Planetarium Hypothesis, the Zoo Hypothesis assumes that the intentions of the ETCs are benign, which could include wanting to avoid interfering with our technological or social development (i.e., the “Prime Directive” from Star Trek).

The central region of the Milky Way, also known as the Zone of Avoidance. Credit: ESO/S. Brunier

As to which possibility is more likely to be true – i.e., intelligent life is non-existent (or extremely rare) vs. they are hiding from us – Crawford and Schulze-Makuch have somewhat opposite views. “For reasons given in the article, my own view is that life (and technological life especially) is likely to be so transformative that we really should see evidence of it if it exists and isn’t hiding,” said Crawford. “Therefore, I think if it does exist, then probably it must be hiding – aka the ZH. My own view is that it is more likely that ETI does not exist than that it is hiding.”

“I think that the Zoo Hypothesis is more likely,” Schulze-Makuch countered. “I believe so because (1) of the Copernican Principle. While I do think that humanity is something very special, being a technologically advanced life form, I can´t fathom that we are truly unique or so rare in that capability that – for practical reasons – nothing is out there.” The second reason, said Schulze-Makuch, has to do with the recent release of the so-called UFO Report, which demonstrated that unidentified aerial phenomena (UAP) are far more common than previously known:

“While we can´t make a true scientific argument based on these, given their speculative nature, there are so many cases by now, quite a few with multiple lines of evidence, that we cannot simply ignore it. And if some of them can actually be attributed to ETI, it would mean that they don´t interfere with Earth matters or at least not to a large extent or clearly visible to us.”

This perhaps raises another possible resolution: humanity has been looking for technosignatures in the wrong places. Perhaps, rather than simply observing distant stars for signs of transmissions or other technological activity, we should also look for evidence of advanced civilizations closer to home. This is the path being pursued by Professor Avi Loeb and his colleagues at the Galileo Project, which hopes to complement conventional SETI by searching for evidence of ETC technology and artifacts within our Solar System.

What to Do?

Regardless of which possibility could be true, there’s the inevitable question: how do we find out? According to Crawford and Schulze-Makuch, the only thing we can do is to keep exploring the Universe systematically. This includes SETI surveys and searches for ETC artifacts within the Solar System because, as they write, “we can only assert an absence of evidence if we have searched for evidence sufficiently hard.” In the meantime, exoplanet studies are transitioning from discovery to characterization, which will be aided considerably by next-generation telescopes like the James Webb Space Telescope.

This artist’s impression shows a Super-Earth orbiting the Sun-like star HD 85512 in the southern constellation of Vela (The Sail). Credit: ESO

The ability to determine the chemical composition of exoplanet atmospheres could ultimately reveal indications of life or biological processes (“biosignatures”), thus putting tighter constraints on habitability. As they indicate, “such observations have the potential to constrain the prevalence of abiogenesis in the Universe, and possibly also the prevalence of biological complexity and intelligence.” Herein lies another difference between the Zoo and the Planetarium Hypothesis, which is that the former is more likely to be discoverable. As Schulze-Makuch summarized:

“If we are living in a simulation of some sort, we may never find out. But if the zoo hypothesis is correct, we would eventually. Our technology is getting more and more sophisticated, so we would catch up to ETI, and even if ETI could still hide their spacecraft, eventually, we would see their home worlds. But even hiding their spacecraft would get more and more difficult, and as sophisticated as they are, they would not be error-free, and accidents would happen. It is then tempting to attribute some of the UAP sightings as such… and this is still very speculative, but with more and more sensors coming online, we should be able to get a clearer picture soon.”

“Given our technological progress (and assuming the Zoo Hypothesis is correct), I think we might get some proof of ETI within 15 years (and I have bet a bottle of whiskey with Ian on this). But the timeline is, of course, difficult to predict and depends to a large degree also on how fast the progress will be, and how attentive the “Zoo keepers” are or what their aim is.”

As always, all we can do is search in anticipation of what we may find. At this point, there are literally hundreds of scenarios of where ETCs may be and why they’ve eluded detection for this long. Being able to test these theories with greater and greater precision in the coming years is going to be mighty exciting, almost as exciting as the prospect of finding something someday!

Further Reading: Nature Astronomy

The post After all of This Time Searching for Aliens, Are We Stuck With The Zoo Hypothesis? appeared first on Universe Today.

Palaeontologists can’t agree on whether fossils from several small dinosaurs represent juvenile Tyrannosaurus rex or smaller adults of a separate species that lived alongside them

You know how some constellations take a little bit of imagination to see?  Yes, Leo looks a bit like a lion and Orino a bit like a hunter but then we drift into the realms of powerful levels of imagination to be able to see Pegasus as a flying horse or Telescopium as a telescope! Even squinting or tilting your head really doesn’t make them visible. I found the same problem when looking at images of two stone disks discovered in Italy recently at the entrance to an ancient fort! Teams that have examined the stones have matched the subtle markings on them to positions of 28 bright stars in the sky! I had to really look to see it but I think they might actually be right! 

The two stones were unearthed in Rupinpiccolo protohistoric (the transition period between prehistory and the earliest recorded history) hill fort in north eastern Italy. There were chisel marks all over the stone and it was suggested that these may form markings to represent bright stars in the night sky. 

The marks were thought to be chiselled into the stones and, given that many human cultures seem to recognise the same popular patterns in the stars, it seemed likely that they could be identified. The team employed statistical analysis against known astronomical asterisms with results that showed little error!

There were 29 marks on the stone in all and the paper by Paolo Molaro and Federico Bernardini analysed exactly which stars they matched! Nine of them matched the tail of Scorpious, five represented Orion including the stars of the belt, Betelgeuse and Rigel and another nine seemed to correlate with the Pleiades cluster. On the reverse of the disk there were a further five marks that could represent Cassiopeia but there was one mark that couldn’t be explained! The marks did indeed seem to represent all the bright stars in each of the constellations (with exception of Bellatrix and Saiph which may have been eroded) recorded giving credibility to the finding. 

This spectacular visible light wide-field view of part of the famous belt of the great celestial hunter Orion shows the region of the sky around the Flame Nebula. The whole image is filled with glowing gas clouds illuminated by hot blue young stars. It was created from photographs in red and blue light forming part of the Digitized Sky Survey 2. The field of view is approximately three degrees.

A mark slightly north of Orion however has not yet been identified, perhaps it represented a nova or supernova that has not been recorded anywhere else. The mark is close to Mu Orionis which is a pair of physical binaries but also lies close to the location of Epsilon Sagittarii. I must confess though, having read the accuracy to which the marks seem to have been made, the innacuracy of this makes me subscribe to the nova/supernova possibility. Follow up observations will be needed to test this hypothesis. 

Whether the stones truly represent the sky will require further analysis. The work of Molaro and Bernardini certainly seem to be pointing to this conclusion but it may be too early to tell, the absence of a couple of prominent stars and the presence of an unidentified object casts a little doubt but 28 marks matching the positions of 28 stars must be far more than just co-incidence. The marks on the stones are thought to have been made between 1800 and 400 BCE and if they do indeed map to the stars then it must be one of the oldest sky maps ever found.

Source : Possible stellar asterisms carved on a protohistoric stone

The post An Ancient Stone Found in Italy is an Accurate Map of the Night Sky appeared first on Universe Today.

Astrophysicists outline the links between atmospheric oxygen and the potential rise of advanced technology on distant planets.

Chemists found a way to use electricity to boost a type of chemical reaction often used in synthesizing new candidates for pharmaceutical drugs. The research is an advance in the field of electrochemistry and shows a path forward to designing and controlling reactions -- and making them more sustainable.

Researchers developed an artificial intelligence tool to quickly analyze gene activities in medical images and provide single-cell insight into diseases in tissues and tissue micro-environments.

While many of us were celebrating the end of 2023 and the coming of 2024, the Sun was having its own celebration blasting an X5.0 flare from sunspot region 3536. Records show this to be the most powerful flare seen since 10 September 2017 when an X8.2 flare erupted. The flare is expected to arrive around Jan 2 – EEK that’s today! Get your aurora watching kit out! 

I live in the UK in a county called Norfolk.  It is a wonderful rural area with a coast line that faces the north and there is no land between it and the Arctic. That means that if we do get treated to auroral activity, Norfolk is a pretty good place to see it, albeit its southerly latitude (52 degrees) compared to other parts of the UK. I don’t live on the north coast but I do have good friends who do, one of whom is a bit of a guru when it comes to the northern lights and frankly never seems to sleep. And so it is that I often receive messages at quite unsociable hours telling me to get out and look! Sometimes, I just beg for there not to be anything for a change so I can get some sleep! 

The cause of so much disturbed sleep is solar activity and in particular, solar flares. The Sun is a giant sphere of plasma, an electrically charged gas. As the Sun rotates at different speeds (slower at the poles than at the equator) the plasma drags the magnetic field lines with it winding them up tighter and tighter. The field lines often get twisted and when the tension is too much, there is a tremendous explosion as the stored up energy is released as a flare. 

A solar flare, as it appears in extreme ultra-violet light. Some stars emit superflares similar to this, but many times brighter and stronger than those from the Sun. Credit: NASA/SFC/SDO

Flares are classified by their brightness in X-rays in the wavelength 1 to 8 Angstrom Units. First there are classes from A, B, C, M and X with A being the lowest and X the highest. There are then the subdivisions from 1 to 9. X5.0 is a pretty big thing when it comes to flares and we haven’t seen anything of this magnitude for quite some years. 

The charged particles from the flare charge – pardon the pun – out into space and if they encounter Earth, then they cause the gas particles in our atmosphere to glow giving rise to the northern lights. I should add at this point the northern lights are known as aurora borealis and visible in the northern hemisphere while the southern lights are known as aurora australis and visible in the southern hemisphere.  

A photograph of an aurora at Ny-Ålesund, Norway, November 2018. Image Credit: Ahmed Ghalib, VISIONS-2 payload team.

Whether this particular flare will cause aurora is yet to be confimred as it is a very difficult phenomenon to predict.  Keep a weather eye toward the north pole (or south if you are in southern hemipshere) and keep a look out on the space weather prediction sites like NOAA (National Oceanic and Atmospheric Administration) for the latest updates. If the northern lights do put on a show, all you need to do is wrap up warm, get yourself outside, comfortable, wait and watch. Happy hunting. 

Source : X5.0 Flare Closes Out the 2023 Year

The post The Sun Just Blasted its Strongest Flare in 6 Years. Get Ready for Auroras appeared first on Universe Today.

There are many mysteries in the world of astronomy and a fair number relate to the processes during the end of the life of a super massive star. Throw in the complexity of collisions and you have a real head scratching problem on your hands. In 2017 colliding neutron stars were detected and the data has allowed a new simulation to be tested with predictions beautifully matching observation.

Neutron stars are stellar corpses no more than 10km or 20km across. They are thought to form when a supermassive star goes supernova at the end of its life and undergoes gravitational collapse.  The collapse causes the remains to be compressed down to incredibly high densities, of the region 450 million billion kilograms per cubic metre (that’s equivalent to the density of an atomic nucleus). To put this into context, under the gravitational collapse, all the space between the components of atomic nuclei is squeezed out creating a gigantic neutron several kilometres across!

A new supernova in M101. Credit: Craig Stocks

It seems quite a common occurence for neutron stars to orbit in binary systems and as they do, slowly eek away energy in the form of gravity waves. These waves are like those on the ocean instead propagate through the fabric of space-time. Eventually, sufficient energy is lost that the neutron stars collide and it is this that has allowed teams of astronomers to study the processes during some of the most extreme conditions found in the Universe. 

An international team that involved the Max Planck Institute for Gravitational Physics and the University of Potsdam have used a new software tool to simulate the physical processes from neutron star mergers (otherwise known as a kilonova).  The team also utilised X-ray observations, radio signals, nuclear physics calculations and even data from Earth based accelerators and for the first time plugged the whole lot into the simulations. 

On 17 August the LIGO/Virgo team detected two neutron stars colliding in an elliptical galaxy in Hydra. The collision was identiifed from gravitational wave and gamma ray observations and by studying such high energy collisions we can learn more about the formation of heavy elements at extreme pressures and densities far greater than found in atomic nuclei.

Artist’s conception of a neutron star merger. This process also creates heavy elements. Credit: Tohoku University

The results were very promising with the predictions from the model matching observation. Now the team are running further observations with gravitational wave detectors as they hunt down the next neutron star merger to use the tool again and further enhance its model.

Source : The Goldmine of a Neutron Star Collision

The post Simulation Perfectly Matches What We See When Neutron Stars Collide appeared first on Universe Today.

Over 6,000 light-years from Earth, an open star cluster and its nebula cover a swathe of sky over 270 light-years across. It’s called the Running Chicken Nebula, and it’s more than just one object. The Running Chicken Nebula, also called IC 2944, also contains IC 2948, the brightest part of the Chicken, as well as several Bok Globules and smaller nebulae. The bright star Lambda Centauri is near the visual center of the Chicken but is actually much closer to Earth.

This vast image spans 25 full Moons and is a composite image made up of hundreds of separate images carefully stitched together that contains 1.5 billion pixels. The European Southern Observatory’s VLT Survey Telescope captured the images. They’re from an observing campaign aimed at studying the lifecycle of stars.

The Running Chicken Nebula comprises several clouds, the most prominent of which are labelled in this image from the VLT Survey Telescope (VST), hosted at ESO’s Paranal site. Gum 39, 40, and 41 are emission nebulae within the Chicken. The region is also home to multiple Bok globules, smaller isolated nebula made of dense gas and dust, which are normally active regions of star formation. Image Credit: ESO/VPHAS+ team. Acknowledgement: CASU

The Running Chicken is full of scientific intrigue, but its visual appeal draws us all in. The region is a vast stellar nursery, lit up by young stars emitting powerful radiation. The radiation both lights up the gas and shapes it into intriguing patterns, creating the natural artwork that the powerful telescope brings into our visual range.

This zoomed-in portion of the image shows the primary nebula region, showing off the intricate forms and colours created by the interplay of energetic young stars and the gas that surrounds them. Image Credit: ESO/VPHAS+ team. Acknowledgement: CASU

Powerful young stars and their energetic winds give the nebula its form and colour, but some parts of the nebula resist the energy. These are called Bok globules, and they’re dense clumps of gas and dust that can withstand the powerful UV energy from the young stars. They’re normally active star formation regions themselves and usually form double or multiple star systems, though the globules in the Running Chicken don’t seem to be forming any.

This zoomed-in image shows Bok globules in the lower left and upper right. Bok globules are isolated dense clumps of gas and dust that resist the radiation from nearby young stars. They’re typically active star formation regions and contain up to 50 solar masses of gas and dust and are typically about one light-year across. Image Credit: ESO/VPHAS+ team. Acknowledgement: CASU

The Running Chicken is both an emission and a reflection nebula. Reflection nebulae reflect the light from nearby stars, while emission nebulae absorb starlight and then emit it at different wavelengths. It’s part of what makes the nebula so interesting.

The Running Chicken is also home to three smaller, separate nebulae named after their discoverer, astronomer Colin Gum. Gum 41 is dominated by a bright blue star in its center named HD 100099, which is actually two hot, massive, and young stars so close together that they can’t be resolved separately. HD 100099’s powerful UV energy turns the hydrogen gas red. Gum 41 takes the shape of a classic Stromgren sphere, a shell of gas around an O-type star. There’s actually gas outside the sphere, but the edge of the sphere is delineated by the central stars’ weakened light.

This zoomed-in image shows the Gum 41 nebula and the double-star HD 1000999 that powers it. The star’s ferocious stellar winds are carving out a cavity in the nebula, lighting it up and giving it its shape. Ridges of brighter, denser gas build up where the star’s wind slams into the surrounding material. Image Credit: ESO/VPHAS+ team. Acknowledgement: CASU

Regions full of hot red gas, like the Running Chicken Nebula, are signposts for star formation. Only massive, hot young stars have enough energy to light up their gaseous surroundings like this. Unlike our Sun, these stars don’t live very long, so neither do these nebula. Eventually, much of the gas will be dissipated, and only slow-burning, long-lived stars will reside there, and they won’t have the power to light things up like this again.

If you can’t clearly see a running chicken, you’re not alone. Some say that Gum 39 is the chicken’s head with Gum 41 an extended wingtip and IC 2948 forming the bulk of the chicken’s body. Some see it differently, and there seems to be no widespread agreement.

Regardless if you see a chicken or not (I don’t), the object is fascinating and rich in instructive detail.

You should definitely download the large 3.2 GB image and explore it.

The post You’ll Need all the Internet to Download the Full Resolution of this New Running Chicken Nebula Image appeared first on Universe Today.