Scientists Use X-Rays from Faraway Galaxy Cluster to Reveal Secrets of Plasma

Most visible matter in the universe doesn’t look like our textbook picture of a nucleus surrounded by tethered electrons. Out beyond our borders, inside massive clusters, galaxies swim in a sea of plasma – a form of matter in which electrons and nuclei wander unmoored.

Though it makes up the majority of the visible matter in the universe, this plasma remains poorly understood; scientists do not have a theory that fully describes its behavior, especially at small scales.

However, a University of Chicago astrophysicist led a study that provides a brand-new glimpse of the small-scale physics of such plasma. Using NASA’s Chandra X-ray Observatory, scientists took a detailed look at the plasma in a distant galaxy cluster and discovered the flow of plasma is much less viscous than expected and, therefore, turbulence occurs on relatively small scales – an important finding for our numerical models of the largest objects in the universe.

“High-resolution X-ray observations allowed us to learn some surprising truths about the viscosity of these plasmas,” said Irina Zhuravleva, an assistant professor of astrophysics and first author of the study, published June 17 in Nature Astronomy. “One might expect that variations in density that arise in the plasma are quickly erased by viscosity; however, we saw the opposite – the plasma finds ways to maintain them.”

Scattered around the universe are massive clusters of galaxies, some of them millions of light-years across containing thousands of galaxies. They sit in a type of plasma that we cannot recreate on Earth. It is extremely sparse – on the order of a sextillion times less dense than air on Earth – and has very weak magnetic fields, tens of thousands of times weaker than we experience on the Earth’s surface. To study this plasma, therefore, scientists must rely on cosmic laboratories such as clusters of galaxies.

Zhuravleva and the team chose a relatively nearby galaxy cluster called the Coma Cluster, a gigantic, bright cluster made up of more than 1,000 galaxies. They chose a less dense region away from the cluster center, where they hoped to be able to capture the average distance that particles travel between interactions with NASA’s Chandra X-ray Observatory. In order to build a high-quality map of the plasma, they observed the Coma cluster for almost 12 days – much longer than a typical observing run.

One thing that jumped out was how viscous the plasma was – how easily it’s stirred. “One could expect to see the viscosity resisting chaotic motions of plasma as we zoom in to smaller and smaller scales,” Zhuravleva said. But that didn’t happen; the plasma was clearly turbulent even on such small scales.

“It turned out that plasma behavior is more similar to the swirling motions of milk stirred in a coffee mug than the smoother ones that honey makes,” she said.

Such low viscosity means that microscopic processes in plasma cause small irregularities in the magnetic field, causing particles to collide more frequently and making the plasma less viscous. Alternately, Zhuravleva said, viscosity could be different along and perpendicular to magnetic field lines.

Understanding the physics of such plasmas is essential for improving our models of how galaxies and galaxy clusters form and evolve with time.

“It is exciting that we were able to use observations of clusters of galaxies to understand fundamental properties of intergalactic plasmas,” said Zhuravleva. “Our observations confirm that clusters are great laboratories that can sharpen theoretical views on plasmas.”

Other scientists on the study were affiliated with Stanford University, the Max Planck Institute for Astrophysics in Germany, the Space Research Institute in Russia, the University of Oxford, Niels Bohr International Academy, SLAC National Accelerator Laboratory, Harvard-Smithsonian Center for Astrophysics, Masaryk University, Eötvös Loránd University and Hiroshima University.

What Have We Learned from 20 Years of X-rays?

This year marks the 20th anniversary of two landmark missions: the Chandra X-ray Observatory, one of NASA’s Great Observatories, which launched July 23, 1999, and the X-ray Multi-Mirror mission (XMM-Newton), which launched a few months later on December 10th. Together, these satellites revolutionized X-ray astronomy, bringing it on par with astronomy at other wavelengths. We celebrate the history of X-ray astronomy in the August 2019 issue; here, we mark seven discoveries heralded by these two missions.

The Anatomy of a Supernova

To astronomers’ surprise, Chandra’s image of Cassiopeia A, the bloom of gas left over after a massive star went supernova some 340 years ago, revealed a star turned inside out. While massive stars fuse the heaviest elements in their cores and lighter elements in surrounding, onion-like layers, the Cas A explosion had flung clumps of iron to the outermost regions. The find suggests the star’s contents mixed together right before or after its core collapsed (or both).

Stellar Nurseries

XMM-Newton surveyed low-mass stars forming in the Taurus Molecular Cloud while Chandra examined massive stars coming together in the Orion Nebula. Most of the X-rays in these images, including the Chandra Ultra-deep Orion Project pictured above, come from young stars. In some cases interacting stellar winds from massive young stars produce the X-rays. The surveys have given astronomers a wealth of data on the newborn stars’ magnetic fields.

Black Hole Physics

With Chandra and XMM-Newton, astronomers could for the first time estimate black hole spin. By measuring how a black hole’s strong gravity smears the emissions from iron ions, astronomers can see how close the gas comes to the event horizon — the closer it comes, the faster the black hole is spinning. Astronomers have used this and other X-ray-based methods to gauge the spins of dozens of black holes.

Monitoring by Chandra and XMM-Newton has also shed light on the slumbering beast at the center of the Milky Way known as Sgr A*. While Sgr A* doesn’t seem to be devouring gas in the manner of the supermassive black holes that power distant quasars, it’s doing something that sets off roughly daily X-ray flares. Sometimes they’re accompanied by infrared sizzles, but other times the X-rays pop on their own. The flares may originate in snapping magnetic fields, the occasional ingestion of an asteroid, or something else entirely — the jury’s still out.

Jets of Change

The combination of X-ray and radio observations of galaxy clusters solved a long-term mystery: The hot gas between galaxies in clusters ought to cool over time, raining down on the clusters’ central galaxies and forming stars by the handful. But in many clusters astronomers haven’t found the expected stellar newborns. Turns out radio-emitting jets from the central galaxies’ supermassive black holes blow bubbles into the surrounding X-ray-emitting gas, sending out pressure waves that pump heat back into the surrounding medium, which prevents it from cooling. Astronomers soon realized that this concept of “black hole feedback” might affect everything from galaxy evolution to cosmology.

Extragalactic X-ray Background

From the launch of the Aerobee rocket in 1962, astronomers had known that the X-ray sky wasn’t dark, instead teeming with high-energy photons. The Einstein Observatory showed that supermassive black holes, too far away or faint to be seen individually, could explain this background. But it was Chandra that sharpened the view, resolving almost all of the background into its individual sources. Data from Chandra and XMM-Newton suggest that most of the sources that remain undetected are shrouded in gas and dust.

Hot Jupiters and Habitability

X-ray observations have provided direct evidence of star-planet interactions, such as when XMM-Newton caught flares from the HD 17156 system that appeared whenever the hot Jupiter came closest to its star. X-ray data also temper ideas of habitability: XMM-Newton observations revealed that high-energy radiation irradiates the three Earth-size planets in Trappist-1’s so-called habitable zone and has probably long ago stripped them of their atmospheres. Likewise, observations showed that Proxima Centauri b receives 250 times more X-rays from its star than Earth does from the Sun; its habitability, too, is uncertain.

Dark Matter, Dark Energy

Galaxy clusters have proven key to testing dark matter and understanding dark energy. X-ray observations first revealed the wildly hot gas within clusters — gas that would have drifted away if it weren’t for the cluster’s dark matter, which gravitationally holds it in place. Then, astronomers observed clusters dating back to when the universe was less than half its current age, estimating the growth of these huge structures over cosmic time. The result: solid evidence for the existence of dark energy and a unique way to gauge its density and equation of state.

 

Big Earthquakes Might Make Sea Level Rise Worse

A GEOLOGIC ONE-TWO punch rocked the South Pacific in September 2009, as a magnitude 8.1 earthquake struck off the coast of the island nation of Samoa, followed mere moments later by a similarly intense temblor. A towering tsunami soon crashed onto the shores of islands nearby, leaving more than 180 dead and communities in ruins in Samoa, the neighboring U.S. territory of American Samoa, and surrounding islands.

But a new study, published in the Journal of Geophysical Research: Solid Earth, reveals that the quakes also sparked a slow-burning danger for the more than 55,000 residents of American Samoa: sea level rise that is five times as fast as the global average.

Like other island and coastal regions around the world, Samoa and American Samoa are facing encroaching waters as our warming world sends sea levels soaring at accelerating rates. In the wake of the mega-quakes, though, the researchers discovered that these Pacific islands are also sinking. The situation is particularly concerning for American Samoa, where the team estimates that, over the next 50 to a hundred years, local sea levels could rise by roughly a foot in addition to the anticipated effects of climate change.

While the contributions of big earthquakes won’t be the same everywhere, the discovery emphasizes the sometimes overlooked effects that geology can have on the increasing number of people around the world who call coastlines home. (Also find out how powerful quakes are priming the region around Mount Everest for a huge disaster.)

“Everybody is talking about climate change issues … but they overlooked the impact of the earthquake and associated land subsidence,” says study leader Shin-Chan Han of the University of Newcastle, Australia, referring to documents from regional governments on sea level rise.

“This is a really important thing to point out,” says geophysicist Laura Wallace of the geoscience consultancy firm GNS Science, Te Pū Ao, in New Zealand, who was not involved in the study. “It obviously has a big impact on the relative sea level changes people are going to see in places like [the Samoan islands].”

Geologic geometry

Plate tectonics is constantly reshaping the surface of our planet—a role particularly evident during an earthquake. Generally speaking, these events occur where tectonic plates are colliding or sliding against each other, building up geologic stress. When that pent-up energy is released suddenly, it can send blocks of the planet’s crust careening out of place. (Find out how smaller “hidden” earthquakes are affecting California.)

But not all the change from a big earthquake is immediate. Unlike the rigid crust, the rocks of the mantle below flow like cold molasses and gradually adjust to the sudden surface jolt, Wallace says. This can cause either sinking or uplift of the land that can continue for decades after a temblor strikes.

This prolonged landscape deformation is what intrigues Han. For years, he’s scoured data from the Gravity Recovery and Climate Experiment, or GRACE, satellites to hunt for the rise and fall of land after a quake. This satellite duo orbited Earth in a line from 2002 to 2017 and precisely tracked the gap between the spacecraft. As they passed over zones with slightly more mass, and thus stronger gravity, the leading craft would feel the tug just before the trailing one. This tweaked the space in between and registered as a wobble in the planet’s gravitational field that can reveal changes in the landmass below.

In the case of the 2009 earthquake, such changes were minute on a day-to-day basis. But eventually, the effects were large enough that Han saw something strange happening in the Samoan islands while poring over the GRACE data.

A rare coincidence

The 2009 event was a particularly unusual earthquake that initially baffled scientists, since the pair of powerful temblors ripped through the Earth nearly at the same time. One broke along a so-called normal fault, created due to the flex of the oceanic crust as it plunges under another tectonic plate in what’s known as a subduction zone. Another quake broke within the subduction zone due to the compressive forces of the colliding plates.

The researchers investigated the lingering impacts of these quakes using a combination of GRACE data and local GPS and tide gauge records. They then built a computer model to tease apart the complex interplay between the temblors and what is happening at the surface.

This data showed slow sinking of the landscape, driven primarily by the normal-fault quake. This particular earthquake causes one side of the landscape to fall in relation to the other, which sent the nearby islands sinking downward.

The team found that nearly a decade after the event, the island of Samoa has sunk by roughly 0.4 inches a year. The situation is particularly acute for American Samoa, which has seen more than 0.6 inches of subsidence each year, and it doesn’t look like it’s stopping anytime soon.

The pace outstrips the estimated rate of global sea level rise, which is creeping upward at some 0.13 inches a year. Flooding and seawater intrusion in freshwater aquifers are already grave concerns for residents of American Samoa, Han says, and the latest find only adds to the worry.

Bathtub oceans

This latest study emphasizes the need for greater awareness and continued monitoring to mitigate the potential effects of mega-quakes, Wallace says. However, predicting such sea level effects before an earthquake strikes is not feasible, since earthquake prediction itself remains elusive.

“This might be a problem that suddenly causes you heartburn next week,” Freymueller says, “or it might not cause any problem for the next century.”

This latest study emphasizes the need for greater awareness and continued monitoring to mitigate the potential effects of mega-quakes, Wallace says. However, predicting such sea level effects before an earthquake strikes is not feasible, since earthquake prediction itself remains elusive.

“This might be a problem that suddenly causes you heartburn next week,” Freymueller says, “or it might not cause any problem for the next century.”

Site Of Biggest Ever Meteorite Collision In The UK Discovered

Scientists believe they have discovered the site of the biggest meteorite impact ever to hit the British Isles.

Evidence for the ancient, 1.2 billion years old, meteorite strike, was first discovered in 2008 near Ullapool, NW Scotland by scientists from Oxford and Aberdeen Universities. The thickness and extent of the debris deposit they found suggested the impact crater — made by a meteorite estimated at 1km wide — was close to the coast, but its precise location remained a mystery.

In a paper published today in Journal of the Geological Society, a team led by Dr Ken Amor from the Department of Earth Sciences at Oxford University, show how they have identified the crater location 15-20km west of a remote part of the Scottish coastline. It is buried beneath both water and younger rocks in the Minch Basin.

Dr Ken Amor said: ‘The material excavated during a giant meteorite impact is rarely preserved on Earth, because it is rapidly eroded, so this is a really exciting discovery. It was purely by chance this one landed in an ancient rift valley where fresh sediment quickly covered the debris to preserve it.

‘The next step will be a detailed geophysical survey in our target area of the Minch Basin.’

Using a combination of field observations, the distribution of broken rock fragments known as basement clasts and the alignment of magnetic particles, the team was able to gauge the direction the meteorite material took at several locations, and plotted the likely source of the crater.

Dr Ken Amor said: ‘It would have been quite a spectacle when this large meteorite struck a barren landscape, spreading dust and rock debris over a wide area.’

1.2 billion years ago most of life on Earth was still in the oceans and there were no plants on the land. At that time Scotland would have been quite close to the equator and in a semi-arid environment. The landscape would have looked a bit like Mars when it had water at the surface.

Earth and other planets may have suffered a higher rate of meteorite impacts in the distant past, as they collided with debris left over from the formation of the early solar system.

However, there is a possibility that a similar event will happen in the future given the number of asteroid and comet fragments floating around in the solar system. Much smaller impacts, where the meteorite is only a few meters across are thought to be relatively common perhaps occurring about once every 25 years on average.

It is thought that collisions with an object about 1 km (as in this instance) across occur between once every 100,000 years to once every one million years — but estimates vary.

One of the reasons for this is that our terrestrial record of large impacts is poorly known because craters are obliterated by erosion, burial and plate tectonics.

Part VII – Coming Back Around to Earth’s Magnetic Reversal

New findings suggest a series of current events are weakening the Earth’s magnetic field. Above the liquid outer core is the mantle – made up of viscous rock composition which can be molded or shaped due to intense heat and high pressure, this is called convection. At the boundary between Earth’s core and mantle there is an intense heat exchange – this is called convection.

What creates Earth’s magnetic field is the process through which a rotating, convecting, and electrically conducting fluid which makes up the geodynamo mechanism. Recent studies indicate a slow flowing solid mantle and its reciprocal connection with a hot fast flowing outer core – is the central focus of Earth’s magnetic field weakening. The outcome of this convection between Earth’s outer core and mantle is the production of mantle plumes and the formation of fluid ‘crystallization’. Mantle plumes are a reaction to the Earth’s dipole magnetic core acting as a thermostat.

As a result of a weakened magnetic field coupled with a deep solar minimum, is allowing an alarming amount of galactic cosmic rays to enter our planets environment. In a paper published in the journal American Geophysical Union (AGU) Space Weather, associate professor Nathan Schwadron of the UNH Institute for the Study of Earth, Oceans, and Space (EOS) and the department of physics; says that due to this solar cycles vast drop in solar activity, a stream of cosmic ray particles are flooding Earth’s atmosphere – and further driving in and through Earth’s core.

Additionally, a major consequence of a weakened magnetic field, in conjunction with an inundation of space radiation, allows for the redistribution of gas and fluids which could contribute to Earth’s tilt and wobble. It is this action/reaction which could affect the convection process allowing for the north/south magnetic field lines to bounce around northern latitudes. This is known as geomagnetic excursion.

My research suggests radiation produced by GCRs has a significant influence on Earth’s core by increasing temperatures. In viewing Earth as a living entity, a natural reaction to overheating would be to find a way to cool down. And that’s exactly what Earth does. When our planet becomes overheated…it sweats. Yes, just like us humans when we get overheated, we sweat through our pores. When Earth becomes overheated it sweats through its pores called ‘mantle plumes’. Earth, just like humans is always seeking to maintain its ambient temperature.

In relation to this current moderate-term cycle i.e. 20,000-40,000 years – in conjunction with this long-term cycle i.e. 22myr -60myr (million years) my study’s identify a pattern of a weakening magnetic field, and influx of highly charged particles sets up the perfect conditions to produce a magnetic excursion followed by a magnetic reversal.

**Thank you for your much needed contributions. Every little bit helps, and those of you who have the means to sponsor this research, please step forward. Go to the click here button to support this work.  CLICK HERE

Part – VIII How Far Along Are We In This Cycle?

 

Thermal Analog Black Hole Agrees With Hawking Radiation Theory

A team of researchers at the Israel Institute of Technology has found that a thermal analog black hole they created agrees with the Hawking radiation theory. In their paper published in the journal Nature, the group describes building their analog black hole and using data from it to test its temperature. Silke Weinfurtner with the University of Nottingham has published a News and Views piece on the work done by the team in the same journal issue.

One of Stephen Hawking’s theories suggested that not all matter that approaches a black hole falls in—he argued that in some cases in which entangled pairs of particles arise, only one of them would fall in, while the other escaped. The escaping particles were named Hawking radiation. Hawking also predicted that the radiation escaping from a black hole would be thermal and that its temperature would depend on the size of the black hole. Testing the theory has been difficult because of the nature of black holes—any radiation escaping from them would be too faint to observe. To get around that problem, researchers have been working on creating black hole analogs in the lab. In this new effort, the researchers built one designed to absorb sound instead of light. With such an analog, pairs of phonons served as stand-ins for the entangled particles in a real black hole.

The experiment consisted of chilling a group of rubidium atoms and using lasers to create a Bose-Einstein condensate. The atoms were then forced to flow in a way that resembled the trapping that occurs with a real black hole. With such a flow, sound waves were unable to escape under normal circumstances. In their experiment, the researchers were able to force one of a pair of phonons to fall into the flow of atoms while the other was allowed to escape. As they did so, the researchers took measurements of both phonons, allowing them to estimate their temperature to .035 billionths of a kelvin. And in so doing, they found it agreed with Hawking’s prediction. They also found agreement that the radiation from such a system would be thermal.

The work does not prove the theory, of course; the only way to do that will be to develop technology capable of actually measuring the radiation from a real black hole—but it does give the theory more credence.

Part IV – Cycles Within Cycles, Within Cycles and ‘Science Of Cycles’

Here I am writing, then re-writing and then re-writing again. Partly because I find this exploratory research exhilarating, partly because it affirms the direction I chose to follow beginning mostly in 2012. And of course new information which was not available just a few years ago, and then formulating these strings of thought which has brought on a few spattering of “You’re kidding, no way, I thought so, and just plain wow”. Once again, as in my research of the Sun-Earth connection, but to a less noticeable degree, the right hand was not quite sure what the left hand was doing or aware of.

Those of you familiar with my first book “Solar Rain” will remember how I conveyed my unexpected surprise, when I realized how two of our greatest scientific bodies – NASA and NOAA, simply did not communicate with each other leaving me with no choice but to run back and forth as I pieced together NASA’s knowledge of space, and NOAA’s knowledge weather. When you put the two together you have “space-weather”.

A recent study published in the science journal ‘Nature’, indicates a direct connection between the acceleration of charged particles such as galactic cosmic rays and its effect on humans and animals. Charged particles come in many forms. From the Sun, they come in the form of solar flares, CMEs (coronal mass ejections), coronal holes, filament, and gamma ray burst. The more powerful and damaging particles are the galactic cosmic rays which comes from outside our solar system. These subatomic particles, made up of around ninety percent protons move through space at close to the speed of light. Magnetic fields deflect and distort the path of the particles, making it near impossible to determine their point of origin. Collision of stars, supernovae, even dark matter have all been named as a possible source.

Note: If you find this information of interest and useful, please consider supporting us with your donations. I am also looking for a sponsors that would help carrying this important research forward. Go to the click here button to support this work.                              CLICK HERE

As mentioned previously, during times of high solar activity (expansion), cosmic rays are better reflected from entering Earth’s atmosphere. However, during times of low solar activity (contraction), cosmic rays are far more abundant therefore have the potential to cause significant damage to our planet and all those living on it. Moreover, when you factor in the two current events happening concurrently, the scenario adds anecdotal averment of how far along this cycle we reside. First) A weakening magnetic field diminishing 10x faster than original estimates. Second) Evidence of an extended solar minimum which is going beyond one, two, three, or possibly more cycles allowing a profusion of galactic cosmic rays entering our atmosphere, with the higher energy particles penetrating deep into the Lithosphere, Mantle, and some research says right through the other side.

When scenario’s such as this occur, one must go beyond the better known short-term cycles comprised of averaging 11 yr. and 22 yr-cyl; while looking deeper into the less known medium ‘extended cycles’ such as the Milankovitch Cycle, the Laschamp Event, and the Maunder Minimum indicating that some cycles commingle while others supplant with periodicities ranging from Maunder’s 60-70 yr-cyl, to Laschamp’s 40,000 and 60,000 yr-cyl, to Milankovitch’s 23,000, 41,000, and 100,000 yr-cyl.

Then we have long-term cycles which can be traced back 550 million years.

*My eyes hurt, I have to stop here. I will pick it up tomorrow with “long-term cycles”