From Techniche Universitat Munchen via Science Alert: “Scientists Have Found Evidence a Strange Group of Quantum Particles Are Basically Immortal”

From Techniche Universitat Munchen

Science Alert

17 JUN 2019
MICHELLE STARR

(Verreson et al., Nature Physics, 2019)

Nothing lasts forever. Humans, planets, stars, galaxies, maybe even the Universe itself, everything has an expiration date. But things in the quantum realm don’t always follow the rules. Now, scientists have found that quasiparticles in quantum systems could be effectively immortal.

That doesn’t mean they don’t decay, which is reassuring. But once these quasiparticles have decayed, they are able to reorganise themselves back into existence, possibly ad infinitum.

This seemingly flies right in the face of the second law of thermodynamics, which asserts that entropy in an isolated system can only move in an increasing direction: things can only break down, not build back up again.

Of course, quantum physics can get weird with the rules; but even quantum scientists didn’t know quasiparticles were weird in this particular manner.

“Until now, the assumption was that quasiparticles in interacting quantum systems decay after a certain time,” said physicist Frank Pollman of the Technical University of Munich.

“We now know that the opposite is the case: strong interactions can even stop decay entirely.”

Quasiparticles aren’t particles the way we typically think of them, like electrons and quarks. Rather, they’re the disturbances or excitations in a solid caused by electrical or magnetic forces that, collectively, behave like particles.

Phonons – the discrete units of vibrational energy that oscillate the atoms in a crystal lattice, for example – are often classified as quasiparticles, as are polarons, electrons trapped in a lattice surrounded by a cloud of polarisation.

The researchers involved with this latest study developed numerical methods for calculating the complex interactions of these quasiparticles, and ran simulations on a powerful computer to observe how they decay.

“The result of the elaborate simulation: admittedly, quasiparticles do decay, however new, identical particle entities emerge from the debris,” said physicist Ruben Verresen of the Technical University of Munich and the Max Planck Institute for the Physics of Complex Systems.

“If this decay proceeds very quickly, an inverse reaction will occur after a certain time and the debris will converge again. This process can recur endlessly and a sustained oscillation between decay and rebirth emerges.”

And, the physicists pointed out, it doesn’t violate the second law of thermodynamics after all. That’s because the oscillation is a wave that is transformed into matter, which is covered under the quantum mechanical concept of wave-particle duality.

Their entropy is not decreasing, but remaining constant. That’s still pretty weird, but not physics-breaking weird.

In fact, the finding has solved a couple of other head-scratchers. For example, there’s a magnetic compound Ba3CoSb2O9 used in experiments that’s been previously found to be unexpectedly stable. Now it looks like the key might be the magnetic quasiparticles it contains, called magnons. According to the simulation, they rearrange themselves after decay.

Another potential example is helium: it becomes a resistance-free superfluid at a temperature of absolute zero, and this peculiar property could be explained by the fact this gas is full of quasiparticles called rotons.

At the moment, the work is only in the theoretical realm, but the researchers believe this quasiparticle immortality imbues it with strong potential for long-lasting data storage in quantum computing systems.

The research has been published in Nature Physics.

See the full article here .

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Techniche Universitat Munchin is one of Europe’s top universities. It is committed to excellence in research and teaching, interdisciplinary education and the active promotion of promising young scientists. The university also forges strong links with companies and scientific institutions across the world. TUM was one of the first universities in Germany to be named a University of Excellence. Moreover, TUM regularly ranks among the best European universities in international rankings.

From University of Washington via Science Alert: Women in STEM- “This Incredible Orbit Map of Our Solar System Makes Our Brains Ache” Eleanor Lutz

From University of Washington

via

Science Alert

(Eleanor Lutz)

17 JUN 2019
EVAN GOUGH

If you want to know what a talent for scientific visualizations looks like, check out Eleanor Lutz. She’s a PhD student in biology at the University of Washington, and at her website Tabletop Whale, you can see her amazing work on full display.

Her latest piece is a map showing all the orbits of over 18,000 asteroids in the Solar System. It includes 10,000 asteroids that are over 10 km in diameter, and about 8,000 objects of unknown size.

As the tagline at her website says, she produces “Charts, infographics, and animations about any and all things science.”

This includes things like a “Visual Compendium of Glowing Creatures,” “All the Stars You Can See From Earth,” and a beautiful topographic map of Mercury.

But it’s her newest project that is garnering her a lot of attention in the space community. Lutz is working on an Atlas of Space, and has been for the last year and a half. It’s a collection of ten visualizations including planets, moons, and outer space.

As she says on her website, “I’ve made an animated map of the seasons on Earth, a map of Mars geology, and a map of everything in the solar system bigger than 10 km.”

It’s that map of objects larger than 10 km that is generating buzz.

(Eleanor Lutz)

All of the data for Lutz’s Atlas of Space is public data, freely available. She gets if from sources like NASA and the US Geological Survey.

Part of what drives her is that even though the data is public and freely available, it’s raw. And taking that raw data and turning it into a helpful, and even beautiful, visualization, takes a lot of work.

In an interview with Wired, Lutz said, “I really like that all this data is accessible, but it’s very difficult to visualize. It’s really awesome science, and I wanted everyone to be able to see it in a way that makes sense.”

( Eleanor Lutz)

(Eleanor Lutz)

Lutz’s work is really more than data visualizations. She has a designer’s eye, and some of her work is very artful.

But being a scientist, she’s inspired to share the data and the methods she used to create her work. She plans to publish the open source code for each of her pieces, and also tutorials for how to create them yourself.

It’s difficult to understand our world, or anything in nature really, without engaging with science. Without science, all we have is anecdote and opinion.

But science is all about data, and dense data is not everyone’s cup of tea. It’s taxing and time-consuming to understand.

Lutz’s work is making it easier. In an interview with Wired, she said, “There’s a knowledge barrier to accessing some of the interesting, awesome things about science. There are so many facts and equations, and I want those cool ideas to be accessible.”

To access some of those cool ideas she’s talking about, visit her website, tabletopwhale.com, where you can explore her work and her methods. You can also purchase prints there.

This article was originally published by Universe Today. Read the original article.

See the full article here .

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The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
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From Science Alert: “We Have a Problem With The Purported Stellar Source of Earth’s Gold”

From Science Alert

14 JUN 2019
MICHELLE STARR

(ESO/VISTA/J. Emerson)

Part of ESO’s Paranal Observatory, the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light.
Credit: ESO/Y. Beletsky, with an elevation of 2,635 metres (8,645 ft) above sea level

The origins of the Solar System’s heavy elements such as gold and platinum have been a source of great interest to astronomers. One of the most popular theories is that they were scattered into space by neutron star collisions.

New research, however, has found another origin: an oft-overlooked type of star explosion, or supernova. These, the researchers assert, could be responsible for at least 80 percent of the heavy elements in the Universe.

The particular type in question are collapsar supernovae, produced by rapidly spinning stars more than 30 times the mass of the Sun; they explode in spectacular fashion before collapsing into black holes.

“Our research on neutron star mergers has led us to believe that the birth of black holes in a very different type of stellar explosion might produce even more gold than neutron star mergers,” said physicist Daniel Siegel of the University of Guelph.

The neutron star collision detection in 2017 brought the first solid evidence that such collisions produce heavy elements. In the electromagnetic data produced by GW 170817, scientists detected, for the first time, the production of heavy elements including gold, platinum and uranium.

As we previously reported, this happens because a powerful explosion, such as a supernova or stellar merger, can trigger the rapid neutron-capture process, or r-process – a series of nuclear reactions in which atomic nuclei collide with neutrons to synthesise elements heavier than iron.

The reactions need to happen quickly enough that radioactive decay doesn’t have a chance to occur before more neutrons are added to the nucleus, which means it needs to happen where there are a lot of free neutrons floating about, such as an exploding star.

In the case of GW 170817, these r-process elements were detected in the disc of material that bloomed out around the neutron stars after they had merged. While working on understanding the physics of this, Siegel and his team realised that the same phenomenon might occur in association with other cosmic explosions.

So, using supercomputers, they simulated the physics of collapsar supernovae. And, boy did they ever strike gold.

“Eighty percent of these heavy elements we see should come from collapsars,” Siegel said.

“Collapsars are fairly rare in occurrences of supernovae, even more rare than neutron star mergers – but the amount of material that they eject into space is much higher than that from neutron star mergers.”

Moreover, the quantities and distribution of these elements produced in the simulation were “astonishingly similar” to what we have here on Earth, he noted.

So does that mean that 0.3 percent of Earth’s r-process elements didn’t come from a neutron star collision 4.6 billion years ago, as a different team of astronomers found earlier this year? Well, not necessarily. Under the parameters of Siegel’s simulations, up to 20 percent of these elements could still have come from neutron star and black hole smash-ups.

The team hopes the James Webb Space Telescope, currently slated for a 2021 launch, could shed more light on the matter. Its sensitive instruments could detect the radiation pointing to a collapsar supernova in a distant galaxy, as well as elemental abundances across the Milky Way.

“Trying to nail down where heavy elements come from may help us understand how the galaxy was chemically assembled and how the galaxy formed,” Siegel said.

“This may actually help solve some big questions in cosmology as heavy elements are a nice tracer.”

The research has been published in Nature.

See the full article here .

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From Science Alert: “Astronomers Find First Evidence of an Odd Radio ‘Bridge’ Connecting 2 Galaxy Clusters”

From Science Alert

7 JUN 2019
MICHELLE STARR

(M. Murgia/INAF)

A colossal magnetic field stretching between two clusters of galaxies has been observed for the first time. Roughly a billion light-years away, the ‘bridge’ of radio-emitting plasma spans 10 million light-years, following a filament in the mysterious cosmic web that connects the Universe.

The space between clusters of galaxies isn’t completely dark and empty. Long strands of diffuse and tenuous gas and plasma stretch between them; these are called filaments, the entire network of which constitutes the cosmic web.

Cosmic web Millenium Simulation Max Planck Institute for Astrophysics

But they’re very difficult to study, as faint as they are in a Universe teeming with bright things.

Previous observations with ground-based radio telescopes had shown ‘haloes’ of radio emission indicating the presence of a magnetic field in the central region of some clusters – some of which contain thousands of galaxies – but no one had ever seen a magnetic field connecting one cluster to another.

So the discovery of a magnetic field in the filament between merging clusters Abell 0399 and Abell 0401 is something extraordinary.

“Our group had discovered that both clusters have a radio halo. More recently, the Planck satellite has shown that the two systems are connected by a thin filament of matter,” said astronomer Federica Govoni of the National Institute for Astrophysics in Italy (INAF).

ESA/Planck 2009 to 2013

“The presence of this filament stimulated our curiosity and prompted us to investigate whether the magnetic field could extend beyond the center of the clusters, permeating the filament of matter that connects them.”

Using the low-frequency radio telescope LoFar, which consists of 25,000 antennas across 51 locations, the team homed in on the filament, detecting a ‘ridge’ of low-frequency radio emission extending between them.

ASTRON LOFAR Radio Antenna Bank, Netherlands

(M. Murgia/INAF)

This is synchrotron radiation produced by electrons zipping along the filament at relativistic velocities, only possible if the magnetic field is acting as a synchrotron, or particle accelerator.

“We typically observe this emission mechanism in action in individual galaxies and even in galaxy clusters, but never before has a radio emission been observed connecting two of these systems,” said INAF astronomer Matteo Murgia.

But there is a slight hiccup: the electrons are covering way more distance than is expected – which means there has to be another element at play. And that element could be the clusters themselves.

Even though they’re separated by a distance of millions of light-years, Abell 0399 and Abell 0401 are creating a great deal of gravitational disturbance in the space around them as they draw inexorably closer together.

The team ran computer simulations to see if any of the dynamics of this merger could be influencing the acceleration of the electrons. Lo and behold, they found an answer. In the simulations, shock waves generated by the merger re-accelerated high-speed electrons, resulting in an emission consistent with the LoFar observations.

But that’s just one potential mechanism. We won’t know for sure until more observations are made.

We also don’t know if other filaments also contain magnetic fields, or if it’s a property unique to Abell 0399 and 0401, or if it’s only found in merging galaxies.

We don’t know where the pre-existing relativistic electrons came from – their velocity implies an energetic origin that could have ejected them at speed, such as supernovae. Nor do we know how prevalent these pre-existing relativistic electrons are in the cosmic web.

If their origin is something common, such as supernovae, there could be more of them around than we could have ever guessed.

It’s certainly given scientists a lot to think about. Not to mention how awesome it is to see scientists following a hunch, and having it pay off.

“With great satisfaction,” Govoni said, “the image obtained with the LoFar radio telescope confirmed our intuition, showing what can be defined as a sort of ‘aurora’ on cosmic scales.”

The research has been published in Science.

See the full article here .

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From Science Alert: “Something’s Hiding in Our Outer Solar System, But It Might Not Be Planet Nine”

From Science Alert

25 MAY 2019
MICHELLE STARR

Dwarf planet Sedna, one of the detached TNOs. (NASA/JPL-Caltech)

Somewhere in the outer reaches of the Solar System, beyond the orbit of Neptune, something wonky is happening. A few objects are orbiting differently from everything else, and we don’t know why.

A popular hypothesis is that an unseen object called Planet Nine could be messing with these orbits; astronomers are avidly searching for this planet. But earlier this year physicists came up with an alternative explanation they think is more plausible.

Instead of one big object, the orbital wobblies could be caused by the combined gravitational force of a number of smaller Kuiper Belt or trans-Neptunian objects (TNOs). That’s according to astrophysicists Antranik Sefilian of the University of Cambridge in the UK and Jihad Touma of the American University of Beirut in Lebanon.

If it sounds familiar, that’s because Sefilian and Touma are not the first to think of this idea – but their calculations are the first to explain significant features of the strange orbits of these objects, while taking into account the other eight planets in the Solar System.

A hypothesis for Planet Nine was first announced in a 2016 study. Astronomers studying a dwarf planet in the Kuiper Belt noticed that several TNOs were “detached” from the strong gravitational influence of the Solar System’s gas giants, and had weird looping orbits that were different from the rest of the Kuiper Belt.

Kuiper Belt. Minor Planet Center

But the orbits of these six objects were also clustered together in a way that didn’t appear random; something seemed to have tugged them into that position. According to modelling, a giant, heretofore unseen planet could do so.

So far, this planet has remained elusive – not necessarily odd, since there are considerable technical challenges to seeing a dark object that far away, especially when we don’t know where it is. But its evasiveness is prompting scientists to seek alternative explanations.

“The Planet Nine hypothesis is a fascinating one, but if the hypothesised ninth planet exists, it has so far avoided detection,” Sefilian said back in January when their study was released, adding that the team wanted to see if there was a less dramatic explanation of the weird TNO orbits.

“We thought, rather than allowing for a ninth planet, and then worry about its formation and unusual orbit, why not simply account for the gravity of small objects constituting a disk beyond the orbit of Neptune and see what it does for us?”

The researchers created a computer model of the detached TNOs, as well as the planets of the Solar System (and their gravity), and a huge disc of debris past Neptune’s orbit.

By applying tweaks to elements such as the mass, eccentricity and orientation of the disc, the researchers were able to recreate the clustered looping orbits of the detached TNOs.

“If you remove Planet Nine from the model, and instead allow for lots of small objects scattered across a wide area, collective attractions between those objects could just as easily account for the eccentric orbits we see in some TNOs,” Sefilian said.

This solves a problem that scientists from the University of Colorado Boulder had when they first floated the collective gravity hypothesis last year. Although their calculations were able to account for the gravitational effect on the detached TNOs, they couldn’t explain why their orbits were all tilting the same way.

And there’s still another problem with both models: in order to produce the observed effect, the Kuiper Belt needs a collective gravity of at least a few Earth masses.

Current estimates, however, put the mass of the Kuiper Belt at just 4 to 10 percent of Earth’s mass.

But, according to Solar System formation models, it should be much higher; and, Sefilian notes, it’s hard to view the entirety of a debris disc around a star when you’re inside it, so it’s possible that there’s a lot more to the Kuiper Belt than we’re able to see.

“While we don’t have direct observational evidence for the disc, neither do we have it for Planet Nine, which is why we’re investigating other possibilities,” Sefilian said.

“It’s also possible that both things could be true – there could be a massive disk and a ninth planet. With the discovery of each new TNO, we gather more evidence that might help explain their behaviour.”

The team’s research was published in The Astronomical Journal.

See the full article here .

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From Science Alert: “SpaceX Just Launched The First 60 of Nearly 12,000 High-Speed Internet Satellites”

From Science Alert

24 MAY 2019
DAVE MOSHER

(Mark Handley/University College London)

SpaceX, the rocket company founded by Elon Musk, successfully launched its first five dozen Starlink telecommunications satellites on Thursday night.

If all goes according to plan in the coming weeks, the new fleet of experimental spacecraft may pave the way for a global, ultra-fast, and lucrative internet product, possibly within a couple of years.

“Starlink will connect the globe with reliable and affordable high-speed broadband services,” SpaceX tweeted just before the launch from Cape Canaveral, Florida

SpaceX broadcast the inaugural Starlink mission, which launched aboard a Falcon 9 rocket at 10:30 p.m. ET. A little more than an hour after liftoff, the rocket’s upper stage deployed all 30,000 pounds’ (13,600 kilograms’) worth of satellites at once – the heaviest payload SpaceX has ever launched.

(Mark Handley/University College London)

The spacecraft were released about 273 miles (440 kilometers) above Earth, somewhere over the Indian Ocean about halfway between Australia and Antarctica.

Musk previously described the deployment as an odd yet efficient way to get five dozen spacecraft off a rocket.

“This will look kind of weird compared to normal satellite deployments,” Musk told reporters during a call on May 15.

When a rocket launches many satellites at once, typically a device at the top of the rocket’s uppermost stage deploys them, one by one, with complex and heavy spring-loaded mechanisms. SpaceX launched one such mission in December, deploying a cornucopia of 64 satellites with one rocket.

But SpaceX eschewed that approach for an unusual one: It slowly spun the rocket’s upper stage, then released its payload like an overhand baseball pitch – except instead of a baseball, it was the entire stack of flat-packed Starlink satellites.

“There are no deployment mechanisms between those spacecraft, so they really are slowly fanning out like a deck of cards into space,” Tom Praderio, a SpaceX software engineer, said while hosting the mission’s webcast.

Praderio quickly added: “You can kind of see one breaking away from the pack right now. Those spacecraft will slowly disperse over time.”

The .gif below shows the Starlink deployment 360 percent faster than it actually happened.

Big plans for Starlink’s future

Each Starlink satellite is roughly the size of an office desk and weighs about 500 pounds (227 kilograms), comes with a single solar panel, and has antennas to shuttle data to and from the ground.

Each spacecraft has a weak yet highly efficient Hall thruster, or ion engine, that shoots out krypton gas. Musk said the engine would help each Starlink avoid other satellites, dodge known space junk (though experts are reasonably worried about the scheme), and – once it has neared the end of its useful life – deorbit and destroy itself.

Most immediately, the engines will help Starlink spacecraft slowly ascend to a higher orbit of 342 miles (550 kilometers) above Earth.

(SpaceX via Twitter)

SpaceX’s first 60 Starlink satellites lack a critical component, though: laser beams interlinks.

Each future spacecraft will use such lasers to connect to four other satellites, forming a robust mesh network above Earth meant to move internet traffic at close to the speed of light in a vacuum. (That’s nearly 50% faster than fibre-optic cables can transmit data on the ground, and it would grant Starlink a huge advantage in cutting lag.)

With this first experimental batch, though, Musk said SpaceX would test the Starlink internet concept by routing data from one satellite to another through existing ground cables.

SpaceX’s goal with Starlink is to launch up to 12,000 similar satellites – nearly seven times the number of operational spacecraft in orbit now – before a 2027 deadline established by the Federal Communications Commission. To achieve that amount, SpaceX would have to launch more than one Starlink mission a month over the next eight years.

But not nearly that many are required to make the concept work and bring global internet access.

(Mark Handley/University College London)

Musk said SpaceX had “sufficient capital” to get Starlink operational and suggested the Starlink project could start making money long before the full constellation maxed out.

“For the system to be economically viable, it’s really on the order of 1,000 satellites,” Musk said, “which is obviously a lot of satellites, but it’s way less than 10,000 or 12,000.”

The pervasiveness of the overhead satellites also means Starlink could bring almost lag-free broadband internet to most regions of Earth, as well as aeroplanes, ships, and even cars (perhaps Tesla electric vehicles to start). Musk has said multiple times that he’d like to make such internet access affordable, particularly in areas with little to no web service.

Mark Handley, a computer-networking researcher at University College London who has studied Starlink, previously told Business Insider that the project could affect the lives of “potentially everybody” by bringing high-speed and pervasive broadband to most parts of the world.

“This is the most exciting new network we’ve seen in a long time,” Handley said.

See the full article here .

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From Science Alert: “For The First Time, The Geometry of an Electron Has Been Mapped”

From Science Alert

24 MAY 2019
MICHELLE STARR

(Camenzind et al., PRL, 2019)

If you’ve ever opened a science textbook, you’ve probably seen a picture of an atom, with a cluster of protons and neutrons making up its nucleus, around which whirls a swarm of electrons. But you also probably know that all these particles aren’t shaped like neat little spheres, as usually depicted.

As far as we know, electrons don’t actually have a ‘shape’ per se – rather, they are either point particles or they are behaving like a wave, which changes shape depending on its energy. Now, for the first time, physicists have revealed the mapping of a single electron in an artificial atom.

The technique involves the use of quantum dots, tiny semiconducting crystals on nanometre scales. You may have heard of quantum dot display technology, such as QLED televisions, but they’re useful for a lot more than watching Avengers in high definition.

They are also referred to as artificial atoms because they can basically trap electrons and confine their movement in three dimensions, holding them in place with electric fields. These trapped electrons behave like electrons bound to an atom, and remain in specific locations.

Using a spectroscope, the researchers were able to determine the energy levels in a quantum dot, observing how they behave in magnetic fields of varying strength and orientation.

This in turn allowed the team to calculate the shape of an electron’s wave function within the quantum dot, down to scales even smaller than a nanometre.

“To put it simply, we can use this method to show what an electron looks like for the first time,” said physicist Daniel Loss of the University of Basel.

But that wasn’t all they did. By tuning the electric field, they were able to change the shape of the electron movement, controlling their spins in a highly targeted and precise manner.

This has tremendous implications for future research and technology. It could play a role in quantum entanglement research, since successful entanglement requires the wave functions of two electrons to be oriented along the same plane. Being able to control the shape of an electron’s wave function could be vastly beneficial.

As for technology, the spin rate of an electron is a candidate for use as a qubit, the smallest unit of information in a quantum computer, but only if the spin can be brought under control.

Since this spin is partially dependent on the geometry of an electron, this is one potential method for achieving that control.

The research has been published in two papers in Physical Review Letters and Physical Review B.

See the full article here .

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From Science Alert: “Stunning Sonar Image Just Revealed Largest Underwater Volcano Eruption Ever Detected”

From Science Alert

(MAYOBS – CNRS/IPGP/IFREMER/BRGM

22 MAY 2019
MICHELLE STARR

In November last year, geologists announced they’d picked up something really weird: a huge seismic event originating in the island of Mayotte in the Indian Ocean, felt all across the globe, source unknown. A few months later, scientists used modelling to produce an answer – hypothesising a giant underwater volcanic eruption.

And now it seems that is pretty likely to be the case. Scientists travelled out to where they think the swarm’s epicentre is located, and they found a large active volcano, rising 800 metres (2,624 feet) from the seafloor, and sprawling up to 5 kilometres (3.1 miles) across.

A large active volcano that wasn’t there six months prior.

If these volcanic birth pains didn’t produce the detected seismic activity, that would be a pretty amazing coincidence. But more research is still needed to make absolutely sure.

The seismic rumbles actually started on 10 May 2018. Just a few days later, on 15 May, a magnitude 5.8 quake struck. Since that time, hundreds of seismic rumbles have been detected, most on the smaller side, with the notable exception of the Earth-rattling low-frequency November event.

All those events pointed to a spot around 50 kilometres from the Eastern coast of Mayotte, a French territory and part of the volcanic Cormoros archipelago sandwiched between the Eastern coast of Africa and the Northern tip of Madagascar.

To find out what was going on, a number of French governmental institutes sent a bunch of scientists aboard the Marion Dufresne research vessel to investigate the area.

Marion Dufresne research vessel

Starting in February, the team began monitoring the region. They placed seismometers on the seafloor, 3.5 kilometres deep, and used a multibeam sonar to map the seafloor. They dredged up rocks from far below.

The researchers combined this with data collected from Mayotte to build a comprehensive picture of what was occurring down in the dark depths of the lower bathypelagic.

(MAYOBS – CNRS/IPGP/IFREMER/BRGM)

It’s a fascinating one. Data from the seismometers suggests the existence of a large magma chamber between 20 to 50 kilometres below the surface. This could have been seeping hot magma to the seafloor, where it met the cooler water and contracted, causing the crust to crack.

The plume of volcanic material produced only reached about 2 kilometres upwards, which explains why nothing was visible on the surface. The rocks pulled up from the seafloor were popping – a sign, according to Science, of high-pressure gas escaping from volcanic material.

But that’s not all. GPS data from Mayotte has revealed that the island is both shifting and sinking. It’s moved 10 centimetres eastward and sunk 13 centimetres since May of last year. This suggests the magma chamber that produced the volcano is collapsing and shrinking.

This could help explain how the volcano formed: it’s consistent with a mantle plume formation, where a rising plume of hot rock in Earth’s mantle creates melting at shallow depths. Cormoros is a mantle plume hotspot – the islands were formed by volcanic activity – but, again, this is yet to be confirmed by detailed study.

That research is currently underway.

Meanwhile, the French government is also taking steps to ensure the safety of the residents of Mayotte, where tremors and sinking continue.

“The government is fully mobilised to deepen and continue understanding this exceptional phenomenon and take the necessary measures to better characterise and prevent the risks it would represent,” the French Ministry of the Interior wrote in a press release.

In the meantime, a mission to support civil safety and security has been dispatched to the island.

See the full article here .

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From UC Santa Barbara via Science Alert: “Researchers Just Tested a Prototype Probe Designed to ‘Sail’ Between The Stars”

From UC Santa Barbara

via

Science Alert

13 MAY 2019
MATT WILLIAMS

UCSB

At the University of California, Santa Barbara, researchers with the UCSB Experimental Cosmology Group (ECG) are currently working on ways to achieve the dream of interstellar flight.

Under the leadership of Philip Lubin, the group has dedicated a considerable amount of effort towards the creation of an interstellar mission consisting of directed-energy light sail and a wafer-scale spacecraft (WSS) “wafercraft“.

If all goes well, this spacecraft will be able to reach relativistic speeds (a portion of the speed of light) and make it to the nearest star system (Proxima Centauri) within our lifetimes.

Recently, the ECG achieved a major milestone by successfully testing a prototype version of their wafercraft (aka. the “StarChip”). This consisted of sending the prototype via balloon into the stratosphere to test its functionality and performance.

The launch was conducted in collaboration with the United States Naval Academy in Annapolis on April 12, 2019. This date was selected to coincide with the 58th anniversary of Russian Cosmonaut Yuri Gagarin’s orbital space flight, making him the first human to go to space.

The test consisted of launching the prototype aboard a balloon to an altitude of 32,000 metres (105,000 feet) above Pennsylvania.

As Lubin explained in an interview with UCSB’s The Current:

“It’s part of a process of building for the future, and along the way you test each part of the system to refine it. It’s part of a long-term program to develop miniature spacecraft for interplanetary and eventually for interstellar flight.”

The idea behind the StarChip is simple. By taking advantage of advancements in miniaturization, all the necessary components of an exploratory mission could be mounted on a spacecraft the size of a human hand.

The sail component builds on the concept of a solar sail and developments made with lightweight materials; and together, they add up to a spacecraft that could be accelerated up to 20 percent the speed of light.

For the sake of this flight, the science team that created it put the StarChip through a series of tests designed to gauge its performance in space and ability to explore other worlds.

Aside from seeing how it faired in Earth’s stratosphere (three times higher than the operational ceiling of airplanes), the prototype collected more than 4000 images of the Earth.

As Nic Rupert, a development engineer in Lubin’s lab, explained:

“It was designed to have many of the functions of much larger spacecraft, such as imaging, data transmission, including laser communications, attitude determination and magnetic field sensing. Due to the rapid advancements in microelectronics we can shrink a spacecraft into a much smaller format than has been done before for specialized applications such as ours.”

Prototype StarChip tested by the UCSB Experimental Cosmology Group. (UCSB)

While the StarChip performed flawlessly on this flight, there are some massive technical hurdles ahead.

Considering the distances involved – 4.24 light years (40 trillion kilometres; 25 trillion miles) – and the fact that the spacecraft will need to reach a fraction of the speed of light, the technological requirements are daunting.

As Lubin said:

“Ordinary chemical propulsion, such as that which took us to the Moon nearly 50 years ago to the day, would take nearly one hundred thousand years to get to the nearest star system, Alpha Centauri. And even advanced propulsion such as ion engines would take many thousands of years. There is only one known technology that is able to reach the nearby stars within a human lifetime and that is using light itself as the propulsion system.”

One of the greatest challenges at this point is building an Earth-based laser array that would be capable of accelerated the laser sail.

“If you have a large enough laser array, you can actually push the wafers with a laser sail to get to our goal of 20 percent of the speed of light,” added Rupert. “Then you’d be at Alpha Centauri in something like 20 years.”

Since 2009, the UCSB Experimental Cosmology Group has been researching and developing this concept as part of a NASA Advanced Concepts program called Starlight.

Since 2016, they have received considerable support from Breakthrough Initiatives (the non-profit space exploration program created by Yuri Milner) as part of Breakthrough Starshot.

Solar sail. Breakthrough Starshot image. Credit: Breakthrough Starshot

Rather than creating a single spacecraft, the team hopes that their research will lead to the creation of hundreds and even thousands of waferscale craft that could visit exoplanets in nearby star systems.

These spacecraft would do away with the need for propellant and would be able to make the journey within a few decades rather than centuries or millennia.

In this respect, these spacecraft would be able to reveal whether or not life exists beyond Earth in our lifetimes. Another interesting aspect of the UCSB project involves sending life from Earth to other exoplanets.

Specifically, tardigrades and the nematode C. elegans, two species that have been shown to be highly resistant to radiation, capable of handling the conditions of space, and capable of being cryogenically frozen and revived.

This aspect of their plan is not unlike the proposal made by Claudius Gros of Goethe University’s Institute for Theoretical Physics.

Appropriately named “Project Genesis,” the proposal calls for spacecraft propelled by directed energy to travel to other star systems and seed any “transiently habitable” exoplanets that are there.

In short, life would be given a jumpstart on planets that are habitable but not inhabited.

As David McCarthy, a graduate student in the Department of Electrical and Computer Engineering at UCSB, explained, getting to the point where all is possible is a very iterative process.

“The point of building these things is to know what we want to include in the next version, in the next chip,” he said. “You start with off-the-shelf components because you can iterate quickly and inexpensively.”

With this high-altitude test complete, the UCSB group is aiming for a suborbital first flight next year. Meanwhile, advances in silicon optics and integrated wafer-scale photonics – thanks in part to research being conducted by UCSB’s electrical and computer engineering department – are reducing the cost of mass-producing these tiny spacecraft.

In addition to interstellar travel, this technology could facilitate rapid, low-cost missions to Mars and other locations in the Solar System.

Lubin and his fellow researchers have also spent years exploring applications for planetary defense against comets, mitigating space debris, boosting Earth-orbiting satellites, or remotely powering distant Solar System outposts.

When it comes to directed energy, the possibilities really are staggering.

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

From Cornell University via Science Alert: “Gravitational Waves Could Be Leaving Some Weird Lasting Effects in Their Wake”

From Cornell University

via

Science Alert

8 MAY 2019
MICHELLE STARR

(Henze/NASA)

The faint, flickering distortions of space-time we call gravitational waves are tricky to detect, and we’ve only managed to do so in recent years. But now scientists have calculated that these waves may leave more persistent traces of their passing – traces we may also be able to detect.

Such traces are called ‘persistent gravitational wave observables’, and in a new paper [Physical Review D], an international team of researchers [see paper for science team authors] has refined the mathematical framework for defining them. In the process, they give three examples of what these observables could be.

Here’s the quick lowdown on gravitational waves: When two massive objects such as neutron stars or black holes collide, they send shockwaves through the Universe, rippling the very fabric of space-time itself. This effect was predicted by Einstein in his theory of general relativity in 1916, but it wasn’t until 2015 that we finally had equipment sensitive enough to detect the ripples.

That equipment is an interferometer that shoots two or more laser beams down arms that are several kilometres in length. The wavelengths of these laser beams interfere to cancel each other out, so, normally, no light hits the instrument’s photodetectors.

VIRGO Gravitational Wave interferometer, near Pisa, Italy

Caltech/MIT Advanced aLigo Hanford, WA, USA installation

Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger

Gravity is talking. Lisa will listen. Dialogos of Eide

ESA/eLISA the future of gravitational wave research

Localizations of gravitational-wave signals detected by LIGO in 2015 (GW150914, LVT151012, GW151226, GW170104), more recently, by the LIGO-Virgo network (GW170814, GW170817). After Virgo came online in August 2018

Skymap showing how adding Virgo to LIGO helps in reducing the size of the source-likely region in the sky. (Credit: Giuseppe Greco (Virgo Urbino group)

But when a gravitational wave hits, the warping of space-time causes these laser beams to oscillate, shrinking and stretching. This means that their interference pattern is disrupted, and they no longer cancel each other out – so the laser hits the photodetector. The pattern of the light that hits can tell scientists about the event that created the wave.

But that shrinking and stretching and warping of space-time, according to astrophysicist Éanna Flanagan of Cornell University and colleagues, could be having a much longer-lasting effect.

As the ripples in space-time propagate, they can change the velocity, acceleration, trajectories and relative positions of objects and particles in their way – and these features don’t immediately return to normal afterwards, making them potentially observable.

Particles, for instance, disturbed by a burst of gravitational waves, could show changes. In their new framework, the research team mathematically detailed changes that could occur in the rotation rate of a spinning particle, as well as its acceleration and velocity.

Another of these persistent gravitational wave observables involves a similar effect to time dilation, whereby a strong gravitational field slows time.

Because gravitational waves warp both space and time, two extremely precise and synchronised clocks in different locations, such as atomic clocks, could be affected by gravitational waves, showing different times after the waves have passed.

Finally, the gravitational waves could actually permanently shift the relative positions in the mirrors of a gravitational wave interferometer – not by much, but enough to be detectable.

Between its first detection in 2015 and last year, the LIGO-Virgo gravitational wave collaboration detected a handful of events before LIGO was taken offline for upgrades.

At the moment, there are not enough detections in the bank for a meaningful statistical database to test these observables.

But LIGO-Virgo was switched back on on 1 April, and since then has been detecting at least one gravitational wave event per week.

The field of gravitational wave astronomy is heating up, space scientists are itching to test new mathematical calculations and frameworks, and it won’t be long before we’re positively swimming in data.

This is just such an incredibly exciting time for space science, it really is.

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.