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11 October 2017

There's Another Big Gravitational Wave Announcement on The Way



LIGO and Virgo have announced that they're going to be holding a big press conference on Monday, 16 October at 10am EDT at the Press Club in Washington DC.

"The gathering will begin with an overview of new findings from LIGO, Virgo and partners that span the globe," the National Science Foundation announcement reads, "followed by details from telescopes that work with the LIGO and Virgo collaborations to study extreme events in the cosmos."


Gravitational waves were officially confirmed publicly for the first time in February 2016, when LIGO announced that it had detected the phenomenon caused by a collision between two black holes. Since then, gravitational waves have been detected three more times.

The most recent announcement was in September, when LIGO announced that its collaboration with interferometer Virgo had allowed a much more precise triangulation of the signal.

Prior to that announcement, speculation was flying that the discovery was a collision between two neutron stars, with visuals from optical telescopes.

This time, we're hesitant to make any speculation, other than it seems big. Representatives from 70 other observatories around the world will be at the event, and simultaneous briefings will also be taking place in London and Munich.


There will be two separate panel discussions at the main event, too. The first panel consists of directors and spokespersons from LIGO, Virgo and NASA.

The second panel includes people like David Sand, Nial Tanvir, Eleonora Troja and Andy Howell, who have all performed research into supernovas, and Marcelle Soares-Santos, who is pioneering the Dark Energy Survey's search for an optical counterpart to gravitational wave events.

We're getting pretty excited, you guys. Read more about the announcement here, and tune back into ScienceAlert for the big news on Monday!

09 October 2017

Half the universe’s missing matter has just been finally found

The missing links between galaxies have finally been found

This is the first detection of the roughly half of the normal matter in our universe – protons, neutrons and electrons – unaccounted for by previous observations of stars, galaxies and other bright objects in space.

You have probably heard about the hunt for dark matter, a mysterious substance thought to permeate the universe, the effects of which we can see through its gravitational pull. But our models of the universe also say there should be about twice as much ordinary matter out there, compared with what we have observed so far.

Two separate teams found the missing matter – made of particles called baryons rather than dark matter – linking galaxies together through filaments of hot, diffuse gas.

“The missing baryon problem is solved,” says Hideki Tanimura at the Institute of Space Astrophysics in Orsay, France, leader of one of the groups. The other team was led by Anna de Graaff at the University of Edinburgh, UK.

Because the gas is so tenuous and not quite hot enough for X-ray telescopes to pick up, nobody had been able to see it before.

“There’s no sweet spot – no sweet instrument that we’ve invented yet that can directly observe this gas,” says Richard Ellis at University College London. “It’s been purely speculation until now.”

So the two groups had to find another way to definitively show that these threads of gas are really there.


Both teams took advantage of a phenomenon called the Sunyaev-Zel’dovich effect that occurs when light left over from the Big Seed passes through hot gas. As the light travels, some of it scatters off the electrons in the gas, leaving a dim patch in the cosmic microwave background – our snapshot of the remnants from the birth of the cosmos.

Stack ‘em up

In 2015, the Planck satellite created a map of this effect throughout the observable universe. Because the tendrils of gas between galaxies are so diffuse, the dim blotches they cause are far too slight to be seen directly on Planck’s map.

Both teams selected pairs of galaxies from the Sloan Digital Sky Survey that were expected to be connected by a strand of baryons. They stacked the Planck signals for the areas between the galaxies, making the individually faint strands detectable en masse.

Tanimura’s team stacked data on 260,000 pairs of galaxies, and de Graaff’s group used over a million pairs. Both teams found definitive evidence of gas filaments between the galaxies. Tanimura’s group found they were almost three times denser than the mean for normal matter in the universe, and de Graaf’s group found they were six times denser – confirmation that the gas in these areas is dense enough to form filaments.

“We expect some differences because we are looking at filaments at different distances,” says Tanimura. “If this factor is included, our findings are very consistent with the other group.”

Finally finding the extra baryons that have been predicted by decades of simulations validates some of our assumptions about the universe.

“Everybody sort of knows that it has to be there, but this is the first time that somebody – two different groups, no less – has come up with a definitive detection,” says Ralph Kraft at the Harvard-Smithsonian Center for Astrophysics in Massachusetts.

“This goes a long way toward showing that many of our ideas of how galaxies form and how structures form over the history of the universe are pretty much correct,” he says.

Journal references: arXiv, 1709.05024 and 1709.10378v1

05 October 2017

3-D quantum gas atomic clock offers new dimensions in measurement

JILA's three-dimensional (3-D) quantum gas atomic clock consists of a grid of light formed by three pairs of laser beams. Multiple lasers of various colors are used to cool the atoms, trap them in a grid of light, and probe them for clock operation. A blue laser beam excites a cube-shaped cloud of strontium atoms. Strontium atoms fluorescence strongly when excited with blue light, as seen in the upper right corner behind the vacuum window. Credit: G.E. Marti/JILA

JILA physicists have created an entirely new design for an atomic clock, in which strontium atoms are packed into a tiny three-dimensional (3-D) cube at 1,000 times the density of previous one-dimensional (1-D) clocks. In doing so, they are the first to harness the ultra-controlled behavior of a so-called "quantum gas" to make a practical measurement device.

With so many atoms completely immobilized in place, JILA's cubic quantum gas clock sets a record for a value called "quality factor" and the resulting measurement precision. A large quality factor translates into a high level of synchronization between the atoms and the lasers used to probe them, and makes the clock's "ticks" pure and stable for an unusually long time, thus achieving higher precision.

Until now, each of the thousands of "ticking" atoms in advanced clocks behave and are measured largely independently. In contrast, the new cubic quantum gas clock uses a globally interacting collection of atoms to constrain collisions and improve measurements. The new approach promises to usher in an era of dramatically improved measurements and technologies across many areas based on controlled quantum systems.

The new clock is described in the Oct. 6 issue of Science.

"We are entering a really exciting time when we can quantum engineer a state of matter for a particular measurement purpose," said physicist Jun Ye of the National Institute of Standards and Technology (NIST). Ye works at JILA, which is jointly operated by NIST and the University of Colorado Boulder.

The clock's centerpiece is an unusual state of matter called a degenerate Fermi gas (a quantum gas for Fermi particles), first created in 1999 by Ye's late colleague Deborah Jin. All prior atomic clocks have used thermal gases. The use of a quantum gas enables all of the atoms' properties to be quantized, or restricted to specific values, for the first time.

"The most important potential of the 3-D quantum gas clock is the ability to scale up the atom numbers, which will lead to a huge gain in stability," Ye said. "Also, we could reach the ideal condition of running the clock with its full coherence time, which refers to how long a series of ticks can remain stable. The ability to scale up both the atom number and coherence time will make this new-generation clock qualitatively different from the previous generation."

Until now, atomic clocks have treated each atom as a separate quantum particle, and interactions among the atoms posed measurement problems. But an engineered and controlled collection, a "quantum many-body system," arranges all its atoms in a particular pattern, or correlation, to create the lowest overall energy state. The atoms then avoid each other, regardless of how many atoms are added to the clock. The gas of atoms effectively turns itself into an insulator, which blocks interactions between constituents.

The result is an atomic clock that can outperform all predecessors. For example, stability can be thought of as how precisely the duration of each tick matches every other tick, which is directly linked to the clock's measurement precision. Compared with Ye's previous 1-D clocks, the new 3-D quantum gas clock can reach the same level of precision more than 20 times faster due to the large number of atoms and longer coherence times.

JILA's 3-D quantum gas atomic clock offers new dimensions in measurement

The experimental data show the 3-D quantum gas clock achieved a precision of just 3.5 parts error in 10 quintillion (1 followed by 19 zeros) in about 2 hours, making it the first atomic clock to ever reach that threshold (19 zeros). "This represents a significant improvement over any previous demonstrations," Ye said.

The older, 1-D version of the JILA clock was, until now, the world's most precise clock. This clock holds strontium atoms in a linear array of pancake-shaped traps formed by laser beams, called an optical lattice. The new 3-D quantum gas clock uses additional lasers to trap atoms along three axes so that the atoms are held in a cubic arrangement. This clock can maintain stable ticks for nearly 10 seconds with 10,000 strontium atoms trapped at a density above 10 trillion atoms per cubic centimeter. In the future, the clock may be able to probe millions of atoms for more than 100 seconds at a time.

Optical lattice clocks, despite their high levels of performance in 1-D, have to deal with a tradeoff. Clock stability could be improved further by increasing the number of atoms, but a higher density of atoms also encourages collisions, shifting the frequencies at which the atoms tick and reducing clock accuracy. Coherence times are also limited by collisions. This is where the benefits of the many-body correlation can help.

The 3-D lattice design—imagine a large egg carton—eliminates that tradeoff by holding the atoms in place. The atoms are fermions, a class of particles that cannot be in the same quantum state and location at once. For a Fermi quantum gas under this clock's operating conditions, quantum mechanics favors a configuration where each individual lattice site is occupied by only one atom, which prevents the frequency shifts induced by atomic interactions in the 1-D version of the clock.

JILA researchers used an ultra-stable laser to achieve a record level of synchronization between the atoms and lasers, reaching a record-high quality factor of 5.2 quadrillion (5.2 followed by 15 zeros). Quality factor refers to how long an oscillation or waveform can persist without dissipating. The researchers found that atom collisions were reduced such that their contribution to frequency shifts in the clock was much less than in previous experiments.

"This new strontium clock using a quantum gas is an early and astounding success in the practical application of the 'new quantum revolution,' sometimes called 'quantum 2.0'," said Thomas O'Brian, chief of the NIST Quantum Physics Division and Ye's supervisor. "This approach holds enormous promise for NIST and JILA to harness quantum correlations for a broad range of measurements and new technologies, far beyond timing."

Depending on measurement goals and applications, JILA researchers can optimize the clock's parameters such as operational temperature (10 to 50 nanokelvins), atom number (10,000 to 100,000), and physical size of the cube (20 to 60 micrometers, or millionths of a meter).

Atomic clocks have long been advancing the frontier of measurement science, not only in timekeeping and navigation but also in definitions of other measurement units and other areas of research such as in tabletop searches for the missing "dark matter" in the universe.

23 September 2017

There Are Biophotons in the Brain. Is Something Light-Based Going On?


Over the last 100 years, scientists have realized, first in rats, that neurons in mammalian brains were capable of producing photons, or "biophotons." The photons appear, though faintly, within the visible spectrum, running from near-infrared through violet, or between 200 and 1,300 nanometers. The question is why? 

In biology, of course, “why” is an iffy question that presupposes intent, that is, some conscious designer at work. In fact, many traits just are, due to random mutation, and have simply never been selected out. It’s unknown so far if biophotons just are. But scientists have some exciting suspicions, and a recently published paper asks a tantalizing question: Are there optical communication channels in the brain? If the answer is yes, what’s being communicated? The very notion opens the conversation to a whole other level of operation in the brain that could even be on a previously undiscovered entangled quantum level.

The team wanted to know whether or not there existed an infrastructure over which light could travel from one place to another in the brain across the distances required, focusing on myelinated axons. Axons are the fibers that carry a neuron’s electrical signal outward; myelinated axons are covered in myelin, a fatty substance that electrically insulates the axon.


They modeled such axons, doing computations on how light would behave as the fibers bent, lost or gained thickness in their biophoton-absorbing myelin coating, or how they’d behave when crossing each other. The team concluded that light conduction across myelinated axons is feasible.


The axons could pass between 46% and 96% of the light they receive over a distance of 2 millimeters, the average length of a human brain’s axons, the percentage depending on bending, sheath thickness, etc. They also worked out that, though rat brains can pass just one biophoton per neuron a minute, human brains, with many more neurons, could convey more than a billion biophotons per second. All together, the researchers conclude, “This mechanism appears to be sufficient to facilitate transmission of a large number of bits of information, or even allow the creation of a large amount of quantum entanglement.” So there's what could act as an entire network for light-based communication in place. But we don’t know what, if anything, it’s doing. The researchers proposed a set of in vitro and in vivo experiments for others to perform that could confirm their findings.

Meanwhile, did they say “entanglement?” Given the presence here of photons, the possibility has to cross one’s mind, since they go hand in hand, as it were, with entanglement. In the paper, the scientists are intrigued in particular with the interactions between photons and nuclear spins — the way nuclei turn causes different chemical effects — and how that affects things like magnetoreception in animals.


Given that there’s some distance between the biophotons and nuclear spins, the scientists wonder if there’s entanglement involved, saying, “for individual quantum communication links to form a larger quantum network with an associated entanglement process involving many distant spins, the nuclear spins interfacing with different axons must interact coherently. This, most likely, requires close enough contact between the interacting spins. The involvement of synaptic junctions between individual axons may provide such a proximity mechanism.” And since some people think entanglement could be behind whatever process it is that produces consciousness, well, where is this going to lead?

Researchers demonstrate quantum teleportation of patterns of light


The core element of our quantum repeater is a cube of glass. We put two independent photons in, and as long as we can detect two photons coming out the other sides we know that we can perform entanglement swapping. 

Nature Communications today published research by a team comprising Scottish and South African researchers, demonstrating entanglement swapping and teleportation of orbital angular momentum ‘patterns’ of light. This is a crucial step towards realizing a quantum repeater for high-dimensional entangled states.


Quantum communication over is integral to security and has been demonstrated in and fibre with two-dimensional states, recently over distances exceeding 1200 km between satellites. But using only two states reduces the information capacity of the photons, so the link is secure but slow. To make it secure and fast requires a higher-dimensional alphabet, for example, using patterns of light, of which there are an infinite number. One such pattern set is the (OAM) of light. Increased bit rates can be achieved by using OAM as the carrier of information. However, such photon states decay when transmitted over long distances, for example, due to mode coupling in fibre or turbulence in free space, thus requiring a way to amplify the signal. Unfortunately such “amplification” is not allowed in the quantum world, but it is possible to create an analogy, called a quantum repeater, akin to optical fibre repeaters in classical optical networks.

An integral part of a is the ability to entangle two photons that have never interacted – a process referred to as “entanglement swapping”. This is accomplished by interfering two photons from independent entangled pairs, resulting in the remaining two photons becoming entangled. This allows the establishment of entanglement between two distant points without requiring one photon to travel the entire distance, thus reducing the effects of decay and loss. It also means that you don’t have to have a line of sight between the two places.

Alphabet of OAM modes. OAM modes are sometimes called twisted light as the light appears as a ring with a vortex in the middle. The light can be twisted once, twice, three times and so on to create a high-dimensional alphabet. Credit: Wits University

An outcome of this is that the information of one can be transferred to the other, a process called teleportation. Like in the science fiction series, Star Trek, where people are “beamed” from one place to another, information is “teleported” from one place to another. If two photons are entangled and you change a value on one of them, then other one automatically changes too. This happens even though the two photons are never connected and, in fact, are in two completely different places.


In this latest work, the team performed the first experimental demonstration of entanglement swapping and teleportation for orbital angular momentum (OAM) states of light. They showed that quantum correlations could be established between previously independent photons, and that this could be used to send information across a virtual link. Importantly, the scheme is scalable to higher dimensions, paving the way for long-distance with high .

Schematic of the experiment. Four photons are created, one pair from each entanglement source (BBO). One from each pair (B and C) are brought together on a beam splitter. When all four photons are measured in together one finds that photons A and D, which previously where independent, are now entangled. Credit: Wits University

Background

Present communication systems are very fast, but not fundamentally secure. To make them secure researchers use the laws of Nature for the encoding by exploiting the quirky properties of the quantum world. One such property is entanglement. When two particles are entangled they are connected in a spooky sense: a measurement on one immediately changes the state of the other no matter how far apart they are. Entanglement is one of the core resources needed to realise a quantum network.

Yet a secure communication link over long distance is very challenging: Quantum links using patterns of light languish at short distances precisely because there is no way to protect the link against noise without detecting the photons, yet once they are detected their usefulness is destroyed. To overcome this one can have a repeating station at intermediate distances – this allows one to share information across a much longer without the need for the information to physically flow over that link. The core ingredient is to get independent photons to become entangled. While this has been demonstrated previously with two-dimensional states, in this work the team showed the first demonstration with OAM and in high-dimensional spaces.

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More here.

19 September 2017

Water Worlds of the Universe Revealed -- "Date Back to the Big Seed"


During almost four years of observing the cosmos, the Herschel Space Observatory traced out the presence of water. With its unprecedented sensitivity and spectral resolution at key wavelengths, Herschel revealed this crucial molecule in star-forming molecular clouds, detected it for the first time in the seeds of future stars and planets, and identified the delivery of water from interplanetary debris to planets in our solar system.

Out to much grander scales, beyond our solar system and the Galactic confines of the Milky Way, Herschel has detected water in many other galaxies. As already highlighted by some of its predecessors, the findings corroborate the crucial role of this all-important molecule in the processes that lead to the birth of stars throughout the cosmos.

Herschel’s infrared view of part of the Taurus Molecular Cloud, about 450 light-years from Earth and is the nearest large region of star formation, within which the bright, cold pre-stellar cloud L1544 can be seen at the lower left at top of the page, I surrounded by many other clouds of gas and dust of varying density.

Water is essential to life as we know it on Earth. It covers over 70 percent of our planet's surface and is present in trace amounts in the atmosphere. While it may seem abundant, especially if we're looking at the blue-hued stretch of a lake, sea or ocean, water is only a minor component of the total mass of Earth. In fact, it is not at all clear whether the water that is currently present on our blue planet was there around the time of its formation, 4.6 billion years ago, or it is was delivered by later impacts of smaller celestial objects.


According to one of the leading theories to explain how the solar system came into being, Earth and the inner planets were extremely hot and dry for the first several hundred million years after their formation. In this scenario, water was delivered to these planets only later by violent impacts of small bodies such as meteorites, asteroids, and/or comets – the remaining debris of the protoplanetary disc out of which the planets and their moons took shape.

There are various avenues to investigate the origin of this crucial molecule on our planet, either following the clues in our cosmic neighborhood – the solar system – or looking into the stellar nurseries where analogues of our sun and planets are being born.

ESA's Herschel Space Observatory, an extraordinary mission that was launched in 2009 and that observed the sky at far-infrared and sub-millimetre wavelengths for almost four years, took a comprehensive approach, tracing water from stars and planets in the forming across our Milky Way galaxy to planets and minor solar system bodies in our own neck of the woods.

Water was first detected in star-forming molecular clouds in the late 1960s. At the time, it was the sixth interstellar molecule to be identified, compared to the nearly 200 that are known to date. Ever since its discovery, astronomers suspected that water would be present in a variety of cosmic environments. After all, it is made up of the two most abundant reactive elements that exist – hydrogen, which dates back to the Big Seed, and oxygen, produced in the furnaces of stars throughout the history of the Universe.

The mosaic below combines several observations of the Taurus Molecular Cloud performed by ESA's Herschel Space Observatory. Located about 450 light-years from us, in the constellation Taurus, the Bull, this vast complex of interstellar clouds is where a myriad of stars are being born, and is the closest large region of star formation. 


In fact, water has been observed in celestial objects as diverse as planets, moons, stars, star-forming clouds, and even beyond our Milky Way, in the stellar cradles of other galaxies. However, due to the water vapour present in the Earth's atmosphere, studying this molecule with astronomical observations is anything but trivial.

Over the decades, astronomers have used a wide range of facilities to study water in the cosmos, from ground-based observatories in the dry climate of mountain-tops and airborne telescopes to experiments on stratospheric balloons and space observatories and even on the Space Shuttle. Far from the moist environment of our planet, a space telescope is of course the ideal tool to investigate cosmic water.

The first satellite dedicated to this topic, ESA's Infrared Space Observatory (ISO), was launched in 1995 and operated until 1998, shortly followed by NASA's Submillimeter Wave Astronomy Satellite (SWAS) and Spitzer Space Telescope, and by the Swedish-led, international Odin satellite.

Stepping into this long-established tradition, Herschel pushed the quest of cosmic water to new heights with a phenomenal piece of hardware, the Heterodyne Instrument for the Far Infrared (HIFI) – one of the three instruments on board.

To reveal the presence of a molecule in a cosmic source, astronomers look for a set of very distinctive fingerprints, or lines, in the source's spectrum, which are caused by rotation or vibration transitions in the structure of the molecule.

These lines are observed within a stretch of the electromagnetic spectrum, covering infrared to microwave wavelengths, depending on the type of molecule and its temperature. In the case of water, some of the most interesting lines – the ones that correspond to the lowest energetic configuration of water vapour, in other words its ground or 'cold' state – are found in the far-infrared and sub-millimetre ranges, which are inaccessible from the ground.

Specially designed for the hunt for water and other molecules, Herschel's HIFI instrument had an unprecedented spectral resolution that could target about 40 different water lines, each coming from a different transition of the water molecule and thus sensitive to a different temperature.

In particular, unlike its predecessors, Herschel was sensitive to two different transitions of the ground state of water that correspond to the two 'spin' forms of the molecule, called ortho and para, in which the spins of the hydrogen nuclei have different orientations. This key feature allowed astronomers to determine the temperatures under which the water formed by comparing the relative amounts of ortho and para water.

Two of the observatory's Key Programs– Water in Star-forming regions with Herschel and Water and Related Chemistry in the solar system – dedicated several hundred hours to the quest for cosmic water.

Exploiting the outstanding data collected by HIFI, along with observations performed with Herschel's two other instruments, the Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE), astronomers have been able to greatly expand our understanding of the role of water in the Universe.

While water vapor in star-forming regions had been known for quite a while, Herschel discovered it, for the first time, in a pre-stellar core – a cold lump of dense material that will later turn into a star. The pre-stellar core, called Lynds 1544, is located in the Taurus molecular cloud, a vast region of gas and dust that is incubating the seeds of future stars and planets.

With the Herschel data, astronomers could estimate also the amount of water vapor in Lynds 1544 – the equivalent of over 2000 times the water content of Earth's oceans. Spectrum of water vapor shown below. The water vapor derives from icy dust grains, hinting at a reservoir of over a thousand times more water in the form of ice. If any planets are to emerge around the star taking shape from this core, it is likely that some of the water detected by Herschel will find its way to the planets as well.


En route to becoming stars, pre-stellar cores keep accreting matter from their parent cloud until they separate from it, turning into a protostar, an independent object that is collapsing under its own gravity. Normally, a rotating disc of gas and dust – a protoplanetary disc – takes shape around protostars, providing the material for the formation of future planets. Finally, when nuclear reactions ignite in the core of the protostar, counteracting the collapse, a fully-fledged star is born.

Herschel has spotted water in objects spanning all stages of star formation, including in a large number of low-mass protostars found in many nearby star-forming regions.

For the first time, astronomers using Herschel have detected cold water vapour in a protoplanetary disc. While previous studies had revealed either hot water vapour in the inner part of similar discs, or water ice in their outskirts, Herschel's observations targeting the disc around the nearby young star TW Hydrae were the first to identify cold water vapour, with temperatures lower than 100 K, in such an object.

The cold vapour appears to be located in a thin layer at intermediate depths in the disc, where the evaporation of gas and the freeze-out of ice find a balance. The data indicate a small amount of cold vapour, equivalent to about 0.5 per cent of the water in Earth's oceans, but point to a much larger reservoir of water ice – several thousand Earth oceans – in the disc.

This was the first evidence that large amounts of water ice can be stored in the precursor of a planetary system like our own, thus contributing more evidence to tackling the puzzle of the origin of water on Earth and other planets.

Besides proving that water is an important constituent of stars and planets since their early formation, Herschel also followed its trail all the way to our local neighbourhood, the solar system.

To compare water found in different celestial bodies, astronomers analyse the relative abundance of molecules with a slightly different composition. Most notably, they look at the D/H ratio, comparing 'ordinary' water, composed of two hydrogen (H) and one oxygen (O) atoms, and semi-heavy water, where one of the hydrogen atoms appears as deuterium (D), an isotopical form with an extra neutron.


Before Herschel, this measurement had been performed on a handful of comets, all of them thought to originate in the Oort cloud at the outskirts of our solar system, and all of them revealing higher proportions of deuterium to 'normal' hydrogen than that found in Earth's oceans. These results seemed to suggest that comets – icy leftovers of our ancient protoplanetary disc – could not have been the source of our planet's water, while a specific class of meteorites, called Cl carbonaceous chondrites, possessed the 'right' D/H ratio and thus seemed to be the main culprit.

In 2011, Herschel's observations of water in Comet 103P/Hartley 2 reopened this fascinating debate. This measurement was the first of its kind performed for a Jupiter-Family comet – a class of comets with orbits governed by Jupiter's gravity and with much shorter period with respect to their Oort-cloud counterparts – and revealed, for the first time, water with a deuterium to hydrogen proportion similar to that found on our planet.

Herschel contributed two more observations to the debate, finding a Jupiter-Family comet (45P/Honda-Mrkos- Pajdušáková) with Earth-like water, and an Oort-cloud comet (2009P1) with a different blend from that of our planet's water.

The plot thickened when ESA's Rosetta mission reached Comet 67P/Churyumov–Gerasimenko in 2014 and sampled the water content in its atmosphere. Rosetta's comet is also a Jupiter-Family one but, unlike the two observed by Herschel, it does not contain Earth-like water; on the contrary, it turned out to have the highest D/H ratio ever measured for a comet.

While Rosetta revealed that not all Jupiter-Family comets contain water that is similar to that of our planet's oceans, Herschel's earlier detections had importantly pointed out that comets with the right composition do exist and some might indeed have contributed to Earth's water budget.

In fact, current models indicate that a broad and diverse range of minor bodies contributed to the critical role of bringing water to our planet.

Elsewhere in the solar system, Herschel has gone as far as confirming that at least one comet has contributed to enriching a different planet – Jupiter – with water. By investigating the distribution of water vapour in the stratosphere of the giant planet, astronomers found evidence that almost all of it was delivered by the famous impact of Comet Shoemaker-Levy 9 in 1994.

Following water throughout the solar system, Herschel has found this molecule in many more places, from the dwarf planet Ceres, the largest body in the asteroid belt, to a giant torus of water vapour surrounding Saturn, which appears to be supplied by the planet's small moon Enceladus.

As revealed by the NASA/ESA/ASI Cassini mission, Enceladus exhibits plumes of water drawing from the underground ocean lurking under its icy crust.

Farther away from the sun, Herschel revealed highly reflecting surfaces on several Trans-Neptunian Objects (TNOs), indicating that water ice might be present even on these ancient, remote objects. While TNOs date back to the early formation of our solar system, astronomers suspect that their bright icy coating may be more recent – a speculative but not unfeasible hypothesis given the availability of water on outer planets like Uranus and Neptune, and on their major moons. Such a recent coating might also suggest that the surface of these long-thought 'dead' objects can in fact be alive, as highlighted also by the in-situ observations performed in 2015 by NASA's New Horizon probe of another TNO, the dwarf planet Pluto.

Given its chemical composition, water unsurprisingly is ubiquitous in the Universe, and, after Herschel, there is no longer any doubt that cosmic water trails go a long way, from planets to stars, and even to the vastness of interstellar space.

However, Herschel has only begun scratching the surface of the proverbial iceberg, having spotted water in individual cosmic sources that are, in many cases, one of a kind. These exciting discoveries call for future surveys to follow up on Herschel's observations, collecting larger samples of each type of sources to scrutinise water and other molecules and delve into the physical mechanisms underlying their formation and delivery across the cosmos.

31 August 2017

Big Seed – The Movie


If you have ever had to wait those agonizing minutes in front of a computer for a movie or large file to load, you’ll likely sympathize with the plight of cosmologists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory. But instead of watching TV dramas, they are trying to transfer, as fast and as accurately as possible, the huge amounts of data that make up movies of the universe – computationally demanding and highly intricate simulations of how our cosmos evolved after the Big Seed.

In a new approach to enable scientific breakthroughs, researchers linked together supercomputers at the Argonne Leadership Computing Facility (ALCF) and at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign (UI). This link enabled scientists to transfer massive amounts of data and to run two different types of demanding computations in a coordinated fashion – referred to technically as a workflow.

30 August 2017

Researchers propose how the universe became filled with light


Soon after the Big Seed, the universe went completely dark. The intense, seminal event that created the cosmos churned up so much hot, thick gas that light was completely trapped. Much later—perhaps as many as one billion years after the Big Seed—the universe expanded, became more transparent, and eventually filled up with galaxies, planets, stars, and other objects that give off visible light. That’s the universe we know today.

How it emerged from the cosmic dark ages to a clearer, light-filled state remains a mystery.

In a new study, researchers at the University of Iowa offer a theory of how that happened. They think black holes that dwell in the center of galaxies fling out matter so violently that the ejected material pierces its cloudy surroundings, allowing light to escape. The researchers arrived at their theory after observing a nearby galaxy from which ultraviolet light is escaping.

“The observations show the presence of very bright X-ray sources that are likely accreting black holes,” says Philip Kaaret, professor in the UI Department of Physics and Astronomy and corresponding author on the study. “It’s possible the black hole is creating winds that help the ionizing radiation from the stars escape. Thus, black holes may have helped make the universe transparent.”


Kaaret and his team focused on a galaxy called Tol 1247-232, located some 600 million light years from Earth, one of only three nearby galaxies from which ultraviolet light has been found to escape. In May 2016, using an Earth-orbiting telescope called Chandra, the researchers saw a single X-ray source whose brightness waxed and waned and was located within a vigorous star-forming region of Tol 1247-232.

The team determined it was something other than a star.

“Stars don’t have changes in brightness,” Kaaret says. "Our sun is a good example of that.

“To change in brightness, you have to be a small object, and that really narrows it down to a black hole,” he says.

But how would a black hole, whose intense gravitational pull sucks in everything around it, also eject matter?


The quick answer is no one knows for sure. Black holes, after all, are hard to study, in part because their immense gravitational pull allows no light to escape and because they’re embedded deep within galaxies. Recently, however, astronomers have offered an explanation: The jets of escaping matter are tapping into the accelerated rotational energy of the black hole itself.

Imagine a figure skater twirling with outstretched arms. As the skater folds her arms closer to her body, she spins faster. Black holes operate much the same way: As gravity pulls matter inward toward a black hole, the black hole likewise spins faster. As the black hole’s gravitational pull increases, the speed also creates energy.

“As matter falls into a black hole, it starts to spin and the rapid rotation pushes some fraction of the matter out,” Kaaret says. “They’re producing these strong winds that could be opening an escape route for ultraviolet light. That could be what happened with the early galaxies.”

Kaaret plans to study Tol 1247-232 more closely and find other nearby galaxies that are leaking ultraviolet light, which would help corroborate his theory.

20 August 2017

Poll: Plurality Believes Pro-White Groups Were *Not* Mostly To Blame For Violence In Charlottesville



Since our national future of Antifa reds slugging it out with alt-right brownshirts in running street battles looks increasingly assured, we might as well start tracking reaction polls like this:
Watching media coverage, you’d think Trump is nearly alone in believing “both sides” share fault for the Charlottesville violence. Turns out, most Republicans have his back…
Far more blame “the far right groups” for Charlottesville (46%) than “the counter-protesters” (9%), but a remarkable 40% concur with Trump’s assertion that both were equally responsible. 
“Beneath the surface, we see the same partisan division: Two-thirds of Democrats (66%) blame the far-right groups rather than the counter-protesters (6%), while Republicans overwhelmingly blame both sides equally (64%). About the same proportion of Republicans blame the far-right groups (18%) as the counter-protestors (17%).
As Sean Trende put it, “So basically, a plurality agree with Trump’s characterization of the Charlottesville events, or are to his right.” Indeed. Given a binary choice of whether the alt-right or counter-protesters bears most of the blame for the violence, people are far more likely to blame the alt-right. It was their rally, Nazis are known for violence, one of them actually killed someone on the other side. That’s why, I assume, even Republicans are (slightly) more likely to blame the alt-right than the left-wing protesters. Under the circumstances it’s hard to see the white nationalists as relatively blameless for what happened.

Once you include the option of blaming both groups equally, though, you end up with a plurality (49 percent) who say either that blame should be shared or that the counter-protesters were mainly at fault. If you’re wondering why Trump’s job approval has ticked up a point and a half since Sunday despite the brutal media coverage, that may explain some of it. Although more likely it’s the politics of the debate over Confederate monuments that’s helping him, as Democrats have stupidly zeroed in on that despite the fact that most of the public shares Trump’s view that they should be left in place.

As much as partisan interests are driving reaction here, don’t overlook the fact that nearly a quarter of Democrats — 24 percent — agree with Trump that both sides bear equal responsibility for what happened. (It’s even higher among indies at 38 percent, although a majority of 51 percent blames the “far-right groups.”) That’s an impressively large and resilient minority given the torrents of condemnation in stark moral terms that Trump has endured this week. It’s one thing for Republicans to stick with him, as their agenda depends on Trump’s political credibility. Democrats, though, have every partisan reason to hammer him over this, yet a quarter are holding firm on apportioning blame for the violence equally. I wonder if there’s a segment of the left that’s already aware of, and uncomfortable with, Antifa’s tactics and unwilling to absolve them of responsibility for throwing down with neo-Nazis. Probably too much to hope for.

09 August 2017

Two habitable planets hailed as 'optimal targets for interstellar colonisation' detected just 12 light years away


Two potentially habitable "super-Earths" orbit a star just 12 light years away that is our nearest sun-like neighbour, scientists have discovered.

The worlds at the edges of Tau Ceti's "habitable zone" belong to a solar system of four rocky planets similar in size to Earth.


British-led astronomers speculate that the system might be a potential candidate for future interstellar colonisation.

But life on the new outposts may be far from peaceful. There is evidence of a massive debris disc circling the star, increasing the chances of the planets being pounded by asteroids and comets.

A key aspect of the discovery was the detection of exoplanets with masses as low as 1.7 times the Earth's, making them the smallest worlds ever spotted around a sun-like star.

The scientists used the "wobble" method of planet finding that measures the influence of gravitational interaction on a star.

As a planet orbits, it causes its parent star to wobble by a tiny degree. Astronomers can see the signature of this effect in the star's light.

Lead researcher Dr Fabo Feng, from the University of Hertfordshire, said: "We're getting tantalisingly close to observing the correct limits required for detecting Earth-like planets.

"Our detection of such weak wobbles is a milestone in the search for Earth analogues and the understanding of the Earth's habitability through comparison with these."

Sun-like stars hold out the best hope of finding planets beyond the solar system that host life. Tau Ceti, a favourite destination of science fiction writers, is very similar to the sun both in size and brightness.


Like the sun, it has a "habitable zone", a narrow region around it where conditions are favourable for Earth-like life.

Within the habitable, or "Goldilocks" zone, temperatures are not too hot or too cold but just right for surface water to exist as a liquid. A habitable zone planet could have oceans, lakes and rivers.

Neither of Tau Ceti's "super-Earths" lie in the centre of its habitable zone. One orbits on the inner border and the other on the outer. The Earth is situated halfway between the middle of the sun's habitable zone and its inner boundary.

The astronomers analysed starlight wavelength data obtained from the European Southern Observatory in Chile and the Keck observatory on Mauna Kea, Hawaii. Their findings are to be published in the Astronomical Journal.

Co-author Dr Mikko Tuomi, also from the University of Hertfordshire, said improved techniques were making it easier to distinguish between light signals caused by the presence of planets and stellar activity.


Two Tau Ceti signals previously identified in 2013 were now known not to have a planetary origin.

"But no matter how we look at the star, there seems to be at least four rocky planets orbiting it," Dr Tuomi said.

"We're slowly learning to tell the difference between wobbles caused by planets and those caused by stellar active surface.

"This enabled us to verify the existence of the two outer, potentially habitable, planets in the system."

Immortality & Mind: Dalai Lama Brainstorms the Universe With Russian Scientists





Leading neuroscientists and philosophers from Russia took part in the first-ever joint conference with the Dalai Lama and Buddhist scholars that was held in New Delhi to discuss matters such as and the nature of consciousness.


The scientists realized that they needed a new theory about the nature of consciousness and its relation to brain activity, and so decided to turn to the Buddhist scholars for assistance.

Konstantin Anokhin, prominent Russian neurobiologist and member of both Russian Academy of Sciences and Russian Academy of Medical Sciences, told RIA Novosti that Russian scientists have been studying consciousness for over 150 years, and their materialistic conception of consciousness differs from the classic materialism of Western science.
"I believe that what we need now is a new, bold fundamental theory instead of experiments… This is our message to Buddhist science: we need a theory that isn’t based on subjective experience alone. This new theory may influence our methods and techniques, and draw the attention to meditation," Anokhin said.
Notable Russian neurolinguistics researcher Tatyana Chernigovskaya who acted as moderator during the conference concurred with Anokhin.
"The amount of empirical data that we have grows by the minute. We’ve even reached an impasse of sorts because we don’t know what to do with this data. We could sort it, of course, and there are processing methods available, but we are not advancing further. If I study each and every cell in your body, I won’t learn anything about your personality. And delving into brains and pulling out each and every neuron out won’t help me understand how it works. Okay, so we’ve studied 30 billion more neurons, now what? What question have we answered? None. We need a genius who can tell us ‘you need to ask a different question.’ It’s clear that at this point that a new theory is badly needed," Chernigovskaya said, adding that philosophy plays a key role in this matter.
For the Good of Mankind

The goal of the conference was to facilitate dialogue between Russian scientists and Buddhist scholars related to a variety of scientific disciplines such as physics, cosmology, biology and axiology.

"I’ve had useful discussions with scientists for more than 30 years with two purposes in mind. The first is to extend our knowledge. Until the late 20th century scientists mostly investigated external phenomena, including the brain. These were things they could measure and which a third person could agree about. However, in the late 20th century and early 21st century more and more scientists have begun to find evidence that experiences such as meditation and mind training affect our brains in previously unforeseen ways—this is called neuroplasticity," the Dalai Lama said.
The second purpose, he added, was to help raise awareness and foster compassion among people, to help stop the endless cycle of violence and to deal with the issue of disparity between rich and poor.
"We have to learn from experience and enter into dialogue, remembering that other people are our brothers and sisters. We have to live together. The global economy and the effects of climate change are not limited by national borders. It’s the idea of ‘us’ and ‘them’ we have to restrain, because it so easily becomes the basis for violence. We have to educate people to understand that we are all part of humanity,” he added.
Dalai Lama: Consciousness Does Not Equal Brain

According to the Buddhist leader, consciousness consists of several layers and is not fully connected to the brain.

"For example, these different levels of consciousness manifest during sleep, when we do not possess our senses but remain aware, or when a person faints. Even when a man dies, we (Buddhists) know that the consciousness continues to exist," he said.


The Dalai Lama explained that, according to Buddhist teachings, consciousness is intrinsically connected to life, and the most subtle level of consciousness is “devoid of genetic basis” and transfers from one life to another as part of the rebirth cycle.

He also remarked that it is very hard to tell whether an artificial intelligence can possess a consciousness.
"Everything in the world is determined by cause-effect relationships, and a consciousness – even the most subtle level of it – can only be the continuation of consciousness. But artificial intelligence is just particles," the Dalai Lama said.
Professor David Dubrovsky from the Russian Academy of Sciences’ Institute of Philosophy also pointed out that a thought is devoid of physical dimensions such as mass or length, and that it all comes down to explaining the relation between thoughts and brain activity.

"It is called the ‘hard problem’ of consciousness. Western science has been dominated by reductionist concepts that narrowed thought processes down to physical processes or to behaviorism. The prevalent concepts in Russia, however, have retained the aspects of subjective reality and non-physical process," Dubrovsky said.

The Origins of the Big Seed

The participants of the conference also broached the Big Bang theory, as Konstantin Anokhin argued that consciousness did not exist when Earth was devoid of life, and that consciousness appeared as a result of evolution.

"The origins of consciousness lie in emotions. Even the simplest organisms have emotions; they’re capable of experiencing satisfaction or suffering depending on whether they succeed or fail to achieve something," Anokhin said.

"But the Big Bang must require a vast amount of energy, so where did it come from?" the Buddhist spiritual leader inquired.

"Not from the mind or consciousness," Anokhin replied.
"But how do you know that? Energy is immaterial. We need to explain why vast amounts of energy have material basis … There’s a contradiction here," Dalai Lama retorted.

He also remarked that on the most subtle level, consciousness and rocks were created out of the same particles.

"So why does one particle become a rock while another becomes consciousness?" Dalai Lama mused.

Schrodinger’s Cat and Language

During the conference professor Tatyana Chernigovskaya also presented her report – Cheshire Smile of Schrodinger’s Cat: Language and Consciousness.

She cited Niels Bohr, one of the pioneers of quantum mechanics, who said that the observer is a part of the scientific paradigm and that the results of an experiment are influenced by the person who conducts it, and Albert Einstein who called the intuitive mind “a sacred gift,” adding that many prominent scientists in the past claimed that the outside world is "built from the inside."
"Would music or mathematics continue to exist without those who listen and think? My answer is ‘no’: Without man, Mozart’s music would merely become vibrations of air," Chernigovskaya said.

She added that neuroscientists should focus their attention on music and music and language, especially poetry.

"Today a new science called biolinguistics seeks to discover universal traits of the evolution of biological systems and language," Chernigovskaya said.

The Dalai Lama also remarked that her findings have a lot in common with Buddhist teachings about the interdependence of all things.