Quantum Sound...

Credit: Getty Images

Topics: Modern Physics, Phonons, Quantum Mechanics, Theoretical Physics

Researchers have gained control of the elusive “particle” of sound, the phonon. Although phonons—the smallest units of the vibrational energy that makes up sound waves—are not matter, they can be considered particles the way photons are particles of light. Photons commonly store information in prototype quantum computers, which aim to harness quantum effects to achieve unprecedented processing power. Using sound instead may have advantages, although it would require manipulating phonons on very fine scales.

Until recently, scientists lacked this ability; just detecting an individual phonon destroyed it. Early methods involved converting phonons to electricity in quantum circuits called superconducting qubits. These circuits accept energy in specific amounts; if a phonon’s energy matches, the circuit can absorb it—destroying the phonon but giving an energy reading of its presence.

In a new study, scientists at JILA (a collaboration between the National Institute of Standards and Technology and the University of Colorado Boulder) tuned the energy units of their superconducting qubit so phonons would not be destroyed. Instead the phonons sped up the current in the circuit, thanks to a special material that created an electric field in response to vibrations. Experimenters could then detect how much change in current each phonon caused.

“There’s been a lot of recent and impressive successes using superconducting qubits to control the quantum states of light. And we were curious—what can you do with sound that you can’t with light?” says Lucas Sletten of U.C. Boulder, lead author of the study published in June in Physical Review X. One difference is speed: sound travels much slower than light. Sletten and his colleagues took advantage of this to coordinate circuit-phonon interactions that sped up the current. They trapped phonons of particular wavelengths (called modes) between two acoustic “mirrors,” which reflect sound, and the relatively long time sound takes to make a round trip allowed the precise coordination. The mirrors were a hair’s width apart—similar control of light would require mirrors separated by about 12 meters.

Trapping the Tiniest Sound, Leila Sloman, Scientific American

Weird...

Credit: Shutterstock

Topics: God Particle, Higgs Boson, Large Hadron Collider, Standard Model, Theoretical Physics

c. 1400, "having power to control fate, from weird (n.), from Old English wyrd "fate, chance, fortune; destiny; the Fates," literally "that which comes," from Proto-Germanic *wurthiz (source also of Old Saxon wurd, Old High German wurt "fate," Old Norse urðr "fate, one of the three Norns"), from PIE *wert- "to turn, to wind," (source also of German werden, Old English weorðan "to become"), from root *wer- (2) "to turn, bend." For sense development from "turning" to "becoming," compare phrase turn into "become."

Etymology online: Weird

We all know and love the Higgs boson — which to physicists' chagrin has been mistakenly tagged in the media as the "God particle" — a subatomic particle first spotted in the Large Hadron Collider (LHC) back in 2012. That particle is a piece of a field that permeates all of space-time; it interacts with many particles, like electrons and quarks, providing those particles with mass, which is pretty cool.

But the Higgs that we spotted was surprisingly lightweight. According to our best estimates, it should have been a lot heavier. This opens up an interesting question: Sure, we spotted a Higgs boson, but was that the only Higgs boson? Are there more floating around out there doing their own things?

But the Higgs that we spotted was surprisingly lightweight. According to our best estimates, it should have been a lot heavier. This opens up an interesting question: Sure, we spotted a Higgs boson, but was that the only Higgs boson? Are there more floating around out there doing their own things?

Physicists Search for Monstrous Higgs Particle. It Could Seal the Fate of the Universe.
Paul Sutter, Astrophysicist, Live Science

In Finnegan's Wake...

Murray Gell-Mann won the 1969 Nobel Prize in Physics.Credit: Santa Fe Institute

Topics: Nobel Laureate, Nobel Prize, Particle Physics, Quarks, Standard Model, Theoretical Physics

The Nobel Prize in Physics 1969 was awarded to Murray Gell-Mann "for his contributions and discoveries concerning the classification of elementary particles and their interactions."

The Nobel Prize in Physics 1969. NobelPrize.org. Nobel Media AB 2019. Wed. 29 May 2019. < https://www.nobelprize.org/prizes/physics/1969/summary/ >

Murray Gell-Mann, one of the founders of modern particle physics, died on 24 May, aged 89. Gell-Mann’s most influential contribution was to propose the theory of quarks — fundamental particles that make up most ordinary matter.

To bring order to a plethora of recently discovered subatomic particles, in 1961 Gell-Mann proposed a set of rules based on symmetries in the fundamental forces of nature. The rules classified subatomic particles called hadrons into eight groups, a scheme he named the eightfold way in a reference to Buddhist philosophy.

In 1964, he realized that such rules would naturally arise if the particles were composed of two, three or more fundamental particles, held together by the strong nuclear force. (US–Russian physicist George Zweig came to the same conclusion independently in the same year.) Protons and neutrons, for example, would be made up of three of these more fundamental particles, which Gell-Man named quarks, inspired by a quote — “Three quarks for Muster Mark!” — from James Joyce’s 1939 novel Finnegan's Wake. [1]

Quarks and Leptons are the building blocks which build up matter, i.e., they are seen as the "elementary particles". In the present standard model, there are six "flavors" of quarks. They can successfully account for all known mesons and baryons (over 200). The most familiar baryons are the proton and neutron, which are each constructed from up and down quarks. Quarks are observed to occur only in combinations of two quarks (mesons), three quarks (baryons). There was a recent claim of observation of particles with five quarks (pentaquark), but further experimentation has not borne it out. [2]

1. Murray Gell-Mann, father of quarks, dies - US physicist was one of the chief architects of the standard model of particle physics. Davide Castelvecchi, Nature
2. Hyperphysics: Quarks

Doppelgänger...

(Courtesy: shutterstock/tomertu)

Topics: Antimatter, Astrophysics, Cosmology, Dark Matter, Star Trek, Theoretical Physics

Our universe could be the mirror image of an antimatter universe extending backwards in time before the Big Bang. So claim physicists in Canada, who have devised a new cosmological model positing the existence of an “antiuniverse” which, paired to our own, preserves a fundamental rule of physics called CPT symmetry. The researchers still need to work out many details of their theory, but they say it naturally explains the existence of dark matter.

Standard cosmological models tell us that the universe – space, time and mass/energy – exploded into existence some 14 billion years ago and has since expanded and cooled, leading to the progressive formation of subatomic particles, atoms, stars and planets.

However, Neil Turok of the Perimeter Institute for Theoretical Physics in Ontario reckons that these models’ reliance on ad-hoc parameters means they increasingly resemble Ptolemy’s description of the solar system. One such parameter, he says, is the brief period of rapid expansion known as inflation that can account for the universe’s large-scale uniformity. “There is this frame of mind that you explain a new phenomenon by inventing a new particle or field,” he says. “I think that may turn out to be misguided.”

Instead, Turok and his Perimeter Institute colleague Latham Boyle set out to develop a model of the universe that can explain all observable phenomena based only on the known particles and fields. They asked themselves whether there is a natural way to extend the universe beyond the Big Bang – a singularity where general relativity breaks down – and then out the other side. “We found that there was,” he says.

The answer was to assume that the universe as a whole obeys CPT symmetry. This fundamental principle requires that any physical process remains the same if time is reversed, space inverted and particles replaced by antiparticles. Turok says that this is not the case for the universe that we see around us, where time runs forward as space expands, and there’s more matter than antimatter.

Our universe has antimatter partner on the other side of the Big Bang, say physicists
Cosmology, Physics World

Ultra-bright X-rays...

Overview: Advanced Photon Source, Argonne National Laboratory

Topics: High Energy Physics, Particle Physics, Theoretical Physics, X-rays

The upgrade of the U.S. Department of Energy’s Advanced Photon Source at Argonne National Laboratory will make it between 100 and 1,000 times brighter than it is today.

“That factor is such a big change, it’s going to revolutionize the types of science that we can do,” said Stephen Streiffer, Argonne Associate Laboratory Director for Photon Sciences and Director of the APS.

“We’ll be able to look at the structure of materials and chemical systems in the interior of things — inside a turbine blade or a catalytic reactor — almost down to the atomic scale. We haven’t been able to do that before. Given that vast change, we can only dream about the science we’re going to do.”

In December, DOE approved the technical scope, cost estimate and plan of work for an upgrade of APS.

The APS upgrade has been in the works since 2010. The upgrade will reveal a new machine that will allow its 5,500 annual users from university, industrial, and government laboratories to work at a higher spatial resolution, or to work faster with a brighter beam (a beam with more X-rays focused on a smaller spot) than they can now.

Beam Us Up: Ultra-bright X-ray beams expanding the boundaries of research
Steve Koppes, Argonne National Laboratory

The Perfect Fluid...

If collisions between small projectiles -- protons (p), deuterons (d), and helium-3 nuclei (3He) -- and gold nuclei (Au) create tiny hot spots of quark-gluon plasma, the pattern of particles picked up by the detector should retain some 'memory' of each projectile's initial shape. Measurements from the PHENIX experiment match these predictions with very strong correlations between the initial geometry and the final flow patterns. Credit: Javier Orjuela Koop, University of Colorado, Boulder

Topics: Astrophysics, Fluid Mechanics, Nuclear Physics, Relativity, Theoretical Physics

Nuclear physicists analyzing data from the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC)—a U.S. Department of Energy (DOE) Office of Science user facility for nuclear physics research at Brookhaven National Laboratory—have published in the journal Nature Physics additional evidence that collisions of miniscule projectiles with gold nuclei create tiny specks of the perfect fluid that filled the early universe.

Scientists are studying this hot soup made up of quarks and gluons—the building blocks of protons and neutrons—to learn about the fundamental force that holds these particles together in the visible matter that makes up our world today. The ability to create such tiny specks of the primordial soup (known as quark-gluon plasma) was initially unexpected and could offer insight into the essential properties of this remarkable form of matter.

"This work is the culmination of a series of experiments designed to engineer the shape of the quark-gluon plasma droplets," said PHENIX collaborator Jamie Nagle of the University of Colorado, Boulder, who helped devise the experimental plan as well as the theoretical simulations the team would use to test their results.

Compelling evidence for small drops of perfect fluid, Brookhaven National Laboratory, Phys.org

BOCs @ Home...

Quantum games: Artist’s impression of the Alice Challenge experimental setup. (Courtesy: ScienceAtHome/Aarhus University)

Topics: Bose-Einstein Condensate, Electromagnetic Radiation, Quantum Mechanics, Theoretical Physics

Citizen scientists have outperformed physicists in creating Bose–Einstein condensates (BECs) of ultracold atoms. That is the finding of an international team of scientists and social scientists, which ran the first-ever optimization challenge in which the public was able to create a BEC remotely by manipulating laser beams and magnetic fields. Optimization experts using state-of-the-art algorithms took a similar challenge and both groups created BECs containing more atoms than the physicists who had built the experiment – even though the physicists had months to perfect their techniques.

By studying the behavior of the 600 citizen scientists who participated, the team has uncovered insights into what makes human problem solving unique. As well as providing hints for creating advanced algorithms based on human intuition, the study suggests how to exploit the best of human and artificial intelligence in the future.

The research was done by Jacob Sherson and colleagues at Aarhus University in Denmark, Ulm University in Germany and the University of Sussex in the UK. Sherson and some of his colleagues have been involved in the ScienceAtHome project, which develops games that use the brainpower of the general public to solve quantum science challenges. In 2016, they described how more than 10,000 players of one of these games – Quantum Moves –had efficiently optimized operations that could run a hypothetical quantum computer. “[With Quantum Moves], we documented that humans can contribute to solving complex challenges,” says Sherson. “With our current work we now take on the challenge of starting to answer how they contribute.”

Citizen scientists excel at creating Bose–Einstein condensates
Benjamin Skuse, Physics World

Nouveau Paradox...

Credit: Getty Images

Topics: Modern Physics, Quantum Mechanics, Schrödinger's Cat, Theoretical Physics

In the world’s most famous thought experiment, physicist Erwin Schrödinger described how a cat in a box could be in an uncertain predicament. The peculiar rules of quantum theory meant that it could be both dead and alive, until the box was opened and the cat’s state measured. Now, two physicists have devised a modern version of the paradox by replacing the cat with a physicist doing experiments—with shocking implications.

Quantum theory has a long history of thought experiments, and in most cases these are used to point to weaknesses in various interpretations of quantum mechanics. But the latest version, which involves multiple players, is unusual: it shows that if the standard interpretation of quantum mechanics is correct, then different experimenters can reach opposite conclusions about what the physicist in the box has measured. This means that quantum theory contradicts itself.

The conceptual experiment has been debated with gusto in physics circles for more than two years—and has left most researchers stumped, even in a field accustomed to weird concepts. “I think this is a whole new level of weirdness,” says Matthew Leifer, a theoretical physicist at Chapman University in Orange, California.

The authors, Daniela Frauchiger and Renato Renner of the Swiss Federal Institute of Technology (ETH) in Zurich, posted their first version of the argument online in April 2016. The final paper appears in Nature Communications on 18 September. (Frauchiger has now left academia.)

Reimagining of Schrödinger's Cat Breaks Quantum Mechanics—and Stumps Physicists, Davide Castelvecchi, Scientific American

Brownian Penroses...

Moving pictures: microscope image of a quasicrystal two days after release. The right half has been color coded. (Courtesy: Po-Yuan Wang and Thomas Mason/Nature)

Topics: Brownian Motion, Einstein, Quasicrystal, Theoretical Physics

A quasicrystal made from tiny Penrose tiles that undergo Brownian motion has been created by Po-Yuan Wang and Thomas Mason at the University of California-Los Angeles. The duo was able to track changes in the 2D structure as tiles moved around, observing a range of effects including melting. As well as shedding further light on the properties of quasicrystals, the new lithographic fabrication technique could be used to study a wide range of colloidal systems.

Until relatively recently, scientists had assumed that all crystals have translational symmetry. This means they comprise a periodically-repeating unit cell of atoms that fills space without any voids. In contrast, quasicrystals do not have translational symmetry – they possess rotational symmetry – but also fill space without any voids.

The unexpected discovery of quasicrystalline materials was made in 1984 by the Israeli materials engineer Dan Shechtman, who was later awarded the 2011 Nobel Prize for Chemistry. Although the discovery was first met with skepticism, hundreds of solid-state quasicrystals have since been discovered. Furthermore, researchers are looking at potential applications of quasicrystals that range from aerospace to coatings of surgical and kitchen utensils.

Brownian motion melts a quasicrystal of tiny Penrose tiles
Soft Matter and Liquids, Physics World

MiniBooNE...

Inside the MiniBooNE tank, photodetectors capture the light created when a neutrino interacts with an atomic nucleus. Reidar Hahn / Fermilab

Topics: Neutrinos, Particle Physics, Quantum Mechanics, Theoretical Physics

Physicists are both thrilled and baffled by a new report from a neutrino experiment at Fermi National Accelerator Laboratory near Chicago. The MiniBooNE experiment has detected far more neutrinos of a particular type than expected, a finding that is most easily explained by the existence of a new elementary particle: a “sterile” neutrino that’s even stranger and more reclusive than the three known neutrino types. The result appears to confirm the anomalous results of a decades-old experiment that MiniBooNE was built specifically to double-check.

The persistence of the neutrino anomaly is extremely exciting, said the physicist Scott Dodelson of Carnegie Mellon University. It “would indicate that something is indeed going on,” added Anže Slosar of Brookhaven National Laboratory.

As for what, no one can say.

The existence of a sterile neutrino would revolutionize physics from the smallest to the largest scales. It would finally break the Standard Model of particle physics that has reigned since the 1970s. It would also demand “a new standard model of cosmology,” Dodelson said. “There are other potential cracks in the standard picture,” he added. “The neutrino paradox could point our way to a new, better model.”

Neutrinos are tiny particles that pass through our bodies by the billions each second but seldom interact. They constantly oscillate between three known types, or “flavors,” called electron, muon and tau. The MiniBooNE experiment shoots a beam of muon neutrinos toward a giant oil tank. On the way to the tank, some of these muon neutrinos should transform into electron neutrinos at a rate determined by the difference in mass between the two. MiniBooNE then monitors the arrival of electron neutrinos, which produce characteristic flashes of radiation on the rare occasions when they interact with oil molecules. In its 15-year run, MiniBooNE has registered a few hundred more electron neutrinos than expected.

The simplest explanation for the surprisingly high number is that some muon neutrinos are oscillating into a different, heavier, fourth kind of neutrino — a sterile one, meaning it never interacts with anything that isn’t a neutrino — and that some of these heavy sterile neutrinos then oscillate into electron neutrinos. The greater mass difference prescribes a higher rate of oscillations and more detections.

Evidence Found for a New Fundamental Particle, Natalie Wolchover, Quanta Magazine

A Clash of Theories...

Each universe in a multiverse contains different levels of dark energy, according to the dominant theory.
STOLK/GETTY IMAGES

Topics: Astrophysics, Cosmology, Dark Energy, Multiverses, Theoretical Physics

A hypothetical multiverse seems less likely after modelling by researchers in Australia and the UK threw one of its key assumptions into doubt.

The multiverse concept suggests that our universe is but one of many. It finds support among some of the world’s most accomplished physicists, including Brian Greene, Max Tegmark, Neil deGrasse Tyson and the late Stephen Hawking.

One of the prime attractions of the idea is that it potentially accounts for an anomaly in calculations for dark energy.

The mysterious force is thought to be responsible for the accelerating expansion of our own universe. Current theories, however, predict there should be rather more of it around than there appears to be. This throws up another set of problems: if the amount of dark energy around was as much as equations require – and that is many trillions of times the level that seems to exist – the universe would expand so rapidly that stars and planets would not form – and life, thus, would not be possible.

The multiverse idea to an extent accounts for and accommodates this oddly small – but life-permitting – dark energy quotient. Essentially it permits a curiously self-serving explanation: there are a vast number of universes all with differing amounts of dark energy. We exist in one that has an amount low enough to permit stars and so on to form, and thus life to exist. (And we find ourselves here, runs the logic, because we couldn’t find ourselves anywhere else.)

So far, so anthropic. But now a group of astronomers, including Luke Barnes from the University of Sydney in Australia and Jaime Salcido from Durham University in the UK, has published two papers in the journal Monthly Notices of the Royal Astronomical Society that show the dark energy and star formation balance isn’t quite as fine as previous estimates have suggested.

Multiverse theory cops a blow after dark energy findings
Andrew Masterson, Cosmos Magazine

ADMX...

A cutaway rendering of the ADMX detector.
Image: ADMX collaboration

Topics: Dark Matter, Particle Physics, Theoretical Physics, Quantum Mechanics

Forty years ago, scientists theorized a new kind of low-mass particle that could solve one of the enduring mysteries of nature: what dark matter is made of. Now a new chapter in the search for that particle has begun.

This week, the Axion Dark Matter Experiment (ADMX) unveiled a new result, published in Physical Review Letters, that places it in a category of one: It is the world’s first and only experiment to have achieved the necessary sensitivity to “hear” the telltale signs of dark matter axions. This technological breakthrough is the result of more than 30 years of research and development, with the latest piece of the puzzle coming in the form of a quantum-enabled device that allows ADMX to listen for axions more closely than any experiment ever built.

ADMX is managed by the U.S. Department of Energy’s Fermi National Accelerator Laboratory and located at the University of Washington. This new result, the first from the second-generation run of ADMX, sets limits on a small range of frequencies where axions may be hiding and sets the stage for a wider search in the coming years.

“This result signals the start of the true hunt for axions,” said Fermilab scientist Andrew Sonnenschein, the operations manager for ADMX. “If dark matter axions exist within the frequency band we will be probing for the next few years, then it’s only a matter of time before we find them.”

ADMX announces breakthrough in axion dark matter detection technology, Fermilab

Order in Chaos...

Cristiano Nisoli. Credit: Los Alamos National Laboratory

Topics: Applied Physics, Materials Science, Theoretical Physics, Thermodynamics

Physicists have identified a new state of matter whose structural order operates by rules more aligned with quantum mechanics than standard thermodynamic theory. In a classical material called artificial spin ice, which in certain phases appears disordered, the material is actually ordered, but in a "topological" form.

"Our research shows for the first time that classical systems such as artificial spin ice can be designed to demonstrate topological ordered phases, which previously have been found only in quantum conditions," said Los Alamos National Laboratory physicist Cristiano Nisoli, leader of the theoretical group that collaborated with an experimental group at the University of Illinois at Urbana-Champaign, led by Peter Schiffer (now at Yale University).

Physicists generally classify the phases of matter as ordered, such as crystal, and disordered, such as gases, and they do so on the basis of the symmetry of such order, Nisoli said.

"The demonstration that these topological effects can be designed into an artificial spin ice system opens the door to a wide range of possible new studies," Schiffer said.

Finding order in disorder demonstrates a new state of matter, Los Alamos National Laboratory

MOND on Maundy...

The image on the right shows the galaxy, full of "globular clusters." The image on the left shows the measurement the researchers used to track the speed of one such object.
Credit: Gemini Observatory / NSF / AURA / W.M. Keck Observatory / Jen Miller / Joy Pollard

Topics: Astronomy, Astrophysics, Cosmology, Dark Matter, Theoretical Physics

Note: I almost didn't blog about this, because the original links at Live Science and Cosmos Magazine lead to "page not found" errors. I was able to find the article on Nature's direct website and provide it here. It's strange both sites had the same bogus links.

Here's a problem: The universe acts like it's a lot more massive than it looks.

Take galaxies, those giant, spinning masses of stars. The laws of motion and gravity tell us how fast these objects should turn given their bulk. But observations through telescopes show them spinning way faster than we'd expect, as if they were actually much more massive than the stars we can see indicate.

Astrophysicists have come up with two main solutions to this problem. Either there's a lot of mass out there in the universe that we can't detect directly, mass scientists call dark matter, or there's no dark matter out there, but there is something missing from our laws of gravity and motion. Researchers call the second proposed solution modified Newtonian dynamics (MOND), which suggests that if the laws are properly tweaked, the universe would make sense without dark matter.

A new paper, published today (March 28) in the journal Nature, provides compelling evidence that there really is dark matter out there and that modifying the laws of physics wouldn't by itself solve the universe's weight problem.

In that study, the researchers found an object that could exist in a universe that has dark matter, but that would be nearly unimaginable in a MOND universe: a totally normal galaxy, one that seems to operate without any dark matter-type forces. [1]

*****

In a study published in the journal Nature, scientists have found a galaxy that appears to contain no dark matter — the unknown material thought to be common in the universe because of its gravitational effect on normal matter.

It was a startling discovery, because galaxies similar to our own Milky Way generally appear to contain 30 times more of the mysterious substance than normal matter, while smaller galaxies can contain up to 400 times as much.

The dark-matter-free galaxy, called NGC 1052-DF2, lies 65 million light years away in the constellation Cetus. It initially caught the attention of astronomers because, while it’s about the size of the Milky Way, it contains only 0.5% as many stars.

“That makes it very diffuse,” says the study’s lead author, Pieter van Dokkum of Yale University, in Connecticut, US. “You can look straight through it. You can see galaxies behind it.”

It was discovered by a special, low-tech telescope in New Mexico called the Dragonfly Telephoto Array, which consists of a bundle of 400-millimetre camera lenses of the same type used by sports photographers, and can scan the sky for large, dim objects. So far, it’s found 23 of them, but NGC 1052-DF2 (the DF is for “Dragonfly”) stood out because it wasn’t just a big, diffuse blob. [2]

1. Astrophysicists Claim They Found a 'Galaxy Without Dark Matter', Rafi Letzter, Live Science
2. Found: a galaxy devoid of dark matter, Richard A Lovett, Cosmos Magazine

To Be, or Not to Be...

Stephanie Wehner is part of the team trying to build a true quantum network across Europe. Credit: Marcel Wogram for Nature

Topics: Internet, Quantum Computer, Quantum Mechanics, Schrödinger’s cat, Theoretical Physics, Women in Science

Cultural reference: Hamlet, Act III, scene I.

The sobering part is, Europe will likely build a quantum Internet before us, China will commercialize clean energy; everywhere else will have MAGLEV (magnetic levitation) bullet trains that go 200 mph (while we're stuck with the ones that fatally crash at 80), our bridges, railroads and general infrastructure crumbling (toll road taxed to death) from a malignant narcissist, political amateur conman's claim of being "great again."

Before she became a theoretical physicist, Stephanie Wehner was a hacker. Like most people in that arena, she taught herself from an early age. At 15, she spent her savings on her first dial-up modem, to use at her parents’ home in Würzburg, Germany. And by 20, she had gained enough street cred to land a job in Amsterdam, at a Dutch Internet provider started by fellow hackers.

A few years later, while working as a network-security specialist, Wehner went to university. There, she learnt that quantum mechanics offers something that today’s networks are sorely lacking — the potential for unhackable communications. Now she is turning her old obsession towards a new aspiration. She wants to reinvent the Internet.

The ability of quantum particles to live in undefined states — like Schrödinger’s proverbial cat, both alive and dead — has been used for years to enhance data encryption. But Wehner, now at Delft University of Technology in the Netherlands, and other researchers argue that they could use quantum mechanics to do much more, by harnessing nature’s uncanny ability to link, or entangle, distant objects, and teleporting information between them. At first, it all sounded very theoretical, Wehner says. Now, “one has the hope of realizing it”.

The quantum internet has arrived (and it hasn’t), Davide Castelvecchi, Nature

Through a Glass, Darkly...

A simulation of the dark matter distribution in the universe 13.6 billion years ago.
ILLUSTRATION COURTESY VOLKER SPRINGEL, MAX PLANCK INSTITUTE FOR ASTROPHYSICS, ET AL, NatGeo

Topics: Astrophysics, Dark Matter, Neutrons, Research, Theoretical Physics

Alliteration source: "For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known." 1 Corinthians 13:12

Scientists at the University of Sussex have disproved the existence of a specific type of axion - an important candidate 'dark matter' particle - across a wide range of its possible masses.

The data were collected by an international consortium, the Neutron Electric Dipole Moment (nEDM) Collaboration, whose experiment is based at the Paul Scherrer Institut in Switzerland. Data were taken there and, earlier, at the Institut Laue-Langevin in Grenoble.

Professor Philip Harris, Head of Mathematical and Physical Sciences at the University of Sussex, and head of the nEDM group there, said:

"Experts largely agree that a major portion of the mass in the universe consists of 'dark matter'. Its nature, however, remains completely obscure. One kind of hypothetical elementary particle that might make up the dark matter is the so-called axion. If axions with the right properties exist it would be possible to detect their presence through this entirely novel analysis of our data.

"We've analyzed the measurements we took in France and Switzerland and they provide evidence that axions – at least the kind that would have been observable in the experiment – do not exist. These results are a thousand times more sensitive than previous ones and they are based on laboratory measurements rather than astronomical observations. This does not fundamentally rule out the existence of axions, but the scope of characteristics that these particles could have is now distinctly limited.

"The results essentially send physicists back to the drawing board in our hunt for dark matter."

Hunt for dark matter is narrowed by new research, Phys.org
More information: C. Abel et al. Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields, Physical Review X (2017). DOI: 10.1103/PhysRevX.7.041034

Minuscule to Immense...

Artwork by Ana Kova

Topics: Astrophysics, Big Bang, Neutrinos, Particle Physics, Theoretical Physics

In particle physics, scientists study the properties of the smallest bits of matter and how they interact. Another branch of physics—astrophysics—creates and tests theories about what’s happening across our vast universe.

While particle physics and astrophysics appear to focus on opposite ends of a spectrum, scientists in the two fields actually depend on one another. Several current lines of inquiry link the very large to the very small.

The seeds of cosmic structure

For one, particle physicists and astrophysicists both ask questions about the growth of the early universe.

In her office at Stanford University, Eva Silverstein explains her work parsing the mathematical details of the fastest period of that growth, called cosmic inflation.

“To me, the subject is particularly interesting because you can understand the origin of structure in the universe,” says Silverstein, a professor of physics at Stanford and the Kavli Institute for Particle Astrophysics and Cosmology. “This paradigm known as inflation accounts for the origin of structure in the most simple and beautiful way a physicist can imagine.”

Scientists think that after the Big Bang, the universe cooled, and particles began to combine into hydrogen atoms. This process released previously trapped photons—elementary particles of light.

The glow from that light, called the cosmic microwave background, lingers in the sky today. Scientists measure different characteristics of the cosmic microwave background to learn more about what happened in those first moments after the Big Bang.

According to scientists’ models, a pattern that first formed on the subatomic level eventually became the underpinning of the structure of the entire universe. Places that were dense with subatomic particles—or even just virtual fluctuations of subatomic particles—attracted more and more matter. As the universe grew, these areas of density became the locations where galaxies and galaxy clusters formed. The very small grew up to be the very large.

Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

What can particles tell us about the cosmos?
The minuscule and the immense can reveal quite a bit about each other.
Amanda Solliday, Symmetry Magazine

Big to Small...

The cosmos can be considered as a collider for human to access the results of particle physics experiments at ultimate high energies. Credit: Department of Physics, HKUST

Topics: Cosmology, Particle Physics, Standard Model, Theoretical Physics

Our observable universe is the largest object that physicists study: It spans a diameter of almost 100 billion light years. The density correlations in our universe, for example, correlations between numbers of galaxies at different parts of the universe, indicate that our vast universe has originated from a stage of cosmic inflation.

On the other hand, elementary particles are the smallest object that physicists study. A particle physics Standard Model (SM) was established 50 years ago, describing all known particles and their interactions.

Are density distributions of the vast universe and the nature of smallest particles related? In a recent research, scientists from HKUST and Harvard University revealed the connection between those two aspects, and argued that our universe could be used as a particle physics "collider" to study the high energy particle physics. Their findings mark the first step of cosmological collider phenomenology and pave the way for future discovery of new physics unknown yet to mankind.

The research was published in the journal Physical Review Letters on June 29, 2017 and the preprint is available online.

"Ongoing observations of cosmological microwave background and large scale structures have achieved impressive precision, from which valuable information about primordial density perturbations can be extracted, " said Yi Wang, a co-author of the paper and an assistant professor at HKUST's department of physics. "A careful study of this SM background would be the prerequisite for using the cosmological collider to explore any new physics, and any observational signal that deviates from this background would then be a sign of physics beyond the SM."

Scientist reveal new connections between small particles and the vast universe, Xingang Chen et al, Standard Model Background of the Cosmological Collider, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.118.261302 , On Arxiv: https://arxiv.org/abs/1610.06597, Phys.org

Dawn's First Light...

Image Source: Link below

Topics: Astronomy, Astrophysics, Big Bang, Black Holes, Cosmology, Theoretical Physics

Not long after the Big Bang, all went dark. The hydrogen gas that pervaded the early universe would have snuffed out the light of the universe’s first stars and galaxies. For hundreds of millions of years, even a galaxy’s worth of stars — or unthinkably bright beacons such as those created by supermassive black holes — would have been rendered all but invisible.

Eventually this fog burned off as high-energy ultraviolet light broke the atoms apart in a process called reionization. But the questions of exactly how this happened — which celestial objects powered the process and how many of them were needed — have consumed astronomers for decades.

Now, in a series of studies, researchers have looked further into the early universe than ever before. They’ve used galaxies and dark matter as a giant cosmic lens to see some of the earliest galaxies known, illuminating how these galaxies could have dissipated the cosmic fog. In addition, an international team of astronomers has found dozens of supermassive black holes — each with the mass of millions of suns — lighting up the early universe. Another team has found evidence that supermassive black holes existed hundreds of millions of years before anyone thought possible. The new discoveries should make clear just how much black holes contributed to the reionization of the universe, even as they’ve opened up questions as to how such supermassive black holes were able to form so early in the universe’s history.

In the first years after the Big Bang, the universe was too hot to allow atoms to form. Protons and electrons flew about, scattering any light. Then after about 380,000 years, these protons and electrons cooled enough to form hydrogen atoms, which coalesced into stars and galaxies over the next few hundreds of millions of years.

Starlight from these galaxies would have been bright and energetic, with lots of it falling in the ultraviolet part of the spectrum. As this light flew out into the universe, it ran into more hydrogen gas. These photons of light would break apart the hydrogen gas, contributing to reionization, but as they did so, the gas snuffed out the light.

Quanta Magazine: Discoveries Fuel Fight Over Universe’s First Light
Ashley Yeager

Genius...

Screen shot from the Genius series on Nat Geo: Einstein on Ars Technica

Topics: Einstein, History, Politics, Relativity, Theoretical Physics

I'm obviously a fan of Einstein for his stance on Civil Rights for African Americans, his views on women's rights, his friendship with Paul Robeson and his views that were decades ahead of his time on social issues that were just percolating in the political cauldron of the day. Above all, he shows the positive impact of an immigrant in our American "melting pot."

I often read biographies of the people we consider giants in science and engineering. What I find disarming and charming is the discovery they, like us, were quite flawed and human with their own eccentricities and foibles. It's easy to deify heroes with the distance of time.

Like most young people, the young Einstein was amorous and prolific in his couplings. He was also indifferent to the emotional impact many of his romantic betrayals had on his many partners, Elsa Einstein acknowledging as much in the first chapter of the Nat Geo series: Genius (ahem: he's sober shtoofing his secretary in one of the first scenes, right before a class. I don't know if that's actual history or hyperbole, but I've read he took off for weeks at a time in full knowledge - and disrespect - of his second spouse).

Excerpt of an interview with Ron Howard at SXSW (South by Southwest) by Ars Technica:

AUSTIN, Texas—Writer, director, and actor Ron Howard is very careful when considering his place in the geek-media universe. Over 20 years ago, his film Apollo 13 kicked off a trajectory of major science-and-heart storytelling, which recently crystallized as an ongoing series-development deal with National Geographic's TV channel.

Apollo 13 convinced Howard that audiences had more hunger for science stories than he'd assumed. "It surprised me pleasantly how interested people were in the science of it. The irony that there were virtually no computers then, and they had to use slide rules... I realized that none of these things were lost on the audience. In fact, it was very engaging. I learned that it wasn't just the adventure or the emotion. There was an intellectual component to what was entertaining and engaging the audiences." He then quoted Neil Degrasse Tyson to remind me that TV's CSI broke the dam open for an even wider audience given the series had major characters applying scientific thought, as opposed to "odd characters hidden away in a room somewhere with a lab coat on."

The pilot episode sees these distinct Einstein eras explored chronologically, and for older Einstein, that means facing the changing political climate in Germany and taking steps toward immigrating to the United States. (Rush, I should add, is absolutely masterful in his performance as the older Einstein, with snark, wit, and charm rolled together in a delightfully light German accent.) Howard insists that the entire sequence, which includes a rise of German nationalism and public hatred for immigrants and scientific thought, had already been locked down before the last American Presidential election concluded.

"It's suddenly politically prescient, which we were... aware of this as we were shooting," Howard says. "Of course, it's not just the United States. There's a call to conservative nationalism [worldwide]. Closing borders, blocking immigrants, imposing controls. That's been going on around the world for some years now—but one of the pressures, the surprises for me, in reading Walter's book, that we really depict episode after episode, are the times when institutional thinkers would impose a barrier to Einstein. And sometimes a threat. Imagine how close we came to not benefiting from his genius! That's shocking. If there's a cautionary element to this story, I hope it's that."

It's also a reminder of the maxim: “History doesn’t repeat itself but it often rhymes,” as Mark Twain is often reputed to have said. Quote investigator sites several possible sources other than the witty writer.

National Geographic: Genius