On relativistic quantum mechanics of the Majorana particle: quaternions, paired plane waves, and orthogonal representations of the Poincaré group

On relativistic quantum mechanics of the Majorana particle: quaternions, paired plane waves, and orthogonal representations of the Poincaré group 

ΓΙΑ ΝΑ ΚΑΤΕΒΑΣΕΤΕ Η ΝΑ ΔΙΑΒΑΣΕΤΕ ΤΟ ΑΡΘΡΟ ΓΙΑ ΤΑ MAJORANA ΣΩΜΑΤΙΔΙΑ ΤΗΣ ΣΧΕΤΙΚΙΣΤΙΚΗΣ ΚΒΑΝΤΙΚΗΣ ΜΗΧΑΝΙΚΗΣ ΠΑΤΗΣΤΕ ΣΤΟΝ ΕΠΟΜΕΝΟ ΣΥΝΔΕΣΜΟ ΕΔΩ

 

Solid-state amplifiers power up rare-isotope facility

26 Aug 2022 Sponsored by TRUMPF Hüttinger

The world’s most powerful heavy-ion accelerator, the Facility of Rare Isotope Beams at Michigan State University, exploits transistor-based power amplifiers to generate beam intensities of up to 400 KeV

Going straight: at the heart of the Facility of Rare Isotope Beams is a 500 m linear accelerator that can generate beams of heavy atomic nuclei travelling at half the speed of light (Courtesy: FRIB)

In May 2022 the long-awaited Facility for Rare Isotope Beams (FRIB) opened its doors to scientists who are eager to experiment with exotic atomic nuclei that in many cases have never before existed on Earth. The FRIB, built over the last eight years at Michigan State University in the US, is expected to shed new light on fundamental questions in nuclear physics, including how most of the elements in the universe are created in stars and supernova explosions, while also enabling important innovations in fields as diverse as medicine, materials discovery, and environmental science.

 

Protons contain intrinsic charm quarks, machine-learning analysis suggests

23 Aug 2022

The Large Hadron Collider: evidence for intrinsic charm quarks in protons has been found in LHC data. (Courtesy: Maximilien Brice/CERN)

A 40-year-old debate about charm quarks in protons may have been settled by a new machine-learning analysis of data from the Large Hadron Collider (LHC) at CERN and other facilities. However, not all particle physicists agree with this assessment.

 

Bitcoin encryption is safe from quantum computers – for now

01 Feb 2022

A blueprint for a quantum computer that uses trapped ions as qubits. (Courtesy: Ion Quantum Technology Group, University of Sussex)

How big does a quantum computer need to be to accomplish something useful? Physicists from the University of Sussex, UK recently set out to answer this question for two pragmatic computational tasks: breaking the encryption used in Bitcoin transactions and simulating the behaviour of an agriculturally important nitrogen-fixing molecule. By estimating the number of quantum bits, or qubits, that different types of quantum computers would need for each task, members of the team say their theoretical study should help other researchers decide which designs to pursue.

 

Glinting sunlight reveals methane emissions from offshore platforms

18 Aug 2022

Offshore emissions: the locations of targeted platforms are shown as diamonds. The average persistence adjusted emission rate for each source is shown in terms of both the circle radii and infill colours (yellow and the smallest circles correspond to a 500 kg/h emission rate, while cerise and the largest circles correspond to 2000 kg/h and higher). (Courtesy: AK Ayasse et al 2022 Environ. Res. Lett. 17 084039).

Methane emissions from offshore oil and gas platforms can be systematically mapped using a sun-glint-based remote sensing method, researchers from the US have shown. Their new approach could help inform efforts to reduce methane release and improve national emissions inventories.

 

Laser manipulation turns white blood cells into medicinal microrobots

25 Aug 2022

Creating microrobots: Neutrophils, white blood cells that play a key role in the body’s immune system, can be remotely activated and navigated by light for targeted delivery of nanomedicine. (Courtesy: iStock/Dr_Microbe)

White blood cells can be harnessed as natural, biocompatible microrobots through the use of lasers, researchers from China have reported. The finding, which the team demonstrated in living zebrafish, could pave the way towards a new method of targeted drug delivery for precision treatment of diseases.

 

Ultrathin photoacoustic imaging probe fits inside a needle

26 Aug 2022

Tiny imaging device: First author Tianrui Zhao holding the photoacoustic endoscope probe, which can fit inside a medical needle with an inner diameter of just 0.6 mm. (Courtesy: Tianrui Zhao from King’s College London)

A team of UK researchers has designed a novel endoscope that uses sound and light to image tissue samples on molecular scales, based around a detector that’s small enough to fit inside a medical needle. In their study, Wenfeng Xia and colleagues at King’s College London and University College London improved several key aspects of the photoacoustic imaging technique – ensuring fast imaging times without sacrificing the size of the equipment required.

 

Quantum physics sets a speed limit for fastest possible optoelectronic switch

26 Apr 2022 Isabelle Dumé

An international research group has found a maximum value for how fast a computer can become. (Courtesy: © Oliver Wolf – TU Graz)

Optoelectronic switches can operate up to 1000 trillion times a second – a rate of 1 petahertz – before quantum processes wreck their effectiveness, say researchers in Germany and Austria. The result places a fundamental speed limit on classical information processing, while the experimental techniques used to achieve it could help physicists obtain a better understanding of a wide range of phenomena with applications in coherent electronics.

 

Logic gate breaks speed record

28 Jun 2022 Isabelle Dumé

Towards ultrafast logic gates (Courtesy: University of Rochester illustration / Michael Osadciw)

The first logic gate to operate at femtosecond timescales could help usher in an era of information processing at petahertz frequencies – a million times faster than today’s gigahertz-scale computers. The new gate, developed by researchers at the University of Rochester in the US and the Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) in Germany, is an application of lightwave electronics – essentially, shuffling electrons around with light fields – and harnesses both real and virtual charge carriers.

 

Detonation nanodiamonds could deliver nanoscale thermometry inside cells

23 Aug 2022

Temperature sensor: Detonated nanodiamonds with silicon-vacancy centres exhibit a linear red shift with increasing temperature. (Courtesy: KyotoU/Norikazu Mizuochi)

Through an explosive technique, researchers in Japan have produced the smallest nanodiamonds to date, capable of probing microscopic temperature differences in their surrounding environments. With a carefully controlled explosion, followed by a multi-step purification process, Norikazu Mizuochi and a team at Kyoto University fabricated photoluminescent nanodiamonds some 10 times smaller than those produced with existing techniques.

 

Anti-reflection coating allows perfect light transmission

28 Aug 2022 Isabelle Dumé

Sketch of the concept: a disordered medium (top) is made perfectly transmitting by placing a custom-made anti-reflection coating in front of it (bottom). (Courtesy: TU Wien)

A new technique that completely prevents waves from being reflected off surfaces could improve wireless signal reception and biomedical imaging techniques. Developed by researchers in Austria and France, the technique involves first sending the waves through a special anti-reflective structure tailored to match the way waves would normally reflect from the front surface of an object. Notably, it does not require any knowledge of the object’s internal structure, broadening its potential applications.

 

Peter Higgs: the man behind the machine

05 Jul 2022

Taken from the July 2022 issue of Physics World. Members of the Institute of Physics can enjoy the full issue via the Physics World app.

Achintya Rao reviews Elusive: How Peter Higgs Solved the Mystery of Mass by Frank Close

Particle man Peter Higgs visits the CMS experiment at CERN in 2008. (Courtesy: CERN)

As someone who was working at CERN at the time, the 2012 discovery of the Higgs boson is close to my heart. So when reading Elusive: How Peter Higgs Solved the Mystery of Mass I was keen to learn the life story of the scientist after whom the particle is named. Written by particle physicist Frank Close and released to coincide with the 10th anniversary of the discovery, Elusive is an anecdote-filled, meandering – and sometimes confusing – glimpse into the life and work of the theorist Peter Higgs, whose name is one of three associated with the Brout–Englert–Higgs (BEH) mechanism that gives elementary particles their mass.

 

Colourful solar panels could brighten your roof, global warming accelerates snapping shrimp

19 Aug 2022 Hamish Johnston

Rainbow panels: photonic glasses give solar panels colours while maintaining their ability to produce energy. (Courtesy: ACS Nano 2022, DOI: 10.1021/acsnano.2c05840)

Worldwide, solar panels are being installed on rooftops at an astonishing rate. But so far, high-efficiency panels only come in one colour, black, which might put off people who would like a more colourful roof.

 

Gummy bears made from old wind turbines, puffed-up coating makes wood fire resistant

26 Aug 2022 Hamish Johnston

Yummy: a composite resin suitable for making wind turbine blades could be recycled into a variety of products, including these gummy bears. (Courtesy: John Dorgan)

Wind power is great success story, particularly in breezy countries like the UK. However, turbine blades do not last forever and disposing of them has become an environmental concern. Last year I reported how researchers in Germany have come up with a way of separating the balsa wood and fibreglass that makes up the blades. The team then used the wood to create a lightweight yet strong foam that they then used to make a paddle board.

 

The unsung theory: why thermodynamics is as important as quantum mechanics and general relativity

06 Aug 2021

Taken from the August 2021 issue of Physics World where it first appeared under the headline "Hot topic". Members of the Institute of Physics can enjoy the full issue via the Physics World app.

Philip Ball reviews Einstein’s Fridge: the Science of Fire, Ice and the Universe by Paul Sen

Energetic ideas Thermodynamics can explain wide-ranging physical phenomena, from melting ice cream to evaporating black holes. (Courtesy: iStock/john shepherd)

Like many science writers, I have often adopted the conceit that quantum mechanics and general relativity are our two principal (if incompatible) theories of the physical world. With his superb new book Einstein’s Fridge: the Science of Fire, Ice and the Universe, documentary filmmaker Paul Sen has made me doubt that this is the right way to express it.

 

Compact source produces 10 million single photons per second

23 Aug 2022 Ruaridh Smith

Photons on demand: Helen Zeng performing optical measurements to characterize the hBN-solid immersion lens integrated single-photon source. (Courtesy: Helen Zeng)

Single photons are a key foundation for many emerging quantum technologies, but creating the perfect single-photon source is challenging. This is particularly true when trying to develop compact systems that can operate outside the carefully controlled lab environment without bulky sub-zero cooling infrastructure.

 

Quantum computing gets down to business

20 Aug 2022

Martijn Boerkamp reports how investments into quantum computing have ballooned in the past year, bringing huge expectations for the sector

Money spinner Companies and governments are investing billions in the race to commercialize quantum technologies. (Courtesy: Shutterstock/Bartlomiej K Wroblewski)

Quantum research today means big business. What was once seen as a scientific curiosity, quantum computing now promises to transform many aspects of everyday life from cybersecurity to drug development and weather forecasting.

 

When physicists and philosophers realize they share a noble truth

24 Aug 2022 Robert P Crease

Physicists and philosophers of science often appear to operate in different spaces. Robert P Crease reports from a meeting where they were, for once, in the same quantum state

When two become one Physicists and philosophers at a recent meeting in Sweden found they had much in common. (Courtesy: iStock/Floriana)

“When I take an action on the world, something genuinely new comes out.”

 

X-ray microscopy sharpens up

19 Jul 2022 Isabelle Dumé

Constructing a sharp image of precisely arranged concentric layers to image two semiconductor nanowires. (Courtesy: Markus Osterhoff)

A new algorithm that compensates for deficiencies in X-ray lenses could make images from X-ray microscopes much sharper and higher in quality than ever before, say researchers at the University of Göttingen, Germany. Preliminary tests carried out at the German Electron Synchrotron (DESY) in Hamburg showed that the algorithm makes it possible to achieve sub-10-nm resolution and quantitative phase contrast even with highly imperfect optics.

 

Hidden patterns found on the surface of water

19 Aug 2022 Katherine Skipper

Soft and bumpy: work on soft air–water interfaces was pioneered over 10 years ago. (Courtesy: Shutterstock/Grayson)

Scientists in the US have found evidence that the surface of liquid water, even at room temperature, has a structure that looks more and more like ice as the water–air interface is approached. Phillip Geissler and Nathan Odendahl of the University of California, Berkeley, performed computer simulations of the uneven interface between air and water and identified ordered motifs, which they argue share significant commonalities with ice.

 

Topological defects in liquid crystals resemble quantum bits, say mathematicians

27 Aug 2022

Defect bits: representation of two n-bits along a defect line (shown in black). Shown are the orientations of the rod-like molecules that comprise liquid crystals. (Courtesy: Žiga Kos and Jörn Dunkel/Science Advances)

Topological defects in liquid crystals are mathematically analogous to quantum bits, researchers in the US have shown theoretically. If a system based on this principle could be implemented in practice, many of the advantages of quantum computers could be realized in a classical circuit – avoiding the considerable challenges facing those trying to develop practical quantum computers.

 

Underwater ‘snow’ could be growing on Jupiter’s moon Europa

24 Aug 2022

Chilly worlds: mounds of snow-like frazil ice under the Antarctic ice shelf. According to this latest research, Europa’s ice shell could be made of the same stuff. (Courtesy: copyright Helen Glazer 2015/from the project "Walking in Antarctica" (helenglazer.com))

A study of Antarctic ice shelves suggests that the ice shell covering Jupiter’s moon Europa could contain a significant amount of underwater “snow”. This could have important implications for NASA’s upcoming Europa Clipper mission, which aims to use ground penetrating radar to study the ice shell and the ocean beneath.

 

Introduction to Lattice Field Theory (Lecture 3) by Anna Hasenfratz

"ΤΕΧΝΟΛΟΓΊΑ ΠΟΥ ΠΡΟΚΎΠΤΕΙ ΓΙΑ ΤΗΝ ΑΝΤΙΜΕΤΏΠΙΣΗ ΤΩΝ ΔΙΑΦΟΡΩΝ ΜΟΡΦΩΝ ΚΑΡΚΙΝΟΥ"

ΓΙΑ ΝΑ ΔΙΑΒΑΣΕΤΕ ΤΟ ΑΡΘΡΟ ΓΙΑ ΤΗΝ ΤΕΧΝΟΛΟΓΊΑ ΠΟΥ ΠΡΟΚΎΠΤΕΙ ΓΙΑ ΤΗΝ ΑΝΤΙΜΕΤΏΠΙΣΗ ΤΩΝ ΔΙΑΦΟΡΩΝ ΜΟΡΦΩΝ ΚΑΡΚΙΝΟΥ ΠΑΤΗΣΤΕ ΣΤΟΝ ΕΠΟΜΕΝΟ ΣΥΝΔΕΣΜΟ ΕΔΩ

 

Radiation damage is spotted using calorimetry technique

15 Aug 2022

Longer life New analysis technique could help extend the lives of some nuclear power plants. (Courtesy: iStock/RelaxFoto.de)

Material defects caused by radiation damage can be characterized by measuring the energy that the defects release when heated. That is the conclusion of researchers in the US and Finland, who say their new approach could lead to better techniques for quantifying the diminished performance of irradiated materials – something that could have important implications for the operation of ageing nuclear power plants.

 

Photothermal surgical dressing prevents skin cancer recurrence

04 Aug 2022

Photothermal therapy: A novel surgical dressing promotes tissue healing and prevents tumour recurrence by eliminating residual melanoma cells. It could also enable smaller surgical resections than standard procedures. (Courtesy: University of Nottingham/Adv. Functional Mater. 10.1002/adfm.202205802)

A highly effective surgical dressing designed for patients with skin cancer could speed up the healing process after surgery. Developed by researchers in the UK and China, the dressing also exploits photothermal effects to prevent tumours from reappearing.

 

iTEARS platform diagnoses disease from patients’ tears

16 Aug 2022

Detecting disease from a teardrop: A nanomembrane system isolates exosomes from tears, allowing researchers to rapidly analyse them for disease biomarkers. (Courtesy: iStock/leonovo)

Researchers in the US and China have developed a new technique for quickly and accurately diagnosing eye-related diseases, by detecting biomolecular signatures in patients’ tears. Developed by a team led by Luke Lee at Harvard Medical School and Fei Liu at Wenzhou Medical University, the iTEARS system uses oscillating nanoporous membranes to isolate encased biomolecules from impurities, making them far easier to study and classify.

 

Vortices appear in an electron fluid

16 Aug 2022 Isabelle Dumé

Electrons flowing in vortices Top: Schematic experimental layout showing samples of Au (a) and WTe2 (b) together with the device used to measure current flow. Bottom: Normalized current densities measured experimentally in c) Au and d) WTe2 showing laminar and vortical flows. (Courtesy: A Aharon)

An international team of physicists has observed electrons flowing in whirlpool-like patterns known as vortices for the first time. Long predicted, but never before seen in experiments, this evidence of fluid-like behaviour could be exploited to make more efficient electronics.

 

Dwarf galaxies appear to be missing dark-matter halos

16 Aug 2022

Holding together The dwarf galaxy NGC1427A is in the Fornax galaxy cluster. Observations of the distortions of the galaxy are not in line with the presence of a dark matter halo. (Courtesy: ESO)

A study of the gravitational distortion of dwarf galaxies appears to support a theory of modified gravity rather than the existence of dark matter – the latter being a key component of the Standard Model of cosmology.

CANCER RELATIONSHIP WITH BIODIVERSITY" & "Cancer-on-chip technology: current applications in major cancer types, challenges, and future prospects"

 ΓΙΑ ΝΑ ΔΙΑΒΑΣΕΤΕ Η ΝΑ ΚΑΤΕΒΑΣΕΤΕ ΤΟ ΑΡΘΡΟ ΓΙΑ THN "CANCER RELATIONSHIP WITH BIODIVERSITY" ΚΑΙ "Cancer-on-chip technology: current applications in major cancer

types, challenges, and future prospects"

ΠΑΤΗΣΤΡΕ ΣΤΟΝ ΕΠΟΜΕΝΟ ΣΥΝΔΕΣΜΟ ΕΔΩ

 

Ultrasound sticker provides continuous imaging of internal organs

18 Aug 2022

Continuous imaging: The stamp-sized device sticks to skin and can provide continuous ultrasound imaging of the heart, lungs and other internal organs. (Courtesy: Felice Frankel)

A wearable ultrasound device can provide 48 hours of continuous imaging of internal organs while patients go about their daily lives. The device – developed by a team headed up at Massachusetts Institute of Technology (MIT) – consists of a rigid piezoelectric ultrasound array that sticks to the skin via a soft bioadhesive hydrogel–elastomer hybrid.

 

Sharp ring of light spotted around supermassive black hole

17 Aug 2022 Hamish Johnston

Sharper image: the photon ring surrounding M87* (in orange) shown with the diffuse background light represented by contour lines. (Courtesy: Perimeter Institute for Theoretical Physics)

A sharp ring of light created by photons racing around the back of a supermassive black hole has been spotted by researchers working on the Event Horizon Telescope (EHT). The observation confirms a prediction of Einstein’s general theory of relativity and sheds further light on the mass of the black hole and the powerful jet of material that emanates from the supermassive object.

 

Physicists identify most complex protein knots

12 Aug 2022

Knotted proteins: The most complex protein knot known to date, with seven crossings predicted by AlphaFold (left) and a simplified representation (right). (Courtesy: ill./©: Maarten Brems, CC BY 4.0)

Scientists in Germany and the US have predicted the most topologically complex knot ever found in a protein using AlphaFold, the artificial intelligence (AI) system developed by Google’s DeepMind.

 

Colourful nanotubes become flame-resistant

10 Aug 2022 Isabelle Dumé

Artist impression of the coloured nanotubes. (Courtesy: R Zhang)

“Structurally colouring” carbon nanotubes with an amorphous layer of titanium dioxide not only makes them easier on the eye, it also makes them flame-resistant.

 

Optoacoustic imaging identifies breast cancer from vascular patterns

10 Aug 2022

Key features: OA-US images illustrating the patterns used to define the feature set for benign and malignant lesions. Arrows indicate the OA feature (specified above the panels); the lesion histopathology is shown below. (Courtesy: CC BY 4.0/Photoacoustics 10.1016/j.pacs.2022.100383)

Adding optoacoustic (OA) imaging to ultrasound (US) could improve the diagnosis of breast cancer, according to findings from a multidisciplinary research team in Cambridge, UK.

 

Anomalous Josephson effect appears in a topological insulator

24 Apr 2022 Isabelle Dumé

Observation of anomalous Josephson effect in Josephson trijunctions. (Courtesy: L Lu)

Researchers at the Institute of Physics, Chinese Academy of Sciences in Beijing, say they have found unambiguous evidence for a condensed-matter phenomenon known as the anomalous Josephson effect (AJE). The phenomenon emerged in structures called Josephson trijunctions, which the researchers constructed from a material that acts as an electrical insulator in its bulk while conducting electricity on its surface.

 

Citizen scientist discovers 34 brown dwarfs in binary systems

08 Aug 2022

Two's company Artist’s conception of a brown dwarf in a binary system with a white dwarf star. (Courtesy: NOIRLab/NSF/AURA/M Garlick)

New research has uncovered 34 new binary-star systems in which low-mass stars partner up with a so-called “failed star” or brown dwarf. The discoveries almost double the number of known systems and could help astronomers better understand where the dividing line between planets and stars is.

 

3D printed sensor lines up for space plasma detection

08 Aug 2022

Low-cost production: The 3D printed plasma sensor performs as well as more expensive, semiconductor sensors, and could prove ideal for use on CubeSats. (Courtesy: The researchers; edited by MIT News)

Researchers at Massachusetts Institute of Technology (MIT) have developed a new 3D printing technique that could make it far easier to build detectors for measuring cold, dense plasma in Earth’s upper atmosphere. Javier Izquierdo-Reyes and colleagues hope that their simple, low-cost approach could open up this region of space to a far wider range of research groups.

 

Excitonic insulators are created in moiré superlattices

10 Aug 2022

Layered approach: both teams created excitonic insulators by twisting the relative orientations of thin sheets in layered materials. (Courtesy: Shutterstock/Mopic)

Excitonic insulators – an exotic type of matter with a ground state comprising bound electron–hole pairs – have been made by two independent research groups.

 

Aftermath of explosive stellar merger seen in a new light

14 Aug 2022

Merger afterglow: artist’s impression of the afterglow that followed the merger of a neutron star with another star. (Courtesy: ALMA (ESO/NAOJ/NRAO) and M Weiss (NRAO/AUI/NSF))

The aftermath of the merger of a neutron star with another star has been observed using millimetre-wavelength light for the first time. The distant merger occurred when the universe was about 5.5 billion years old and was immediately followed by one of the most energetic short-duration gamma-ray bursts (SGRBs) ever spotted by astronomers. It also left behind one of the most luminous afterglows ever seen.

 

Projectile fusion offers new path to clean energy, quantum communications for alien civilizations

14 Jul 2022 Hamish Johnston

from physicswold.com    15/8/2022

 

Device-independent QKD brings unhackable quantum Internet closer

11 Aug 2022

Network node: A vacuum system containing the ion trap used to create the "Bob" node in the Oxford-CEA-Switzerland experiment. (Courtesy: David Nadlinger/University of Oxford)

Two independent research groups have demonstrated a protocol for distributing quantum-encrypted keys via a method that is sure to leave would-be network hackers in the dark. The protocol, dubbed device independent quantum key distribution, was first proposed three decades ago but had not been realized experimentally before due to technical limitations, which the researchers have now overcome.

 

James Webb Telescope caught something unexpected.

16.649 προβολές 8 Αυγ 2022 The James Webb Space Telescope (JWST) has caught two galaxies colliding. In the midst of this cosmic clash, researchers have found something unexpected – there doesn’t seem to be an active supermassive black hole in either galaxy. Read more - https://exoplanetscience.blogspot.com... credit - NASA, ESA, STScl #nasa #jameswebbspacetelescope #jupiter #redspot #webbtelescopefirstcolourimage #webbtelescopenewimage #webbtelescopedeepfield #jwst #universe #mysterioussignal #galaxy #webbtelescopeupdates #jwstimages #photons #firstgalaxy #webbtelescopeupdates #interstellar #webbselfie #webbtelescopeimage #alienlife #jameswebbspacetelescope #nasa #galaxy #galaxycollision #andromeda #largeMagellanicCloud