Did a black-hole merger create a flash in a distant quasar?

13 Jul 2020

Collision course: artist’s impression of a pair of black holes within an active galactic nucleus. (Courtesy: Caltech/R Hurt (IPAC))

A recent electromagnetic signal from a distant quasar could have been created by merging black holes, according to an international team of astronomers led by Matthew Graham at the California Institute of Technology. The researchers made the connection after modelling the aftermath of such a merger in an active galactic nucleus (AGN) and their calculations predict a second related flare from the quasar in the future.

Over the past several years, the LIGO–Virgo observatories have detected gravitational waves from merging black holes. So far, these observations have largely originated from ancient clusters of stellar remnants and no electromagnetic signals from the mergers have been observed. However, Graham’s team believe that electromagnetic signals could be generated when black-hole mergers occur in AGNs including quasars. An AGN is the central core of a galaxy and contains a supermassive black hole that is surrounded by hot, gas-filled accretion discs. AGNs are thought to have dense populations of black holes.

Near infrared fluorescence imaging provides early diagnosis of cracked teeth

10 Jul 2020

Tooth cracks that are not detected in X-ray CT scans (left) can be seen using indocyanine green near‐infrared fluorescence (ICG-NIRF) imaging. (Courtesy: Jian Xu and Zhongqiang Li)

Cracked teeth can be identified in their early stages using near infrared fluorescence (NIRF) imaging, researchers in the US have demonstrated. The approach – which can distinguish between different types of crack and reveal their depth – is more reliable than existing modalities and may help better diagnose the source of otherwise inexplicable toothache.

Cracked teeth are a common condition and, thanks to their potential to allow bacteria across the enamel–dentin junction, also the third highest cause of tooth loss. Despite this, the condition is often overlooked in its early stages. “Cracked teeth can be difficult to diagnose clinically as patients’ symptoms often aren’t reproducible and cracks can be barely visible to the naked eye,” explains oral surgeon James Allison of Newcastle University, who was not involved in the present study.

Brighter prospects for treating a rare lung cancer

13 Jul 2020 Ben Lewis

An antibody–drug complex can be targeted and activated in a cancerous lung, leaving the normal lung healthy. (Courtesy: Kazuhide Sato)

A rare type of cancer affecting the lining of the lung, malignant pleural mesothelioma (MPM) has always been very difficult to treat. That may be about to change, though. Kazuhide Sato and his colleagues at Nagoya University have found a potential new treatment that combines light and a targeted antibody, according to their latest research published in Cells.

MPM, most often caused by exposure to asbestos, is often diagnosed late and has a very poor prognosis, with almost no options for treatment. To overcome this, Sato adapted a strategy recently developed for treating other cancers: near-infrared photoimmunotherapy (NIR-PIT).

ο μυστικό του τέλειου καφέ κρύβεται στο ψυγείο

ο μυστικό του τέλειου καφέ κρύβεται στο ψυγείο

Το μυστικό του τέλειου καφέ κρύβεται στο ψυγείο

Οι παγωμένοι κόκκοι καφέ όταν αλέθονται προσφέρουν πιο ομοιόμορφο αποτέλεσμα και πλούσια γεύση γεμάτη αρώματα

Για απολαυστικό καφέ με γεμάτο άρωμα παγώστε τους κόκκους του καφέ πριν από το άλεσμα, υποστηρίζουν βρετανοί ειδικοί από το Πανεπιστήμιο του Μπαθ

Για θεϊκή και γεμάτη γεύση στο καφεδάκι μας το μυστικό είναι οι παγωμένοι κόκκοι, υποστηρίζουν βρετανοί ερευνητές από το Πανεπιστήμιο του Μπαθ. Αναλύοντας τη γεύση μιας τέλειας κούπας καφέ, οι ειδικοί διαπίστωσαν ότι η τοποθέτηση των καβουρδισμένων κόκκων του καφέ στο ψυγείο πριν από το άλεσμά τους οδηγούσε σε ένα πιο ομοιόμορφα αλεσμένο καφέ και με πολύ καλύτερη γεύση κατά την παρασκευή του.

Σύμφωνα με τους ερευνητές, οι χαμηλές θερμοκρασίες ενισχύουν την παραγωγή λεπτότερων και πιο ομοιόμορφων σωματιδίων καφέ κατά το άλεσμα, το οποίο επιτρέπει στη συνέχεια την απελευθέρωση της έντονης γεύσης και των αρωμάτων του.

Τα ευρήματα των ειδικών, τα οποία ανακοινώθηκαν λίγες μόλις ημέρες πριν από το Παγκόσμιο Πρωτάθλημα Barista στο Δουβλίνο (22-25 Ιουνίου), θα μπορούσαν να βρουν άμεση εφαρμογή στον χώρο της βιομηχανίας.

Παγωμένοι κόκκοι να τους πιεις στην κούπα

Στο πλαίσιο της μελέτης τους οι ερευνητές εξέτασαν το αποτέλεσμα του αλέσματος των κόκκων του καφέ σε διάφορες θερμοκρασίες (σε θερμοκρασίες δωματίου και ως τους -160 βαθμούς Κελσίου). Οι ερευνητές διαπίστωσαν ότι όσο περισσότερο παγώνουν οι κόκκοι του καφέ τόσο μεγαλύτερη είναι η απελευθέρωση της πλούσιας γεύσης. Κάτι τέτοιο πρακτικά, εξηγούν οι επιστήμονες, θα μπορούσε να σημαίνει ότι με την ίδια ποσότητα κόκκων θα μπορούσαμε να έχουμε περισσότερο καφέ ή λιγότερο χρόνο παρασκευής.

Ομοιόμορφο άλεσμα, πλούσιο άρωμα και γεύση

Το άλεσμα του καφέ μπορεί να μοιάζει πολύ απλή διαδικασία - το σπάσιμο δηλαδή των κόκκων του καφέ σε μικροσκοπικά κομματάκια τα οποία στη συνέχεια βυθίζονται στο νερό. Ωστόσο, όπως υπογραμμίζουν οι επιστήμονες, πρόκειται για μια βασική διαδικασία η οποία μπορεί να έχει τεράστια επίδραση στη γεύση και στην ποιότητα του καφέ.

«Κάτι τέτοιο θα μπορούσε να επιφέρει αλλαγές ως προς τη γεύση του καφέ, και αυτό επειδή το ομοιόμορφο μέγεθος του αλεσμένου καφέ και η διανομή των σωματιδίων του παίζουν τεράστιο ρόλο ως προς τον ρυθμό της απόσταξης του καφέ» εξηγεί ο ερευνητής δρ Κρίστοφερ Χέντον, ο οποίος πλέον εργάζεται στο Τεχνολογικό Ινστιτούτο της Μασαχουσέτης (ΜΙΤ).

«Θα μπορούσε ακόμη να φέρει ριζικές αλλαγές στη βιομηχανία του καφέ. Ο κόσμος προσπαθεί να παραγάγει καφέ πολύ υψηλής ποιότητας, με πολύ εκλεπτυσμένα εργαλεία και εξοπλισμό, και προτίθεται να δοκιμάσει νέα πράγματα προκειμένου να επιτύχει ένα καλύτερο αποτέλεσμα» προσθέτει ο ίδιος.

Τέλος οι ειδικοί αναφέρουν ότι ενδεχομένως τα νέα τους ευρήματα να βρουν ταχύτερα εφαρμογή στο πλαίσιο των επερχόμενων διαγωνισμών καφέ  ανά την υφήλιο, ενώ δεν αποκλείεται σύντομα να κυκλοφορήσουν και νέες μηχανές αλέσματος καφέ με... ψύξη.

Physicists propose how to entangle macroscopic objects using pulses of light

19 Jun 2020

In a flash: researchers have proposed how to entangle macroscopic objects using short pulses of light. (Courtesy: Jack Clarke, Quantum Measurement Lab, Imperial College London)

Physicists at Imperial College London, UK, and Stockholm University, Sweden, have proposed a new way of creating entanglement between mechanical motion and an optical field, and also between two mechanical oscillators, using short pulses of light. Here research students Jack Clarke and Paulo Sahium along with group director Michael Vanner from the Quantum Measurement Lab at Imperial explain the work.

The research is reported in full in New Journal of Physics, published by IOP Publishing – which also publishes Physics World.

What was the motivation for the research?

Quantum entanglement is one of the most intriguing aspects of physics and allows objects to be more strongly correlated than is allowed classically. Albert Einstein called this perplexing behaviour “spooky action at a distance” and many objections to this radical idea were raised in the early days of quantum mechanics. Fast forward 80 years, and quantum entanglement is a now a well-established phenomenon and is routinely generated between objects such as photons, atoms and molecules.

Active rotation plays a role in the jamming–unjamming transition in living cells

26 Jun 2020 Katherine Skipper

Spinning around: scanning electron microscope image of C. reinhardtii cells (Courtesy: Dartmouth Electron Microscope Facility, Dartmouth College)

New research offers insight into the role of rotation in the self-assembly of living cells. The work is described in Soft Matter and was done by Linda Ravazzano at the University of Milan under the supervision of Stefano Zapperi and in collaboration with Caterina La Porta’s research group.

Computer simulations and experiments with algae provided the team with information about the jamming and unjamming of cells at high densities. This research could lead to a better understanding of the differences between healthy and cancerous cells in human tissue.

The self-assembly of cells into tissues sits firmly at the interface of physics and biology. Cells are complex biological systems that sense changes in their environment and communicate with other cells, but they can also exhibit self-organization that is driven purely by thermodynamics.

Four-charm tetraquark has been spotted at CERN

02 Jul 2020 Hamish Johnston

Charmed existence: conceptual illustration of a tetraquark. (Courtesy: CERN)

The first tetraquark comprising all charm quarks and antiquarks may have been spotted by physicists working on the LHCb experiment on the Large Hadron Collider (LHC) at CERN. The exotic hadron was discovered as it decayed into two J/ψ mesons, each of which is made from a charm quark and charm antiquark. The particle appears to be the first known tetraquark to be made entirely of “heavy quarks”, which are the charm and beauty quarks (but not the top quark, which is the heaviest quark but does not form hadrons).

“Particles made up of four quarks are already exotic, and the one we have just discovered is the first to be made up of four heavy quarks of the same type, specifically two charm quarks and two charm antiquarks,” explains Giovanni Passaleva, who is just stepping down as spokesperson for LHCb. “Up until now, the LHCb and other experiments had only observed tetraquarks with two heavy quarks at most and none with more than two quarks of the same type.”

Spiral patterns in living cells could be used to create biological computers

02 Apr 2020

Rippling egg: vortex-like waves spread out on the cell membrane of a starfish egg. (Courtesy: Nikta Fakhri and colleagues/MIT)

Ripples that appear on the surfaces of newly fertilized eggs closely resemble those found in other physical systems – according to Nikta Fakhri and colleagues at the Massachusetts Institute of Technology. The team discovered the similarity through statistical analysis of the spiral patterns produced by active proteins in newly fertilized starfish eggs. The researchers say that their discovery could lead to the development of biological computers that use ripples to process information.

When the egg cells of many species are fertilized, complex ripples are often propagate across their surfaces (cell membranes) before cell division begins. These waves are produced by a protein called Rho-GTP. This protein mostly sits inactive in the cell’s cytoplasm, but rapidly springs to action and attaches itself to the cell membrane when a separate hormone indicates cell division should begin. These ripples are known to produce intricate patterns as they propagate, but until now, the physical characteristics of the patterns have remained largely unexplored.

Stiffer road surfaces could cut greenhouse-gas emissions

07 Jul 2020

Hard journey: using stiffer materials to build roads such as this Texas freeway could reduce greenhouse gas emissions. (Courtesy: Danazar/CC BY-SA 3.0)

The efficiency of the US transportation sector could be improved significantly by increasing the stiffness of road surfaces, US researchers have shown. Randolph Kirchain and colleagues at the Massachusetts Institute of Technology came to this conclusion through a detailed analysis of the road networks in each US state. Their findings could lead to a meaningful dent in the greenhouse gas emissions produced by US transportation, without the need for costly new technologies.

Although road surfaces may seem completely rigid when we walk on them, it is a different story for large vehicles. As they drive, the wheels of large vehicles compress and elastically deform road surfaces, creating temporary “valleys” from which they must continually escape. Even when driving on flat surfaces, these vehicles are always driving slightly uphill. Kirchain’s team calculates that this is results in an excess fuel consumption of over 2.5 billion tons across a 50-year period.

Transabdominal oximetry offers non-invasive monitor of foetal health

07 Jul 2020 Lydia Wilson

Daniel Fong (left) and Soheil Ghiasi (right) with their novel foetal oximetry system. (Courtesy: University of California, Davis)

Researchers in the US have designed and tested a novel oximetry system that offers a non-invasive approach for monitoring foetal blood-oxygen levels, an indicator of foetal wellbeing, during active labour. A more objective and accurate measure of foetal blood oxygenation could improve both mother and infant birth outcomes.

If left unaddressed, foetal asphyxia, or oxygen deprivation, can cause long-term disabilities, developmental delays or even death. Therefore, any indication of foetal asphyxia during active labour commonly prompts an emergency Caesarean delivery, or C-section.

The current method of evaluating foetal wellbeing, known as cardiotocography, attempts to indirectly assess foetal oxygen saturation by monitoring the relationship between uterine contractions and foetal heart rate over time. Despite its widespread use for over 50 years, cardiotocography has failed to decrease the rates of complications associated with foetal asphyxia. Instead, it has contributed to increasing rates of C-section, which itself poses dangers to both mother and baby.

Cryogenics makes the European Spallation Source a hot property in neutron science

06 Jul 2020

Cryogenics is a core enabling technology at the European Spallation Source, a next-generation neutron-science facility under construction in Sweden. Joe McEntee talks to John G Weisend II, group leader for specialized technical services at ESS, about the secrets of success at ultralow temperatures

Big science: an aerial view over the ESS construction site in Lund, Sweden, taken in February 2020. (Courtesy: Perry Nordeng/ESS)

Large-scale neutron facilities – one of the mainstays of Europe’s “big science” infrastructure – are routinely used by researchers to understand material properties on the atomic scale, spurring advances across a spectrum of scientific discovery – from clean energy and environmental technology to pharma and healthcare, from structural biology and nanotech to food science and cultural heritage. Industry users, meanwhile, use neutrons to probe deep into engineering components, gaining unique insights into the stresses and strains that affect turbine blades, gas pipelines, fuel cells and the like.

From virus spikes to narwhal tusks, physicists discover universal design for stingers

From virus spikes to narwhal tusks, physicists discover universal design for stingers

03 Jul 2020

Universal stingers: this plant has something in common with a swordfish. (Courtesy: Kaare Jensen/Technical University of Denmark)

From virus spikes to narwhal tusks, the stingers of many living organisms have the same basic mechanical design. Now a team of physicists led by Kaare Jensen has studied the mechanical properties of more than 200 natural and manmade stingers to discover why.

The researchers at the Technical University of Denmark found a clear relationship between the structural properties of stingers large and small – thereby solving a long-standing evolutionary mystery. As a bonus, their work could lead to artificial structures that better mimic the desirable properties of natural stingers.

Tabletop device might snare gravitational waves using tiny diamonds

07 Jul 2020

Making waves: artist’s impression of gravitational waves being broadcast by a pair of black holes. (Courtesy: LIGO/T Pyle)

Rather than the kilometre-length observatories of today, future gravitational-wave detectors could be just a few metres long. That is the goal of physicists in the UK and the Netherlands, who have put forward a design for a matter-wave interferometer that would rely on the superposition of tiny objects such as diamond crystals rather than laser beams. They say that the device would be sensitive to low- and mid-frequency gravitational waves.

Gravitational waves were first observed directly in 2015, when the LIGO observatory in the US picked up the emission from a pair of merging black holes. These black holes broadcast a series of ripples through space-time that caused the pairs of perpendicular arms making up LIGO’s interferometers to undergo a series of miniscule expansions and contractions. Those tiny changes were registered as variations in the interference between laser beams sent along the arms.

New material could be used to make a liquid metal robot

New material could be used to make a liquid metal robot

26 May 2020

Handy material This model of a human hand was made using a liquid metal matrix. (Courtesy: Pu Zhang)

A liquid metal lattice that can be crushed but returns to its original shape on heating has been developed by Pu Zhang and colleagues at Binghamton University in the US. The material is held together by a silicone shell and could find myriad uses including soft robotics, foldable antennas and aerospace engineering. Indeed, the research could even lead to the creation of a liquid metal robot evoking the T-1000 character in the film Terminator 2.

The team created the liquid metal lattice using a special mixture of bismuth, indium and tin known as Field’s alloy. This alloy has the relatively unusual property of melting at just 62 °C, which means it can be liquefied with just hot water. Field’s alloy already has several applications – including as a liquid-metal coolant for advanced nuclear reactors.

Calculating the speed of coronal mass ejections could avoid unneeded satellite shutdown

Calculating the speed of coronal mass ejections could avoid unneeded satellite shutdown

30 Jun 2020

Reaching out: a huge coronal mass ejection that was spotted in 2012 by the ESA/NASA Solar Heliospheric Observatory. (Courtesy: NASA/Goddard Space Flight Center)

Satellite operators could be doing more harm than good by shutting down their systems whenever a coronal mass ejection (CME) from the Sun is forecast to arrive at Earth, UK researchers have suggested. Mathew Owens, Mike Lockwood and Luke Barnard at the University of Reading show that the speeds and magnetic field intensities of the bursts could be just as important to consider as their arrival times when deciding when to turn satellite systems off. If applied, their ideas could significantly improve the efficiency of many satellite operations.

LIGO reveals quantum correlations at work in mirrors weighing tens of kilograms

LIGO reveals quantum correlations at work in mirrors weighing tens of kilograms

01 Jul 2020

Large quantum objects: two of LIGO’s mirrors, each weighing 40 kg. (Courtesy: Caltech/MIT/LIGO Lab)

Physicists working on the LIGO gravitational-wave observatory in the US have shown that quantum-scale correlations can leave their mark on macroscopic objects weighing tens of kilograms. The team explored the interplay between the interferometer’s laser beam and its huge test masses, showing that the instrument’s quantum noise could be reduced below an intrinsic limit. This, the researchers say, could boost the future rate of discoveries with such observatories.