Physicists are figuring out how close you can get to a black hole before you are unlikely to escape. That threshold is called the innermost stable circular orbit (ISCO).
Category: physics – Page 257
A new theorem predicts that stationary black holes must have at least one light ring
Black holes, regions in space with such an intense gravitational field that no matter or radiation can escape from them, are among the most mysterious and fascinating cosmological phenomena. Over the past five years or so, astrophysicists collected the first observations of the strong gravitational forces around black holes.
The LIGO-Virgo collaboration was able to detect gravitational waves around these celestial objects using some of the most advanced gravitational-wave detectors in the world. Meanwhile, the Event Horizon Telescope research group captured the very first image of a black hole shadow.
While both these observations are highly promising and captivating, neither of them is likely to unveil the event horizon, the boundary defining the specific region in space around a black hole from which nothing can escape. Nonetheless, they should contain a signature pointing to a neighboring region just outside of the event horizon, wherein light is bent so strongly that its path closes over itself and forms circular orbits known as light rings.
Predictive biology: modelling, understanding and harnessing microbial complexity
Predictive biology is the next great chapter in synthetic and systems biology, particularly for microorganisms. Tasks that once seemed infeasible are increasingly being realized such as designing and implementing intricate synthetic gene circuits that perform complex sensing and actuation functions, and assembling multi-species bacterial communities with specific, predefined compositions. These achievements have been made possible by the integration of diverse expertise across biology, physics and engineering, resulting in an emerging, quantitative understanding of biological design. As ever-expanding multi-omic data sets become available, their potential utility in transforming theory into practice remains firmly rooted in the underlying quantitative principles that govern biological systems. In this Review, we discuss key areas of predictive biology that are of growing interest to microbiology, the challenges associated with the innate complexity of microorganisms and the value of quantitative methods in making microbiology more predictable.
Researchers Have Found a New Way to Convert Waste Heat Into Electricity to Power Small Devices
A thin, iron-based generator uses waste heat to provide small amounts of power.
Researchers have found a way to convert heat energy into electricity with a nontoxic material. The material is mostly iron which is extremely cheap given its relative abundance. A generator based on this material could power small devices such as remote sensors or wearable devices. The material can be thin so it could be shaped into various forms.
There’s no such thing as a free lunch, or free energy. But if your energy demands are low enough, say for example in the case of a small sensor of some kind, then there is a way to harness heat energy to supply your power without wires or batteries. Research Associate Akito Sakai and group members from his laboratory at the University of Tokyo Institute for Solid State Physics and Department of Physics, led by Professor Satoru Nakatsuji, and from the Department of Applied Physics, led by Professor Ryotaro Arita, have taken steps towards this goal with their innovative iron-based thermoelectric material.
New ‘Whirling’ State of Matter Discovered: Self-Induced Spin Glass
The strongest permanent magnets today contain a mix of the elements neodymium and iron. However, neodymium on its own does not behave like any known magnet, confounding researchers for more than half a century. Physicists at Radboud University and Uppsala University have shown that neodymium behaves like a so-called ‘self-induced spin glass,’ meaning that it is composed of a rippled sea of many tiny whirling magnets circulating at different speeds and constantly evolving over time. Understanding this new type of magnetic behavior refines our understanding of elements on the periodic table and eventually could pave the way for new materials for artificial intelligence. The results will be published in Science on May 29, 2020.
“In a jar of honey, you may think that the once clear areas that turned milky yellow have gone bad. But rather, the jar of honey starts to crystallize. That’s how you could perceive the ‘aging’ process in neodymium.” Alexander Khajetoorians, professor in Scanning probe microscopy, together with professor Mikhail Katsnelson and assistant professor Daniel Wegner, found that the material neodymium behaves in a complex magnetic way that no one ever saw before in an element on the periodic table.
Next-gen laser facilities look to usher in new era of relativistic plasmas research
The subject of the 2018 Nobel Prize in physics, chirped pulse amplification is a technique that increases the strength of laser pulses in many of today’s highest-powered research lasers. As next-generation laser facilities look to push beam power up to 10 petawatts, physicists expect a new era for studying plasmas, whose behavior is affected by features typically seen in black holes and the winds from pulsars.
Physicists measure a short-lived radioactive molecule for first time
Researchers at MIT and elsewhere have combined the power of a super collider with techniques of laser spectroscopy to precisely measure a short-lived radioactive molecule, radium monofluoride, for the first time.
Precision studies of radioactive molecules open up possibilities for scientists to search for new physics beyond the Standard Model, such as phenomena that violate certain fundamental symmetries in nature, and to look for signs of dark matter. The team’s experimental technique could also be used to perform laboratory studies of radioactive molecules produced in astrophysical processes.
“Our results pave the way to high-precision studies of short-lived radioactive molecules, which could offer a new and unique laboratory for research in fundamental physics and other fields,” says the study’s lead author, Ronald Fernando Garcia Ruiz, assistant professor of physics at MIT.
A Bar Owner in The UK Has Built a Faraday Cage to Stop Customers Using Their Phones
The owner of a cocktail bar in the UK has turned to physics in an attempt to force his customers to actually talk to other instead of just staring at social media all night.
Steve Tyler, who owns the Gin Tub in East Sussex, has built his very own Faraday cage around the establishment to block mobile phone signals from entering the building.
It’s a pretty ingenious (but controversial) move that involves installing metal mesh in the walls and ceiling of the bar to essentially filter out electromagnetic signals before they enter the building.
New Gravitational-Wave Model Helps Reveal the True Nature of Neutron Stars
Gravitational-wave researchers at the University of Birmingham have developed a new model that promises to yield fresh insights into the structure and composition of neutron stars.
The model shows that vibrations, or oscillations, inside the stars can be directly measured from the gravitational-wave signal alone. This is because neutron stars will become deformed under the influence of tidal forces, causing them to oscillate at characteristic frequencies, and these encode unique information about the star in the gravitational-wave signal.
This makes asteroseismology — the study of stellar oscillations — with gravitational waves from colliding neutron stars a promising new tool to probe the elusive nature of extremely dense nuclear matter.
Modified tattoo electrodes can be used to measure brain activity
In 2015 Francesco Greco, head of the Laboratory of Applied Materials for Printed and Soft electronics (LAMPSe) at the Institute of Solid State Physics at Graz University of Technology, developed so-called “tattoo electrodes” together with Italian scientists.
These are conductive polymers that are printed using an inkjet printer on standard tattoo paper and then stuck to the skin like transfers to measure heart or muscle activity.
This type of electrode, optimized in 2018, opened up completely new paths in electrophysiological examinations, such as electrocardiography (ECG) or electromyography (EMG). Thanks to a thickness of 700 to 800 nanometres — that is about 100 times thinner than a human hair — the tattoos adapt to uneven skin and are hardly noticeable on the body.