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Even gluttons can't eat forever. When black holes at the hearts of galaxies swell to 50 billion times the mass of our sun, they may lose the discs of gas they use as cosmic feedlots. Most galaxies host a supermassive black hole at their centre. Around this is a region of space where gas settles into an orbiting disc. The gas can lose energy and fall inwards, feeding the black hole. But these discs are known to be unstable and prone to crumbling into stars. Theoretically, a black hole could grow so big that it swallows up the stable part...

[This article is much more interesting than its headline] Several years ago it was discovered that the early Solar system contained a significant amount of plutonium-244. Considering its short-lived cycle, plutonium-244 that existed over four billion years ago when Earth formed has long since decayed but its daughter elements have been detected. Plutonium is a radioactive element. Its longest-lived isotope is plutonium-244 with a lifetime of 120 million years. Detection of plutonium-244 in nature would imply that the element was synthesized in astrophysical phenomena not so long ago (at least in Galactic time scales) and hence its origin cannot be...

Rice University scientists are making small, flexible microsupercapacitors in a room-temperature process they claim shows promise for manufacturing in bulk. The technique is based on their method to burn patterns of spongy graphene into plastic sheets with a commercial laser. Credit: Tour Group/Rice University ====================================================================================================================================== Rice University researchers who pioneered the development of laser-induced graphene have configured their discovery into flexible, solid-state microsupercapacitors that rival the best available for energy storage and delivery. The devices developed in the lab of Rice chemist James Tour are geared toward electronics and apparel. They are the subject of a new paper in the...

American space agency, the NASA had recently observed flares of X-rays from a black hole, which goes against the conventional notion that they are compact particles with such huge gravity that even light can't escape. Last month NASA announced that two of its space telescopes caught a huge burst of X-ray spewing out of a super massive black hole. These flairs appeared to be be triggered by the eruption of a charged particle from the black hole, which according to conventional belief doesn't let anything out. The latest findings are in accordance with the theory of Indian astrophysicist Abhas Mitra...

These tungsten ditelluride crystals behave as insulators for current applied in some directions and as conductors for current applied in other directions. The researchers found that this behavior is due to a newly theorized particle, the type-II Weyl fermion. Credit: Wudi Wang and N. Phuan Ong, Princeton University --------------------------------------------------------------------------------------------------------------------------------------- An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act as insulators for current applied in some directions and as conductors for current applied in other...

Gary Prezeau of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., describes the results of his theoretical model that goes some way to explain how streams of dark matter particles may interact with our planet's gravitational field. "A (dark matter) stream can be much larger than the solar system itself, and there are many different streams crisscrossing our galactic neighborhood," said Prézeau in a JPL press release. "When gravity interacts with the cold dark matter gas during galaxy formation, all particles within a stream continue traveling at the same velocity." As these streams begin to interact with a planet, according to...

Physics is built out of philosophically fascinating ideas. Or, at least, ideas that fascinate us as physicists. We are often moved to reverentially proclaim the beauty of various concepts and theories. Sometimes this beauty makes sense to other people (we're made of star stuff) and other times it's opaque (Frobenius manifolds in psuedo-Euclidean spaces). I have my own personal favorite idea. It arises from the philosophically fantastic (but mathematically moderate) workings of Einstein's relativity theory. The theory of special relativity holds that time and space are not separate entities, each operating on its own; rather they are intimately and inextricably...

Researchers have written quantum code on a silicon chip for the first time And so it begins... FIONA MACDONALD 17 NOV 2015           For the first time, Australian engineers have demonstrated that they can write and manipulate the quantum version of computer code on a silicon microchip. This was done by entangling two quantum bits with the highest accuracy ever recorded, and it means that we can now start to program for the super-powerful quantum computers of the future.Engineers code regular computers using traditional bits, which can be in one of two states: 1 or 0. Together, two bits...

Credit: NASA, ESA, S. Baum & C. O’Dea (RIT), R. Perley & W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA) =============================================================================================================== Scientists often use the combined power of multiple telescopes to reveal the secrets of the Universe – and this image is a prime example of when this technique is strikingly effective. The yellow-hued object at the centre of the frame is an elliptical galaxy known as Hercules A, seen by the Earth-orbiting NASA/ESA Hubble Space Telescope. In normal light, an observer would only see this object floating in the inky blackness of space. However, view Hercules A with...

Lasers could heat materials to temperatures hotter than the centre of the Sun in only 20 quadrillionths of a second, according to new research. Theoretical physicists from Imperial College London have devised an extremely rapid heating mechanism that they believe could heat certain materials to ten million degrees in much less than a million millionth of a second. The method, proposed here for the first time, could be relevant to new avenues of research in thermonuclear fusion energy, where scientists are seeking to replicate the Sun’s ability to produce clean energy. The heating would be about 100 times faster than...

Image: J021659-044920. The red and yellow lobes are the galaxy’s radio lobes. The red spot in the center is the visible galaxy. Prathamesh Tamhane/Yogesh Wadadekar. ================================================================================================================== Astronomers in India have discovered a very unusual galaxy, and it’s dying. By now, in fact, it’s probably already dead. The new galaxy, known as J021659-044920, is 9 billion light years away from Earth. That means it’s really old in cosmic terms (but not quite as old as the oldest object astronomers have ever found, a galaxy 13 billion light years away called UDFy-38135539). Viewed in the visible spectrum, J021659-044920spans about 100,000 light years...

On 15 June 2015, V404 Cygni (V404 Cyg), a binary system comprising a sun-like star orbiting a black hole, woke up. A huge outburst of energy across the electromagnetic spectrum 'lit up' the sky. The last such outburst was 1989. Dr Kunal Mooley, a Hintze Research Fellow at the University's Centre for Astrophysical Surveys works on cutting-edge research based on the discovery and detailed study of transients at radio and optical wavelengths using a wide range of telescope facilities such as the Jansky Very Large Array, the Arcminute Microkelvin Imager (AMI), the Palomar Transient Factory, and the Giant Meterwave Radio...

Caltech and The Feynman Lectures Website are pleased to present this online edition of The Feynman Lectures on Physics. Now, anyone with internet access and a web browser can enjoy reading a high quality up-to-date copy of Feynman's legendary lectures.

Researchers could be one step closer to producing energy through nuclear fusion with word that a device called the stellarator is set to go online later this year in Germany. The largest contraption its kind, the Wendelstein 7-X fusion device is housed in a branch of the Max Planck Institute for Plasma Physics (IPP) near Munich. It won’t actually produce energy, the Institute said, but will be used to test the “specially shaped magnet coils which produce a magnetic cage which confines the plasma and keeps it away from the walls of the plasma vessel.”

Explanation: What happens when a star gets too close to a black hole? Recent observations from Earth-orbiting observatories of an event dubbed ASASSN-14li, in a distant galactic center, appears to be giving one star's harrowing story. Although angularly unresolved, variations in high energy light indicate that some of the star became shredded and reformed into a disk swirling around the dark abyss. In the hypothesized scenario envisioned, a jet formed on the spin axis of the black hole. The innermost part of the disk, colored white, glows most strongly in X-rays and may drive a periodic wind, shown in blue....

Photonic devices, which use light to transport large amounts of information quickly, have the potential to enhance or even replace the electronic devices that are ubiquitous in our lives today. But before such optical connections can be integrated into telecommunication systems and computers, researchers need to make it easier to manipulate light at the nanoscale. A new on-chip zero-index metamaterial makes this possible, opening the door for technological innovation and research. This new metamaterial was developed in the lab of Eric Mazur at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), and is described in the...

Explanation: What happens when two black holes collide? This extreme scenario likely occurs in the centers of some merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield. The black regions indicate the event horizons of the dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined Einstein ring. All background stars not only have images visible outside of this Einstein ring, but also have one or more companion images...

The Universe Never Expands Faster Than the Speed of Light Breaking my radio silence here to get a little nitpick off my chest: the claim that during inflation, the universe “expanded faster than the speed of light.” It’s extraordinarily common, if utterly and hopelessly incorrect. (I just noticed it in this otherwise generally excellent post by Fraser Cain.) A Google search for “inflation superluminal expansion” reveals over 100,000 hits, although happily a few of the first ones are brave attempts to squelch the misconception. I can recommend this nice article by Tamara Davis and Charlie Lineweaver, which tries to address...

Scientists at TU Wien (Vienna) have calculated that the meson f0(1710) could be a very special particle -- the long-sought-after glueball, a particle composed of pure force. The prediction that glueballs exist is one of the most important of the Standard Model of particle physics that has not yet been confirmed experimentally. For decades, scientists have been looking for so-called "glueballs". Now it seems they have been found at last. A glueball is an exotic particle, made up entirely of gluons -- the "sticky" particles that keep nuclear particles together. Glueballs are unstable and can only be detected indirectly, by...