Omega Centauri is visible from Earth with the naked eye and is one of the favorite celestial objects for stargazers from the southern hemisphere.
Although the cluster is 17,000 light-years away, located just above the plane of the Milky Way, it appears almost as large as the full Moon when the cluster is seen from a dark rural area.
Exactly how Omega Centauri should be classified has always been a contentious topic. It was first listed in Ptolemy’s catalogue nearly two thousand years ago as a single star. Edmond Halley reported it as a nebula in 1677. In the 1830s the English astronomer John Herschel was the first to recognise it as a globular cluster.
Now, more than a century later, this new result suggests Omega Centauri is not a globular cluster at all, but a dwarf galaxy stripped of its outer stars.
Torn posters, tape and tomato skins may seem like strange research topics for physicists and applied mathematicians, but it's perfectly normal for a team of researchers from the Centre National de la Recherche Scientifique (CNRS) in Paris, the Universidad de Santiago, Chile, and MIT.
Such real-world applications are not only fun to study, but “we can really learn things that will be useful for industry and help us understand the everyday world around us. It is also a great way to motivate students to be interested in science,” says Pedro Reis, one of the authors of the paper and an applied mathematics instructor at MIT.
So they have tackled the issue of why wallpaper never comes off the way you want it. “You want to redecorate your bedroom, so you yank down the wallpaper. You wish that the flap would tear all the way down to the floor, but it comes together in a triangle and you have to start all over again,” said
3-D images are very useful in medicine and now they're gaining ground in physics. Researchers from Hahn-Meitner-Institute (HMI) and the University of Applied Science in Berlin have succeeded in creating a direct, three-dimensional visualization of magnetic fields inside solid, non-transparent materials for the first time.
This could prove invaluable because to understand high temperature superconductivity it is vital to understand how magnetic flux lines are distributed and how these flux lines can be established in materials. With this new experimental setup, it is now possible to visualize magnetic domains in magnetic crystals three-dimensionally.
The researchers in the imaging group used neutrons, subatomic particles that have zero net charge, but do have a magnetic moment, making them ideal for investigating magnetic phenomena in magnetic materials.
While space science has long been excited about advancements in the millimeter-wavelength/terahertz spectra, its potential in biology has been largely untapped. However, since THz radiation primarily excites vibrational modes present in water, imaging of soft tissues could also show a lot of improvement.
Terahertz systems are currently used to do things like examine hidden layers under old artwork
and stop terrorists by seeing through clothes
but they could be used in bio-technology to find genetic mutations without using invasive or toxic fluorescent dyes.
An important step toward that is development of handheld terahertz devices that could replace the bulky, expensive systems available now. Researchers at the the Universities of Leeds and Harvard say a quantum cascade laser is the way to go for small and portable terahertz technology.
Superconductors are materials that conduct electrical currents without any loss below a certain temperature. Normally, high magnetic fields destroy superconductivity, turning the material into a normal conductor.
Novel experiments on organic superconductors revealed a new superconducting phase between the normal conducting and the superconducting state.
Prof. Peter Fulde from the Max Planck Institute for the Physics of Complex Systems in Dresden and Prof. Richard Ferrell predicted the existence of this special superconducting state in 1964, characterized by a spatial modulation of the superconductivity. At about the same time, two further researchers independently predicted the same phase. Therefore, the state is called Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state.
The methodology behind constructing a quantum channel between Space and Earth got a big boost as a research team, led by Paolo Villoresi and Cesare Barbieri from Padova University, have been able to identify individual returning photons after firing and reflecting them off of a space satellite in orbit almost 1,500 kilometres above the earth.
They say their work improves the feasibility of building a completely secure channel for global communication, via satellites in space, using quantum mechanics.
The research team fired photons directly at the Japanese Ajisai Satellite and have been able to prove that the photons received back at the Matera ground-based station, in southern Italy, are the same as those originally emitted.
Graphene, a single-atom-thick sheet of graphite, is a new material which combines aspects of semiconductors and metals.
University of Maryland physicists have shown that in graphene the intrinsic limit to the mobility, a measure of how well a material conducts electricity, is higher than any other known material at room temperature - and 100 times faster than in silicon.
A team of researchers led by physics professor Michael S. Fuhrer of the university's Center for Nanophysics and Advanced Materials, and the Maryland NanoCenter said the findings are the first measurement of the effect of thermal vibrations on the conduction of electrons in graphene, and show that thermal vibrations have an extraordinarily small effect on the electrons in graphene.
Researchers at the National Institute of Standards and Technology (NIST) have set the stage for building the “evolutionary link” between the microelectronics of today built from semiconductor compounds and future generations of devices made largely from complex organic molecules. In an upcoming paper in the Journal of the American Chemical Society, a NIST team demonstrates that a single layer of organic molecules can be assembled on the same sort of substrate used in conventional microchips.
The ability to use a silicon crystal substrate that is compatible with the industry-standard CMOS (complementary metal oxide semiconductor) manufacturing technology paves the way for hybrid CMOS-molecular device circuitry—the necessary precursor to a “beyond CMOS” totally molecular technology—to be fabricated in the near future.
Side and top views of the NIST molecular resistor. Above are schematics showing a cross-section of the full device and a close-up view of the molecular monolayer attached to the CMOS-compatible silicon substrate. Below is a photomicrograph looking down on an assembled resistor indicating the location of the well. Credit: NIST
Researchers at NIST and the Joint Quantum Institute (NIST/University of Maryland) have developed a new method for creating pairs of entangled photons, particles of light whose properties are interlinked in a very unusual way dictated by the rules of quantum physics. The researchers used the photons to test one of the fundamental concepts in quantum theory.
In the experiment, the researchers sent a pulse of light into both ends of a twisted loop of optical fiber. Pairs of photons of the same color traveling in either direction will, every so often, interact in a process known as “four-wave mixing,” converting into two new, entangled photons, one that is redder and the other that is bluer than the originals.
Three-dimensional view of photon-induced fragmentation of a deuterium molecule, showing the angular distribution of one ejected electron in the plane containing the molecular and light polarization axes. Another escaping electron of the same energy is emitted upwards out of the plane. The direction of the molecular axis is given by the exploding nuclei (in green). Credit: Lawrence Berkeley National Lab
Everyone knows computer chips have increased in speed and shrunk in size over the past few decades and their interconnects, the copper wires that transport signals around the chip and to other chips, have shrunk also. As interconnects get smaller, the copper’s resistance increases and its ability to conduct electricity degrades. This means fewer electrons are able to pass through the copper successfully, and any lingering electrons are expressed as heat. This heat can have negative effects on both a computer chip’s speed and performance.
The $260 billion semiconductor industry won't get too excited just yet but they have to take notice of a Rensselaer Polytechnic Institute study comparing the performance of copper nanowires and carbon nanotube bundles for interconnects. It is the first study to examine copper nanowire using quantum mechanics rather than empirical laws.