A new imaging system could help us see deeper into the universe than ever before. The same powerful technology could also help us analyze the chemical makeup of everyday materials such as food and medicines much faster and with greater accuracy than current methods.
In a study published in the journal Nature, researchers from Tsinghua University in China have introduced a tiny device called RAFAEL (Reconfigurable, Adaptive, FAst and Efficient Lithium-niobate spectro-imager) that uses advanced photonics to capture light in exceptional detail with high speed.
RAFAEL is designed to dramatically improve spectroscopy, the technique used to study the physical structure and chemical composition of matter. It is used for everything from mapping deep space to checking for contaminants in water and diagnosing diseases, and it works by breaking down the light that comes from an object and analyzing the different colors (wavelengths). While incredibly powerful, traditional spectrometers often face a trade-off: To get very fine detail you have to block much of the light. Or if you let in a lot of light, you lose resolution or sensitivity.
In 1867, Lord Kelvin imagined atoms as knots in the aether. The idea was soon disproven. Atoms turned out to be something else entirely. But his discarded vision may yet hold the key to why the universe exists.
Now, for the first time, Japanese physicists have shown that knots can arise in a realistic particle physics framework, one that also tackles deep puzzles such as neutrino masses, dark matter, and the strong CP problem.
Their findings, in Physical Review Letters, suggest these “cosmic knots” could have formed and briefly dominated in the turbulent newborn universe, collapsing in ways that favored matter over antimatter and leaving behind a unique hum in spacetime that future detectors could listen for—a rarity for a physics mystery that’s notoriously hard to probe.
3D printing is extremely practical when you want to produce small quantities of customized components. However, this technology has always had one major problem: 3D printers can only process a single material at a time. Until now, objects with different material properties in different areas could only be 3D-printed at great expense, if at all.
Researchers at TU Wien have now developed methods for giving a 3D-printed object not only the desired shape, but also the desired material properties, point by point.
The versatility of this technology has been demonstrated in several applications: for example, it is possible to print an invisible QR code that only becomes visible at certain temperatures.
You can’t have gold until a nucleus decays. The specifics of that process have been hard to pin down, but UT’s nuclear physicists have published three discoveries in one paper explaining key details. The results can help scientists come up with new models to describe the stellar processes that give us heavy elements, as well as make better predictions about the expanding landscape of exotic nuclei.
The work is published in the journal Physical Review Letters.
To meet the growing demands of flexible and wearable electronic systems, such as smart watches and biomedical sensors, electronics engineers are seeking high-performance transistors that can efficiently modulate electrical current while maintaining mechanical flexibility.
Thin-film transistors (TFTs), which are comprised of thin layers of conducting, semiconducting and insulating materials, have proved to be particularly promising for large-area flexible and wearable electronics, while also enabling the creation of thinner displays and advanced sensors.
Despite their potential, the energy-efficiency with which these transistors can switch electrical current has proved difficult to improve. This is due to the so-called thermionic limit, a theoretical threshold that delineates the lowest possible voltage required for a transistor to boost electrical current by a factor of 10 at room temperature when switching between “off” and “on” states.
A research team has developed an innovative parameter, FoMLUE, to evaluate the potential of photoactive materials for semi-transparent organic photovoltaics (ST-OPVs), paving the way for their widespread commercial applications.
A paper reporting the research, “Semitransparent organic photovoltaics with wide geographical adaptability as sustainable smart windows,” has been published in Nature Communications.
Transparent solar cells can be integrated into windows, screens and other surfaces, with immense potential for them to revolutionize the renewable energy sector. However, there are challenges to overcome, one of which is balancing transparency with power conversion efficiency.
A team of astronomers led by Paulo Cortes, a scientist with the U.S. National Science Foundation National Radio Astronomy Observatory and the Joint ALMA Observatory, have made a groundbreaking discovery about how young star systems grow.
Using the powerful Atacama Large Millimeter/submillimeter Array (ALMA), their team observed— for the first time ever— a narrow, spiral-shaped streamer of gas guided by magnetic fields, channeling matter from the surrounding cloud of a star-forming region in Perseus, directly onto a newborn binary star system.
The work is published in The Astrophysical Journal Letters.
As far as particles of light are concerned, the collective is more important than the individual. When they get to decide between two states, they will favor the one that many of their fellow particles have already adopted. However, this collectivist tendency does not kick in until enough photons have assembled in the same place.
If you think of a single atom as a grain of sand, then a wavelength of visible light—which is a thousand times larger than the atom’s width—is comparable to an ocean wave. The light wave can dwarf an atom, missing it entirely as it passes by. This gulf in size has long made it impossible for scientists to see and resolve individual atoms using optical microscopes alone.
Only recently have scientists found ways to break this “diffraction limit,” to see features that are smaller than the wavelength of light. With new techniques known as super-resolution microscopy, scientists can see down to the scale of a single molecule.
And yet, individual atoms have still been too small for optical microscopes —which are much simpler and less expensive than super-resolution techniques—to distinguish, until now.