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Although the universe is expanding at an accelerating rate today, this paper presents a simple mechanism by which a dynamical form of dark energy (known as quintessence) could cause the acceleration to come to end and smoothly transition from expansion to a phase of slow contraction. That raises questions, How soon could this transition occur? And at what point would it be detectable? The conclusions are that the transition could be surprisingly soon, maybe less than 100 million y from now, and yet, for reasons described in the main text, it is not yet detectable today. The scenario is not far-fetched. In fact, it fits naturally with recent theories of cyclic cosmology and conjectures about quantum gravity.

“there’s a new record to report: a new solar cell has hit 39.5 percent efficiency ”.


Scientists keep on pushing the efficiency of solar panels higher and higher, and there’s a new record to report: a new solar cell has hit 39.5 percent efficiency under the standard 1-sun global illumination conditions.

That 1-sun marker is simply a standardized way of measuring a fixed amount of sunlight, and almost 40 percent of that radiation can now be converted into electricity. The previous record for this type of solar panel material was 39.2 percent efficiency.

There are more types of solar cells around than you might have realized. The type used here, triple-junction III-V tandem solar cells, are often deployed in satellites and space vehicles, though they have plenty of potential here on solid ground as well.

Just as electromagnetic energy is quantized into propagating photons, acoustic energy propagates in quanta called phonons. The science of photon behaviour – called quantum electrodynamics – is an important branch of modern physics because it provides a relativistic description of the interaction of light with matter. Scientists have used the theory in a variety of applications such as atomic clocks and quantum computation. In recent years, scientists have begun applying some of the same concepts to phonons in a field called quantum acoustodynamics. Last year, for example, two groups independently used laser-based measurements to entangle the oscillations of membranes in cavities.

Circa 2020 Electricity free grow lights using quantum dot leds.


While costs are coming down for controlled environment agriculture, electricity remains one of the highest because it has to power the LEDs that provide the lighting formula for plant growth. But a materials science company called UbiQD wants to change that by replacing electricity with a more efficient means of lighting: quantum dots.

Quantum dots are semiconductor nanoparticles that can transport electrons. When exposed to UV lighting, these particles emit lights of various colors, and can be adjusted in size to emit a specific color. For example, larger particles emit redder wavelengths, while smaller ones shift to blue.

Via its UbiGro product, UbiQD uses a patented quantum dot technology to create a layer of lighting in greenhouses. Quantum dots are embedded into a film that is installed beneath a greenhouse cover. When illuminated by sunlight, the film converts shorter wavelengths (UV and blue) to longer ones (red/orange), the latter being the most photosynthetically efficient wavelengths.

From TVs, to solar cells, to cutting-edge cancer treatments, quantum dots are beginning to exhibit their unique potential in many fields, but manufacturing them at scale would raise some issues concerning the environment. Scientists at Japan’s Hiroshima University have demonstrated a greener path forward in this area, by using discarded rice husks to produce the world’s first silicon quantum dot LED light.

“Since typical quantum dots often involve toxic material, such as cadmium, lead, or other heavy metals, environmental concerns have been frequently deliberated when using nanomaterials,” said Ken-ichi Saitow, lead study author and a professor of chemistry at Hiroshima University. “Our proposed process and fabrication method for quantum dots minimizes these concerns.”

The type of quantum dots pursued by Saitow and his team are silicon quantum dots, which eschew heavy metals and offer some other benefits, too. Their stability and higher operating temperatures makes them one of the leading candidates for use in quantum computing, while their non-toxic nature also makes them suitable for use in medical applications.

Researchers from PSI’s Spectroscopy of Quantum Materials group together with scientists from Beijing Normal University have solved a puzzle at the forefront of research into iron-based superconductors: the origin of FeSe’s electronic nematicity. Using Resonant inelastic X-ray scattering (RIXS) at the Swiss Light Source (SLS), they discovered that, surprisingly, this electronic phenomenon is primarily spin driven.

Electronic nematicity is believed to be an important ingredient in high-temperature superconductivity, but whether it helps or hinders it is still unknown.

Their findings are published in Nature Physics (“Spin-excitation anisotropy in the nematic state of detwinned FeSe”).

Try to picture a proton — the tiny, positively charged particle within an atomic nucleus — and you may envision a familiar, textbook diagram: a bundle of billiard balls representing quarks and gluons. From the solid sphere model first proposed by John Dalton in 1,803 to the quantum model put forward by Erwin Schrödinger in 1926, there is a storied timeline of physicists attempting to visualize the invisible.

There’s a key aspect of quantum computing you may not have thought about before. Called ‘quantum non-demolition measurements’, they refer to observing certain quantum states without destroying them in the process.

If we want to put together a functioning quantum computer, not having it break down every second while calculations are made would obviously be helpful. Now, scientists have described a new technique for recording quantum non-demolition measurements that shows a lot of promise.

In this case, the research involved mechanical quantum systems – objects that are relatively large in quantum computing terms, but exceedingly tiny for us. They use mechanical motion (such as vibration) to handle the necessary quantum magic, and they can be combined with other quantum systems too.