Lifeboat Foundation

The way electrons interact with photons of light is a vital part of many modern technologies, from lasers to solar panels to LEDs. But the interaction is inherently weak because of a major mismatch in scale: the wavelength of visible light is about 1,000 times larger than an electron, so the way the two things affect each other is limited by that disparity.

Now, researchers at The University of Hong Kong (HKU), MIT and other universities say they have come up with an innovative way to make more robust interactions between photons and electrons possible, that produces a hundredfold increase in the emission of light from a phenomenon called Smith-Purcell radiation. The findings have potential ramifications for both commercial applications and fundamental scientific research, although it will require more years of investigation to put into practice.

The findings are published in Nature by Dr. Yi Yang (Assistant Professor of the Department of Physics at HKU and a former postdoc at MIT), Dr. Charles Roques-carmes (Postdoctoral Associate at MIT) and Professors Marin Soljačić and John Joannopoulos (MIT professors). The research team also included Steven Kooi at MIT’s Institute for Soldier Nanotechnologies, Haoning Tang and Eric Mazur at Harvard University, Justin Beroz at MIT, and Ido Kaminer at Technion-Israel Institute of Technology.

Chemists from Rice University and the University of Texas at Austin discovered more isn’t always better when it comes to packing charge-acceptor molecules on the surface of semiconducting nanocrystals.

The combination of organic and inorganic components in hybrid nanomaterials can be tailored to capture, detect, convert or control light in unique ways. Interest in these materials is high, and the pace of scientific publication about them has grown more than tenfold over the past 20 years. For example, they could potentially improve the efficiency of solar power systems by harvesting energy from wavelengths of sunlight—like infrared—that are missed by traditional photovoltaic solar panels.

To create the materials, chemists marry nanocrystals of light-capturing semiconductors with “charge acceptor” molecules that act as ligands, attaching to the semiconductor’s surface and transporting electrons away from the nanocrystals.

After over a decade of research and testing, Caltech’s Space Solar Power Demonstrator arrived above Earth on Tuesday to begin testing.

A new demo from Caltech will test the viability of unlimited solar power beamed back to Earth from orbit.

A new demo from Caltech is set to launch in January 2023, and it could shake up the way we collect and harvest solar power in the future.

Continue reading “We’re about to get our first demonstration of space-based solar power” »

This month, NASA launched a new Earth-monitoring satellite that will observe fresh water systems across the planet. Now, the satellite has unfurled in space ready to begin science operations, and NASA has shared a video showing the unfolding process.

Named the Surface Water and Ocean Topography (SWOT) satellite, it had been folded up to fit inside the SpaceX Falcon 9 rocket which launched it from Vandenberg Space Force Base in California on December 16. Once the satellite reached space, it had to deploy its solar panel arrays, then unfold its mast and antenna panels. While deploying the solar panel arrays was a quick process, taking place shortly after launch, the unfolding of the antennae was much more involved and took four days.

As the SWOT satellite has a camera at the end of its long master, used for its Ka-band Radar Interferometer (KaRIn) instrument, these cameras were able to capture the unfolding process on video. This instrument is a new type of interferometer that will be able to see the depth of fresh water bodies such as lakes and rivers by using radar pulses. It sends two radar pulses down to the surface with a slight offset, allowing researchers to see the depth of these features. This is possible because of the wide spread of its two antennae, spaced 10 meters apart.

Thus, our SUVI observations captured direct imprints and dynamics of this S-web in the middle corona. For instance, consider the wind streams presented in Fig. 1. Those outflows emerge when a pair of middle-coronal structures approach each other. By comparing the timing of these outflows in Supplementary Video 5, we found that the middle-coronal structures interact at the cusp of the southwest pseudostreamer. Similarly, wind streams in Supplementary Figs. 1 – 3 emerge from the cusps of the HCS. Models suggest that streamer and pseudostreamer cusps are sites of persistent reconnection^30,31. The observed interaction and continual rearrangement of the coronal web features at these cusps are consistent with persistent reconnection, as predicted by S-web models. Although reconnection at streamer cusps in the middle corona has been inferred in other observational studies^32,33 and modelled in three dimensions^30,31, the observations presented here represent imaging signatures of coronal web dynamics and their direct and persistent effects. Our observations suggest that the coronal web is a direct manifestation of the full breadth of S-web in the middle corona. The S-web reconnection dynamics modulate and drive the structure of slow solar wind through prevalent reconnection^9,18.

A volume render of log Q highlights the boundaries of individual flux domains projected into the image plane, revealing the existence of substantial magnetic complexity within the CH–AR system (Fig. 3a and Supplementary Video 7). The ecliptic view of the 3D volume render of log Q with the CH–AR system at the west limb does closely reproduce elongated magnetic topological structures associated with the observed coronal web, confined to northern and southern bright (pseudo-)streamers (Fig. 3b and Supplementary Video 8). The synthetic EUV emission from the inner to middle corona and the white-light emission in the extended corona (Fig. 3c) are in general agreement with structures that we observed with the SUVI–LASCO combination (Fig. 1a). Moreover, radial velocity sliced at 3 R _☉ over the large-scale HCS crossing and the pseudostreamer arcs in the MHD model also quantitatively agree with the observed speeds of wind streams emerging from those topological features (Supplementary Figs. 4 and 6 and Supplementary Information). Thus, the observationally driven MHD model provides credence to our interpretation of the existence of the complex coronal web whose dynamics correlate to the release of wind streams.

The long lifetime of the system allowed us to probe the region from a different viewpoint using the Sun-orbiting STEREO-A, which was roughly in quadrature with respect to the Sun–Earth line during the SUVI campaign (Methods and Extended Data Fig. 6). By combining data from Solar Terrestrial Relations Observatory-Ahead’s (STEREO-A) extreme ultraviolet imager (EUVI)³⁴, outer visible-light coronagraph (COR-2) and the inner visible-light heliospheric imager (HI-1)³⁵, we found imprints of the complex coronal web over the CH–AR system extending into the heliosphere. Figure 4a and the associated Supplementary Video 9 demonstrate the close resemblance between highly structured slow solar wind streams escaping into the heliosphere and the S-web-driven wind streams that we observed with the SUVI and LASCO combination. Due to the lack of an extended field of view, the EUVI did not directly image the coronal web that we observed with SUVI, demonstrating that the SUVI extended field-of-view observations provide a crucial missing link between middle-coronal S-web dynamics and the highly structured slow solar wind observations.

NASA’s unmanned Artemis mission to the moon was a small step toward the ultimate goal of sending humans to Mars and beyond.

The second goal was to figure out how to settle and exploit the resources of the moon for research teams by the middle of the following decade.

In November 2021, while the municipal utility in Marburg, Germany, was performing scheduled maintenance on a hot water storage facility, engineers glued 18 solar panels to the outside of the main 10-meter-high cylindrical tank. It’s not the typical home for solar panels, most of which are flat, rigid silicon and glass rectangles arrayed on rooftops or in solar parks. The Marburg facility’s panels, by contrast, are ultrathin organic films made by Heliatek, a German solar company. In the past few years, Heliatek has mounted its flexible panels on the sides of office towers, the curved roofs of bus stops, and even the cylindrical shaft of an 80-meter-tall windmill. The goal: expanding solar power’s reach beyond flat land. “There is a huge market where classical photovoltaics do not work,” says Jan Birnstock, Heliatek’s chief technical officer.

Organic photovoltaics (OPVs) such as Heliatek’s are more than 10 times lighter than silicon panels and in some cases cost just half as much to produce. Some are even transparent, which has architects envisioning solar panels not just on rooftops, but incorporated into building facades, windows, and even indoor spaces. “We want to change every building into an electricity-generating building,” Birnstock says.

Heliatek’s panels are among the few OPVs in practical use, and they convert about 9% of the energy in sunlight to electricity. But in recent years, researchers around the globe have come up with new materials and designs that, in small, labmade prototypes, have reached efficiencies of nearly 20%, approaching silicon and alternative inorganic thin-film solar cells, such as those made from a mix of copper, indium, gallium, and selenium (CIGS). Unlike silicon crystals and CIGS, where researchers are mostly limited to the few chemical options nature gives them, OPVs allow them to tweak bonds, rearrange atoms, and mix in elements from across the periodic table. Those changes represent knobs chemists can adjust to improve their materials’ ability to absorb sunlight, conduct charges, and resist degradation. OPVs still fall short on those measures. But, “There is an enormous white space for exploration,” says Stephen Forrest, an OPV chemist at the University of Michigan, Ann Arbor.

A little shade could be helpful for some crops and reduce carbon emissions.