The mission has concluded that the solar-powered lander has run out of energy after more than four years on the Red Planet.
Bubbles are ubiquitous, existing in everything from the foam on a beer to party toys for children. Despite this pervasiveness, there are open questions on the behavior of bubbles, such as why some bubbles are more resistant to bursting than others. Now Francois Boulogne and colleagues from the University of Paris-Saclay have taken a step toward answering that question by measuring the temperature of the film surrounding a soap bubble, finding that it can be significantly lower than that of its local environment [1]. The team says that the result could help industrial manufacturers of bubbles better control the stability of their products.
On a sunny day, our bodies cool down by releasing energy into the environment through the evaporation of sweat. Soap films also release energy by losing liquid via evaporation. Researchers studying bubbles have tracked the evaporation of a soap film’s liquid content under different conditions. But those experiments all assumed that the film’s temperature matched that of the environment, an assumption the results of Boulogne and his colleagues challenge.
In their experiments Boulogne and colleagues created a soap bubble from a mixture made of dishwashing liquid, water, and glycerol. They then measured the soap film’s temperature under a variety of environmental conditions. They found that the film could be up to 8 °C colder than the surrounding air. They also found that glycerol content of the soap film impacted this temperature difference, with films containing more glycerol having higher temperatures. Boulogne says that such a large temperature difference could impact bubble stability. But, he adds, further experiments are needed to corroborate that idea.
In physics, weak microwave signals can be amplified with minimal added noise. For instance, artificial quantum systems based on superconducting circuits can amplify and detect single microwave patterns, although at millikelvin temperatures. Researchers can use natural quantum systems for low-noise microwave amplification via stimulated emission effects; however, they generate a higher noise at functionalities greater than 1 Kelvin.
In this new work, published in the journal Science Advances, Alexander Sherman and a team of scientists in chemistry at the Technical-Israel Institute of Technology, Haifa, used electron spins in diamond as a quantum microwave amplifier to function with quantum-limited internal noise above liquid nitrogen temperatures. The team reported details of the amplifier’s design, gain, bandwidth, saturation power and noise to facilitate hitherto unavailable applications in quantum science, engineering and physics.
A few weeks ago, the Defense Advanced Research Projects Agency (DARPA) quietly unveiled a new high-speed missile program called Gambit. The program is meant to leverage a novel method of propulsion that could have far-reaching implications not just in terms of weapons development, but for high-speed aircraft and even in how the Navy’s warships are powered.
This propulsion system, known as a rotation detonation engine (RDE), has the potential to be lighter than existing jet engines while offering a significant boost in power output, range, and fuel efficiency.
Continue reading “The game-changing tech in DARPA’s new missile” »
Rethinking questions and chasing patterns led Newton to find the connection between curves and infinite sums.
The large-scale structure (LSS) of the Universe is obviously nonlinear and very complicated. However, the scale of onset of nonlinearity is well separated from the size of the Universe which makes a large portion of the structure formation modes accessible to perturbation theory (PT). The latter is itself complicated by the time dependence of the lambdaCDM background. The authors provide an exact all-order recursive solution for the PT kernels, which allows them to go beyond the Einstein-de Sitter approximation for the time dependence, and quantify the deviation at the two-loop level in the 10% range, a deviation detectible with upcoming observations.
Lawrence Livermore National Laboratory (LLNL) scientists have created vertically aligned single-walled carbon nanotubes on metal foils that could be a boon for energy storage and the electronics industry.
Vertically aligned carbon nanotubes (VACNTs) have exceptional mechanical, electrical and transport properties in addition to an aligned architecture, which is key for applications such as membrane separation, thermal management, fiber spinning, electronic interconnects and energy storage.
To date, widespread integration of VACNTs into next-generation technologies is thwarted by a lack of compatible, economic, mass-production capabilities. High-quality VACNTs are typically made on substrates such as silicon (Si) or quartz wafers that are rigid, expensive and electrically insulating.
This does not bode well for eco-friendly renewables.
Last month, Europe supported a call by India to phase down fossil fuel use as part of a COP27 deal. Now, partially due to the Russian-Ukrainian war, it seems to be changing its mind.
These projects amount to total investments of more than NOK 200 billion (around $20.
Building a wind power operation that can thrive in icy conditions requires a keen understanding of the underlying physics.
Winter is supposed to be the best season for wind power — the winds are more potent, and since air density increases as the temperature drops, more force is pushing on the blades. But winter also comes with a problem: freezing weather.
Continue reading “How do wind turbines spin during winter? The science behind frozen blades” »
Heat-transport measurements and neutron-scattering spectroscopy probe a form of thermal conduction based on excitations called phasons.
The understanding of how substances conduct heat is of great significance in materials science. It is needed for many important technological applications—from heat management in electronics to temperature control in buildings [1]. Therefore, when an unusual form of thermal transport is identified, materials scientists take notice. Michael Manley of Oak Ridge National Laboratory, Tennessee, and his colleagues have shown that excitations called phasons can provide the main contribution to thermal transport in a material known as fresnoite [2]. Phasons are collective lattice oscillations that occur in certain crystals with an aperiodic lattice structure—fresnoite being one of the best known. The researchers’ demonstration could pave the way for new heat-management strategies.
Thermal conductivity is a measure of a material’s ability to transfer heat. It is a property that we are all abruptly reminded of when we accidentally place our hand on a hot kitchen stove. The temperature gradient between our cooler skin and the hotter surface facilitates a transfer of energy into our hand, resulting in an unpleasant sensation. The notion that different materials conduct heat at different rates is similarly experienced when we perceive the cooling sensation of holding a metal spoon relative to a wooden one.
