Lifeboat Foundation

Scientists typically prefer to work with ordered systems. However, a diverse team of physicists and biophysicists from the University of Groningen found that individual light-harvesting nanotubes with disordered molecular structures still transport light energy in the same way. By combining spectroscopy, molecular dynamics simulations and theoretical physics, they discovered how disorder at the molecular level is effectively averaged out at the microscopic scale. The results were published on 28 September in the Journal of the American Chemical Society.

The double-walled light-harvesting nanotubes self-assemble from molecular building blocks. They are inspired by the multi-walled tubular antenna network of photosynthetic bacteria found in nature. The nanotubes absorb and transport light energy, although it was not entirely clear how. “The nanotubes have similar sizes but they are all different at the molecular level with the molecules arranged in a disordered way,” explains Maxim Pshenichnikov, Professor of Ultrafast Spectroscopy at the University of Groningen.

Researchers say cooling 13,000 years ago is coincident with major volcanic eruption.

Texas researchers from the University of Houston, Baylor University and Texas A&M University have discovered evidence for why the earth cooled dramatically 13,000 years ago, dropping temperatures by about 3 degrees Centigrade.

The evidence is buried in a Central Texas cave, where horizons of sediment have preserved unique geochemical signatures from ancient volcanic eruptions — signatures previously mistaken for extraterrestrial impacts, researchers say.

Continue reading “Sediment Discovered in Texas Cave Upends Meteorite Explanation for Global Cooling” »

SLAC invention uses terahertz radiation to power a miniscule copper accelerator structure.

Particle accelerators generate high-energy beams of electrons, protons and ions for a wide range of applications, including particle colliders that shed light on nature’s subatomic components, X-ray lasers that film atoms and molecules during chemical reactions and medical devices for treating cancer.

As a rule of thumb, the longer the accelerator, the more powerful it is. Now, a team led by scientists at the Department of Energy’s SLAC National Accelerator Laboratory has invented a new type of accelerator structure that delivers a 10 times larger energy gain over a given distance than conventional ones. This could make accelerators used for a given application 10 times shorter.

Continue reading “Invention Using Terahertz Radiation Could Make Particle Accelerators 10 Times Smaller” »

Astrophysicists at the University of Jena (Germany) prove that dust particles in space are mixed with ice.

The matter between the stars in a galaxy – called the interstellar medium – consists not only of gas, but also of a great deal of dust. At some point in time, stars and planets originated in such an environment, because the dust particles can clump together and merge into celestial bodies. Important chemical processes also take place on these particles, from which complex organic – possibly even prebiotic – molecules emerge. However, for these processes to be possible, there has to be water. In particularly cold cosmic environments, water occurs in the form of ice. Until now, however, the connection between ice and dust in these regions of space was unclear. A research team from Friedrich Schiller University Jena and the Max Planck Institute for Astronomy has now proven that the dust particles and the ice are mixed. They report their findings in the current issue of the research journal Nature Astronomy.

Better modelling of physico-chemical processes in space.

Physicists at Chalmers, together with colleagues in Russia and Poland, have managed to achieve ultrastrong coupling between light and matter at room temperature. The discovery is of importance for fundamental research and might pave the way for advances within, for example, light sources, nanomachinery, and quantum technology.

A set of two coupled oscillators is one of the most fundamental and abundant systems in physics. It is a very general toy model that describes a plethora of systems ranging from guitar strings, acoustic resonators, and the physics of children’s swings, to molecules and chemical reactions, from gravitationally bound systems to quantum cavity electrodynamics. The degree of coupling between the two oscillators is an important parameter that mostly determines the behavior of the coupled system. However, the question is rarely asked about the upper limit by which two pendula can couple to each other – and what consequences such coupling can have.

The newly presented results, published in Nature Communications, offer a glimpse into the domain of the so-called ultrastrong coupling, wherein the coupling strength becomes comparable to the resonant frequency of the oscillators. The coupling in this work is realized through interaction between light and electrons in a tiny system consisting of two gold mirrors separated by a small distance and plasmonic gold nanorods. On a surface that is a hundred times smaller than the end of a human hair, the researchers have shown that it is possible to create controllable ultrastrong interaction between light and matter at ambient conditions – that is, at room temperature and atmospheric pressure.

Continue reading “Physicists Play With the Laws of Nature: Controlling Ultrastrong Light-Matter Coupling at Room Temperature” »

Lil bits of info on DNA methylation, clocks.

Breakthrough advances in medicine and better nutrition have dramatically improved the longevity of the average human over the past two centuries. But that’s not to say that some couldn’t go on to live a long life even before the advent of modern medicine. As long as they were spared by disease, wars, and other risks that can bring an untimely death, humans could live to see their 70s, 80s, and even reach 100 years old as far back as ancient Rome.

The longevity of humans is somewhat exceptional among primates. Chimpanzees, our closest living relatives, rarely make it past age 50, despite them sharing over 99% of our DNA. In a new study, researchers think they’ve found our secret: chemical changes along our genome that occurred around 7–8 million years ago when our ancestors branched away from the lineage of chimps.

Continue reading “Humans live much longer than chimps due to a slower epigenetic ‘clock’” »

Particle accelerators generate high-energy beams of electrons, protons and ions for a wide range of applications, including particle colliders that shed light on nature’s subatomic components, X-ray lasers that film atoms and molecules during chemical reactions and medical devices for treating cancer.

As a rule of thumb, the longer the accelerator, the more powerful it is. Now, a team led by scientists at the Department of Energy’s SLAC National Accelerator Laboratory has invented a new type of accelerator structure that delivers a 10 times larger energy gain over a given distance than conventional ones. This could make accelerators used for a given application 10 times shorter.

The key idea behind the technology, described in a recent article in Applied Physics Letters, is to use terahertz radiation to boost particle energies.

Physicists at Chalmers University of Technology in Sweden, together with colleagues in Russia and Poland, have managed to achieve ultra-strong coupling between light and matter at room temperature. The discovery is of importance for fundamental research and might pave the way for advances in light sources, nanomachinery and quantum technology.

A set of two coupled oscillators is one of the most fundamental and widely used systems in physics. It is a very general toy model that describes a plethora of systems including guitar strings, acoustic resonators, the physics of children’s swings, molecules and chemical reactions, gravitationally bound systems, and quantum cavity electrodynamics.

The degree of coupling between the two oscillators is an important parameter that mostly determines the behavior of the coupled system. However, not much is known about the upper limit by which two pendula can couple to each other—and what consequences such coupling can have.

Researchers have created a molecule in a single, precisely characterized quantum state by merging two carefully prepared atoms.

Researchers have demonstrated a quantum molecular assembler—a device that takes individual atoms as inputs and merges them into a molecule in a desired quantum state. The team used lasers to trap and cool one sodium (Na) atom and one cesium (Cs) atom, bring them together, and merge them into an NaCs molecule in a specific quantum state. Such a quantum-controlled molecule is a promising building block for quantum computers and could help researchers study the quantum details of chemical reactions.