Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 502

A proton’s mass is more than just the sum of its parts. And now scientists know just what accounts for the subatomic particle’s heft.

Protons are made up of even smaller particles called quarks, so you might expect that simply adding up the quarks’ masses should give you the proton’s mass. However, that sum is much too small to explain the proton’s bulk. And new, detailed calculations show that only 9 percent of the proton’s heft comes from the mass of constituent quarks. The rest of the proton’s mass comes from complicated effects occurring inside the particle, researchers report in the Nov. 23 Physical Review Letters.

Quarks get their masses from a process connected to the Higgs boson, an elementary particle first detected in 2012 (SN: 7/28/12, p. 5). But “the quark masses are tiny,” says study coauthor and theoretical physicist Keh-Fei Liu of the University of Kentucky in Lexington. So, for protons, the Higgs explanation falls short.

Read more

Engineers know that tiny, super-fast objects can cause damage to spacecraft, but it’s been difficult to understand exactly how the damage happens because the moment of impact is incredibly brief. A new study from MIT seeks to reveal the processes at work that produce microscopic craters and holes in materials. The hope is that by understanding how the impacts work, we might be able to more durable materials.

Accidental space impacts aren’t the only place these mechanisms come into play. There are also industrial applications on Earth like applying coatings, strengthening metallic surfaces, and cutting materials. A better understanding of micro-impacts could also make these processes more efficient. Observing such impacts was not easy, though.

For the experiments, the MIT team used tin particles about 10 micrometers in diameter accelerated to 1 kilometer per second. They used a laser system to launch the projectile that instantly evaporates a surface material and ejects the particles, ensuring consistent timing. That’s important because the high-speed camera pointed at the test surface (also tin) needed specific lighting conditions. At the appointed time, a second laser illuminated the particle allowing the camera to follow the impact at up to 100 million frames per second.

Read more

The experimental investigation of ultracold quantum matter makes it possible to study quantum mechanical phenomena that are otherwise inaccessible. A team led by the Innsbruck physicist Francesca Ferlaino has now mixed quantum gases of two strongly magnetic elements, erbium and dysprosium, and created a dipolar quantum mixture.

A few years ago, it seemed unfeasible to extend the techniques of atom manipulation and deep cooling in the ultracold regime to many-valence-electron atomic species. The reason is the increasing complexity in the atomic spectrum and the unknown scattering properties. However, a team of researchers, led by Ben Lev at Stanford University and an Austrian team directed by Francesca Ferlaino at the University of Innsbruck demonstrated degeneracy of rare-earth species. Ferlaino’s group focused the on and developed a powerful, yet surprisingly simple approach to produce a Bose-Einstein condensate.

“We have shown how the complexity of atomic physics can open up new possibilities,” says Ferlaino. Magnetic species are an ideal platform to create dipolar quantum matter, in which particles interact with each other via a long-range and orientation dependent interaction as little quantum magnets.

Read more

Researchers have developed catalysts that can convert carbon dioxide—the main cause of global warming—into plastics, fabrics, resins, and other products.

The electrocatalysts are the first materials, aside from enzymes, that can turn carbon dioxide and water into carbon building blocks containing one, two, three, or four carbon atoms with more than 99 percent efficiency.

Two of the products—methylglyoxal (C3) and 2,3-furandiol (C4)—can be used as precursors for plastics, adhesives, and pharmaceuticals. Toxic formaldehyde could be replaced by methylglyoxal, which is safer.

Read more

The periodic table is chemistry’s holy text. Not only does it list all of the tools at chemists’ disposal, but its mere shape—where these elements fall into specific rows and columns—has made profound predictions about new elements and their properties that later came true. But few chemists on Earth have a closer relationship with the document than Dawn Shaughnessy, whose team is partially responsible for adding six new elements to table’s ranks.

Shaughnessy leads a team of real-life alchemists. You might be familiar with alchemy as a medieval European practice where mystics attempted to transmute elements into more valuable ones. But rather than turn the element lead into gold, Shaughnessy and her team turned plutonium into flerovium.

Shaughnessy’s parents encouraged her to pursue science from a young age—her father was an engineer, and she had an electronics kit as well as a chemistry set as a child. She’d first thought about doing orthopedic research but didn’t want to cut people open, she explained to me, and chemistry was a natural fit. But when she arrived at the University of California, Berkeley as an undergraduate, she learned that chemistry could be more than just mixing liquids in beakers. She could create the atoms themselves.

Read more