Global Science News for 21 Oct 2019
Archaeologists have identified a grand street in Jerusalem that was built by Pontius Pilate, the Roman prefect of Judea who is famous for overseeing the trial and crucifixion of Jesus.
The Paris Zoological Park is debuting a new exhibit on 'the blob' -- a brainless, single-cell slime mold with incredible problem-solving potential.
Sandia National Laboratories physicists Mark Boslough and Dave Crawford predicted the Hubble Space Telescope would see a rising vapor plume as the Shoemaker-Levy 9 comet crashed into the far side of... Jupiter (Figure 1) in 1994. And sure enough, the plume produced by the impact matched Sandia's computational analysis (Figure 2). A member of the Hubble team told Boslough that the images of the plume's rise and descent "were so eerily like Sandia's predicted models that I showed them side by side for years afterwards."
To create a practical fusion energy reactor, researchers need to control particles known as fast ions. These speedy ions, which are electrically charged hydrogen atoms, provide much of the... self-heating ability of the reactor as they collide with other ions. But they can also quickly escape the powerful magnetic fields used to confine them and overheat the walls of the containment vessel, causing damage.
To understand the fundamental nature of our universe, scientists would like to build particle colliders that accelerate electrons and their antimatter counterparts (positrons) to extreme energies (up... to tera electron volts, or TeV). With conventional technology, however, this requires a machine that is enormously big and expensive (think 20 miles (32 km) long). To shrink the size and cost of these machines, the acceleration of the particles--how much energy they gain in a given distance--must be increased.
Researchers at the DIII-D National Fusion Facility in San Diego have demonstrated a new approach for injecting microwaves into a fusion plasma that doubles the efficiency of a critical technique that... could have major implications for future fusion reactors. The results show that launching the microwaves into the plasma via a novel geometry delivers substantial improvements in the plasma current drive.
Imagine you're getting ready to fly to your favorite vacation destination when suddenly a volcano erupts, sending massive amounts of volcanic ash into the atmosphere, and forcing the cancellation of... your flight. That's exactly what happened in April 2010 when Eyjafjallajokull, a volcano in Iceland, erupted and disrupted air travel in Europe for six days. Scientists are now using plasma physics to predict the characteristics of these hazardous ash plumes.
Grab a mixing bowl from your kitchen, throw in a handful of aluminum balls, apply some high voltage, and watch an elegant dance unfold where particles re-arrange themselves into a distinct "crystal"... pattern. This curious behavior belongs to the phenomenon known as Wigner crystallization, where particles with the same electrical charge repel one another to form an ordered structure.
Magnetic reconnection, a process in which magnetic field lines tear and come back together, releasing large amounts of kinetic energy, occurs throughout the universe. The process gives rise to... auroras, solar flares and geomagnetic storms that can disrupt cell phone service and electric grids on Earth. A major challenge in the study of magnetic reconnection, however, is bridging the gap between these large-scale astrophysical scenarios and small-scale experiments that can be done in a lab.
On a typical day at the world's biggest laser, the National Ignition Facility (NIF) in Livermore, California, you can find scientists casually making star-like conditions using 192 high-powered... lasers. Stars in the universe are formed through a process called nucleosynthesis, which fuses lighter atoms to create new heavier atomic nuclei. Natural elements found here on Earth, such as helium and aluminum, were formed through this process inside of a star not unlike our own sun.
Fusion combines light elements in the form of plasma--"the hot, charged state of matter composed of free electrons and atomic nuclei--"to generate massive amounts of energy. One of the ways that... scientists help heat the plasma is by injecting beams of energetic particles into tokamaks to provide enough energy for plasma particles to overcome mutual repulsion and fuse together. The injected particles, however, can also produce waves that cause plasma energy to leak out of the magnetic fields that confine it, cooling the plasma and helping to quench the fusion reactions. It is therefore beneficial to the development of fusion energy to suppress these waves.
Assembly of the Plasma Liner Experiment (PLX) at Los Alamos National Laboratory is well underway with the installation of 18 of 36 plasma guns in an ambitious approach to achieving controlled nuclear... fusion (Figure 1). The plasma guns are mounted on a spherical chamber, and fire supersonic jets of ionized gas inward to compress and heat a central gas target that serves as fusion fuel. In the meantime, experiments performed with the currently installed plasma guns are providing fundamental data to create simulations of colliding plasma jets, which are crucial for understanding and developing other controlled fusion schemes.
Fusion is a non-carbon-based process for energy production, where lighter atoms fuse into heavier ones. Fusion reactors operate by confining a "soup" of charged particles, known as a plasma, within... powerful magnetic fields. But these magnetic fields must contain the plasma long enough that it can be heated to extreme temperatures--hotter than the sun--where fusion reactions can occur.
The Congolese giant toad looks like the head of a Gaboon viper, and it even hisses like a snake when approached - all to scare off potential predators