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Scientists are hoping that a large battery in a South Dakotan gold mine could lure curious forms of bacteria that may help us understand what powers life as we know it.
That’s because scientists have begun to discover bacteria that live and thrive on electricity alone. Rather than mediating electrons through third-party materials (such as sugar or oxygen) like most organisms do, these bacteria transmit them unaccompanied by anything else. Understanding how these interactions work could give us a glimpse of the kind of life that might exist on other planets.
Early Egyptians left no written record, but they had already figured out the science behind making artificial mummies. An 11-year study on the presence of embalming agents in ancient funerary wrappings push the origins of Egyptian mummification back by more than a millennium. The work was published in PLoS ONE this week.
Asteroid 1950 DA appears impossible at first glance. It spins so rapidly no one could work out why it hadn’t pulled itself apart long ago. Now the mystery has a solution, and it seems the asteroid is using a similar trick to geckos climbing glass walls, with implications for how to tackle objects that might threaten the planet.
Many small asteroids are not so much solid rock as loose piles of rubble. Their gravity is very weak, but in the absence of other forces it can be enough to keep the asteroid together. However, 1950 DA is spinning rapidly.
“We found that 1950 DA is rotating faster than the breakup limit for its density," said Dr Ben Rozitis at the University of Tennessee. "So if just gravity were holding this rubble pile together, as is generally assumed, it would fly apart. Therefore, interparticle cohesive forces must be holding it together."
The spin is rapid enough that, near the equator, an object on the asteroid’s surface would experience “negative gravity” – the acceleration from its turning is stronger than the tiny gravitational pull it can produce and frictional forces can supplement. So how does it hold together?
The answer, Rozitis has claimed in Nature, lies in van der Waals forces between grains of material. These forces, including those between two dipoles, determine whether substances can be dissolved in oil or water and are used by geckos to climb sheer surfaces. The forces exist because many molecules have a slight negative charge at one end and positive charge at the other. When opposite charges align particles are drawn to their neighbors.
The Egyptian pyramids are considered one of the Seven Wonders of the World, and it’s not surprising: when you stare at the massive structures, you can’t help but wonder, “How the hell did they do it?” The stones, some weighing 9,000 pounds, came from far away and needed to be dragged into place. Now, researchers from the University of Amsterdam believe they’ve discovered ancient Egyptians’ cunning strategy to move those massive stones: wet sand.
With the right amount of water, researchers found, sand turns into a sturdy surface that halves the force needed to drag sleds loaded with rocks or statues across the desert. In fact, an ancient wall painting in the tomb of Djehutihotep shows a person pouring water over the sand in front of a sledge.
.There are lots of lines in our planet's cosmic address: Earth, the solar system, the Milky Way galaxy, the Local Group of galaxies, and the Virgo Cluster of galaxy groups. Now astronomers are adding another one: the Laniakea Supercluster, which takes its name from the Hawaiian term for "immense heaven."
Laniakea's outlines and boundaries are laid out for the first time in this week's issue of Nature. Our Milky Way lies on the outskirts of the supercluster, which spans 500 million light-years and contains the mass of 100 quadrillion suns in 100,000 galaxies
When a patient succumbs to an infection, it’s not the mere presence of the pathogen that kills them, but rather the sheer quantity of it. With many deadly diseases, the immune system simply can’t keep up. So bioengineers figured that outsourcing some of those duties could help keep patients alive.
A team of bioengineers led by Donald Ingber at Harvard’s Wyss Institute devised a device to filter pathogens from a patient’s blood. Inspired by the spleen, an organ which filters antibody-coated pathogens from the bloodstream, the “biospleen” works by first injecting specially treated, magnetic nanoparticles into the blood flowing through it. The nanoparticles have a protein attached to their surfaces which adheres to bacteria, viruses, and fungi; the protein-coated nanoparticles work like antibodies, which glom onto foreign objects. The biospleen then uses a magnet to pull out the nanoparticles and the pathogens they’re attached to.
The biospleen is similar in concept to dialysis, which mimics the function of the kidneys, but works on pathogens instead of typical bodily waste.
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