He also mentions the large sum of cash he can make from Starlink.
(Bloomberg) — An exhausted-looking Elon Musk said Monday he’s unsure his rocket company SpaceX will accomplish its foundational mission — getting to Mars — before he dies.
The virtually identical oxygen isotope compositions of the Earth and Moon revealed by Apollo return samples have been a challenging constraint for lunar formation models. For a giant impact scenario to explain this observation, either the precursors to the Earth and Moon had identical oxygen isotope values or extensive homogenization of the two bodies occurred following the impact event. Here we present high-precision oxygen isotope analyses of a range of lunar lithologies and show that the Earth and Moon in fact have distinctly different oxygen isotope compositions. Oxygen isotope values of lunar samples correlate with lithology, and we propose that the differences can be explained by mixing between isotopically light vapour, generated by the impact, and the outermost portion of the early lunar magma ocean. Our data suggest that samples derived from the deep lunar mantle, which are isotopically heavy compared to Earth, have isotopic compositions that are most representative of the proto-lunar impactor ‘Theia’. Our findings imply that the distinct oxygen isotope compositions of Theia and Earth were not completely homogenized by the Moon-forming impact, thus providing quantitative evidence that Theia could have formed farther from the Sun than did Earth.
Astronomers scouring the cosmos for new planets have made a chance discovery, identifying the rare eclipse of two brown dwarfs.
“This is a great example of scientific serendipity,” Adam Burgasser, a co-leading author on this study and a professor of physics at UC San Diego, said in a statement. “While searching for planets, we found an eclipsing brown dwarf binary, a system that is uniquely suited for studying the fundamental physics of these faint celestial objects.”
The pullback will probably not be as severe as the dot-com bust in the early 2000s, when dozens of unprofitable internet firms failed. Today, venture capitalists and other investors still have large pools of money to invest. And certain types of start-ups — like those that make tech for businesses and that typically have steady sales — continue raising large sums of money.
Layoffs. Shutdowns. Uncertainty. After a decade of prosperity, many hot young companies are facing a reckoning.
Collisions between beams of gravitons could convert the hypothesized particles into photons, producing a potentially detectable radio signal that would accompany some gravitational waves.
If gravity and quantum mechanics are to be unified, gravitational waves—usually studied as a classical phenomenon using general relativity—must comprise hypothesized particles called gravitons. In theory, gravitons can interact with each other to produce photons, but these interactions were thought to be vanishingly rare and impossible to detect. In new theoretical work, Raymond Sawyer of the University of California, Santa Barbara, finds that in certain cases, colliding gravitational waves could produce enough radio frequency photons to yield a detectable signal.
An atomically thin materials platform developed by Penn State researchers in conjunction with Lawrence Berkeley National Lab and Oak Ridge National Lab will open a wide range of new applications in biomolecular sensing, quantum phenomena, catalysis and nonlinear optics.
“We have leveraged our understanding of a special type of graphene, dubbed epitaxial graphene, to stabilize unique forms of atomically thin metals,” said Natalie Briggs, a doctoral candidate and co-lead author on a paper in the journal Nature Materials. “Interestingly, these atomically thin metals stabilize in structures that are completely different from their bulk versions, and thus have very interesting properties compared to what is expected in bulk metals.”
Traditionally, when metals are exposed to air they rapidly begin to oxidize—rust. In as short as one second, metal surfaces can form a rust layer that would destroy the metallic properties. In the case of a 2-D metal, this would be the entire layer. If you were to combine a metal with other 2-D materials via traditional synthesis processes, the chemical reactions during synthesis would ruin the properties of both the metal and layered material. To avoid these reactions, the team exploited a method that automatically caps the 2-D metal with a single layer of graphene while creating the 2-D metal.
Vicarious, a secretive 10-year-old startup backed by Mark Zuckerberg, Elon Musk, and Jeff Bezos, reveals its progress and an initial customer.
Over many years, the Mazmanian laboratory has described how Bacteroides fragilis in the gut produces beneficial molecules that protect mice from inflammatory bowel disease and autism-like symptoms. Like a densely populated city, a vast majority of the B. fragilis in the gut live within the central part of the intestinal tube, called the lumen. However, the Mazmanian laboratory discovered in 2013 that some B. fragilis reside in the bacterial equivalent of small towns, nestled into microscopic pockets within the tissue walls lining the tube. These sparse populations are protected by mucus and are largely unaffected by antibiotics, suggesting that they act as population reservoirs that ensure long-term colonization.
“For humans, where we live can dictate how we behave—for example, a person living in a city likely has a different everyday life than a person living in a small rural community,” says former graduate student Gregory Donaldson (PhD ‘18), the first author on the new paper. “For the bacteria that we study, the intestines represent their entire world, so we wanted to know how differently they behave depending on how far away from the intestinal surface they are.”
Though they may live in different habitats within the gut, these B. fragilis populations all have the same genetic code. What may differ, however, is how they express those genes—is a bacterium expressing a gene for replication and division, for example, or perhaps for an enzyme that digests food? Donaldson aimed to measure and compare gene expression in these two populations (intestinal wall tissue and lumen of the gut) to determine what, if any, differences were seen.
Continue reading “Mapping Bacterial Neighborhoods in the Gut” »
An international team of researchers, affiliated with UNIST has for the first time succeeded in demonstrating the ionization cooling of muons. Regarded as a major step in being able to create the world’s most powerful particle accelerator, this new muon accelerator is expected to provide a better understanding of the fundamental constituents of matter.
This breakthrough has been carried out by the Muon Ionization Cooling Experiment (MICE) collaboration, which includes many UK scientists, as well as Professor Moses Chung and his research team in the School of Natural Sciences at UNIST. Their findings have been published in the online version of Nature on February 5, 2020.
“We have succeeded in realizing muon ionization cooling, one of our greatest challenges associated with developing muon accelerators,” says Professor Chung. “Achievement of this is considered especially important, as it could change the paradigm of developing the Lepton Collider that could replace the Neutrino Factory or the Large Hadron Collider (LHC).”
