Researchers at the University of Basel in Switzerland say that they have made the first ever direct measurements of the strength of the tiny van der Waals forces passing between individual atoms. Though weak compared with covalent bonds, van der Waals forces are fundamental for the function of biological systems and define the properties of many organic compounds.
Researchers studied a distant star (white dwarf G191-B2B) where gravity is more than 30,000 times greater than on Earth to test the controversial theory that one of the constants of Nature-the strength of the electromagnetic force, known as alpha-is not a constant. #astrophysics
Quasar RX J1131-1231: Chandra & XMM-Newton Provide Direct Measurement of Distant Black Hole's Spin: Astronomers have directly measured the spin of a supermassive black hole in a quasar that is located 6 billion light years away. This is the most distant black hole where such a measurement has been made. Black holes are defined by just two simple characteristics: mass and spin. Finding out how quickly black holes are spinning reveals important information about how they grow over time.
Black Holes Might Not Be Dead Ends After All: A physical body might be able to cross a wormhole in spite of the extreme tidal forces, suggests a new study by Rubiera-Garcia, of Instituto de Astrofísica e Ciências do Espaço (IA), and his team.
The Puzzling Ophiuchus Stream: Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a “stellar stream.” One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this stream’s mystery.
The Multiverse’s ‘Measure Problem’ | In a Multiverse, What Are the Odds? Testing the multiverse hypothesis requires measuring whether our universe is statistically typical among the infinite variety of universes. But infinity does a number on statistics.