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.
A photon (particle of light) can oust an electron from an atom or molecule, but the electron doesn't depart instantly. With the advent of attosecond (10^-18 second) laser pulses, physicists can measure this brief delay, which can reveal details of atomic structure. But until now, they have only measured it in atoms and simple solids; isolated molecules were too complicated. Now a team has measured the delays for H2O and N2O.
In a new proposed experiment, two toaster-sized "nanosatellites" carrying entangled condensates orbit around the Earth, until one of them moves to a different orbit with a different gravitational field strength. As a result of the change in gravity, the entanglement between the condensates is predicted to degrade by up to 20%. Experimentally testing the proposal may be possible in the near future.
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.
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
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.
Pulsar - A pulsar (pulsating star) is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. Neutron stars are very dense, and have short, regular rotational periods. This produces a very precise interval, between pulses that range from roughly milliseconds to seconds for an individual pulsar. Certain types of pulsars rival atomic clocks in their accuracy in keeping time.