Polarized light is a familiar phenomenon because the scattering or reflection of light results in one of its two components being preferentially absorbed. The majority of sunlight on Earth, for example, is preferentially polarized due to scattering in the atmosphere (this helps make polarized sunglasses effective). Electromagnetic radiation from astrophysical sources can also be polarized, typically because of scattering from elongated…
Tag: polarization
New quantum sensing technique allows high-resolution nuclear magnetic resonance spectroscopy
Nuclear magnetic resonance (NMR) spectroscopy is a widely used tool for chemical analysis and molecular structure recognition. Because it typically relies on the weak magnetic fields produced by a small thermal nuclear spin polarization, NMR suffers from poor sensitivity compared to other analytical techniques. A conventional NMR apparatus typically uses large sample volumes of about a milliliter—large enough to contain around…
Nearly Half of Twitter Accounts Pushing To Reopen America May Be Bots
According to a new study from Carnegie Mellon University, researchers have found that bots may account for between 45 and 60% of Twitter accounts discussing covid-19. The normal level of bot involvement for U.S. and foreign elections, natural disasters, and other politicized events is usually between 10 and 20%. MIT Technology Review reports: Many of those accounts were created in February…
This brown dwarf might look a lot like Jupiter
The cloud bands on brown dwarf Luhman 16A were found via instruments known as polarimeters. An astronomer said they’re like “… an astronomer’s polarized sunglasses. But instead of trying to block out that glare, we’re trying to measure it.” Source: https://earthsky.org/space/brown-dwarfs-banded-clouds-luhman-16a-vlt…
Scientists Explore Underwater Quantum Links For Submarines
An anonymous reader quotes a report from IEEE Spectrum: Underwater quantum links are possible across 30 meters (100 feet) of turbulent water, scientists have shown. Such findings could help to one day secure quantum communications for submarines. […] In the new study, researchers experimented with quantum communications in a “flume tank,” a water tank in which scientists can generate waves to…
Astrophysicists wear 3-D glasses to watch quasars
A team of researchers from Russia and Greece reports a way to determine the origins and nature of quasar light by its polarization. The new approach is analogous to the way cinema glasses produce a 3-D image by feeding each eye with the light of a particular polarization, either horizontal or vertical. The authors of the recent study in the Monthly…
Data from antipodal places: First use of CMB polarization to detect gravitational lensing from galaxy clusters
Galaxies. Amalgamations of stars, interstellar gas, dust, stellar debris and dark matter. They waltz through the cold universe, gravity nurturing their embrace. Occasionally, galaxies snowball into enormous galaxy clusters with masses averaging 100 trillion times that of our sun. Source: https://phys.org/news/2020-01-antipodal-cmb-polarization-gravitational-lensing.html…
Anisotropic radio-wave scattering in the solar corona
Solar radio emission is produced in the turbulent medium of the solar atmosphere, and its observed properties (source position, size, time profile, polarization, etc.) are significantly affected by the propagation of the radio waves from the emitter to the observer. Scattering of radio waves on random density irregularities has long been recognized as an important process for the interpretation of radio…
‘OK Boomer’ Is the New Retort To Older Generations
Teens are increasingly using the phrase “OK boomer” to fire back at older generations’ criticisms. Slashdot reader ItsJustAPseudonym shares an excerpt from an NBC News article: In recent months, the phrase “OK boomer” has become a common retort in the parts of the internet inhabited by teenage and young adult users. On Instagram, the phrase appears as a hashtag alongside memes…
Cows Painted Like Zebras Attract Fewer Flies
Slashdot reader ClickOnThis writes: An article on CNN reports results from a team of Japanese researchers who discovered that painting cows to look like zebras makes them less attractive to biting flies. I think they’re a shoo-in for a 2020 Ig Nobel Prize. From the article: “A team of Japanese researchers recruited six cows and gave them each black-and-white stripes, black…