Today, a group of physicists published the most compact and elegant explanation of one of nature’s simplest phenomena: the way light behaves in the sky above us. This research appears today (Tuesday, 9th November) in the New Journal of Physics, published jointly by the Institute of Physics and Deutsche Physikalische Gesellschaft (German Physical Society).
Michael Berry and Mark Dennis from the University of Bristol, in collaboration with Raymond Lee of the US Naval Academy, have successfully predicted the patterns of polarisation of skylight, explained in broad outline by Lord Rayleigh in 1871, using elliptic integrals – a type of mathematics with deep geometrical roots, often described as “beautiful”.
The blue sky seen through polaroid sunglasses gets darker and brighter as the glasses are rotated. This reveals something almost invisible to our unaided eyes: daylight is polarized light. This means that the light waves vibrate differently in different directions. The effect is strongest at right angles to the sun, and weaker elsewhere. It creates patterns in the sky that look similar to the ridges in human fingerprints and are used by many species of birds and flying insects as an aid to navigation.
Astronomers see 'warm' glow of Uranus's rings
21.06.2019 | University of California - Berkeley
A new force for optical tweezers awakens
19.06.2019 | University of Gothenburg
From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.
Reducing machine downtime, manufacturing defects, and excessive scrap
The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.
Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
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