Physicists from the Technion-Israel Institute of Technology and the University of Central Florida have experimentally observed optical branched flow in liquid soap films.
Instead of producing completely random speckle patterns, the slowly varying disordered potential gives rise to focused filaments that divide to form a pattern resembling the branches of a tree.
A team of researchers from the Technion – Israel Institute of Technology has observed branched flow of light for the very first time. The findings are published in Nature and are featured on the cover of the July 2, 2020 issue.
The study was carried out by Ph.D. student Anatoly (Tolik) Patsyk, in collaboration with Miguel A. Bandres, who was a postdoctoral fellow at Technion when the project started and is now an Assistant Professor at CREOL, College of Optics and Photonics, University of Central Florida. The research was led by Technion President Professor Uri Sivan and Distinguished Professor Mordechai (Moti) Segev of the Technion’s Physics and Electrical Engineering Faculties, the Solid State Institute, and the Russell Berrie Nanotechnology Institute.
When waves travel through landscapes that contain disturbances, they naturally scatter, often in all directions. Scattering of light is a natural phenomenon, found in many places in nature. For example, scattering of light is the reason for the blue color of the sky. As it turns out, when the length over which disturbances vary is much larger than the wavelength, the wave scatters in an unusual fashion: it forms channels (branches) of enhanced intensity that continue to divide, or branch out, as the wave propagates. This phenomenon is known as branched flow. It was first observed in 2001 with electrons, and had been suggested to be ubiquitous and occur also for all waves in nature, for example sound waves and even ocean waves. Now, Technion researchers are bringing branched flow to the domain of light: they have made an experimental observation of branched flow of light.
Picture in your mind the delta of a river — the way the main channel splits into smaller rivulets and tributaries. Something similar occurs in waves as they propagate through a certain kind of medium: the path of the wave splits, breaking up into smaller channels like the branches of a tree.
This is called a branching flow, and it’s been observed in such phenomena as the flow of electrons (electric current), ocean waves, and sound waves. Now, for the first time, physicists have observed it in visible light — and all it took was a laser and a soap bubble.
Depending on the structure of the medium, different things can happen to waves travelling through; they can attenuate, disperse, bend, spread, or continue flowing.
Australian and US physicists say they have calculated the speed of the most complex nuclear reactions and found that they’re, well, really fast. We’re talking as little as a zeptosecond – a billionth of a trillionth of a second (10-21).
The finding follows a comprehensive project to calculate detailed models of the energy flow during nuclear collisions.
Cedric Simenel from the Australian National University worked with Kyle Godbey and Sait Umar from Vanderbilt University to model 13 different pairs of nuclei, using supercomputers at ANU and in the US.
Physicists from the University of Glasgow and the University of Arizona have experimentally verified a half-century-old theory that began as speculation about how an advanced alien civilization could use a rotating black hole to generate energy.
In an experiment performed at Lawrence Berkeley National Laboratory’s 88-inch cyclotron, a team of physicists successfully created a new isotope of the human-made element mendelevium.
A 50-year-old theoretical process for extracting energy from a rotating black hole finally has experimental verification.
Using an analogue of the components required, physicists have shown that the Penrose process is indeed a plausible mechanism to slurp out some of that rotational energy — if we could ever develop the means.
That’s not likely, but the work does show that peculiar theoretical ideas can be brilliantly used to explore the physical properties of some of the most extreme objects in the Universe.
Intensity is rising at CERN. In the superconducting equipment testing hall, an innovative transmission line has set a new record for the transport of electricity. The link, which is 60 metres long, has transported a total of 54 000 amperes (54 kA, or 27 kA in either direction). “It is the most powerful electrical transmission line built and operated to date!” says Amalia Ballarino, the designer and project leader.
The line has been developed for the High-Luminosity LHC (HL-LHC), the accelerator that will succeed the Large Hadron Collider (LHC) and is scheduled to start up at the end of 2027. Links like this one will connect the HL-LHC’s magnets to the power converters that supply them.
The secret to the new line’s power can be summarised in one word: superconductivity.
R. Abbott 1, T. D. Abbott 2, S. Abraham 3, F. Acernese 4,5, K. Ackley 6, C. Adams 7, R. X. Adhikari 1, V. B. Adya 8, C. Affeldt 9,10, M. Agathos 11,12, K. Agatsuma13, N. Aggarwal 14, O. D. Aguiar 15, A. Aich 16, L. Aiello 17,18, A. Ain 3, P. Ajith 19, S. Akcay 11,20, G. Allen 21, A. Allocca 22, P. A. Altin 8, A. Amato 23, S. Anand 1, A. Ananyeva 1, S. B. Anderson 1, W. G. Anderson 24, S. V. Angelova 25, S. Ansoldi 26,27, S. Antier 28, S.
An element that could hold the key to the long-standing mystery around why there is much more matter than antimatter in our universe has been discovered in Physics research involving the University of Strathclyde.
The study has discovered that an isotope of the element thorium possesses the most pear-shaped nucleus yet to be discovered.
Nuclei similar to thorium-228 may now be able to be used to perform new tests to try find the answer to the mystery surrounding matter and antimatter.
