Most of us only ever see a fraction of a full rainbow: an arc. But optically, a full rainbow makes a complete circle. Physics explains why.
Category: physics – Page 105
The ‘Hawking radiation’ emitted by black holes may be able to carry crucial information, a new study suggests. Scientists may have just found the solution to one of astrophysics most mind-boggling mysteries concerning black holes, also known as the ‘Hawking information paradox’. A study published in the journal Physics Letters B last month offers a resolution to a problem the late physicist Stephen Hawking was working on in his final years.
The universe is expanding, but how fast exactly? The answer appears to depend on whether you estimate the cosmic expansion rate—referred to as the Hubble’s constant, or H0—based on the echo of the Big Bang (the cosmic microwave background, or CMB) or you measure H0 directly based on today’s stars and galaxies. This problem, known as the Hubble tension, has puzzled astrophysicists and cosmologists around the world.
A study carried out by the Stellar Standard Candles and Distances research group, led by Richard Anderson at EPFL’s Institute of Physics, adds a new piece to the puzzle. Their research, published in Astronomy & Astrophysics, has achieved the most accurate calibration of Cepheid stars—a type of variable star whose luminosity fluctuates over a defined period—for distance measurements to date based on data collected by the European Space Agency’s (ESA’s) Gaia mission. This new calibration further amplifies the Hubble tension.
The Hubble constant (H0) is named after the astrophysicist who—together with Georges Lemaître—discovered the phenomenon in the late 1920s. It’s measured in kilometers per second per megaparsec (km/s/Mpc), where 1 Mpc is around 3.26 million light years.
Scientists have achieved a “temporal analogue” to the famous double-slit experiment that could lead to new optical technologies. ABSTRACT breaks down mind-bending scientific research, future tech, new discoveries, and major breakthroughs. Scientists have discovered “unexpected physics” by opening up “slits” in time, a new study reports, achieving a longstanding dream that can help to probe the behavior of light and pioneer advanced optical technologies.
An artificial black hole produced using sound waves and a dielectric medium has been created in the lab, according to researchers with an international think tank featuring more than 30 Ph.D. research scientists from around the world.
The researchers say their discovery is significantly more cost-effective and efficient than current methods in use by researchers who want to simulate the effects of a black hole in a laboratory environment.
New York-based Applied Physics first achieved recognition with the 2021 publication of a peer-reviewed theoretical paper detailing the mathematics behind the construction of a physical warp drive. More recently, the organization published a method for using Cal Tech’s Laser Interferometer Gravitational-Wave Observatory (LIGO) to detect the use of warp drives in outer space, co-authored by Dr. Manfred Paulini, the Associate Dean of Physics at Carnegie Mellon University.
Aliens could come to Earth — and they might arrive sooner than you might think.
Writing in the Spectator, Professor Sasha Hinkley, associate professor of astrophysics at the University of Exeter, said it is becoming “increasingly likely” signs of extraterrestrial life will be uncovered “within his lifetime”, though that doesn’t mean we will get to meet them.
Physicists at West Virginia University have overcome a long-standing limitation of the first law of thermodynamics.
Paul Cassak, a professor and associate director of the Center for KINETIC Plasma Physics at West Virginia University, and Hasan Barbhuiya, a graduate research assistant in the Department of Physics and Astronomy, are investigating the conversion of energy in superheated plasmas in space. Funded by the National Science Foundation, their findings, published in the Physical Review Letters journal, are set to revolutionize the understanding of how plasmas in space and labs are heated and could have far-reaching implications in physics and other sciences.
In 2018, a team of scientists at the University of California, Santa Barbara proposed a method for creating Kerr-Newman black holes using lasers. However, this method has not yet been tested experimentally.
The team of scientists, led by Philip Gibbs, proposed to create Kerr-Newman black holes by colliding two high-energy laser beams. The collision would create a plasma that would be compressed and heated to extreme temperatures, creating a black hole.
Note, that micro black holes last within micro seconds, and that we wish to ascertain how to build, in a laboratory, a black hole, which may exist say at least up to 10^−1 seconds and provide a test bed as to early universe gravitational theories. First of all, it would be to determine, if the mini black hole bomb, would spontaneously occur, unless the Kerr-Newmann black hole were carefully engineered in the laboratory. Specifically, we state that this paper is modeling the creation of an actual Kerr Newman black hole via laser physics, or possibly by other means. We initiate a model of an induced Kerr-Newman black Holes, with specific angular momentum J, and then from there model was to what would happen as to an effective charge, Q, creating an E and B field, commensurate with the release of GWs. The idea is that using a frame of reference trick, plus E + i B = −function of the derivative of a complex valued scalar field, as given by Appell, in 1887, and reviewed by Whittaker and Watson, 1927 of their “A Course of Modern Analysis” tome that a first principle identification of a B field, commensurate with increase of thermal temperature, T, so as to have artificially induced GW production. This is compared in part with the Park 1955 paper of a spinning rod, producing GW, with the proviso that both the spinning rod paper, and this artificial Kerr-Newman Black hole will employ the idea of lasers in implementation of their respective GW radiation. The idea is in part partly similar to an idea the author discussed with Dr. Robert Baker, in 2016 with the difference that a B field would be generated and linked to effects linked with induced spin to the Kerr-Newman Black hole. We close with some observations about the “black holes have no hair” theorem, and our problem. Citing some recent suppositions that this “theorem” may not be completely true and how that may relate to our experimental situation. We close with observations from Haijicek, 2008 as which may be pertinent to Quantization of Gravity. Furthermore as an answer to questions raised by a referee, we will have a final statement as to how this problem is for a real black hole being induced, and answering his questions in his review, which will be included in a final appendix to this paper. The main issue which is now to avoid the black hole bomb effect which would entail an explosion of a small black hole in a laboratory. Furthermore as an answer to questions raised by a referee, we will have a final statement as to how this problem is for a real black hole being induced, and answering his questions in his review, which will be included in a final appendix to this paper. In all, the main end result is to try to avoid the so called black hole bomb effect, where a mini black hole would explode in a laboratory setting within say 10^−16 or so seconds, i.e. the idea would be to have a reasonably stable configuration within put laser energy, but a small mass, and to do it over hopefully 1015 or more times longer than the 10^−16 seconds where the mini black hole would quickly evaporate. I.e. a duration of say up to 10^−1 seconds which would provide a base line as to astrophysical modeling of a Kerr-Newman black hole.
10 SpaceX Starships are carrying 120 robots to Mars. They are the first to colonize the Red Planet. Building robot habitats to protect themselves, and then landing pads, structures, and the life support systems for the humans who will soon arrive.
This Mars colonization mini documentary also covers they type of robots that will be building on Mars, the solar fields, how Elon Musk and Tesla could have a battery bank station at the Mars colony, and how the Martian colony expands during the 2 years when the robots are building. Known as the Robotic Age of Mars.
Additional footage from: SpaceX, NASA/JPL/University of Arizona, ICON, HASSEL, Tesla, Lockhead Martin.
A building on Mars sci-fi documentary, and a timelapse look into the future.
Sparse regression for plasma physics
Posted in physics
Many scientific problems can be formulated as sparse regression, i.e., regression onto a set of parameters when there is a desire or expectation that some of the parameters are exactly zero or do not substantially contribute. This includes many problems in signal and image processing, system identification, optimization, and parameter estimation methods such as Gaussian process regression. Sparsity facilitates exploring high-dimensional spaces while finding parsimonious and interpretable solutions. In the present work, we illustrate some of the important ways in which sparse regression appears in plasma physics and point out recent contributions and remaining challenges to solving these problems in this field. A brief review is provided for the optimization problem and the state-of-the-art solvers, especially for constrained and high-dimensional sparse regression.