It’s a fundamental law of physics that even the most ardent science-phobe can define: matter falls down under gravity. But what about antimatter, which has the same mass but opposite electrical charge and spin? According to Einstein’s general theory of relativity, gravity should treat matter and antimatter identically. Finding even the slightest difference in their free-fall rate would therefore lead to a revolution in our understanding. While the free fall of matter has been measured with an accuracy of around one part in 100 trillion, no direct measurement for antimatter has yet been performed due to the difficulty in producing and containing large quantities of it.
Category: physics – Page 196
A novel computer algorithm, or set of rules, that accurately predicts the orbits of planets in the solar system could be adapted to better predict and control the behavior of the plasma that fuels fusion facilities designed to harvest on Earth the fusion energy that powers the sun and stars.
The algorithm, devised by a scientist at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), applies machine learning, the form of artificial intelligence (AI) that learns from experience, to develop the predictions. “Usually in physics, you make observations, create a theory based on those observations, and then use that theory to predict new observations,” said PPPL physicist Hong Qin, author of a paper detailing the concept in Scientific Reports. “What I’m doing is replacing this process with a type of black box that can produce accurate predictions without using a traditional theory or law.”
Qin (pronounced Chin) created a computer program into which he fed data from past observations of the orbits of Mercury, Venus, Earth, Mars, Jupiter, and the dwarf planet Ceres. This program, along with an additional program known as a “serving algorithm,” then made accurate predictions of the orbits of other planets in the solar system without using Newton’s laws of motion and gravitation. “Essentially, I bypassed all the fundamental ingredients of physics. I go directly from data to data,” Qin said. “There is no law of physics in the middle.”
Chair emeritus, SETI institute — the search for extraterrestrial intelligence.
Dr. Jill Tarter is Chair Emeritus for SETI (Search for Extraterrestrial Intelligence) Research at the SETI Institute, a not-for-profit research organization whose mission is to explore, understand, and explain the origin and nature of life in the universe, and to apply the knowledge gained to inspire and guide present and future generations.
Dr. Tarter received her Bachelor of Engineering Physics Degree with Distinction from Cornell University and her Master’s Degree and a Ph.D. in Astronomy from the University of California, Berkeley. She served as Project Scientist for NASA’s SETI program, the High Resolution Microwave Survey, and has conducted numerous observational programs at radio observatories worldwide. Since the termination of funding for NASA’s SETI program in 1993, she has served in a leadership role to secure private funding to continue the exploratory science. Currently, she serves on the management board for the Allen Telescope Array, an innovative array of 350 (when fully realized) 6-m antennas at the Hat Creek Radio Observatory, it will simultaneously survey the radio universe for known and unexpected sources of astrophysical emissions, and speed up the search for radio emissions from other distant technologies by orders of magnitude.
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A team of physicists and chemists from the University of Bristol hope to recycle radioactive material directly from a former nuclear power plant in Gloucestershire to generate ultra-long-lasting power sources.
SpaceX won a NASA contract Feb. 4 to launch a small astrophysics mission, continuing its string of similar agency contracts over the last two years.
WASHINGTON — SpaceX won a NASA contract Feb. 4 to launch a small astrophysics spacecraft, continuing the company’s string of similar agency contracts over the last two years.
NASA awarded a contract to SpaceX for the launch of the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) spacecraft on a Falcon 9 in June 2024. The value of the launch contract is $98.8 million, which includes the launch itself and other “mission-related costs,” the agency said.
In a new report on Science Advances, Mark Elowitz, and a team of scientists in physical sciences, optical physics, planetary science and radiation research in the U.S., U.K., India, and Taiwan, presented the first analysis of far-ultraviolet reflectance spectra of regions on Rhea’s leading and trailing hemispheres—as collected by the Cassini ultraviolet imaging spectrograph during targeted flybys. In this work, they specifically aimed to explain the unidentified broad absorption feature centered near 184 nanometers of the resulting spectra. Using laboratory measurements of the UV spectroscopy of a set of molecules, Elowitz et al. found a good fit to Rhea’s spectra with both hydrazine monohydrate and several chlorine-containing molecules. They showed hydrazine monohydrate to be the most plausible candidate to explain the absorption feature at 184 nm.
MIT researchers and colleagues have discovered an important—and unexpected—electronic property of graphene, a material discovered only about 17 years ago that continues to surprise scientists with its interesting physics. The work, which involves structures composed of atomically thin layers of materials that are also biocompatible, could usher in new, faster information-processing paradigms. One potential application is in neuromorphic computing, which aims to replicate the neuronal cells in the body responsible for everything from behavior to memories.
Nikolai Kardashev, creator of the civilization ranking scale, outstanding space explorer, specialist in experimental and theoretical astrophysics and radio astronomy, Doctor of Physical and Mathematical Sciences, Director of the Astro Space Center of the Lebedev Physical Institute, died in August 3, 2019. The Russian scientist was 87 years old.
The scientist’s most famous work is the Kardashev Scale — the cosmic civilization ranking system. As part of the Search for Extraterrestrial Intelligence (SETI), he proposed a model of cosmic civilisations and calculated the scale of ranking civilisations
The Kardashev Scale
In 1963, he studied the quasar CTA-102. It was the first contribution of Soviet scientists to SETI, since the radio source CTA-102 was first assumed to be evidence of an extraterrestrial civilization.
In his paper ‘Transmission of Information by Extraterrestrial Civilisations’, published in 1964, Kardashev explored the idea that other galactic civilisations may have existed for billions of years before ours, so they would be far more advanced. He proposed a theoretical scale of technological development of civilisations based on the amount of energy that civilization is able to utilize. According to the theory, there are 3 main types of advanced civilisations:
Astronomers from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and CSIRO have just observed bizarre, never-seen-before behavior from a ‘radio-loud’ magnetar—a rare type of neutron star and one of the strongest magnets in the Universe.
Their new findings, published in the Monthly Notices of the Royal Astronomical Society (MNRAS), suggest magnetars have more complex magnetic fields than previously thought – which may challenge theories of how they are born and evolve over time.
Magnetars are a rare type of rotating neutron star with some of the most powerful magnetic fields in the Universe. Astronomers have detected only thirty of these objects in and around the Milky Way —most of them detected by X-ray telescopes following a high-energy outburst.
Richard Feynman, one of the most respected physicists of the twentieth century, said “What I cannot create, I do not understand.” Not surprisingly, many physicists and mathematicians have observed fundamental biological processes with the aim of precisely identifying the minimum ingredients that could generate them. One such example are the patterns of nature observed by Alan Turing. The brilliant English mathematician demonstrated in 1952 that it was possible to explain how a completely homogeneous tissue could be used to create a complex embryo, and he did so using one of the simplest, most elegant mathematical models ever written. One of the results of such models is that the symmetry shown by a cell or a tissue can break under a set of conditions.