Well, that changes our hunt for aliens.
Category: physics – Page 6
Researchers at the University of Turku, Finland, have succeeded in producing sensors from single-wall carbon nanotubes that could enable major advances in health care, such as continuous health monitoring. Single-wall carbon nanotubes are nanomaterial consisting of a single atomic layer of graphene.
A long-standing challenge in developing the material has been that the nanotube manufacturing process produces a mix of conductive and semi-conductive nanotubes which differ in their chirality, i.e., in the way the graphene sheet is rolled to form the cylindrical structure of the nanotube. The electrical and chemical properties of nanotubes are largely dependent on their chirality.
Han Li, Collegium Researcher in materials engineering at the University of Turku, has developed methods to separate nanotubes with different chirality. In the current study, published in Physical Chemistry Chemical Physics, the researchers succeeded in distinguishing between two carbon nanotubes with very similar chirality and identifying their typical electrochemical properties.
Blog post with audio player, show notes, and transcript: https://www.preposterousuniverse.com/podcast/2019/06/17/epis…formation/
Patreon: https://www.patreon.com/seanmcarroll.
Cosmologists have a standard set of puzzles they think about: the nature of dark matter and dark energy, whether there was a period of inflation, the evolution of structure, and so on. But there are also even deeper questions, having to do with why there is a universe at all, and why the early universe had low entropy, that most working cosmologists don’t address. Today’s guest, Anthony Aguirre, is an exception. We talk about these deep issues, and how tackling them might lead to a very different way of thinking about our universe. At the end there’s an entertaining detour into AI and existential risk.
Anthony Aguirre received his Ph.D. in Astronomy from Harvard University. He is currently associate professor of physics at the University of California, Santa Cruz, where his research involves cosmology, inflation, and fundamental questions in physics. His new book, Cosmological Koans, is an exploration of the principles of contemporary cosmology illustrated with short stories in the style of Zen Buddhism. He is the co-founder of the Foundational Questions Institute, the Future of Life Institute, and the prediction platform Metaculus.
Like engineers who design high-performance Formula One race cars, scientists want to create high-performance plasmas in twisty fusion systems known as stellarators. Achieving this performance means that the plasma must retain much of its heat and stay within its confining magnetic fields.
To ease the creation of these plasmas, physicists have created a new computer code that could speed up the design of the complicated magnets that shape the plasma, making stellarators simpler and more affordable to build.
Known as QUADCOIL, the code helps scientists rule out plasma shapes that are stable but require magnets with overly complicated shapes. With this information, scientists can instead devote their efforts to designing stellarators that can be built affordably.
Our understanding of black holes, time and the mysterious dark energy that dominates the universe could be revolutionized, as new University of Sheffield research helps unravel the mysteries of the cosmos.
Black holes—areas of space where gravity is so strong that not even light can escape—have long been objects of fascination, with astrophysicists, theoretical physicists and others dedicating their lives to revealing their secrets. This fascination with the unknown has inspired numerous writers and filmmakers, with novels and films such as “Interstellar” exploring these enigmatic objects’ hold on our collective imagination.
According to Einstein’s theory of general relativity, anyone trapped inside a black hole would fall toward its center and be destroyed by immense gravitational forces. This center, known as a singularity, is the point where the matter of a giant star, which is believed to have collapsed to form the black hole, is crushed down into an infinitesimally tiny point. At this singularity, our understanding of physics and time breaks down.
A multi-institutional team of physicists and engineers has developed a laser-based radiation detection system that operates from as far away as 10 meters and perhaps farther. Their research is published in the journal Physical Review Applied.
Working with nuclear material, whether in creating weapons or energy, requires monitoring radiation levels to ensure the safety of workers. However, most detectors only allow for testing in close proximity to the source, which means a worker can be in danger of overexposure before they know it has happened. In this new study, the team assigned themselves the goal of developing a new type of system or device that could be used to test from much farther away.
The team started by noting that radiation interacts with molecules in the air around it, resulting in the creation of free electrons, so it should be possible to measure the energy of those electrons using a laser beam. In testing their ideas, they found that firing a laser into irradiated air did lead to molecule collisions, which produced free electrons.
From 2035, the Einstein Telescope will be able to study gravitational waves with unprecedented accuracy. For the telescope, researchers from Jena have manufactured highly sensitive sensors made entirely of glass for the first time.
Gravitational waves are distortions of space-time caused by extreme astrophysical events, such as the collision of black holes. These waves propagate at the speed of light and carry valuable information about such events throughout the universe. In the future, the Einstein Telescope will measure these waves with unprecedented precision, making it a world-leading instrument for detecting gravitational waves.
In order to minimize the impact of noise on the measurements, the telescope is to be built up to 300 meters underground. But even there, there are still mechanical vibrations, caused, for example, by distant earthquakes or road traffic above ground. Highly sensitive vibration sensors will measure these remaining vibrations.
Density functional theory (DFT) is a cornerstone tool of modern physics, chemistry, and engineering used to explore the behavior of electrons. While essential in modeling systems with many electrons, it suffers from a well-known flaw called self-interaction error. A recent study has identified a new area where a correction for this error breaks down.
An international collaboration headed by researchers in the Department of Physics has shown that additive manufacturing offers a realistic way to build large-scale plastic scintillator detectors for particle physics experiments.
In 2024, the T2K Collaboration started to collect new neutrino data following several upgrades to the experiment that included new types of detectors. One of these, called SuperFGD, has a mass of about 2 tons of sensitive volume and is made of approximately two million cubes. Each cube is made of plastic scintillator (PS) material that emits light when a charged particle passes through it.
Neutrinos carry no charge, as their name indicates, but they sometimes interact with other particles, then produce electrons, protons, muons or pions that can be detected. Each PS cube is traversed by three orthogonal optical fibers that collect the scintillation light and guide it to 56,000 photodetectors. The data reveal three-dimensional (3D) particle tracks, which in turn allow researchers to learn more about neutrinos.