Nearly 75 years after the puzzling first detection of the kaon, scientists are still looking to the particle for hints of physics beyond their current understanding.
Extremely massive fundamental particles could exist, but they would seriously mess with our understanding of quantum mechanics.
O,.o kaons in action for interstellar travel: D.
Interstellar probes and future interstellar travel will require relativistic rockets. The problem is that such a rocket drive requires that the rocket exhaust velocity from the fuel also is relativistic, since otherwise the rocket thrust is much too small: the total mass of the fuel will be so large that relativistic speeds cannot be reached in a reasonable time and the total mass of the rocket will be extremely large. Until now, no technology was known that would be able to give rocket exhaust at relativistic speed and a high enough momentum for relativistic travel. Here, a useful method for relativistic interstellar propulsion is described for the first time. This method gives exhaust at relativistic speeds and is a factor of at least one hundred better than normal fusion due to its increased energy output from the annihilation-like meson formation processes. It uses ordinary hydrogen as fuel so a return travel is possible after refuelling almost anywhere in space. The central nuclear processes have been studied in around 20 publications, which is considered to be sufficient evidence for the general properties. The nuclear processes give relativistic particles (kaons, pions and muons) by laser-induced annihilation-like processes in ultra-dense hydrogen H. The kinetic energy of the mesons is 1300 times larger than the energy of the laser pulse. This method is superior to the laser-sail method by several orders of magnitude and is suitable for large spaceships.
Scientists at Freie Universität Berlin develop a deep learning method to solve a fundamental problem in quantum chemistry.
A team of scientists at Freie Universität Berlin has developed an artificial intelligence (AI) method for calculating the ground state of the Schrödinger equation in quantum chemistry. The goal of quantum chemistry is to predict chemical and physical properties of molecules based solely on the arrangement of their atoms in space, avoiding the need for resource-intensive and time-consuming laboratory experiments. In principle, this can be achieved by solving the Schrödinger equation, but in practice this is extremely difficult.
Up to now, it has been impossible to find an exact solution for arbitrary molecules that can be efficiently computed. But the team at Freie Universität has developed a deep learning method that can achieve an unprecedented combination of accuracy and computational efficiency. AI has transformed many technological and scientific areas, from computer vision to materials science. “We believe that our approach may significantly impact the future of quantum chemistry,” says Professor Frank Noé, who led the team effort. The results were published in the reputed journal Nature Chemistry.
Researchers recently resolved a long-standing question in quantum physics, about how long it takes a single atom to tunnel through a barrier.
While many institutions are developing quantum computers, making a quantum internet requires a way to transfer the information between computers. This is accomplished by a phenomenon called quantum teleportation, in which two atoms separated by large distances are made to act as if they are identical.
Don Lincoln writes about recent research that has brought us closer to actualizing the goal of a quantum internet, giving us both hope and fear about what it could mean for the future.
Until recently, scientists believed that only very massive nuclei could have excited zero-spin states of increased stability with a significantly deformed shape. Meanwhile, an international team of researchers from Romania, France, Italy, the USA and Poland showed in their latest article that such states also exist in much lighter nickel nuclei. Positive verification of the theoretical model used in these experiments allows describing the properties of nuclei unavailable in Earth laboratories.
More than 99.9 per cent of the mass of an atom comes from the atomic nucleus, the volume of which is over a trillion times smaller than the volume of the entire atom. Hence, the atomic nucleus has an amazing density of about 150 million tons per cubic centimeter. This means that one tablespoon of nuclear matter weighs almost as much as a cubic kilometer of water. Despite their very small size and incredible density, atomic nuclei are complex structures made of protons and neutrons. One may expect that such extremely dense objects would always take spherical form. In reality, however, the situation is quite different: most nuclei are deformed—they exhibit shape flattened or elongated along one or even two axes, simultaneously. To find the favorite form of a given nucleus, it is customary to construct a landscape of the potential energy as a function of deformation. One may visualize such landscape by drawing a map on which the plane coordinates are the deformation parameters, i.e.
O,.o circa 2018.
The ongoing search for the graviton—the proposed fundamental particle carrying gravitational force—is a crucial step in physicists’ long journey toward a theory of everything.
The U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) is collaborating with private industry on cutting-edge fusion research aimed at achieving commercial fusion energy. This work, enabled through a public-private DOE grant program, supports efforts to develop high-performance fusion grade plasmas. In one such project PPPL is working in coordination with MIT’s Plasma Science and Fusion Center (PSFC) and Commonwealth Fusion Systems, a start-up spun out of MIT that is developing a tokamak fusion device called “SPARC.”
The goal of the project is to predict the leakage of fast “alpha” particles produced during the fusion reactions in SPARC, given the size and potential misalignments of the superconducting magnets that confine the plasma. These particles can create a largely self-heated or “burning plasma” that fuels fusion reactions. Development of burning plasma is a major scientific goal for fusion energy research. However, leakage of alpha particles could slow or halt the production of fusion energy and damage the interior of the SPARC facility.
A multitasking nanomachine that can act as a heat engine and a refrigerator at the same time has been created by RIKEN engineers. The device is one of the first to test how quantum effects, which govern the behavior of particles on the smallest scale, might one day be exploited to enhance the performance of nanotechnologies.
Conventional heat engines and refrigerators work by connecting two pools of fluid. Compressing one pool causes its fluid to heat up, while rapidly expanding the other pool cools its fluid. If these operations are done in a periodic cycle, the pools will exchange energy and the system can be used as either a heat engine or a fridge.
It would be impossible to set up a macroscale machine that does both tasks simultaneously—nor would engineers want to, says Keiji Ono of the RIKEN Advanced Device Laboratory. “Combining a traditional heat engine with a refrigerator would make it a completely useless machine,” he says. “It wouldn’t know what to do.”
A viable quantum internet—a network in which information stored in qubits is shared over long distances through entanglement—would transform the fields of data storage, precision sensing and computing, ushering in a new era of communication.
This month, scientists at Fermi National Accelerator Laboratory—a U.S. Department of Energy national laboratory affiliated with the University of Chicago—along with partners at five institutions took a significant step in the direction of realizing a quantum internet.
In a paper published in PRX Quantum, the team presents for the first time a demonstration of a sustained, long-distance teleportation of qubits made of photons (particles of light) with fidelity greater than 90%.
