In a paper published earlier this month in Physical Review Letters, a team of physicists led by Jonathan Richardson of the University of California, Riverside, showcases how new optical technology can extend the detection range of gravitational-wave observatories such as the Laser Interferometer Gravitational-Wave Observatory, or LIGO, and pave the way for future observatories.
Since 2015, observatories like LIGO have opened a new window on the universe. Plans for future upgrades to the 4-kilometer LIGO detectors and the construction of a next-generation 40-kilometer observatory, Cosmic Explorer, aim to push the gravitational-wave detection horizon to the earliest times in the history of the universe, before the first stars formed. However, realizing these plans hinges on achieving laser power levels exceeding 1 megawatt, far beyond LIGO’s capabilities today.
The research paper reports a breakthrough that will enable gravitational-wave detectors to reach extreme laser powers. It presents a new low-noise, high-resolution adaptive optics approach that can correct the limiting distortions of LIGO’s main 40-kilogram mirrors which arise with increasing laser power due to heating.
Astrophysicists have unearthed a surprising diversity in the ways in which white dwarf stars explode in deep space after assessing almost 4,000 such events captured in detail by a next-gen astronomical sky survey. Their findings may help us more accurately measure distances in the universe and further our knowledge of “dark energy.”
The dramatic explosions of white dwarf stars at the ends of their lives have for decades played a pivotal role in the study of dark energy—the mysterious force responsible for the accelerating expansion of the universe. They also provide the origin of many elements in our periodic table, such as titanium, iron and nickel, which are formed in the extremely dense and hot conditions present during their explosions.
A major milestone has been achieved in our understanding of these explosive transients with the release of a major dataset, and associated 21 publications in an Astronomy & Astrophysics special issue.
In April 1982, Prof. Dan Shechtman of the Technion–Israel Institute of Technology made the discovery that would later earn him the 2011 Nobel Prize in Chemistry: the quasiperiodic crystal. According to diffraction measurements made with an electron microscope, the new material appeared “disorganized” at smaller scales, yet with a distinct order and symmetry apparent at a larger scale.
This form of matter was considered impossible, and it took many years to convince the scientific community of the discovery’s validity. The first physicists to theoretically explain this discovery were Prof. Dov Levine, then a doctoral student at the University of Pennsylvania and now a faculty member in the Technion Physics department, and his advisor, Prof. Paul Steinhardt.
The key insight that enabled their explanation was that quasicrystals were, in fact, periodic—but in a higher dimension than the one in which they exist physically. Using this realization, the physicists were able to describe and predict mechanical and thermodynamic properties of quasicrystals.
Until his dying days, the giant of 20th-century physics obsessed over the underpinnings of space and time, and how we can all share the same version of them.
Before arriving at Janelia three years ago, Postdoctoral Scientist Antonio Fiore was designing and building optical instruments like microscopes and spectrometers. Fiore, a physicist by training, came to the Pedram Lab to try something new.
“I focused on the physics rather than investing in the biological applications of the optics I was developing,” Fiore says. “I came to the Pedram Lab in search of a different kind of impact, joining a team that explores areas of biology that need new tools, while keeping a connection to light microscopy.”
Researchers have developed a novel experimental platform to measure the electric fields of light trapped between two mirrors with a sub-cycle precision.
These electro-optic Fabry-Pérot resonators will allow for precise control and observation of light-matter interactions, particularly in the terahertz (THz) spectral range. The study is published in the journal Light: Science & Applications.
The researchers are from the Department of Physical Chemistry at the Fritz Haber Institute of the Max Planck Society and the Institute of Radiation Physics at Helmholtz Center Dresden-Rossendorf.
Combining concepts from statistical physics with machine learning, researchers at the University of Bayreuth have shown that highly accurate and efficient predictions can now be made as to whether a substance will be liquid or gaseous under given conditions. They have published their findings in Physical Review X.
Observation of a glass of water reveals that the water exists in two distinct phases: liquid and gas. Even at room temperature, water molecules are constantly evaporating from the surface of the liquid water and passing into the gas phase. At the same time, some of the water molecules from the gas condense back into the liquid.
The transition from one phase to the other depends on temperature and pressure. Above a critical temperature, the simultaneous coexistence of gas and liquid disappears. The resulting supercritical fluid no longer forms an interface. This is important for industrial processes such as separation, cleaning and production.