O,.o!!!!! Circa 2018
High-energy laser pulses cause electrons to oscillate, giving off gamma rays that produce electrons and positrons.
Circa 2000
A 1940 paper by Gamow and Mario Schoenberg was the first in a subject we now call particle astrophysics. The two authors presciently speculated that neutrinos could play a role in the cooling of massive collapsing stars. They named the neutrino reaction the Urca process, after a well known Rio de Janeiro casino. This name might seem a strange choice, but not to Gamow, a legendary prankster who once submitted a paper to Nature in which he suggested that the Coriolis force might account for his observation that cows chewed clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
In the 1940s Gamow began to attack, with his colleague Ralph Alpher, the problem of the origin of the chemical elements. Their first paper on the subject appeared in a 1948 issue of the Physical Review. At the last minute Gamow, liking the sound of ‘alpha, beta, gamma’, added his old friend Hans Bethe as middle author in absentia (Bethe went along with the joke, but the editors did not). Gamow and Alpher, with Robert Herman, then pursued the idea of an extremely hot neutron-dominated environment. They envisioned the neutrons decaying into protons, electrons and anti-neutrinos and, when the universe had cooled sufficiently, the neutrons and protons assembling heavier nuclei. They even estimated the photon background that would be necessary to account for nuclear abundances, suggesting a residual five-degree background radiation.
Using a groundbreaking new technique at the National Institute of Standards and Technology (NIST), an international collaboration led by NIST researchers has revealed previously unrecognized properties of technologically crucial silicon crystals and uncovered new information about an important subatomic particle and a long-theorized fifth force of nature.
By aiming subatomic particles known as neutrons at silicon crystals and monitoring the outcome with exquisite sensitivity, the NIST scientists were able to obtain three extraordinary results: the first measurement of a key neutron property in 20 years using a unique method; the highest-precision measurements of the effects of heat-related vibrations in a silicon crystal; and limits on the strength of a possible “fifth force” beyond standard physics theories.
The researchers report their findings in the journal Science.
Physicists sifting through old particle accelerator data have found evidence of a highly-elusive, never-before-seen process: a so-called triangle singularity.
First envisioned by Russian physicist Lev Landau in the 1950s, a triangle singularity refers to a rare subatomic process where particles exchange identities before flying away from each other. In this scenario, two particles — called kaons — form two corners of the triangle, while the particles they swap form the third point on the triangle.
Black holes are regions of space-time with huge amounts of gravity. Scientists originally thought that nothing could escape the boundaries of these massive objects, including light.
The precise nature of black holes has been challenged ever since Albert Einstein’s general theory of relativity gave rise to the possibility of their existence. Among the most famous findings was English physicist Stephen Hawking’s prediction that some particles are actually emitted at the edge of a black hole.
Physicists have also explored the workings of vacuums. In the early 1970s, as Hawking was describing how light can escape a black hole’s gravitational pull, Canadian physicist William Unruh proposed that a photodetector accelerated fast enough could “see” light in a vacuum.
CERN Courier
Jennifer Ngadiuba and Maurizio Pierini describe how ‘unsupervised’ machine learning could keep watch for signs of new physics at the LHC that have not yet been dreamt up by physicists.
In the 1970s, the robust mathematical framework of the Standard Model ℠ replaced data observation as the dominant starting point for scientific inquiry in particle physics. Decades-long physics programmes were put together based on its predictions. Physicists built complex and highly successful experiments at particle colliders, culminating in the discovery of the Higgs boson at the LHC in 2012.
Tiny particles from distant galaxies have caused plane accidents, election interference and game glitches. This video is sponsored by Brilliant. The first 200 people to sign up via https://brilliant.org/veritasium get 20% off a yearly subscription.
This video was inspired by the RadioLab Podcast “Bit Flip” https://ve42.co/BF — they’re brilliant science storytellers.
Quantum radar was proposed as a solution more than a decade ago. Some quantum technologies, such as the entanglement of subatomic particles, could in theory boost the sensitivity of a radar.
Quantum particles in a man-made electromagnetic storm bounced back after hitting stealth object, increasing chance of detection, according to Tsinghua University team.
Graphene, hexagonally arranged carbon atoms in a single layer with superior pliability and high conductivity, could advance flexible electronics according to a Penn State-led international research team. Huanyu “Larry” Cheng, Dorothy Quiggle Career Development Professor in Penn State’s Department of Engineering Science and Mechanics (ESM), heads the collaboration, which recently published two studies that could inform research and development of future motion detection, tactile sensing and health monitoring devices.
Investigating how laser processing affects graphene form and function
Several substances can be converted into carbon to create graphene through laser radiation. Called laser-induced graphene (LIG), the resulting product can have specific properties determined by the original material. The team tested this process and published their results in SCIENCE CHINA Technological Sciences.
Silvia Musolino defended her Ph.D. on new theoretical insights in quantum physics by studying gases at the lowest temperatures consisting of many atoms.
A practical way to study quantum mechanics is provided by gases that have extremely low density and consist of many atoms, often more than one hundred thousand, cooled down to temperatures close to the absolute zero. Silvia Musolino studied different types of interactions between these atoms, providing new pathways for future research on new technologies such as quantum computers.
Quantum mechanical laws govern the physics at the atomic scale and is distinguished by classical mechanics, which deals mainly with natural phenomena we can see, hear, or touch. However, even quantum mechanics influences our daily life. Transistors, which are crucial components of electronic devices, are based on quantum mechanical effects. Moreover, quantum mechanics paves the way for new technologies that may strongly impact our lives, such as quantum computers.
