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Paul Dirac

From that insight, Dirac built an entirely new formulation of the theory using what he called “q-numbers” (quantum numbers)—abstract quantities that don’t commute. He independently rediscovered aspects of Hilbert’s operator theory, though he preferred his own algebraic route because he found mathematicians’ obsession with convergence and existence theorems unappealing.

Paul Adrien Maurice Dirac (, dih-RAK ; [ 3 ] 8 August 1902 – 20 October 1984) was a British theoretical physicist who is considered to be one of the founders of quantum mechanics. [ 4 ] [ 5 ] Dirac laid the foundations for both quantum electrodynamics and quantum field theory, coining the former term. [ 6 ] [ 7 ] [ 8 ] [ 9 ] He was Lucasian Professor of Mathematics at the University of Cambridge from 1932 to 1969, and a professor of physics at Florida State University from 1970 to 1984. Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger “for the discovery of new productive forms of atomic theory.” [ 10 ]

Dirac graduated from the University of Bristol with a Bachelor of Science in Electrical Engineering in 1921, and a Bachelor of Arts in Mathematics in 1923. [ 11 ] Dirac then graduated from St John’s College, Cambridge, with a Doctor of Philosophy in Physics in 1926, writing the first ever thesis on quantum mechanics. [ 12 ]

He formulated the Dirac equation, one of the most important results in physics, in 1928. [ 7 ] It connected special relativity and quantum mechanics and predicted the existence of antimatter. [ 13 ] He wrote a famous paper in 1931, [ 14 ] which further predicted the existence of antimatter. [ 15 ] [ 16 ] [ 13 ] Dirac also contributed greatly to the reconciliation of general relativity with quantum mechanics. He contributed to Fermi–Dirac statistics, which describes the behaviour of fermions, particles with half-integer spin. His 1930 monograph, The Principles of Quantum Mechanics, is one of the most influential texts on the subject. [ 17 ] He and Schrödinger tied for eighth in a Physics World poll of the greatest physicists of all time. [ 18 ] .

Evidence of scaling advantage for the quantum approximate optimization algorithm on a classically intractable problem

We study the scaling of QAOA TTS with the problem size on the low autocorrelation binary sequences (LABS) problem (15, 16), also known as the Bernasconi model in statistical physics (17, 18). The LABS problem has applications in communications engineering, where the low autocorrelation sequences are used for designing radar pulses (15, 19). To solve LABS, one has to produce a sequence of N bits that minimizes a specific quartic objective.

We choose LABS to study the scaling of QAOA TTS for the following three reasons. First, the complexity of LABS grows rapidly, with optimal solutions known only for N ≤ 66 and the best heuristics producing approximate solutions of quality decaying with N for N 200 (20, 21). This makes it a promising candidate problem, since only a few hundred qubits are required to tackle classically intractable instances. Second, the performance of classical solvers for LABS has been benchmarked (20, 21) in terms of the scaling of their TTS with problem size. Since optimal solutions are only known for N ≤ 66, the scaling of TTS for all classical solvers is obtained by fitting results for N ≤ 66. We reproduce these results and observe that that the scaling of classical solvers at N ≤ 40 matches the behavior for N up to 66 reported in the literature. This provides evidence that the scaling we observe for QAOA at N ≤ 40 will similarly extrapolate to larger N. Third, LABS has only one instance per problem size N. Combined with the hardness of LABS, this makes it possible to reliably study the scaling of QAOA at large problem sizes, where simulating tens or hundreds of random instances would be computationally infeasible.

We obtain the scaling by performing noiseless exact simulation of QAOA with fixed schedules. Our results are enabled by a custom algorithm-specific graphics processing unit (GPU) simulator (22), which we execute using up to 1,024 GPUs per simulation on the Polaris supercomputer accessed through the Argonne Leadership Computing Facility. We find that the TTS of QAOA with number of layers p = 12 grows as 1.46N, which is improved to 1.21N if combined with quantum minimum finding. This scaling is better than that of the best classical heuristic, which has a TTS that grows as 1.34N. We note that we do not propose any new quantum algorithms in this work. Instead, we study a general quantum optimization heuristic with broad applicability (namely, QAOA) and make no specific modifications to adapt it to the LABS problem.

Leaving gravity behind: Experiment from ISS reveals how particles alter turbulent flow behavior

After traveling hundreds of miles above Earth and spending months aboard the International Space Station, a University of Delaware experiment has returned to campus, bringing new data on how turbulence behaves in microgravity.

The project, led by assistant professor of mechanical engineering Tyler Van Buren, is designed to study how particles influence turbulent flows. From dust in the air to sand in coastal zones and bubbles at the sea surface, particles can change how flows behave.

Van Buren compares it to an energetic crowd moving around while carrying objects.

Optical device uses humidity to unlock hidden information and offers new option for data storage

Engineers at the University of California San Diego have developed an optical device that reveals hidden images and changes colors in response to different levels of humidity. The technology, published in Light: Science & Applications, could lead to the development of new anti-counterfeiting labels, secure data storage, interactive displays, and environmental sensors.

The device works by displaying different images depending on moisture levels in the air. Under normal conditions or low humidity levels, one image (UC San Diego Triton logo) is visible. When humidity increases, a second image (UC San Diego library logo) emerges and conceals the first. This transition can be triggered even when a person breathes on the device. It happens in a fraction of a second and can be repeated many times.

“You can imagine using this as a built-in security feature with the environment acting like a key that unlocks different pieces of information,” said study first author Asad Nauman, an electrical and computer engineering postdoctoral researcher at UC San Diego. “One example would be something like a credit card security tag, where you can blow on it and reveal a hidden code. Another application would be an environmental sensor that changes color as the humidity changes.”

China’s Human Artificial Embryo Experiment Progressing Well in Space

China has begun the world’s first space experiment on human artificial embryos, with samples now aboard its space station and the study progressing smoothly, scientists announced Wednesday.

Delivered by the Tianzhou-10 cargo craft launched earlier this week, the human artificial embryo samples have been installed in the space station’s experimental module by the orbiting taikonauts, according to the Technology and Engineering Center for Space Utilization under the Chinese Academy of Sciences, which is in charge of the experiment.

“The experiment is going very well,” said Yu Leqian, the project leader for the artificial embryo space science experiment. “A pre-set automated system changes the culture medium for the samples every day.” According to Yu, through this study, scientists aim to conduct preliminary research on issues related to long-term human habitation, survival and reproduction in space.

Prof. RHO Jun-seok Advances Metalens Technology from Manufacturing to Display Applications in Two Nature Papers

Nanoprinting imprinting metalenses 100x faster than lithography.

Professor RHO Jun-seok from the Departments of Mechanical Engineering and Chemical Engineering at POSTECH has gained international attention for developing a mass-production process for metalenses and a switchable 2D-3D display technology based on them. The two studies were simultaneously published in the April 30 issue of Nature. This marks the first case in Korea of a researcher publishing two separate papers as corresponding author in the same issue of the journal.

A metalens is a flat optical device that controls light using nanoscale structures rather than curved glass. By replacing bulky glass lenses with engineered surface patterns, optical systems become far thinner and lighter. Because this enables control of light at scales smaller than its wavelength, metamaterials are often regarded as a Nobel Prize–worthy field of research.

The first study addressed a key barrier to commercialization: large-scale manufacturing. Production has so far relied on expensive and complex semiconductor fabrication processes due to the extreme precision required, making it slow, costly, and largely limited to laboratory research. To overcome this, Prof. RHO’s team developed a Roll-to-Roll Nanoimprint process enabling continuous production using a cylindrical roller. Instead of fabricating nanoscale structures one by one on rigid molds, flexible polymer molds were used to imprint patterns onto thin films. This shifts fabrication from a one-at-a-time process to continuous factory-scale production. The team produced over 300 metalenses per second, about 100 times faster than conventional methods, while maintaining consistent performance over a 200-meter process.

Surface design transforms thermal management and enables frictionless systems

A research team led by Professor Steven Wang, Associate Vice President (Resources Planning) and Associate Professor in the Department of Mechanical Engineering and School of Energy and Environment, has designed a revolutionary capillary structure that can trigger the Leidenfrost effect, offering a practical solution for the temperature-regulated Leidenfrost effect without requiring complex surface engineering.

The study, titled “Capillary Leidenfrost Effect”, was recently published in the journal Nature Physics.

The Leidenfrost effect is a physical phenomenon discovered in 1756. It occurs when a liquid droplet touches a surface much hotter than its boiling point, forming a vapor layer that makes it levitate and hover, slowing down evaporation. A simple example is water on a very hot pan: the drops sizzle and disappear quickly, but once it reaches the Leidenfrost point, they bead up, skate and dance around on a steam barrier, and last much longer before evaporating. This effect is ubiquitous in a wide range of laboratory and industrial applications.

Collective vibrations unlock fast ion flow in superionic crystals

In the race to develop safer, faster-charging solid-state batteries and more efficient thermoelectric conversion technologies, engineers and scientists have long faced a fundamental challenge: how to ensure ions move through hard, solid materials as quickly as they do in liquids?

A team led by Prof. Zhou Yanguang, Associate Professor in the Department of Mechanical and Aerospace Engineering (MAE) at The Hong Kong University of Science and Technology (HKUST), discovered a novel mechanism for rapid ion transport in solids, opening new avenues for materials design.

The study shows that the ionic transport is governed by collective dynamics. The results were published in the journal Physical Review Letters, titled “Fast Ionic Transport Governed by Collective Vibrational Dynamics.”

Capsida’s Trailblazing Moment: What the Field Owes the Next BBB Program

An insightful perspective on what biological factors may have been the cause of a patient’s death after receiving a blood-brain-barrier crossing AAV treatment. It’s crucial for the field to think about this carefully as we move forward.

TheBioMLClinic

Brief disclosure: I am a named inventor on patents and author on publications related to AAV capsid engineering and CNS gene delivery, developed during my time at the Broad Institute. I now operate independently. This post does not represent any prior employer, current advisory client, or collaborator. The mechanistic analysis presented here is my own scientific interpretation of publicly available data. Full disclosures at the bottom.

‘Designer’ superconducting diamond: Researchers uncover path to multi-modality quantum chips

Diamond is extremely valuable to science and technology not for its sparkle but for its extreme hardness, high thermal conductivity, transparency to a large fraction of the light spectrum, and a host of other exceptional properties. Two decades ago, scientists discovered another advantage: under the right conditions, diamond can become a superconductor—allowing electricity to flow through it with zero resistance.

Until recently, though, they knew little about how that happens, limiting its use in high-tech applications.

Now researchers from the Pennsylvania State University, the University of Chicago Pritzker School of Molecular Engineering (PME), and the U.S. Department of Energy National Quantum Information Science Research Center Q-NEXT, led by Argonne National Laboratory, have uncovered new insights into the physics behind the phenomenon by carefully creating high-quality diamond, isolating electronic signatures from material noise, and revealing the fundamental mechanisms that had long remained hidden.

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