Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog – Page 25

Get the latest international news and world events from around the world.

Log in for authorized contributors

New controls can stretch, blur and even reverse quantum time flow

In new research published in Physical Review X, scientists have designed quantum control protocols that generate processes more consistent with time flowing backward than forward. The protocols—techniques to control quantum systems—modify a quantum system’s “arrow of time,” the concept of time as moving in one forward direction. The work opens up possibilities for energy extraction from quantum systems and for quantum state preparation.

A quantum system, such as a collection of qubits, is governed by the laws of quantum mechanics. The team’s control protocols can prevent the emergence of the arrow of time in a quantum system or even invert its direction—that is, cause quantum time to appear to flow in reverse.

As an application of their research, the team leveraged their control protocols to design a measurement engine that extracts energy from quantum measurements performed on the system.

Superconducting quantum processor performs well with significantly less wiring

Quantum computers, computing systems that process information using quantum mechanical effects, could outperform classical computers on some computational tasks. These computers rely on qubits, the basic units of quantum information, which can exist in multiple states (0, 1 or both simultaneously), due to quantum effects known as superposition and entanglement.

Many of the quantum computers developed in recent years are based on conventional superconductors, materials that exhibit an electrical resistance of zero at extremely low temperatures. To operate reliably and exhibit superconductivity, circuits based on these materials need to be cooled down to millikelvin temperatures.

In quantum computers, each qubit typically requires its own control line. This means that engineers need to introduce several wires that carry electrical pulses (i.e., signal lines), and the number of necessary wires increases with the number of qubits. As quantum computers grow larger, this can be problematic, as processors become harder to build and reliably operate.

Quantum computers could have a fundamental limit after all

The performance of quantum computers could cap out after around 1,000 qubits, according to a new analysis published in the Proceedings of the National Academy of Sciences. Through new calculations, Tim Palmer at the University of Oxford has reconsidered the mathematical foundations underlying the quantum principles behind the technology, concluding that restrictions on the information-carrying capacity of large quantum systems could make their computing power far more limited than many researchers predict.

For some time, quantum physicists have been growing increasingly excited—and concerned—about the seemingly limitless potential of quantum computers. In a classical computer, information content generally grows linearly as the number of bits increases. But in a quantum computer, each extra qubit doubles the number of quantum states the system can occupy.

Since these states can encode multiple possibilities at the same time, the overall system appears to become exponentially more powerful with each added qubit—at least according to our current understanding of quantum mechanics.

Superconducting chip generates tunable terahertz waves for compact imaging

A tiny crystal chip which uses terahertz radiation to see clearly through a wide range of materials could find applications in health care, biological research, and security screening. Researchers from Scotland and Japan have developed a lightweight superconducting chip, which they say could unlock the full potential of terahertz imaging technologies and lead to the development of more powerful and portable devices.

The team’s paper, titled “Terahertz Imaging System with On-Chip Superconducting Josephson Plasma Emitters for Nondestructive Testing,” is published in IEEE Transactions on Applied Superconductivity.

Terahertz radiation lies between the microwave and infrared frequencies of the electromagnetic spectrum. It passes easily and harmlessly through a wide range of materials, and can be used to identify the characteristic “fingerprint” of molecules and biological materials as it does so, allowing them to be detected and analyzed.

Stealth superstorms reveal lightning on Jupiter: Beyond the superbolt

Jupiter’s lightning has long been of interest to planetary scientists, as it marks stormy spots where researchers can look to learn more about convection in Jupiter’s atmosphere. Observing lightning from a distance can be tricky, so scientists have focused on the bolts that are easiest to study: strong flashes that strike at night. As a result, some studies have concluded that lightning bolts on Jupiter are all similar to the strongest lightning on Earth, known as “superbolts.” This conclusion was recently questioned, however, when the high-sensitivity star tracker camera on NASA’s Juno spacecraft detected faint, shallow lightning.

For a study published in AGU Advances, Michael Wong and colleagues took a closer look, focusing on a period in 2021 and 2022 when lightning in Jupiter’s North Equatorial Belt was highly localized within powerful, isolated storms the researchers labeled “stealth superstorms.” This unusual meteorology allowed researchers to pinpoint the location of lightning more accurately.

Instead of looking only at visible light, the scientists used data from the Microwave Radiometer instrument and the Waves experiment—radio wave detectors carried by Juno, which has been orbiting Jupiter for the past 10 years. Radio waves are just one form of electromagnetic radiation produced by lightning, but they’re an especially informative form because scientists can study them even when clouds or other components of the atmosphere block visual cues. The approach allowed the researchers to look beyond the strong nocturnal bolts other researchers have focused on.

One-step coating keeps fabrics superhydrophobic after tens of thousands of abrasion cycles

Developing robust water-repellent textiles is critical for outdoor, protective, and industrial applications. However, achieving long-lasting water repellency under mechanical stress has been a major challenge.

Now, a research team led by Prof. Dong Zhichao from the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences has developed a new one-step fabrication strategy—termed MARS (Molecularly Assembled Robust Superhydrophobic Shell)—for producing superhydrophobic fabrics with stable mechanical performance under harsh conditions.

The findings were published in Nature Communications on March 20.

Scientists Identified a Speech Trait That Foreshadows Cognitive Decline

Early signs of Alzheimer’s disease may be hidden in the way a person speaks, but it’s not yet clear which details of our diction are most critical for diagnosis.

A study from 2023 suggests that as we age, how we say something may matter more than what we say. Researchers at the University of Toronto think the pace of everyday speech may be a better indicator of cognitive decline than difficulty finding a word.

“Our results indicate that changes in general talking speed may reflect changes in the brain,” said cognitive neuroscientist Jed Meltzer when the research was published.

/* */