The world’s urban population increased by 785 million people between 2000 and 2020, but that tells only part of the story. Now, a research team including an expert from the University of Michigan has dug into the demographics of more than 10,000 individual cities to obtain insights that can be lost in the aggregate. The findings are published in the journal Nature Cities.
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.”
Quantum computers have the potential to transform science, accelerating breakthroughs in drug development, cosmology, materials science, nuclear physics, and more.
To make this future a reality, researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) are partnering with industry, academia, and the national labs to drive advances across the quantum computing “stack”—the hardware, software, and controls designed to ensure error-corrected quantum calculations.
“Making a functional quantum computer requires much more than qubits alone. It takes an entire technology stack that can harness quantum science for real-world applications,” said Chris Spitzer, operations lead at the Advanced Quantum Testbed (AQT).
Using the unprecedented imaging and spectroscopic power of the NASA/ESA/CSA James Webb Space Telescope, researchers have mapped the motion and composition of gas orbiting a black hole in the centre of Abell2744-QSO1, a tiny galaxy more than 13 billion light-years away. The results suggest that the 50-million-solar-mass black hole predates its host galaxy, possibly forming within the first second of the Big Bang, and must have been immense from the start.