Lifeboat Foundation

As we approach two full years of the COVID-19 pandemic, we now know it spreads primarily through airborne transmission. The virus rides inside tiny microscopic droplets or aerosol ejected from our mouths when we speak, shout, sing, cough, or sneeze. It then floats within the air, where it can be inhaled by and transmitted.

This inspired researchers in India to explore how we can better understand and engineer airflow to mitigate the transmission of COVID-19. To do this, they used their knowledge of airflow around aircraft and engines to tailor the airflow within indoor spaces.

In Physics of Fluids, they report computer simulations of airflow within a public washroom showing infectious aerosols in dead zones can linger up to 10 times longer than the rest of the room. These dead zones of trapped air are frequently found in corners of a room or around furniture.

The research team lead by professor Pan Jian-Wei has upgraded their photonic quantum computer, demonstrating in a new published study phase-programmable Gaussian boson sampling (GBS) which produces up to 113 photon detection events out of a 144-mode photonic circuit. According to the researchers, the Jiuzhang 2.0 Photonic Quantum Computer (九章二号) is 10 billion times faster than its earlier version. The study “Phase-Programmable Gaussian Boson Sampling Using Stimulated Squeezed Light” was published in the journal Physical Review.

Credit: China Media Group(CMG)/China Central Television (CCTV)

The device you are currently reading this article on was born from the silicon revolution. To build modern electrical circuits, researchers control silicon’s current-conducting capabilities via doping, which is a process that introduces either negatively charged electrons or positively charged “holes” where electrons used to be. This allows the flow of electricity to be controlled and for silicon involves injecting other atomic elements that can adjust electrons—known as dopants—into its three-dimensional (3D) atomic lattice.

Silicon’s 3D lattice, however, is too big for next-generation electronics, which include ultra-thin transistors, new devices for optical communication, and flexible bio-sensors that can be worn or implanted in the human body. To slim things down, researchers are experimenting with materials no thicker than a single sheet of atoms, such as graphene. But the tried-and-true method for doping 3D silicon doesn’t work with 2D graphene, which consists of a single layer of carbon atoms that doesn’t normally conduct a current.

Rather than injecting dopants, researchers have tried layering on a “charge-transfer layer” intended to add or pull away electrons from the graphene. However, previous methods used “dirty” materials in their charge-transfer layers; impurities in these would leave the graphene unevenly doped and impede its ability to conduct electricity.

Integrated quantum photonics (IQP) is a promising platform for realizing scalable and practical quantum information processing. Up to now, most of the demonstrations with IQP focus on improving the stability, quality, and complexity of experiments for traditional platforms based on bulk and fiber optical elements. A more demanding question is: “Are there experiments possible with IQP that are impossible with traditional technology?”

This question is answered affirmatively by a team led jointly by Xiao-Song Ma and Labao Zhang from Nanjing University, and Xinlun Cai from Sun Yat-sen University, China. As reported in Advanced Photonics, the team realizes quantum communication using a chip based on silicon photonics with a superconducting nanowire single-photon detector (SNSPD). The excellent performance of this chip allows them to realize optimal time-bin Bell state measurement and to significantly enhance the key rate in quantum communication.

The single photon detector is a key element for quantum key distribution (QKD) and highly desirable for photonic chip integration to realize practical and scalable quantum networks. By harnessing the unique high-speed feature of the optical waveguide-integrated SNSPD, the dead time of single-photon detection is reduced by more than an order of magnitude compared to the traditional normal-incidence SNSPD. This in turn allows the team to resolve one of the long-standing challenges in quantum optics: Optimal Bell-state measurement of time-bin encoded qubits.

On a chilly evening last fall, I stared into nothingness out of the floor-to-ceiling windows in my office on the outskirts of Harvard’s campus. As a purplish-red sun set, I sat brooding over my dataset on rat brains. I thought of the cold windowless rooms in downtown Boston, home to Harvard’s high-performance computing center, where computer servers were holding on to a precious 48 terabytes of my data. I have recorded the 13 trillion numbers in this dataset as part of my Ph.D. experiments, asking how the visual parts of the rat brain respond to movement.

Printed on paper, the dataset would fill 116 billion pages, double-spaced. When I recently finished writing the story of my data, the magnum opus fit on fewer than two dozen printed pages. Performing the experiments turned out to be the easy part. I had spent the last year agonizing over the data, observing and asking questions. The answers left out large chunks that did not pertain to the questions, like a map leaves out irrelevant details of a territory.

But, as massive as my dataset sounds, it represents just a tiny chunk of a dataset taken from the whole brain. And the questions it asks—Do neurons in the visual cortex do anything when an animal can’t see? What happens when inputs to the visual cortex from other brain regions are shut off?—are small compared to the ultimate question in neuroscience: How does the brain work?

There’s no question about it: climate technology is in again.

Over the past several quarters, entrepreneurial activity and investment interest in climate tech have skyrocketed. New funds devoted specifically to climate have launched at an astonishing rate in 2021: from blue-chip venture capital firms like Union Square Ventures, from large private equity players like TPG and General Atlantic, from a whole new breed of climate-specific VCs like Lowercarbon Capital. Scarcely a day goes by now without a climate tech startup announcing a major new funding round. A whopping $49 billion of venture capital funding will pour into climate tech in 2021.

BlackRock CEO Larry Fink aptly captured the current ebullience when he declared last week that “the next 1,000 unicorns” will be in climate tech.

Advances make high-density, 5D optical storage practical for long-term data archiving.

Researchers have developed a fast and energy-efficient laser-writing method for producing high-density nanostructures in silica glass. These tiny structures can be used for long-term five-dimensional (5D) optical data storage that is more than 10,000 times denser than Blue-Ray optical disc storage technology.

“Individuals and organizations are generating ever-larger datasets, creating the desperate need for more efficient forms of data storage with a high capacity, low energy consumption and long lifetime,” said doctoral researcher Yuhao Lei from the University of Southampton in the UK. “While cloud-based systems are designed more for temporary data, we believe that 5D data storage in glass could be useful for longer-term data storage for national archives, museums, libraries or private organizations.”

The change occurs as SpaceX prepares for a nationwide rollout of Starlink before the end of the month.

Facebook founder Mark Zuckerberg accused other tech companies of “stifling innovation” with high fees and little choice for consumers during a live stream on Thursday, all while his company faces an antitrust lawsuit from the federal government and heightened pressure from Congress over recently-leaked internal documents

Zuckerberg made the comments at the Facebook Connect event Thursday, where he announced the company has changed its name to Meta.

He also laid out the company’s plans to build a metaverse — a virtual reality experience where people can meet online. His comments seemed to allude to mobile operating systems like those created by Apple and Google, though he did not mention any company by name or specify the types of platforms he was talking about.