Lifeboat Foundation

We argue in a model-independent way that the Hilbert space of quantum gravity is locally finite-dimensional. In other words, the density operator describing the state corresponding to a small region of space, when such a notion makes sense, is defined on a finite-dimensional factor of a larger Hilbert space. Because quantum gravity potentially describes superpo-sitions of different geometries, it is crucial that we associate Hilbert-space factors with spatial regions only on individual decohered branches of the universal wave function. We discuss some implications of this claim, including the fact that quantum field theory cannot be a fundamental description of Nature.

Israeli scientists say they have opened a possible new path to fighting infertility, by identifying a mechanism that seems to harm eggs when it malfunctions.

In peer-reviewed research published on Thursday in the journal Science, a team of Hebrew University researchers outline a mechanism they identified in studies of zebrafish and mice.

They say it plays a key role in ensuring that chromosomes inside eggs are organized correctly, so that they can be fertilized and produce healthy offspring.

Please describe the mindset needed to be a roboticist.

In order to be a roboticist, you need to have an open mindset and an insatiable sense of curiosity. You need to be able to understand the needs of people and how they accomplish tasks before you can develop robots that can meet these requirements. That’s how we can maximise usefulness in the robots of tomorrow.

When you walk through our office, you will also notice that roboticists come from all walks of life and many different disciplines. So we encourage anyone who is interested in robots to apply for a job with us.

Scientists have found a new method to measure people’s mental imagery abilities, offering insight into “aphantasia”, the condition of not being able to visualize images in the mind.

An interesting photo taken on Mars by NASA.

This image was taken by Mast Camera (Mastcam) onboard NASA’s Mars rover Curiosity on Sol 3,466 (2022−05−07 07:58:16 UTC).

Quanta of light—photons—form the basis of quantum key distribution in modern cryptographic networks. Before the huge potential of quantum technology is fully realized, however, several challenges remain. A solution to one of these has now been found.

In a paper published in the journal Science, teams led by David Novoa, Nicolas Joly and Philip Russell report a breakthrough in frequency up-conversion of single photons, based on a hollow-core photonic crystal fiber (PCF) filled with hydrogen gas. First a spatio-temporal hologram of molecular vibrations is created in the gas by stimulated Raman scattering. This hologram is then used for highly efficient, correlation-preserving frequency conversion of single photons. The system operates at a pressure-tuneable wavelength, making it potentially interesting for quantum communications, where efficient sources of indistinguishable single-photons are unavailable at wavelengths compatible with existing fiber networks.

The approach combines quantum optics, gas-based nonlinear optics, hollow-core PCF, and the physics of molecular vibrations to form an efficient tool that can operate in any spectral band from the ultraviolet to the mid-infrared—an ultra-broad working range inaccessible to existing technologies. The findings may be used to develop fiber-based tools in technologies such as quantum communications, and quantum-enhanced imaging.

Physicists from Paderborn University have developed a novel concept for generating individual photons—tiny particles of light that make up electromagnetic radiation—with tailored properties, the controlled manipulation of which is of fundamental importance for photonic quantum technologies. The findings have now been published in the journal Nature Communications.

Professor Artur Zrenner, head of the “nanostructure optoelectronics” research group, explains how tailored desired states have so far posed a challenge: “Corresponding sources are usually based on light emissions from individual semiconductor quantum emitters, which generate the photons. Here, the properties of the emitted photons are defined by the fixed properties of the quantum emitter, and can therefore not be controlled with full flexibility.”

To get around the problem, the scientists have developed an all-optical, non-linear method to tailor and control single photon emissions. Based on this concept, they demonstrate laser-guided energy tuning and polarization control of photons (i.e., the light frequency and direction of oscillation of electromagnetic waves).

A new publication in Opto-Electronic Advances overviews dynamic metasurfaces and metadevices empowered by graphene.

Metasurfaces, artificial subwavelength structured interfaces, exhibit unprecedented capabilities to manipulate electromagnetic (EM) waves ranging from visible to terahertz and microwave frequencies.

In the past decade, static metasurfaces and metadevices have been researched extensively. Due to the passive nature of building blocks in general made of metals and/or dielectrics, however, their functionalities cannot be actively tuned in situ after fabrication, which seriously impedes their application scenarios such as varifocal lens, dynamic holography, and beam steering in LiDAR. Motivated by those significant requirements, scientists have struggled for years to improve the dynamical tunability of metasurfaces, and introducing active materials or components into the passive metasurfaces has been proposed as the first thought strategy.

Breakthrough hints other cells in central nervous system, such as the brain, could be restored.