However, when photons are contained within structures that are smaller than their wavelength, these measures collapse into each other, and so the definition is of total angular momentum (TAM). It’s this feature, only occurring for photons confined in this way, that has now been entangled for the first time.
Researchers at Technion-Israel Institute of Technology used gratings to confine photons within a circular or spiral nanoscale platform and mapped their states, entangling the TAMs of pairs of photons before scattering them to free space. Entangling TAMs might seem like a minor development, seeing that SAMs and OAMs have each been entangled before, but the authors write: “We observe that entanglement in TAM leads to a completely different structure of quantum correlations of photon pairs, compared with entanglement related to the two constituent angular momenta.”
Quantum entanglement is considered key to quantum computing. The authors propose their work could lead to information processing conducted using the entangled TAMs of photons confined to chips. Entangling TAMs allows quantum processors based around photons to be smaller than would be possible if one of the properties that only emerges under less confined conditions was used. That potentially enables the miniaturization of future quantum computers.
What if humanity’s future isn’t on Earth—or even other planets—but in colossal artificial worlds built in space? In this episode, we explore the O’Neill Cylinder, a visionary space habitat that could house millions, serve as interstellar arks, and transform the cosmos into a network of orbital civilizations. Join us as we dive into the design, potential, and profound societal implications of these Islands in the Sky.
Watch my exclusive video Post-Consciousness Civilizations: https://nebula.tv/videos/isaacarthur–… Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/isaacarthur Get a Lifetime Membership to Nebula for only $300: https://go.nebula.tv/lifetime?ref=isa… Use the link gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30. Visit our Website: http://www.isaacarthur.net Join Nebula: https://go.nebula.tv/isaacarthur Support us on Patreon: / isaacarthur Support us on Subscribestar: https://www.subscribestar.com/isaac-a… Facebook Group: / 1,583,992,725,237,264 Reddit: / isaacarthur Twitter: / isaac_a_arthur on Twitter and RT our future content. SFIA Discord Server: / discord Credits: The O’Neill Cylinder Space Habitat: Islands In The Sky Episode 496; April 24, 2025 Written, Produced & Narrated by: Isaac Arthur Edited by: Briana Brownell Graphics: Anthrofuturism, Apogii.uk, Katie Byrne, Jarred Eagley, Jeremy Jozwik, Justin Dixon, Ken York YD Visual, Sergio Botero, Udo Schroeter Select imagery/video supplied by Getty Images Music Courtesy of Epidemic Sound http://epidemicsound.com/creator Markus Junnikkala, “A Fleet Behind the Moon” Phase Shift, “Forest Night” Kai Engel, “Endless Story About Sun and Moon” Chris Zabriskie, “Unfoldment, Revealment”, “A New Day in a New Sector” Taras Harkavyi, “Alpha and…” Stellardrone, “Red Giant”, “Billions and Billions“ Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/isaacarthur. Get a Lifetime Membership to Nebula for only $300: https://go.nebula.tv/lifetime?ref=isa… Use the link gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.
Visit our Website: http://www.isaacarthur.net. Join Nebula: https://go.nebula.tv/isaacarthur. Support us on Patreon: / isaacarthur. Support us on Subscribestar: https://www.subscribestar.com/isaac-a… Facebook Group: / 1583992725237264 Reddit: / isaacarthur. Twitter: / isaac_a_arthur on Twitter and RT our future content. SFIA Discord Server: / discord. Credits: The O’Neill Cylinder Space Habitat: Islands In The Sky. Episode 496; April 24, 2025 Written, Produced & Narrated by: Isaac Arthur. Edited by: Briana Brownell. Graphics: Anthrofuturism, Apogii.uk, Katie Byrne, Jarred Eagley, Jeremy Jozwik, Justin Dixon, Ken York YD Visual, Sergio Botero, Udo Schroeter. Select imagery/video supplied by Getty Images. Music Courtesy of Epidemic Sound http://epidemicsound.com/creator. Markus Junnikkala, \
This book dives into the holy grail of modern physics: the union of quantum mechanics and general relativity. It’s a front-row seat to the world’s brightest minds (like Hawking, Witten, and Maldacena) debating what reality is really made of. Not casual reading—this is heavyweight intellectual sparring.
☼ Key Takeaways: ✅ Spacetime Is Not Continuous: It might be granular at the quantum level—think “atoms of space.” ✅ Unifying Physics: String theory, loop quantum gravity, holography—each gets a say. ✅ High-Level Debates: This is like eavesdropping on the Avengers of physics trying to fix the universe. ✅ Concepts Over Calculations: Even without equations, the philosophical depth will bend your brain. ✅ Reality Is Weirder Than Fiction: Quantum foam, time emergence, multiverse models—all explored.
This isn’t a how-to; it’s a “what-is-it?” If you’re obsessed with the ultimate structure of reality, this is your fix.
☼ Thanks for watching! If the idea of spacetime being pixelated excites you, drop a comment below and subscribe for more mind-bending content.
The political news these days is enough to make some Chicagoans wish they were a million miles away. But consider this: Even in the depths of space, there’s no escape from politics.
The $10 billion James Webb Space Telescope is literally parked 1 million miles away. In the nearly three years since it became operational, “Webb,” as it’s called, has made some incredible findings.
Webb uses infrared scanning to show how stars and galaxies form, and to study the atmospheres of distant planets. Its capabilities complement the aging Hubble Space Telescope, which orbits Earth at an altitude of only 340 miles or so.
Researchers from Max Born Institute have demonstrated a successful way to control and manipulate nanoscale magnetic bits—the building blocks of digital data—using an ultrafast laser pulse and plasmonic gold nanostructures. The findings were published in Nano Letters.
All-optical, helicity-independent magnetization switching (AO-HIS) is one of the most interesting and promising mechanisms for this endeavor, where the magnetization state can be reversed between two directions with a single femtosecond laser pulse, serving as “0s” and “1s” without any external magnetic field or complex wiring. This opens up exciting possibilities for creating memory devices that are not only faster and more robust but also consume far less power.
Ultrafast light-driven control of magnetization on the nanometer-length scale is key to achieving competitive bit sizes in next-generation data storage technology. However, it is currently not well understood to what extent basic physics processes such as heat transfer at the nanoscale and the propagation of magnetic domain walls limit the minimum achievable bit size.
Ultrafast light-driven control of magnetization on the nanometer length scale is key to achieve competitive bit sizes in next generation data storage technology. Researchers at Max Born Institute in Berlin and of the large scale facility Elettra in Trieste, Italy, have successfully demonstrated the ultrafast emergence of all-optical switching by generating a nanometer scale grating by interference of two pulses in the extreme ultraviolet spectral range.
The physics of optically driven magnetization dynamics on the femtosecond time scale is of great interest for two main reasons: first, for a deeper understanding of the fundamental mechanisms of nonequilibrium, ultrafast spin dynamics and, second, for the potential application in the next generation of information technology with a vision to satisfy the need for both faster and more energy efficient data storage devices.
All–optical switching (AOS) is one of the most interesting and promising mechanisms for this endeavor, where the magnetization state can be reversed between two directions with a single femtosecond laser pulse, serving as “0s” and “1s.” While the understanding of the temporal control of AOS has progressed rapidly, knowledge on ultrafast transport phenomena on the nanoscale, important for the realization of all-optical magnetic reversal in technological applications, has remained limited due to the wavelength limitations of optical radiation. An elegant way to of overcoming these restrictions is to reduce the wavelengths to the extreme ultraviolet (XUV) spectral range in transient grating experiments. This technique is based on the interference of two XUV beams leading to a nanoscale excitation pattern and has been pioneered at the EIS-Timer beamline of the free-electron laser (FEL) FERMI in Trieste, Italy.
Researchers have long recognized that quantum communication systems would transmit quantum information more faithfully and be impervious to certain forms of error if nonlinear optical processes were used. However, past efforts at incorporating such processes could not operate with the extremely low light levels required for quantum communication.
Now, a team at the University of Illinois Urbana-Champaign has improved the technology by basing the nonlinear process on an indium-gallium-phosphide nanophotonic platform. The result is substantially more efficient than prior systems, meaning that it requires much less light and operates all the way down to single photons, the smallest unit of light. For the first time, there is a path forward to making quantum communication systems with nonlinear optics feasible.
“Our nonlinear system transmits quantum information with 94% fidelity, compared to the theoretical limit of 33% on systems using linear optical components,” said Kejie Fang, an Illinois professor of electrical and computer engineering and the project lead. “This alone demonstrates the power of quantum communication with nonlinear optics. The big problem to solve is efficiency. By using a nanophotonic platform, we saw the efficiency increase by enough to show that the technology is promising.”
Scientists have created an ultra-thin light source that emits pairs of polarization-entangled photons. These specially correlated photons hold promise for future quantum technologies, including ultra-secure communication, powerful computation, and high-precision measurements. This light source is particularly small, pure, efficient, and versatile.
Entangled photons share a unique connection. By measuring one photon’s properties, scientists can instantly determine the properties of its entangled partner, regardless of distance. This phenomenon has the potential to revolutionize fields like communication, computation and metrology.
Human cyborgs are individuals who integrate advanced technology into their bodies, enhancing their physical or cognitive abilities. This fusion of man and machine blurs the line between science fiction and reality, raising questions about the future of humanity, ethics, and the limits of human potential. From bionic limbs to brain-computer interfaces, cyborg technology is rapidly evolving, pushing us closer to a world where humans and machines become one.
