Optical frequency combs—laser sources that emit evenly spaced colors of light—are foundational, ubiquitous tools for precision measurement, found in optical clocks, gas-sensing spectrometers, and instruments that detect the light signatures of exoplanets. Traditionally, frequency combs are produced by large, fiber-laser systems ranging from the size of a shoebox to a refrigerator.
Engineers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are at the forefront of shrinking these powerful laser sources onto photonic chips to make “microcombs” at millimeter to micron scales, useful not only for their smaller size, but in next-generation telecommunications applications, such as generating multiple data carriers over a single optical fiber.
New research led by Marko Lončar, the Tiantsai Lin Professor of Electrical Engineering and Applied Physics, describes a new, generalized model for how to design so-called resonant electro-optic microcombs on thin-film lithium niobate, a material featuring a strong electro-optic effect, or the ability to efficiently mix electronic signals with optical ones.
“When engineering a computer, you need to know the circuitry of the central processing unit. If you don’t know how everything is wired together, you can’t understand its function, optimize it or fix it when something breaks. We are approaching the brain the same way,” said study leader Boxuan Zhao, a professor of cell and developmental biology at the University of Illinois Urbana-Champaign.
“Our technology enables simultaneous mapping of thousands of neural connections with single-synapse resolution —a capability that doesn’t exist in any current technology. It is directly applicable to understanding circuit dysfunction in neurodegenerative diseases and could provide a platform for developing circuit-guided therapeutic interventions,” he said.
Could we sculpt dead planets into living worlds? From artificial crusts and orbital mirrors to taming tectonics and engineering biospheres, this is your definitive guide to turning alien rocks into second Earths.
Watch my exclusive video Fishbowl Starships — Water As Shielding — 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 https://gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $36. Visit our Website: http://www.isaacarthur.net 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: Interstellar Travel: Can We Survive The Long Journey? Episode 725; June 15, 2025 Written, Produced & Narrated by: Isaac Arthur Graphics: Jarred Eagley Jeremy Jozwik Ken York YD Visual Mafic Studios Sergio Botero Select imagery/video supplied by Getty Images Music Courtesy of Epidemic Sound http://epidemicsound.com/creator Chris Zabriskie, “Unfoldment, Revealment”, “A New Day in a New Sector”, “Oxygen Garden”, “Wonder Cycle” Kai Engel, “Endless Story About Sun and Moon” Taras Harkavyi, “Alpha and…” Dark Future, “Staring Through” pt1 Miguel Johnson. “The Commanders”, “Far From Home” Lombus, “Hydrogen Sonata”, “Cosmic Soup” Aerium, “Deijocht” Stellardrone, “Red Giant”, “Solar Eclipse”, “Billions and Billions” Chapters 0:00 Intro 5:33 What is Terraforming? 8:27 Terraforming vs Para-Terraforming 11:54 Planets vs Megastructures 14:05 Terraforming vs Bioforming 17:14 The Inevitable Hybrid Approach 20:59 Ethics & Debate: Preservation vs. Transformation 22:42 Terraforming as a Civilization-Scale Endeavor 23:46 Terraforming Technologies & Techniques 24:42 Artificial Gravity Solutions 27:58 Atmospheric Manipulation 31:25 Bioforming & Genetic Engineering 34:06 Comet & Asteroid Bombardment 39:43 Domes & Worldhouses 43:24 Geoengineering & Climate Control 47:05 Hydrospheric Engineering 49:58 Magnetosphere Generation 53:35 Fishbowl Starships 55:02 Mass & Orbital Adjustments 1:00:17 Mega-Mirrors & Solar Shades 1:04:30 Oxygenation & Soil Processing 1:07:39 Planetary Shells & Artificial Crusts 1:10:37 Terraforming Nanotechnology 1:14:04 Tidal & Seismic Stabilization 1:18:45 From Theory to Practice: Adapting Terraforming to Specific Worlds 1:20:27 Extreme Radiation Levels 1:23:57 Frequent Asteroid & Meteor Impacts 1:27:41 High Gravity 1:30:29 Highly Eccentric Orbits 1:34:46 Hostile Native Life 1:38:25 Intense Volcanism 1:40:55 Long or Erratic Day/Night Cycles 1:51:09 Low Light Levels 1:52:57 No Air 1:54:25 No Magnetosphere 1:56:17 No Seasons 1:58:13 No Water 2:00:48 Short or Long Years & Seasons 2:02:05 Tidally Locked 2:03:32 Tidally Wracked 2:04:36 Too Cold 2:05:36 Too Hot 2:06:21 Too Much Air 2:07:05 Too Much Ocean 2:08:44 Too Much Solar Wind 2:11:13 Toxic or Corrosive Atmosphere or Surface 2:14:09 Unstable Tectonics 2:15:10 Wrong Air Composition 2:16:21 Final Thoughts. 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 https://gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $36.
Visit our Website: http://www.isaacarthur.net. 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: Interstellar Travel: Can We Survive The Long Journey? Episode 725; June 15, 2025 Written, Produced & Narrated by: Isaac Arthur. Graphics: Jarred Eagley. Jeremy Jozwik. Ken York YD Visual. Mafic Studios. Sergio Botero. Select imagery/video supplied by Getty Images. Music Courtesy of Epidemic Sound http://epidemicsound.com/creator. Chris Zabriskie, \
Microbial bioelectronic sensors use living bacteria that can create an electrical signal in response to the presence of a target substance, or analyte. These types of sensors offer many advantages over other types of biosensors based on proteins and enzymes: The bacteria can perform multiple functions, survive in a variety of environments and even grow and regenerate for potential long-term use.
However, building devices using living bacteria poses several challenges. The mediators some bacteria use to send and receive electrons, creating the electric signal, can be swept away from the sensor by liquid environments researchers would want to monitor, like wastewater. Some mediators are toxic to humans or the environment. Rice University researcher Rafael Verduzco developed a safe bioelectronic sensor that allows for effective electronic communication even in liquid environments. The study was recently published in the journal Advanced Materials.
“This system uses a naturally occurring polymer chitosan, which is found in the hard outer shells of crustaceans. In our system, the chitosan also acts kind of like a shell to keep the bacteria from escaping. It is also modified to have anchor points the mediators can attach to, which are critical to transport electrons,” said Verduzco, corresponding author on the paper and the A.J. Hartsook Professor of Chemical and Biomolecular Engineering. “This material provides a flexible way to encapsulate the bacteria and enhance electronic signals. Since it’s based on a low-cost and renewable polymer, we think it has great potential for real-world applications.”
Researchers have created a method called optovolution that uses light to guide the evolution of proteins with dynamic behaviors. By engineering yeast cells so their survival depended on proteins switching states at the right time, scientists could rapidly select the best-performing variants. The technique produced new light-sensitive proteins that respond to different colors and improved optogenetic systems. It even evolved a protein that behaves like a tiny logic gate, activating genes only when two signals are present.
What governs the speed at which raindrops fall, sediment settles in river estuaries, and matter is ejected during a supernova? These questions circle around one, deceitfully simple factor: the rate at which a fluid filled with particles mixes with a particle-free one. Raindrops travel from one layer of air to another; sediment falls from river to seawater, and ejecta travels from the exploding star through the surrounding dust cloud. The same principle dictates sediment mixing in rising smoke, dust storms, nuclear explosions, hydrocarbon refining, metal smelting, wastewater treatment, and more.
New simulations have now provided researchers and engineers with unprecedented access to these fundamental fluid mechanics. While plainly visible in everyday life, the phenomenon has eluded scientific scrutiny due to their complexity. For the first time, researchers have derived a general formulation of how layers of heavy particles mix and described the common characteristics of the phenomena.
Simone Tandurella, study first author and Ph.D. student in the Complex Fluids and Flows Unit at OIST, explains, “Both the simulations and the model we obtain enable exciting research into a wide range of fundamental physics phenomena, as well as applied research in fluid engineering. They provide the basic puzzle pieces that can help us understand fluid-particle instabilities at large scales.”
A recent study in Advanced Science reports an innovative, low-cost polymer heat exchanger that could transform how industries manage heat. The device was developed by a Rice University research team led by Daniel J. Preston, assistant professor of mechanical engineering.
Heat exchangers are essential to modern technology. They improve and reduce waste by transferring heat between fluids, enabling safe and effective operation of everyday appliances like computers, cars and refrigerators as well as large-scale systems such as industrial plants and rockets.
Made of metal, current heat exchangers are heavy and bulky, prone to rusting and clogging and costly to buy and maintain. As heat-generating infrastructure grows—from data centers and desalination plants to compact electronics and space technologies—engineers are seeking lighter, more compact and affordable alternatives.
Engineering silicon carbide (SiC) with tailored morphologies for electronics and structural reinforcement materials has always been a costly and time-consuming affair, but scientists can now do it in a flash. A new study shows how discarded glass and silicon-rich coal waste can be turned into valuable SiC nanowires in seconds using a process known as Fluorine-Assisted Flash (FAF) Joule heating, where a quick pulse of electricity instantly heats up the reaction mixture to extremely high temperatures.
In FAF, the fluorine additives trigger the catalytic materials, such as the iron oxides found naturally in waste glass, to act as seeds that drive selective growth of one-dimensional nanowires in under a minute and with an impressive yield of 96%. When used as a reinforcement material in composites, SiC nanowires emerged as clear winners over SiC powders in providing hardness and wear resistance. The findings are published in Matter.
An international research team led by Alexander Kuznetsov at the Paul Drude Institute for Solid State Electronics (PDI) in Berlin has demonstrated a fundamentally new way to control the condensation of hybrid light-matter particles. Using coherent acoustic driving to dynamically reshape the energy landscape of a semiconductor microcavity, the researchers achieved deterministic steering of a macroscopic quantum state into its lowest energy configuration.
In collaboration with long-term partners from the National Scientific and Technical Research Council CONICET and the Bariloche Atomic Center and Balseiro Institute in Argentina, the team experimentally realized a universal scheme for selectively transferring populations within a multilevel quantum system using strong time periodic modulation.
