Jun 16, 2025 12:42 AM
(This post was last modified: Jun 16, 2025 12:54 AM by C C.)
Is gravity just entropy rising? Long-shot idea gets another look.
https://www.quantamagazine.org/is-gravit...-20250613/
INTRO: Isaac Newton was never entirely happy with his law of universal gravitation. For decades after publishing it in 1687, he sought to understand how, exactly, two objects were able to pull on each other from afar. He and others came up with several mechanical models, in which gravity was not a pull, but a push. For example, space might be filled with unseen particles that bombard the objects on all sides. The object on the left absorbs the particles coming from the left, the one on the right absorbs those coming from the right, and the net effect is to push them together.
Attempts at modeling gravity as a consequence of rising entropy have cropped up now and again for several decades. Entropic gravity is very much a minority view. But it’s one that won’t die, and even detractors are loath to dismiss it altogether. The new model has the virtue of being experimentally testable — a rarity when it comes to theories about the mysterious underpinnings of the universal attraction.
Those theories never quite worked, and Albert Einstein eventually provided a deeper explanation of gravity as a distortion of space and time. But Einstein’s account, called general relativity, created its own puzzles, and he himself recognized that it could not be the final word. So the idea that gravity is a collective effect — not a fundamental force, but the outcome of swarm behavior on a finer scale — still compels physicists.
Earlier this year, a team of theoretical physicists put forward what might be considered a modern version of those 17th-century mechanical models. “There’s some kind of gas or some thermal system out there that we can’t see directly,” said Daniel Carney of Lawrence Berkeley National Laboratory, who led the effort. “But it’s randomly interacting with masses in some way, such that on average you see all the normal gravity things that you know about: The Earth orbits the sun, and so forth.”
This project is one of the many ways that physicists have sought to understand gravity, and perhaps the bendy space-time continuum itself, as emergent from deeper, more microscopic physics. Carney’s line of thinking, known as entropic gravity, pegs that deeper physics as essentially just the physics of heat. It says gravity results from the same random jiggling and mixing up of particles — and the attendant rise of entropy, loosely defined as disorder — that governs steam boilers, car engines and refrigerators... (MORE - details)
Can new chemistry make EVs that charge in 5 min or less?
https://cen.acs.org/materials/electronic...eb/2025/06
INTRO: A time traveler visiting from the 1960s might be somewhat disappointed by the state of technological progress in 2025. There are no flying cars, no space hotels, no robot butlers.
But even though they can’t fly, cars are going through a major transformation from loud, jerky, smelly gas guzzlers to sleek electric vehicles (EVs) that quietly hum along roads. Nearly one in five new cars sold in 2023 were electric or plug-in hybrids, according to an International Energy Agency report.
The thing holding back EV adoption right now—besides the relatively high sticker price—is how long it takes to charge the battery, according to industry analyst Sam Adham of the research firm CRU Group.
EVs charge slowly. For some owners, the only practical way to charge is being parked for hours— say, overnight or while they’re at work. That’s very different from the gas and diesel vehicles people are used to, which can be refueled in 5 min or so. The fastest chargers can add enough juice in 15 or 20 min to get someone to their next stop, but that’s not the same as filling up the tank.
For someone living in an apartment building or a dense city neighborhood, without a place they can charge overnight, owning an EV might not be practical if they can’t charge it quickly. Likewise, a delivery company might not be able to justify a fleet of electric vans that have to charge for hours when they could be moving products.
It didn’t used to be this way. “Ten years ago, no one cared about fast charging,” says Venkat Srinivasan, a battery researcher at Argonne National Laboratory. The accepted definition of fast charging has changed in the past decade, he says: 15 min used to be considered fast enough, but car buyers are now demanding 5.
Fast battery charging is also a benefit to the companies that make charging stations. Faster charging means they can sell more energy to more customers in the course of a day. (Many companies also price fast charging higher.)
There’s no ‘perfect’ battery for electric vehicles yet, and honestly, there might never be one single ideal solution... (MORE - details)
https://www.quantamagazine.org/is-gravit...-20250613/
INTRO: Isaac Newton was never entirely happy with his law of universal gravitation. For decades after publishing it in 1687, he sought to understand how, exactly, two objects were able to pull on each other from afar. He and others came up with several mechanical models, in which gravity was not a pull, but a push. For example, space might be filled with unseen particles that bombard the objects on all sides. The object on the left absorbs the particles coming from the left, the one on the right absorbs those coming from the right, and the net effect is to push them together.
Attempts at modeling gravity as a consequence of rising entropy have cropped up now and again for several decades. Entropic gravity is very much a minority view. But it’s one that won’t die, and even detractors are loath to dismiss it altogether. The new model has the virtue of being experimentally testable — a rarity when it comes to theories about the mysterious underpinnings of the universal attraction.
Those theories never quite worked, and Albert Einstein eventually provided a deeper explanation of gravity as a distortion of space and time. But Einstein’s account, called general relativity, created its own puzzles, and he himself recognized that it could not be the final word. So the idea that gravity is a collective effect — not a fundamental force, but the outcome of swarm behavior on a finer scale — still compels physicists.
Earlier this year, a team of theoretical physicists put forward what might be considered a modern version of those 17th-century mechanical models. “There’s some kind of gas or some thermal system out there that we can’t see directly,” said Daniel Carney of Lawrence Berkeley National Laboratory, who led the effort. “But it’s randomly interacting with masses in some way, such that on average you see all the normal gravity things that you know about: The Earth orbits the sun, and so forth.”
This project is one of the many ways that physicists have sought to understand gravity, and perhaps the bendy space-time continuum itself, as emergent from deeper, more microscopic physics. Carney’s line of thinking, known as entropic gravity, pegs that deeper physics as essentially just the physics of heat. It says gravity results from the same random jiggling and mixing up of particles — and the attendant rise of entropy, loosely defined as disorder — that governs steam boilers, car engines and refrigerators... (MORE - details)
Can new chemistry make EVs that charge in 5 min or less?
https://cen.acs.org/materials/electronic...eb/2025/06
INTRO: A time traveler visiting from the 1960s might be somewhat disappointed by the state of technological progress in 2025. There are no flying cars, no space hotels, no robot butlers.
But even though they can’t fly, cars are going through a major transformation from loud, jerky, smelly gas guzzlers to sleek electric vehicles (EVs) that quietly hum along roads. Nearly one in five new cars sold in 2023 were electric or plug-in hybrids, according to an International Energy Agency report.
The thing holding back EV adoption right now—besides the relatively high sticker price—is how long it takes to charge the battery, according to industry analyst Sam Adham of the research firm CRU Group.
EVs charge slowly. For some owners, the only practical way to charge is being parked for hours— say, overnight or while they’re at work. That’s very different from the gas and diesel vehicles people are used to, which can be refueled in 5 min or so. The fastest chargers can add enough juice in 15 or 20 min to get someone to their next stop, but that’s not the same as filling up the tank.
For someone living in an apartment building or a dense city neighborhood, without a place they can charge overnight, owning an EV might not be practical if they can’t charge it quickly. Likewise, a delivery company might not be able to justify a fleet of electric vans that have to charge for hours when they could be moving products.
It didn’t used to be this way. “Ten years ago, no one cared about fast charging,” says Venkat Srinivasan, a battery researcher at Argonne National Laboratory. The accepted definition of fast charging has changed in the past decade, he says: 15 min used to be considered fast enough, but car buyers are now demanding 5.
Fast battery charging is also a benefit to the companies that make charging stations. Faster charging means they can sell more energy to more customers in the course of a day. (Many companies also price fast charging higher.)
There’s no ‘perfect’ battery for electric vehicles yet, and honestly, there might never be one single ideal solution... (MORE - details)