Nov 24, 2020 11:16 PM
Warp Drive News. Seriously!
INTRO (Sabine Hossenfelder): As many others, I became interested in physics by reading too much science fiction. Teleportation, levitation, wormholes, time-travel, warp drives, and all that, I thought was super-fascinating. But of course the depressing part of science fiction is that you know it’s not real. So, to some extent, I became a physicist to find out which science fiction technologies have a chance to one day become real technologies. Today I want to talk about warp drives because I think on the spectrum from fiction to science, warp drives are on the more scientific end. And just a few weeks ago, a new paper appeared about warp drives that puts the idea on a much more solid basis... (MORE)
https://www.youtube-nocookie.com/embed/8VWLjhJBCp0
Geometry Reveals How the World Is Assembled From Cubes
https://www.quantamagazine.org/geometry-...-20201119/
INTRO: On a mild autumn day in 2016, the Hungarian mathematician Gábor Domokos arrived on the geophysicist Douglas Jerolmack’s doorstep in Philadelphia. Domokos carried with him his suitcases, a bad cold and a burning secret. The two men walked across a gravel lot behind the house, where Jerolmack’s wife ran a taco cart. Their feet crunched over crushed limestone. Domokos pointed down.
“How many facets do each of these gravel pieces have?” he said. Then he grinned. “What if I told you that the number was always somewhere around six?” Then he asked a bigger question, one that he hoped would worm its way into his colleague’s brain. What if the world is made of cubes?
At first, Jerolmack objected. Houses can be built out of bricks, but Earth is made of rocks. Obviously, rocks vary. Mica flakes into sheets; crystals crack on sharply defined axes. But from mathematics alone, Domokos argued, any rocks that broke randomly would crack into shapes that have, on average, six faces and eight vertices. Considered together, they would all be shadowy approximations converging on a sort of ideal cube. Domokos had proved it mathematically, he said. Now he needed Jerolmack’s help to show that this is what nature does.
“It was geometry with an exact prediction that was borne out in the natural world, with essentially no physics involved,” said Jerolmack, a professor at the University of Pennsylvania. “How in the hell does nature let this happen?”
Over the next few years, the pair chased their geometric vision from microscopic fragments to rock outcrops to planetary surfaces and even to Plato’s Timaeus, suffusing the project with an additional air of mysticism. The foundational Greek philosopher, writing around 360 BCE, had matched his five Platonic solids with five supposed elements: earth, air, fire, water and star stuff. With either foresight or luck or a little of both, Plato paired cubes, the most stackable shape, with earth. “I was like, oh, OK, now we’re getting a little bit metaphysical,” Jerolmack said.
But they kept finding cuboid averages in nature, plus a few non-cubes that could be explained with the same theories. They ended up with a new mathematical framework: a descriptive language to express how all things fall apart. When their paper was published earlier this year, it came titled like a particularly esoteric Harry Potter novel: “Plato’s Cube and the Natural Geometry of Fragmentation.”
Several geophysicists contacted by Quanta say the same mathematical framework might also help with problems like understanding erosion from cracked cliff faces, or preventing hazardous rock slides. “That is really, really exciting,” said the University of Edinburgh geomorphologist Mikaël Attal, one of two scientists who reviewed the paper before publication. The other reviewer, the Vanderbilt geophysicist David Furbish, said, “A paper like this makes me think: Can I somehow make use of these ideas?” (MORE)
INTRO (Sabine Hossenfelder): As many others, I became interested in physics by reading too much science fiction. Teleportation, levitation, wormholes, time-travel, warp drives, and all that, I thought was super-fascinating. But of course the depressing part of science fiction is that you know it’s not real. So, to some extent, I became a physicist to find out which science fiction technologies have a chance to one day become real technologies. Today I want to talk about warp drives because I think on the spectrum from fiction to science, warp drives are on the more scientific end. And just a few weeks ago, a new paper appeared about warp drives that puts the idea on a much more solid basis... (MORE)
Geometry Reveals How the World Is Assembled From Cubes
https://www.quantamagazine.org/geometry-...-20201119/
INTRO: On a mild autumn day in 2016, the Hungarian mathematician Gábor Domokos arrived on the geophysicist Douglas Jerolmack’s doorstep in Philadelphia. Domokos carried with him his suitcases, a bad cold and a burning secret. The two men walked across a gravel lot behind the house, where Jerolmack’s wife ran a taco cart. Their feet crunched over crushed limestone. Domokos pointed down.
“How many facets do each of these gravel pieces have?” he said. Then he grinned. “What if I told you that the number was always somewhere around six?” Then he asked a bigger question, one that he hoped would worm its way into his colleague’s brain. What if the world is made of cubes?
At first, Jerolmack objected. Houses can be built out of bricks, but Earth is made of rocks. Obviously, rocks vary. Mica flakes into sheets; crystals crack on sharply defined axes. But from mathematics alone, Domokos argued, any rocks that broke randomly would crack into shapes that have, on average, six faces and eight vertices. Considered together, they would all be shadowy approximations converging on a sort of ideal cube. Domokos had proved it mathematically, he said. Now he needed Jerolmack’s help to show that this is what nature does.
“It was geometry with an exact prediction that was borne out in the natural world, with essentially no physics involved,” said Jerolmack, a professor at the University of Pennsylvania. “How in the hell does nature let this happen?”
Over the next few years, the pair chased their geometric vision from microscopic fragments to rock outcrops to planetary surfaces and even to Plato’s Timaeus, suffusing the project with an additional air of mysticism. The foundational Greek philosopher, writing around 360 BCE, had matched his five Platonic solids with five supposed elements: earth, air, fire, water and star stuff. With either foresight or luck or a little of both, Plato paired cubes, the most stackable shape, with earth. “I was like, oh, OK, now we’re getting a little bit metaphysical,” Jerolmack said.
But they kept finding cuboid averages in nature, plus a few non-cubes that could be explained with the same theories. They ended up with a new mathematical framework: a descriptive language to express how all things fall apart. When their paper was published earlier this year, it came titled like a particularly esoteric Harry Potter novel: “Plato’s Cube and the Natural Geometry of Fragmentation.”
Several geophysicists contacted by Quanta say the same mathematical framework might also help with problems like understanding erosion from cracked cliff faces, or preventing hazardous rock slides. “That is really, really exciting,” said the University of Edinburgh geomorphologist Mikaël Attal, one of two scientists who reviewed the paper before publication. The other reviewer, the Vanderbilt geophysicist David Furbish, said, “A paper like this makes me think: Can I somehow make use of these ideas?” (MORE)