Feb 8, 2022 06:48 PM
(This post was last modified: Feb 9, 2022 02:28 AM by C C.)
Quantum holograms don’t even need to “see” their subject
https://spectrum.ieee.org/quantum-hologr...cted-light
EXCERPTS: A hologram is an image that, when illuminated, acts much like a 2D window looking onto a 3D scene. Conventional holography creates holograms by using a laser beam to scan an object and encode its data onto a recording medium such as a film or plate.
[...] Now, with the help of the surreal nature of quantum physics, Gräfe and his colleagues have discovered a way to create holograms of items without ever detecting any light from them. “The light that illuminates the object is never detected,” Gräfe says. “The light that is detected never interacted with the object.”
[...] One consequence of quantum physics is entanglement, wherein multiple particles are linked and can influence each other instantly regardless of how far apart they are. One way to generate entangled photons is by shining a beam of light at a special so-called “nonlinear crystal” that can split each photon into two lower-energy, longer-wavelength photons (These resulting pairs are not necessarily both the same wavelength.)
In the new study, the researchers used a nonlinear crystal to split a violet laser beam into two beams, one far-red, the other near-infrared. They next used the far-red beam to illuminate a sample—a glass plate engraved with symbols—whereas they used a camera to record the near-infrared light. With the help of entanglement, they could use data from the near-infrared light to reconstruct a hologram based off the details of the object the far-red beam scanned.
“It is possible to carry out imaging and holography by having different light for illumination and detection by exploiting the quantum properties of light,” Gräfe says... (MORE - missing details)
Spinal Implant Enables Paralyzed Man With Severed Spine to Walk Again
https://www.insidescience.org/news/chimp...eir-wounds
INTRO: In 2017, Michel Roccati was in a motorbike accident that left his lower body completely paralyzed. In 2020, he walked again, thanks to a breakthrough new spinal cord implant. The implant sends electrical pulses to his muscles, mimicking the action of the brain, and could one day help people with severe spinal injuries stand, walk, and exercise.
It builds on long-running research into using electrical pulses to improve quality of life for people with spinal cord injuries, including a 2018 study by the same team that helped people with partial lower-body paralysis walk again. "It was a very emotional experience," Roccati told journalists of the first time the electrical pulses were activated and he took a step.
He was one of three patients involved in the study, published Monday in the journal Nature Medicine, all of them unable to move their lower bodies after accidents... (MORE - missing details)
https://www.youtube-nocookie.com/embed/4wUADfnCMdc
https://spectrum.ieee.org/quantum-hologr...cted-light
EXCERPTS: A hologram is an image that, when illuminated, acts much like a 2D window looking onto a 3D scene. Conventional holography creates holograms by using a laser beam to scan an object and encode its data onto a recording medium such as a film or plate.
[...] Now, with the help of the surreal nature of quantum physics, Gräfe and his colleagues have discovered a way to create holograms of items without ever detecting any light from them. “The light that illuminates the object is never detected,” Gräfe says. “The light that is detected never interacted with the object.”
[...] One consequence of quantum physics is entanglement, wherein multiple particles are linked and can influence each other instantly regardless of how far apart they are. One way to generate entangled photons is by shining a beam of light at a special so-called “nonlinear crystal” that can split each photon into two lower-energy, longer-wavelength photons (These resulting pairs are not necessarily both the same wavelength.)
In the new study, the researchers used a nonlinear crystal to split a violet laser beam into two beams, one far-red, the other near-infrared. They next used the far-red beam to illuminate a sample—a glass plate engraved with symbols—whereas they used a camera to record the near-infrared light. With the help of entanglement, they could use data from the near-infrared light to reconstruct a hologram based off the details of the object the far-red beam scanned.
“It is possible to carry out imaging and holography by having different light for illumination and detection by exploiting the quantum properties of light,” Gräfe says... (MORE - missing details)
Spinal Implant Enables Paralyzed Man With Severed Spine to Walk Again
https://www.insidescience.org/news/chimp...eir-wounds
INTRO: In 2017, Michel Roccati was in a motorbike accident that left his lower body completely paralyzed. In 2020, he walked again, thanks to a breakthrough new spinal cord implant. The implant sends electrical pulses to his muscles, mimicking the action of the brain, and could one day help people with severe spinal injuries stand, walk, and exercise.
It builds on long-running research into using electrical pulses to improve quality of life for people with spinal cord injuries, including a 2018 study by the same team that helped people with partial lower-body paralysis walk again. "It was a very emotional experience," Roccati told journalists of the first time the electrical pulses were activated and he took a step.
He was one of three patients involved in the study, published Monday in the journal Nature Medicine, all of them unable to move their lower bodies after accidents... (MORE - missing details)