Aug 7, 2020 10:12 PM
(This post was last modified: Aug 8, 2020 12:02 AM by C C.)
Physicists have a massive problem as Higgs boson refuses to misbehave
https://www.newscientist.com/article/225...misbehave/
EXCERPT: Physicists have spotted the Higgs boson performing a new trick [...] The Higgs boson ... is the particle that gives all other fundamental particles mass, according to the standard model of particle physics. However, despite the work of thousands of researchers around the world, nobody has been able to figure out exactly how it does that or why some particles are more massive than others.
[...] Some researchers have suggested that particles have different masses because there is more than one type of Higgs boson, with each type of Higgs coupled to a different mass range of other particles. ... the new discovery makes it more likely there is only one Higgs. That behaviour is exactly what we expect from the standard model. ... But that leaves the mystery of why particles have different masses completely unanswered. ... it is somewhat frustrating because we know the standard model is incomplete – in addition to not explaining why particles have different masses, it also doesn’t account for dark matter or dark energy. Nevertheless, experimental results have been entirely in line with the model... (MORE - details)
Spacetime wave packets: New class of laser defies laws of light physics
https://newatlas.com/physics/spacetime-w...efraction/
EXCERPT: . . . But the new laser beams don’t follow this basic law of light. And it’s not just Snell’s Law either – the team says they also ignore Fermat’s Principle, which says that light always takes the shortest possible path. “This new class of laser beams has unique properties that are not shared by common laser beams,” says Ayman Abouraddy, principal investigator of the study. “Spacetime wave packets can be arranged to behave in the usual manner, to not change speed at all, or even to anomalously speed up in denser materials. As such, these pulses of light can arrive at different points in space at the same time.”
This has some major implications for optical communications technologies. The team uses the example of a plane sending messages encoded in light to two submarines, at the same depth but different distances away. Normally, the message would arrive at the closer sub first, but with spacetime wave packets the pulses could be propagated to reach both at the exact same time. While it may sound like this technology is contradicting some key laws of physics, the team stresses that it’s actually still in line with special relativity... (MORE - details)
Physicists watch quantum particles tunnel through solid barriers. Here's what they found.
https://www.livescience.com/quantum-tunn...sured.html
EXCERPTS: . . . Quantum tunneling is a phenomenon where an atom or a subatomic particle can appear on the opposite side of a barrier that should be impossible for the particle to penetrate. It's as if you were walking and encountered a 10-foot-tall (3 meters) wall extending as far as the eye can see. Without a ladder or Spider-man climbing skills, the wall would make it impossible for you to continue.
However, in the quantum world, it is rare, but possible, for an atom or electron to simply "appear" on the other side, as if a tunnel had been dug through the wall. "Quantum tunneling is one of the most puzzling of quantum phenomena," said study co-author Aephraim Steinberg ... "And it is fantastic that we're now able to actually study it in this way."
Quantum tunneling is not new to physicists. It forms the basis of many modern technologies [...] Researchers had previously tried to measure the amount of time it takes for tunneling to occur, with varying results. One of the difficulties in earlier versions of this type of experiment is identifying the moment tunneling starts and stops. To simplify the methodology, the researchers used magnets to create a new kind of "clock" that would tick only while the particle was tunneling.
[...] As expected, most of the rubidium atoms bounced off the barrier. However, due to quantum tunneling, about 3% of the atoms penetrated the barrier and appeared on the other side. Based on the precession of those atoms, it took them about 0.6 milliseconds to traverse the barrier... (MORE - details)
Chemists help create brightest-ever fluorescent materials
https://www.chem.indiana.edu/2020/08/iu-...materials/
RELEASE: Researchers at Indiana University Bloomington and the University of Copenhagen have developed patent-pending materials to address key setbacks to using fluorescent dyes as solid-state materials in academic and commercial applications. Amar FloodAmar Flood, the James Jackson Professor of Chemistry in the College of Arts and Sciences at Indiana University, and Bo Wegge Laursen, professor of chemistry at the University of Copenhagen, have created materials called small-molecule, ionic isolation lattices, or SMILES, which are the brightest-known fluorescent materials. Their research paper, “Plug-and-Play Optical Materials from Fluorescent Dyes and Macrocycles,” is published in the August issue of the peer-reviewed journal Chem.
“Think of SMILES like a light bulb, but instead of being turned on with electricity, they are turned on with light, including ultraviolet and visible light,” Flood said. “These SMILES pack a lot of dyes inside a material that can absorb a lot of light and then re-radiate it as light without much loss. Fluorescence is critical to applications in optical materials and polymers including diagnostics, photonics and solar energy,” he added. “While fluorescent dyes are potential key components of these materials, electronic coupling between them in the solid state quenches their emission, preventing their reliable use in applications.”
The key advancement made with SMILES is their brightness, which contrasts with the quenching of the emission typically seen in other fluorescent materials. Normalized for volume, the SMILES materials operate at 7,000 brightness units, which is the highest-known level. Flood said the brightness is the result of the molecular glue that makes the small-molecule dyes stick together in a checkerboard lattice. When the dyes are isolated from one another in the alternating checkerboard pattern, they “turn on their bright properties,” he said.
Flood, Laursen and their teams are interested in using the dyes in academic research topics. “A range of exciting new uses can be envisioned,” Flood said. “We will use SMILES in light upconversion, which is considered for solar harvesting, and in circularly polarized luminescence needed for 3D displays. We also will use the dyes in switchable materials, which are common to photochromic glass that becomes darker when it is exposed to light or ultraviolet radiation.”
Flood disclosed his discovery to the IU Innovation and Commercialization Office, which has filed a patent application with the United States Patent and Trademark Office. Flood has licensed his discovery from IU ICO and has launched a startup company called Halophore to commercialize it. “There are several commercial applications for SMILES, including medical diagnostics, solar concentrators, lasers and more,” Flood said. “Additionally, SMILES materials are simple to incorporate into commodity products such as polymers.”
https://www.newscientist.com/article/225...misbehave/
EXCERPT: Physicists have spotted the Higgs boson performing a new trick [...] The Higgs boson ... is the particle that gives all other fundamental particles mass, according to the standard model of particle physics. However, despite the work of thousands of researchers around the world, nobody has been able to figure out exactly how it does that or why some particles are more massive than others.
[...] Some researchers have suggested that particles have different masses because there is more than one type of Higgs boson, with each type of Higgs coupled to a different mass range of other particles. ... the new discovery makes it more likely there is only one Higgs. That behaviour is exactly what we expect from the standard model. ... But that leaves the mystery of why particles have different masses completely unanswered. ... it is somewhat frustrating because we know the standard model is incomplete – in addition to not explaining why particles have different masses, it also doesn’t account for dark matter or dark energy. Nevertheless, experimental results have been entirely in line with the model... (MORE - details)
Spacetime wave packets: New class of laser defies laws of light physics
https://newatlas.com/physics/spacetime-w...efraction/
EXCERPT: . . . But the new laser beams don’t follow this basic law of light. And it’s not just Snell’s Law either – the team says they also ignore Fermat’s Principle, which says that light always takes the shortest possible path. “This new class of laser beams has unique properties that are not shared by common laser beams,” says Ayman Abouraddy, principal investigator of the study. “Spacetime wave packets can be arranged to behave in the usual manner, to not change speed at all, or even to anomalously speed up in denser materials. As such, these pulses of light can arrive at different points in space at the same time.”
This has some major implications for optical communications technologies. The team uses the example of a plane sending messages encoded in light to two submarines, at the same depth but different distances away. Normally, the message would arrive at the closer sub first, but with spacetime wave packets the pulses could be propagated to reach both at the exact same time. While it may sound like this technology is contradicting some key laws of physics, the team stresses that it’s actually still in line with special relativity... (MORE - details)
Physicists watch quantum particles tunnel through solid barriers. Here's what they found.
https://www.livescience.com/quantum-tunn...sured.html
EXCERPTS: . . . Quantum tunneling is a phenomenon where an atom or a subatomic particle can appear on the opposite side of a barrier that should be impossible for the particle to penetrate. It's as if you were walking and encountered a 10-foot-tall (3 meters) wall extending as far as the eye can see. Without a ladder or Spider-man climbing skills, the wall would make it impossible for you to continue.
However, in the quantum world, it is rare, but possible, for an atom or electron to simply "appear" on the other side, as if a tunnel had been dug through the wall. "Quantum tunneling is one of the most puzzling of quantum phenomena," said study co-author Aephraim Steinberg ... "And it is fantastic that we're now able to actually study it in this way."
Quantum tunneling is not new to physicists. It forms the basis of many modern technologies [...] Researchers had previously tried to measure the amount of time it takes for tunneling to occur, with varying results. One of the difficulties in earlier versions of this type of experiment is identifying the moment tunneling starts and stops. To simplify the methodology, the researchers used magnets to create a new kind of "clock" that would tick only while the particle was tunneling.
[...] As expected, most of the rubidium atoms bounced off the barrier. However, due to quantum tunneling, about 3% of the atoms penetrated the barrier and appeared on the other side. Based on the precession of those atoms, it took them about 0.6 milliseconds to traverse the barrier... (MORE - details)
Chemists help create brightest-ever fluorescent materials
https://www.chem.indiana.edu/2020/08/iu-...materials/
RELEASE: Researchers at Indiana University Bloomington and the University of Copenhagen have developed patent-pending materials to address key setbacks to using fluorescent dyes as solid-state materials in academic and commercial applications. Amar FloodAmar Flood, the James Jackson Professor of Chemistry in the College of Arts and Sciences at Indiana University, and Bo Wegge Laursen, professor of chemistry at the University of Copenhagen, have created materials called small-molecule, ionic isolation lattices, or SMILES, which are the brightest-known fluorescent materials. Their research paper, “Plug-and-Play Optical Materials from Fluorescent Dyes and Macrocycles,” is published in the August issue of the peer-reviewed journal Chem.
“Think of SMILES like a light bulb, but instead of being turned on with electricity, they are turned on with light, including ultraviolet and visible light,” Flood said. “These SMILES pack a lot of dyes inside a material that can absorb a lot of light and then re-radiate it as light without much loss. Fluorescence is critical to applications in optical materials and polymers including diagnostics, photonics and solar energy,” he added. “While fluorescent dyes are potential key components of these materials, electronic coupling between them in the solid state quenches their emission, preventing their reliable use in applications.”
The key advancement made with SMILES is their brightness, which contrasts with the quenching of the emission typically seen in other fluorescent materials. Normalized for volume, the SMILES materials operate at 7,000 brightness units, which is the highest-known level. Flood said the brightness is the result of the molecular glue that makes the small-molecule dyes stick together in a checkerboard lattice. When the dyes are isolated from one another in the alternating checkerboard pattern, they “turn on their bright properties,” he said.
Flood, Laursen and their teams are interested in using the dyes in academic research topics. “A range of exciting new uses can be envisioned,” Flood said. “We will use SMILES in light upconversion, which is considered for solar harvesting, and in circularly polarized luminescence needed for 3D displays. We also will use the dyes in switchable materials, which are common to photochromic glass that becomes darker when it is exposed to light or ultraviolet radiation.”
Flood disclosed his discovery to the IU Innovation and Commercialization Office, which has filed a patent application with the United States Patent and Trademark Office. Flood has licensed his discovery from IU ICO and has launched a startup company called Halophore to commercialize it. “There are several commercial applications for SMILES, including medical diagnostics, solar concentrators, lasers and more,” Flood said. “Additionally, SMILES materials are simple to incorporate into commodity products such as polymers.”
