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Category: particle physics – Page 298

Electrons Filming Themselves

Two groups demonstrate innovative ways to capture the ultrafast motion of electrons in atoms and molecules.

Electrons move so quickly inside of atoms and molecules that they are challenging to “capture on film” without blurring the images. One way to take fast snapshots is to ionize an atom or molecule and then use the released electrons as probes of the cloud out of which they originate. Now Gabriel Stewart at Wayne State University in Michigan and colleagues [1] and Antoine Camper at the University of Oslo in Norway and colleagues [2] have improved this “self-probing” technique. The demonstrations could lead to a better understanding of the electron motion that underpins many fundamental processes.

Scientists need to complete three key tasks to measure the evolution of an electron cloud that moves and changes on an ultrafast timescale. The first is to exactly record the beginning of the evolution—analogous to pressing “start” on a mechanical stopwatch. The second is to track how much time has gone by since the starting event—analogous to precisely measuring the ticking of the stopwatch’s second hand. And the third is to take a quick snapshot of the electron cloud so that it looks frozen in time.

Quantum Telescopes Could Offer Clearer Views of Our Solar System and Beyond

Scientists want to use quantum mechanics to capture higher-resolution images of the night sky.

For the purposes of astronomy, the two beams are collected by two telescopes that are separated by some distance (called baseline interferometry). But despite its effectiveness, classic interferometry is subject to some limitations. Andrei Nomerotski, an astrophysicist with the BNL and a co-author on the paper, explained to Universe Today via email.

“Interferometry is a way to increase the effective aperture of telescopes and to improve the angular resolution or astrometric precision,” he said. “The main difficulty here is to maintain the stability of this optical path to very high precision, which should be much smaller than the photon wavelength, to preserve the photon’s phase. This limits the practical baselines to a few hundred meters.”

In recent years, scientists have investigated the possibility of using quantum principles to enable next-generation astronomy. The basic idea is that photons could be transferred between observatories without physical connections that are expensive to build and maintain. The key is to take advantage of quantum entanglement, a phenomenon where particles interact and share the same quantum state — despite being separated by considered distance.

Researchers at CERN break “The Speed of Light”

Scientists said they recorded particles travelling faster than light – a finding that could overturn one of Einstein’s fundamental laws of the universe. Antonio Ereditato, spokesman for the international group of researchers, saidthat measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done.

Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics | Lex Fridman Podcast #359

Andrew Strominger is a theoretical physicist at Harvard. Please support this podcast by checking out our sponsors:
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EPISODE LINKS:
Andrew’s website: https://www.physics.harvard.edu/people/facpages/strominger.
Andrew’s papers:
Soft Hair on Black Holes: https://arxiv.org/abs/1601.00921
Photon Rings Around Warped Black Holes: https://arxiv.org/abs/2211.

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OUTLINE:
0:00 — Introduction.
1:12 — Black holes.
6:16 — Albert Einstein.
25:44 — Quantum gravity.
29:56 — String theory.
40:44 — Holographic principle.
48:41 — De Sitter space.
53:53 — Speed of light.
1:00:40 — Black hole information paradox.
1:08:20 — Soft particles.
1:17:27 — Physics vs mathematics.
1:26:37 — Theory of everything.
1:41:58 — Time.
1:44:24 — Photon rings.
2:00:05 — Thought experiments.
2:08:26 — Aliens.
2:14:04 — Nuclear weapons.

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Smooth sailing for electrons in graphene: Measuring fluid-like flow at nanometer resolution

Physicists at the University of Wisconsin-Madison have directly measured the fluid-like flow of electrons in graphene at nanometer resolution for the first time. The results appear in the journal Science today.

Graphene, an atom-thick sheet of arranged in a , is an especially pure electrical conductor, making it an ideal material to study with very low resistance. Here, researchers intentionally add impurities at known distances, and find that electron flow changes from gas-like to fluid-like as the temperature rises.

“All conductive materials contain impurities and imperfections that block electron flow, which causes resistance. Historically, people have taken a low-resolution approach to identifying where resistance comes from,” says Zach Krebs, a physics graduate student at UW-Madison and co-lead author of the study. “In this study, we image how charge flows around an impurity and actually see how that impurity blocks current and causes resistance, which is something that hasn’t been done before to distinguish gas-like and fluid-like electron flow.”

Researchers develop greener alternative to fossil fuels

Researchers at the University of North Carolina at Chapel Hill Department of Chemistry have engineered silicon nanowires that can convert sunlight into electricity by splitting water into oxygen and hydrogen gas, a greener alternative to fossil fuels.

Fifty years ago, scientists first demonstrated that liquid water can be split into oxygen and using electricity produced by illuminating a semiconductor electrode. Although hydrogen generated using is a promising form of clean energy, low efficiencies and have hindered the introduction of commercial solar-powered hydrogen plants.

An economic feasibility analysis suggests that using a slurry of electrodes made from nanoparticles instead of a rigid solar panel design could substantially lower costs, making solar-produced hydrogen competitive with fossil fuels. However, most existing particle-based light-activated catalysts, also referred to as photocatalysts, can absorb only , limiting their energy-conversion efficiency under solar illumination.

Scientists From Tennessee Are Trying To Open a Portal To a Parallel Universe

Scientists at Tennessee’s Oak Ridge National Laboratory are attempting to establish a doorway to a parallel reality. The goal of the project is to depict a world that is nearly comparable to ours and where life is mirrored. The experiment’s leader, Leah Broussard, told NBC that the strategy is a little crazy, but it will completely transform the game. If the studies are successful, particles will be able to morph into images of themselves, allowing them to burrow through a solid wall. This might demonstrate that the cosmos we observe is merely half of what exists. Broussard revealed that he believes the test will yield a result of zero.

The Dark Forest by Liu Cixin (Part 3) — Science Fiction Audiobook

https://youtube.com/watch?v=JfQWe–kciM&feature=share

This is the second novel in “Remembrance of Earth’s Past”, the near-future trilogy written by China’s multiple-award-winning science fiction author, Cixin Liu.

In The Dark Forest, Earth is reeling from the revelation of a coming alien invasion — four centuries in the future. The aliens’ human collaborators have been defeated but the presence of the sophons, the subatomic particles that allow Trisolaris instant access to all human information, means that Earth’s defense plans are exposed to the enemy. Only the human mind remains a secret.

This is the motivation for the Wallfacer Project, a daring plan that grants four men enormous resources to design secret strategies hidden through deceit and misdirection from Earth and Trisolaris alike. Three of the Wallfacers are influential statesmen and scientists but the fourth is a total unknown. Luo Ji, an unambitious Chinese astronomer and sociologist, is baffled by his new status. All he knows is that he’s the one Wallfacer that Trisolaris wants dead.

#audiobook.
#sciencefiction.
#fiction.
#fantastic

The Dark Forest by Liu Cixin (Part 2) — Science Fiction Audiobook

https://youtube.com/watch?v=0zOL6-u5GJo&feature=share

This is the second novel in “Remembrance of Earth’s Past”, the near-future trilogy written by China’s multiple-award-winning science fiction author, Cixin Liu.

In The Dark Forest, Earth is reeling from the revelation of a coming alien invasion — four centuries in the future. The aliens’ human collaborators have been defeated but the presence of the sophons, the subatomic particles that allow Trisolaris instant access to all human information, means that Earth’s defense plans are exposed to the enemy. Only the human mind remains a secret.

This is the motivation for the Wallfacer Project, a daring plan that grants four men enormous resources to design secret strategies hidden through deceit and misdirection from Earth and Trisolaris alike. Three of the Wallfacers are influential statesmen and scientists but the fourth is a total unknown. Luo Ji, an unambitious Chinese astronomer and sociologist, is baffled by his new status. All he knows is that he’s the one Wallfacer that Trisolaris wants dead.

#audiobook.
#sciencefiction.
#fiction.
#fantastic