Even space and time if it’s quantum.
What will be the ultimate fate of our universe? There are a number of theories and possibilities, but at present the most likely scenario seems to be that the universe will continue to expand, most mass will eventually find its way into a black hole, and those black holes will slowly evaporate into Hawking Radiation, resulting in what is called the “heat death” of the universe. Don’t worry, this will likely take 1.7×10106 years, so we got some time.
But what about objects, like stellar remnants, that are not black holes? Will the ultimate fate of the universe still contain some neutron stars and cold white dwarfs that managed to never get sucked up by a black hole? To answer this question we have to back up a bit and talk about Hawking Radiation.
Stephen Hawking famously proposed this idea in 1975 – he was asked if black holes have a temperature, and that sent him down another type of hole until Hawking Radiation popped out as the answer. But what is Hawking Radiation? The conventional answer is that the vacuum of space isn’t really nothing, it still contains the quantum fields that make up spacetime. Those quantum field do not have to have zero energy, and so occasionally virtual particles will pop into existence, always in pairs with opposite properties (like opposite charge and spin), and then they join back together, cancelling each other out. But at the event horizon of black holes, the distance at which light can just barely escape the black hole’s gravity, a virtual pair might occur where one particle gets sucked into the black hole and the other escapes. The escaping particle is Hawking Radiation. It carries away a little mass from the black hole, causing it to glow slightly and evaporate very slowly.
University of Washington researchers have discovered they can detect atomic “breathing,” or the mechanical vibration between two layers of atoms, by observing the type of light those atoms emitted when stimulated by a laser. The sound of this atomic “breath” could help researchers encode and transmit quantum information.
The researchers also developed a device that could serve as a new type of building block for quantum technologies, which are widely anticipated to have many future applications in fields such as computing, communications and sensor development.
The researchers published these findings June 1 in Nature Nanotechnology.
Quantum effects are phenomena that occur between atoms and molecules that can’t be explained by classical physics. It has been known for more than a century that the rules of classical mechanics, like Newton’s laws of motion, break down at atomic scales. Instead, tiny objects behave according to a different set of laws known as quantum mechanics.
For humans, who can only perceive the macroscopic world, or what’s visible to the naked eye, quantum mechanics can seem counterintuitive and somewhat magical. Things you might not expect happen in the quantum world, like electrons “tunneling” through tiny energy barriers and appearing on the other side unscathed or being in two different places at the same time in a phenomenon called superposition.
I am trained as a quantum engineer. Research in quantum mechanics is usually geared toward technology. However, and somewhat surprisingly, there is increasing evidence that nature – an engineer with billions of years of practice — has learned how to use quantum mechanics to function optimally. If this is indeed true, it means that our understanding of biology is radically incomplete. It also means that we could possibly control physiological processes by using the quantum properties of biological matter.
Ruoming Peng/University of Washington.
This is according to a press release published by the institution on Friday.
The quantum fluctuations that pervade empty space spontaneously give birth to pairs of particles and antiparticles. Ordinarily, these pairs annihilate so promptly that their existence is virtual. But a powerful field can pull a pair’s members apart for long enough that their existence becomes real. In 1951 Julian Schwinger calculated how strong an electric field needs to be to beget electron–positron pairs. Now Michael Wondrak and his colleagues of Radboud University in the Netherlands have proposed that particle pairs can be brought into existence by the immense gravitational tidal forces around a black hole [1].
Wondrak and his colleagues considered all the paths a pair of virtual particles could take during their brief existence. If the vacuum is stable, all pairs that are created are also destroyed. But a strong field destabilizes the vacuum, makes some paths more likely than others, and leads to a deficit of pairs that recombine. The deficit is balanced by a net outflow of real particles, which, in the case of a black hole’s gravitational field, leads to the black hole’s eventual evaporation.
The theorists’ approach is sufficiently general that it could reproduce not only Schwinger’s effect but also Stephen Hawking’s 1974 proposal that if a particle–antiparticle pair springs into virtual existence near a black hole’s event horizon, one member could fall in while the other escapes. What’s more, the researchers found that Hawking’s effect is a special case of a more general phenomenon. Pulling virtual particles into existence depends only on the stretching of spacetime wrought by a curved gravitational field and does not require an event horizon as Hawking originally suggested. One intriguing implication is that a neutron star, whose Schwarzschild radius lies beneath the stellar surface, can also beget particle pairs and decay.
Turning Lead Into Gold
Posted in chemistry, particle physics
Year 2021 😗😁
They were indeed correct that lead could be turned into gold — even if they were dead wrong about how it could be done. Now, modern science routinely takes us far beyond even the wildest dreams of the alchemists.
One of the most famous stories of nuclear transmutation comes from the 1970s, when nuclear chemist and Nobel laureate Glenn Seaborg worked at the Lawrence Berkeley National Laboratory alongside colleague Walt Loveland and then-graduate student Dave Morrissey. The scientists were using a super-heavy ion linear accelerator to bombard atoms with ions as heavy as uranium at relativistic speeds. “Among the ones we bombarded was lead-208,” Loveland says.
Accelerating the ions close to the speed of light allowed them to study nuclear reaction mechanisms. “We would measure the products, mostly concentrating on the yields,” Loveland says. Some of those yields were gold. “It was all relatively routine stuff. Then Seaborg said, ‘Hey, look at this — you’re transforming lead into gold, doing the alchemists’ dream reaction.’” He suggested that Morrissey write a paper on the research and present it at the upcoming American Chemical Society annual meeting in Miami.
A new demonstration involving hundreds of entangled atoms tests Schrödinger’s interpretation of Einstein, Rosen, and Podolsky’s classic thought experiment.
In 1935, Einstein, Podolsky, and Rosen (EPR) presented an argument that they claimed implies that quantum mechanics provides an incomplete description of reality [1]. The argument rests on two assumptions. First, if the value of a physical property of a system can be predicted with certainty, without disturbance to the system, then there is an “element of reality” to that property, meaning it has a value even if it isn’t measured. Second, physical processes have effects that act locally rather than instantaneously over a distance. John Bell subsequently proposed a way to experimentally test these “local realism” assumptions [2], and so-called Bell tests have since invalidated them for systems of a few small particles, such as electrons or photons [3].
An unusual kind of superconductor harbors magnetic vortices that researchers predict should be readily observable thanks to the striped configurations they adopt.
In a nematic superconductor, electron pairs are bound more strongly in one, spontaneously chosen, lattice direction than in the others. This rotational symmetry breaking of the pairs’ wave function is just one of this type of superconductor’s unusual properties. A leading candidate to exhibit nematic superconductivity, copper-doped bismuth selenide, is also predicted to sustain surface charge-carrying quasiparticles known as Majorana fermions, which researchers think could be used for superconducting quantum technologies. What’s more, nematic superconductors harbor topological solitons known as skyrmions, whose complexity gives them many ways to arrange themselves and whose small size and low energy have attracted interest for data storage technologies. Now Thomas Winyard of the University of Edinburgh, UK, and colleagues have calculated the various skyrmion configurations that could arise in a nematic superconductor [1, 2].
The physicist Tony Skyrme came up with the concept of a skyrmion in 1961 when working on a particle physics problem. In the 2000s, the quasiparticle was then linked to condensed-matter systems when it was discovered that quasiparticles could also be used to explain magnetic vortices in certain thin films.
“” This achievement connects synchrotron X-rays with quantum tunneling process to detect X-ray signature of an individual atom and opens many exciting research directions including the research on quantum and spin (magnetic) properties of just one atom using synchrotron X-rays,” Hla said.”
A team of scientists from Ohio University, Argonne National Laboratory, the University of Illinois-Chicago, and others, led by Ohio University Professor of Physics, and Argonne National Laboratory scientist, Saw Wai Hla, have taken the world’s first X-ray SIGNAL (or SIGNATURE) of just one atom. This groundbreaking achievement could revolutionize the way scientists detect the materials.