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Quantum Physics

Comfortably Numb said:
Physicists Suggest All Matter May Be Made Up of Energy 'Fragments'

Source: sciencealert.com
Date: 11 December, 2020

Matter is what makes up the Universe, but what makes up matter? This question has long been tricky for those who think about it – especially for the physicists.

Reflecting recent trends in physics, my colleague Jeffrey Eischen and I have described an updated way to think about matter. We propose that matter is not made of particles or waves, as was long thought, but – more fundamentally – that matter is made of fragments of energy.

The ancient Greeks conceived of five building blocks of matter – from bottom to top: earth, water, air, fire and aether. Aether was the matter that filled the heavens and explained the rotation of the stars, as observed from the Earth vantage point.

These were the first most basic elements from which one could build up a world. Their conceptions of the physical elements did not change dramatically for nearly 2,000 years.

Then, about 300 years ago, Sir Isaac Newton introduced the idea that all matter exists at points called particles. One hundred fifty years after that, James Clerk Maxwell introduced the electromagnetic wave – the underlying and often invisible form of magnetism, electricity and light.

The particle served as the building block for mechanics and the wave for electromagnetism – and the public settled on the particle and the wave as the two building blocks of matter. Together, the particles and waves became the building blocks of all kinds of matter.

This was a vast improvement over the ancient Greeks' five elements but was still flawed. In a famous series of experiments, known as the double-slit experiments, light sometimes acts like a particle and at other times acts like a wave. And while the theories and math of waves and particles allow scientists to make incredibly accurate predictions about the Universe, the rules break down at the largest and tiniest scales.

Einstein proposed a remedy in his theory of general relativity. Using the mathematical tools available to him at the time, Einstein was able to better explain certain physical phenomena and also resolve a longstanding paradox relating to inertia and gravity.

But instead of improving on particles or waves, he eliminated them as he proposed the warping of space and time.

Using newer mathematical tools, my colleague and I have demonstrated a new theory that may accurately describe the Universe. Instead of basing the theory on the warping of space and time, we considered that there could be a building block that is more fundamental than the particle and the wave.

[...]

https://www.sciencealert.com/physic...-to-describe-matter?__twitter_impression=true
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I think the idea of matter being fragments of energy is a good suggestion and I'd go with that.
 
Quantum Experiment Reveals Particles Can Form Collectives Out of Almost Nothing

Source: sciencealert.com
Date: 18 December, 2020

How many particles do you need before individual atoms start behaving collectively? According to new research, the number is incredibly low. As few as six atoms will start transitioning into a macroscopic system, under the right conditions.

Using a specially designed ultra-cold laser trap, physicists observed the quantum precursor of the transition from a normal to a superfluid phase – offering a way to study the emergence of collective atomic behaviour and the limits of macroscopic systems.

Many-body physics is the field that seeks to describe and understand the collective behaviour of large numbers of particles: a bucket of water, for example, or a canister of gas. We can describe these substances in terms of their density, or their temperature – the way the substance is acting as a whole.

[...]

https://www.sciencealert.com/quantu...hase-transition-can-begin-with-just-six-atoms
 
New type of atomic clock keeps time even more precisely

A newly-designed atomic clock uses entangled atoms to keep time even more precisely than its state-of-the-art counterparts. The design could help scientists detect dark matter and study gravity's effect on time.

Source: sciencedaily.com
Date: 16 December, 2020

Atomic clocks are the most precise timekeepers in the world. These exquisite instruments use lasers to measure the vibrations of atoms, which oscillate at a constant frequency, like many microscopic pendulums swinging in sync. The best atomic clocks in the world keep time with such precision that, if they had been running since the beginning of the universe, they would only be off by about half a second today.

Still, they could be even more precise. If atomic clocks could more accurately measure atomic vibrations, they would be sensitive enough to detect phenomena such as dark matter and gravitational waves. With better atomic clocks, scientists could also start to answer some mind-bending questions, such as what effect gravity might have on the passage of time and whether time itself changes as the universe ages.

Now a new kind of atomic clock designed by MIT physicists may enable scientists explore such questions and possibly reveal new physics.

The researchers report in the journal Nature that they have built an atomic clock that measures not a cloud of randomly oscillating atoms, as state-of-the-art designs measure now, but instead atoms that have been quantumly entangled. The atoms are correlated in a way that is impossible according to the laws of classical physics, and that allows the scientists to measure the atoms' vibrations more accurately.

The new setup can achieve the same precision four times faster than clocks without entanglement.

https://www.sciencedaily.com/releases/2020/12/201216113301.htm
 
Artificial intelligence solves Schrödinger's equation

Source: phys.org
Date: 21 December 2020

A team of scientists at Freie Universität Berlin has developed an artificial intelligence (AI) method for calculating the ground state of the Schrödinger equation in quantum chemistry. The goal of quantum chemistry is to predict chemical and physical properties of molecules based solely on the arrangement of their atoms in space, avoiding the need for resource-intensive and time-consuming laboratory experiments. In principle, this can be achieved by solving the Schrödinger equation, but in practice this is extremely difficult.

Up to now, it has been impossible to find an exact solution for arbitrary molecules that can be efficiently computed. But the team at Freie Universität has developed a deep learning method that can achieve an unprecedented combination of accuracy and computational efficiency. AI has transformed many technological and scientific areas, from computer vision to materials science. "We believe that our approach may significantly impact the future of quantum chemistry," says Professor Frank Noé, who led the team effort. The results were published in the reputed journal Nature Chemistry.

Central to both quantum chemistry and the Schrödinger equation is the wave function—a mathematical object that completely specifies the behavior of the electrons in a molecule. The wave function is a high-dimensional entity, and it is therefore extremely difficult to capture all the nuances that encode how the individual electrons affect each other. Many methods of quantum chemistry in fact give up on expressing the wave function altogether, instead attempting only to determine the energy of a given molecule. This however requires approximations to be made, limiting the prediction quality of such methods.

[...]

https://phys.org/news/2020-12-artificial-intelligence-schrdinger-equation.html
 
Nice description of the blinding if the measurements to prevent bias:

As early as March, the Muon g-2 experiment at Fermi National Accelerator Laboratory (Fermilab) will report a new measurement of the magnetism of the muon, a heavier, short-lived cousin of the electron. The effort entails measuring a single frequency with exquisite precision. In tantalizing results dating back to 2001, g-2 found that the muon is slightly more magnetic than theory predicts. If confirmed, the excess would signal, for the first time in decades, the existence of novel massive particles that an atom smasher might be able to produce, says Aida El-Khadra, a theorist at the University of Illinois, Urbana-Champaign. “This would be a very clear sign of new physics, so it would be a huge deal.”

https://www.sciencemag.org/news/202...ence&utm_source=Contractor&utm_medium=Twitter
 
This has come up as a YouTube suggestion and I thought the video was a commendable, clear explanation.

Parallel Worlds Probably Exist. Here’s Why


I note it's claimed to have '15m views'.

You can count myself amongst those of the 15m others who remain unconvinced a cat can be both dead and alive at the same time, until you look at it and then the cat becomes one or the other. :)
 
"Quantum Time Crystals" discovered

"A time crystal, first proposed by physicist Frank Wilczek in 2012, is a phase of matter which repeats in time, similar to how a regular crystal's structure repeats in space. What that means is that the particles in the crystal perpetually switch between two states without requiring the input of more energy and without losing any energy."

https://www.jpost.com/science/researchers-create-time-crystal-with-quantum-computers-687856


A state of matter called "Quantum Spin Liquid" has been observed for the first time

"The state of matter they found is called quantum spin liquid, which has special properties that produce long-range quantum entanglement — a phenomenon in which particles' states are connected even when the particles are separated by distance."

https://www.jpost.com/science/never-before-seen-state-of-matter-could-advance-quantum-tech-688505
 
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Funny, Einstein said Quantum Physics was “ spooky “ and he never felt comfortable with Quantum Physics.
 
If CERN creates a black hole that destroys the solar system, I will not send them a Christmas Card this year for being bad.
 
charliebrown said:
If CERN creates a black hole that destroys the solar system, I will not send them a Christmas Card this year for being bad.
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My son Escet did his particle physics post-doc at CERN and had a whale of a time. He and I were present for the announcement of the finding of the Higgs boson.

When I was chatting to him on Messenger or summat while my nephew was doing some carpentry for me, Nephew asked me to tell Escet to change the laws of physics so he could hang the door straight. :chuckle:
 
They have put a qubit (digital thing) in quantum superposition with a tardigrade (living thing).
The person who posts this understands what this means. I do not. But it sounds cool anyway:
https://infoproc.blogspot.com/2021/12/macroscopic-superposition-states.html

We observe coupling between the animal in cryptobiosis and a superconducting quantum bit and prepare a highly entangled state between this combined system and another qubit. The tardigrade itself is shown to be entangled with the remaining subsystems. The animal is then observed to return to its active form after 420 hours at sub 10 mK temperatures and pressure of 6×10−6 mbar, setting a new record for the conditions that a complex form of life can survive.
 
uair01 said:
They have put a qubit (digital thing) in quantum superposition with a tardigrade (living thing).
The person who posts this understands what this means. I do not. But it sounds cool anyway:
https://infoproc.blogspot.com/2021/12/macroscopic-superposition-states.html

We observe coupling between the animal in cryptobiosis and a superconducting quantum bit and prepare a highly entangled state between this combined system and another qubit. The tardigrade itself is shown to be entangled with the remaining subsystems. The animal is then observed to return to its active form after 420 hours at sub 10 mK temperatures and pressure of 6×10−6 mbar, setting a new record for the conditions that a complex form of life can survive.
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Somebody tell me what this means - and what it doesn't. There doesn't seem to be enough detail to tell me exactly what happened - or what superposed states potentially happened - to the tardigrade.

Edit: Nevermind.

Peers dispute claim that tardigrades were entangled with qubits
...
Virtually all of those with an opinion pointed out that the work by the researchers in this new effort did not involve entanglement.
...
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https://phys.org/news/2021-12-peers-dispute-tardigrades-entangled-qubits.html
 
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A century of quantum mechanics questions the fundamental nature of reality

By Tom Siegfried
12 January, 2022
sciencenews.org

Scientists are like prospectors, excavating the natural world seeking gems of knowledge about physical reality. And in the century just past, scientists have dug deep enough to discover that reality’s foundations do not mirror the world of everyday appearances. At its roots, reality is described by the mysterious set of mathematical rules known as quantum mechanics.

Conceived at the turn of the 20th century and then emerging in its full form in the mid-1920s, quantum mechanics is the math that explains matter. It’s the theory for describing the physics of the microworld, where atoms and molecules interact to generate the world of human experience. And it’s at the heart of everything that made the century just past so dramatically unlike the century preceding it. From cell phones to supercomputers, DVDs to pdfs, quantum physics fueled the present-day electronics-based economy, transforming commerce, communication and entertainment.

But quantum theory taught scientists much more than how to make computer chips. It taught that reality isn’t what it seems.

“The fundamental nature of reality could be radically different from our familiar world of objects moving around in space and interacting with each other,” physicist Sean Carroll suggested in a recent tweet. “We shouldn’t fool ourselves into mistaking the world as we experience it for the world as it really is.”

In a technical paper backing up his tweet, Carroll notes that quantum theory consists of equations that describe mathematical entities roaming through an abstract realm of possible natural events. It’s plausible, Carroll argues, that this quantum realm of mathematical possibilities represents the true, fundamental nature of reality. If so, all the physical phenomena we perceive are just a “higher-level emergent description” of what’s really going on.

“Emergent” events in ordinary space are real in their own way, just not fundamental, Carroll allows. Belief that the “spatial arena” is fundamental “is more a matter of convenience and convention than one of principle,” he says.

Carroll’s perspective is not the only way of viewing the meaning of quantum math, he acknowledges, and it is not fully shared by most physicists. But everybody does agree that quantum physics has drastically remodeled humankind’s understanding of nature. In fact, a fair reading of history suggests that quantum theory is the most dramatic shift in science’s conception of reality since the ancient Greeks deposed mythological explanations of natural phenomena in favor of logic and reason. After all, quantum physics itself seems to defy logic and reason.

(...)

https://www.sciencenews.org/article/quantum-theory-history-reality-uncertainty-physics

The aforesaid technical paper:

Reality as a Vector in Hilbert Space
Sean M. Carroll

I defend the extremist position that the fundamental ontology of the world consists of a vector in Hilbert space evolving according to the Schrödinger equation. The laws of physics are determined solely by the energy eigenspectrum of the Hamiltonian. The structure of our observed world, including space and fields living within it, should arise as a higher-level emergent description. I sketch how this might come about, although much work remains to be done.

(...)

https://arxiv.org/abs/2103.09780
 
Hairy Black Holes -

‘Quantum hair’ could resolve Hawking’s black hole paradox, say scientists​

Stephen Hawking’s black hole information paradox has bedevilled scientists for half a century and led some to question the fundamental laws of physics. Now scientists say they may have resolved the infamous problem by showing that black holes have a property known as “quantum hair”.
https://www.theguardian.com/science...hen-hawking-black-hole-paradox-say-scientists
 
Floyd1 said:
quarks, the tiniest particles known to humankind, group together.
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1657020401317.png
 
https://www.yahoo.com/lifestyle/objective-reality-may-not-exist-135100526.html
Objective Reality May Not Exist at All, Quantum Physicists Say

Stav Dimitropoulos
Sat, July 9, 2022 at 9:51 AM·7 min read

  • One of the biggest mysteries in quantum mechanics is whether physical reality exists independent of its observer.
  • New research from Brazil provides strong evidence that there might be mutually exclusive, yet complementary physical realities in the quantum realm.
  • Future research on the great quantum debate might give us super-disruptive quantum technologies—and probably startling answers to the world’s greatest mysteries.
Does reality exist, or does it take shape when an observer measures it? Akin to the age-old conundrum of whether a tree makes a sound if it falls in a forest with no one around to hear it, the above question remains one of the most tantalizing in the field of quantum mechanics, the branch of science dealing with the behavior of subatomic particles on the microscopic level.
- ADVERTISEMENT -

In a field where intriguing, almost mysterious phenomena like “quantum superposition” prevail—a situation where one particle can be in two or even “all” possible places at the same time—some experts say reality exists outside of your own awareness, and there’s nothing you can do to change it. Others insist “quantum reality” might be some form of Play-Doh you mold into different shapes with your own actions. Now, scientists from the Federal University of ABC (UFABC) in the São Paulo metropolitan area in Brazil are adding fuel to the suggestion that reality might be “in the eye of the observer.”

In their new research, published in the journal Communications Physics in April, the scientists in Brazil attempted to verify the “complementarity principle” the famous Danish physicist Niels Bohr proposed in 1928. It states that objects come with certain pairs of complementary properties, which are impossible to observe or measure at the same time, like energy and duration, or position and momentum. For example, no matter how you set up an experiment involving a pair of electrons, there’s no way you can study the position of both quantities at the same time: the test will illustrate the position of the first electron, but obscure the position of the second particle (the complementary particle) at the same time.
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Physicists observe wormhole dynamics using a quantum computer

30 November, 2022
California Institute of Technology / Science Daily

Scientists have, for the first time, developed a quantum experiment that allows them to study the dynamics, or behavior, of a special kind of theoretical wormhole. The experiment has not created an actual wormhole (a rupture in space and time), rather it allows researchers to probe connections between theoretical wormholes and quantum physics, a prediction of so-called quantum gravity. Quantum gravity refers to a set of theories that seek to connect gravity with quantum physics, two fundamental and well-studied descriptions of nature that appear inherently incompatible with each other.

(...)

Wormholes are bridges between two remote regions in spacetime. They have not been observed experimentally, but scientists have theorized about their existence and properties for close to 100 years. In 1935, Albert Einstein and Nathan Rosen described wormholes as tunnels through the fabric of spacetime in accordance with Einstein's general theory of relativity, which describes gravity as a curvature of spacetime. Researchers call wormholes Einstein-Rosen bridges after the two physicists who invoked them, while the term "wormhole" itself was coined by physicist John Wheeler in the 1950s.
(End of extract)

How very fascinating.

Another remarkable achievement, for s relatively nascent civilisation and it does seem to offer theoretically conceivable solutions to space travel?

https://www.sciencedaily.com/releases/2022/11/221130114712.htm
 
Is quantum physics real ?

Someone said make up anything you want with quantum physics.

Is light a particle or a wave ?
 
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