Defining degree of the quantumness of things + 6 questions physicists ask + Unsolved

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The Black Hole information loss problem is unsolved. Because it’s unsolvable. (Sabine Hossenfelder)

EXCERPT: The claim is that the black hole information loss problem is “nearing its end”. So today I am here to explain why the black hole information loss problem is not only unsolved but will remain unsolved because it’s for all practical purposes unsolvable... (MORE - video)

Six questions physicists ask when evaluating scientific claims

EXCERPTS: . . . The goal of science is to search for truth through impartial analysis. But according to University of Texas at Austin professor Peter Onyisi, scientists must also consider the human element. “There is a significant amount of human interpretation in the sciences,” Onyisi says. “We try to put things in this picture with absolute rules to remove the human judgment. But the human judgment is actually very important.” Here are six questions physicists ask themselves when judging the merit and meaning of a scientific claim... (MORE)

COVERED: (1)Where did the data come from? ..... (2)How was the data collected and handled? ..... (3)How exceptional is the data? ..... (4)Are the results statistically significant? ..... (5)How significant is the significance? ..... (6)Were the results confirmed by an independent experiment?

Physicists discover the 'Kings and Queens of Quantumness'

EXCERPT: . . . physicists have found a way to mathematically define the degree of quantumness that anything - be it particle, atom, molecule or even a planet - exhibits. [...] classical objects like billiard balls are secretly quantum systems, so there exists some infinitesimally small probability that they will, say, tunnel through the side of a pool table. This suggests that there is a continuum, with "classicalness" on one end and "quantumness" on the other.

[...] Previous attempts at quantifying quantumness always looked at specific quantum systems [...] Sanchez-Soto and their team searched instead for a generalized way of defining extremes in quantum states. "We can apply this to any quantum system - atoms, molecules, light or even combinations of those things - by using the same guiding principles," Goldberg said. The team found that these quantum extremes could come in at least two different types, naming some Kings and others Queens for their superlative nature. They reported their findings Nov. 17 in the journal AVS Quantum Science.

So what exactly does it mean for something to be "the most quantum?" Here is where the work gets tricky, since it is highly mathematical and difficult to easily visualize. But Pieter Kok, a physicist at the University of Sheffield in England, who was not involved in writing the new paper, suggested a way to get some grasp on it. One of the most basic physical systems is a simple harmonic oscillator - that is, a ball on the end of a spring moving back and forth, Kok told Live Science.

A quantum particle would be on the classical extreme if it behaved like this ball and spring system, found at specific points in time based on the initial kick it received. But if the particle were to be quantum mechanically smeared out so that it had no well-defined position and was found throughout the pathway of the spring and ball, it would be in one of these quantum extreme states.

[...] Goldberg said that the most readily apparent applications should come from quantum metrology, where engineers attempt to measure physical constants and other properties with extreme precision. ... But the findings could also help researchers in fields such as fiber optical communications, information processing and quantum computing... (MORE - details)
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Quantifying Quantumness: A Mathematical Project ‘of Immense Beauty’

RELEASE: Large objects, such as baseballs, vehicles, and planets, behave in accordance with the classical laws of mechanics formulated by Sir Isaac Newton. Small ones, such as atoms and subatomic particles, are governed by quantum mechanics, where an object can behave as both a wave and a particle.

The boundary between the classical and quantum realms has always been of great interest. Research reported in AVS Quantum Science, by AIP Publishing, considers the question of what makes something “more quantum” than another - is there a way to characterize “quantumness”? The authors report they have found a way to do just that.

The degree of quantumness is important for applications such as quantum computing and quantum sensing, which offer advantages that are not found in their classical counterparts. Understanding these advantages requires, in turn, an understanding of the degree of quantumness of the physical systems involved.

Rather than proposing a scale whose values would be associated with the degree of quantumness, the authors of this study look at extrema, namely those states that are either the most quantum or the least quantum. Author Luis Sanchez-Soto said the idea for the study came from a question posed at a scientific meeting. “I was giving a seminar on this topic when someone asked me the question: ‘You guys in quantum optics always talk about the most classical states, but what about the most quantum states?’” he said.

It has long been understood that so-called coherent states can be described as quasi-classical. Coherent states occur, for example, in a laser, where light from multiple photon sources are in phase making them the least quantum of states.

A quantum system can often be represented mathematically by points on a sphere. This type of representation is called a Majorana constellation, and for coherent states, the constellation is simply a single point. Since these are the least quantum of states, the most quantum ones would have constellations that cover more of the sphere.

The investigators looked at several ways that other scientists have explored quantumness and considered the Majorana constellation for each way. They then asked what the most evenly distributed set of points on a sphere for this approach is. As Sanchez-Soto and his colleagues considered the question of quantumness, they realized it was a mathematical project “of immense beauty,” in addition to being useful.

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