May 15, 2019 03:59 PM
(This post was last modified: May 15, 2019 04:30 PM by C C.)
Quantum Mechanics is wrong. There, I’ve said it. (Sabine Hossenfelder)
http://backreaction.blogspot.com/2019/05...e-ive.html
EXCERPT: . . . You see, in quantum mechanics we give quantum properties to particles. But we know that, strictly speaking, the interactions between these particles must also have quantum properties. If we give these interactions quantum properties, we call that “second quantization.” It is not used in quantum mechanics. Second quantization results in a larger mathematical framework called “quantum field theory”. The Standard Model of particle physics is a quantum field theory. Sometimes we use the word “quantum theory” to refer to both, quantum mechanics and quantum field theory together. [...] So, yes, quantum mechanics is technically wrong. It’s only an approximation to the more complete framework of quantum field theory. But as the statistician George Box summed it up “All models are wrong, but some are useful.” And whatever your misgivings are about quantum mechanics, there is no denying that it is useful. (MORE - details)
Would an antimatter orange have fallen on Newton's head like an apple?
https://news.cnrs.fr/opinions/apples-ora...ntigravity
EXCERPT: . . . What effect does gravity have on antimatter? Some theories in the 1980s posit a kind of antigravity that would manifest itself through a repulsion between masses of matter and antimatter! Such a phenomenon would be a major violation of the weak equivalence principle. In short, any experimental demonstration of such an effect would turn our understanding of fundamental physics upside down. Observing such a repulsion would also raise a problem with regard to the conservation of energy, although this could explain why we find almost no antimatter in our local Universe, as it would simply have been pushed away by matter.
A number of attempts were made to measure the effect of gravitation on antiprotons during the mid-1990s, but the gravitational interaction is so weak in comparison to electric interaction that they all failed. The tiniest charge on the vacuum chamber's walls exerts a force on electrically charged antiprotons that is many orders of magnitude more intense than gravitation.
Three projects were subsequently launched to test the behaviour of antimatter by measuring the effect of terrestrial gravitation on antihydrogen, which contrary to the antiproton is electrically neutral. These three experiments, AEGIS,3 GBAR,4 and Alpha-g,5 will use CERN's antiproton source to study the behaviour of antimatter in the face of gravity. (MORE)
The Downside of Chemistry Automation
https://blogs.sciencemag.org/pipeline/ar...automation
INTRO: Automation in chemistry (especially industrial chemistry) is so pervasive that we hardly even notice it any more. (I have a whole talk that I give that’s partly on that very subject). But what is automation for? That’s the subject of this short piece in ACS Med. Chem. Letters by Jeffrey Pan of AbbVie. The answer would seem obvious, and fits into my rule of thumb that any question that can be phrased in the form “I wonder how come they. . .” has the answer “Money”. The obvious reason for R&D automation is indeed to save money, in those situations where repetitive tasks done by human beings can be sped up and standardized by machine.
But the easy opportunities for this sort of thing have been picked off by now. More capable equipment can take on more complicated jobs, but you have to decide if the throughput of the tasks it can do justifies its higher expense. We all depend on the systems that have shown their worth in labor and time savings (autosamplers!), to the point that we regard them as a necessary part of our work – but many readers will have also experienced the frustration of working with a machine that actually makes your life more difficult under the guise of helping you out. “Can you start this gizmo and then walk away and go to lunch without regretting it?” is a useful question to ask, and to answer honestly. And remember, “Sometimes” is equivalent to “No”.
The other choice is to make the machine’s task simpler and change your processes, but that doesn’t always work out... (MORE)
http://backreaction.blogspot.com/2019/05...e-ive.html
EXCERPT: . . . You see, in quantum mechanics we give quantum properties to particles. But we know that, strictly speaking, the interactions between these particles must also have quantum properties. If we give these interactions quantum properties, we call that “second quantization.” It is not used in quantum mechanics. Second quantization results in a larger mathematical framework called “quantum field theory”. The Standard Model of particle physics is a quantum field theory. Sometimes we use the word “quantum theory” to refer to both, quantum mechanics and quantum field theory together. [...] So, yes, quantum mechanics is technically wrong. It’s only an approximation to the more complete framework of quantum field theory. But as the statistician George Box summed it up “All models are wrong, but some are useful.” And whatever your misgivings are about quantum mechanics, there is no denying that it is useful. (MORE - details)
Would an antimatter orange have fallen on Newton's head like an apple?
https://news.cnrs.fr/opinions/apples-ora...ntigravity
EXCERPT: . . . What effect does gravity have on antimatter? Some theories in the 1980s posit a kind of antigravity that would manifest itself through a repulsion between masses of matter and antimatter! Such a phenomenon would be a major violation of the weak equivalence principle. In short, any experimental demonstration of such an effect would turn our understanding of fundamental physics upside down. Observing such a repulsion would also raise a problem with regard to the conservation of energy, although this could explain why we find almost no antimatter in our local Universe, as it would simply have been pushed away by matter.
A number of attempts were made to measure the effect of gravitation on antiprotons during the mid-1990s, but the gravitational interaction is so weak in comparison to electric interaction that they all failed. The tiniest charge on the vacuum chamber's walls exerts a force on electrically charged antiprotons that is many orders of magnitude more intense than gravitation.
Three projects were subsequently launched to test the behaviour of antimatter by measuring the effect of terrestrial gravitation on antihydrogen, which contrary to the antiproton is electrically neutral. These three experiments, AEGIS,3 GBAR,4 and Alpha-g,5 will use CERN's antiproton source to study the behaviour of antimatter in the face of gravity. (MORE)
The Downside of Chemistry Automation
https://blogs.sciencemag.org/pipeline/ar...automation
INTRO: Automation in chemistry (especially industrial chemistry) is so pervasive that we hardly even notice it any more. (I have a whole talk that I give that’s partly on that very subject). But what is automation for? That’s the subject of this short piece in ACS Med. Chem. Letters by Jeffrey Pan of AbbVie. The answer would seem obvious, and fits into my rule of thumb that any question that can be phrased in the form “I wonder how come they. . .” has the answer “Money”. The obvious reason for R&D automation is indeed to save money, in those situations where repetitive tasks done by human beings can be sped up and standardized by machine.
But the easy opportunities for this sort of thing have been picked off by now. More capable equipment can take on more complicated jobs, but you have to decide if the throughput of the tasks it can do justifies its higher expense. We all depend on the systems that have shown their worth in labor and time savings (autosamplers!), to the point that we regard them as a necessary part of our work – but many readers will have also experienced the frustration of working with a machine that actually makes your life more difficult under the guise of helping you out. “Can you start this gizmo and then walk away and go to lunch without regretting it?” is a useful question to ask, and to answer honestly. And remember, “Sometimes” is equivalent to “No”.
The other choice is to make the machine’s task simpler and change your processes, but that doesn’t always work out... (MORE)