Aug 23, 2018 03:39 PM
A Lenient Causal Arrow of Time? (video)
https://www.fetzer-franklin-fund.org/med...man-video/
INTRO: The literature on Bell’s theorem includes much discussion of different definitions of locality, e.g., Bell’s locality vs. signal locality, or parameter independence vs. outcome independence. In contrast, Bell’s reviews of the topic identify “locality” with “local causality,” which is a mathematical condition representing the causal arrow of time. Elsewhere, the role of an arrow of time as an assumption leading to Bell’s theorem is downplayed, or completely omitted. An exception is the work of Huw Price, which requires complete time-reversal symmetry. It is argued that the time is ripe to seek mathematical theories in which neither the causal arrow of time nor time-reversal symmetry hold in a strict manner. As an example, the possibility that time-reversal symmetry is broken by a low-entropy-in-the-past condition is considered. For classical theories, those in which the state of the system at one time determines the state at other times, such symmetry-breaking leads to a strict causal arrow of time. For stochastic theories, the situation is less clear, but the emergence of an arrow of time for information is an intriguing possibility. The conclusion is that candidates for a “deeper-level theory” for Quantum Mechanics can only be stochastic theories with a “lenient” causal arrow of time.
MORE (video): https://www.fetzer-franklin-fund.org/med...man-video/
Time to rewrite the textbooks (chemistry)
https://www.chemistryworld.com/opinion/t...71.article
EXCERPT: ‘Scientists are looking to rewrite the textbook’, ‘these results are going to require rewriting the textbooks’, ‘this is textbook-changing stuff’. These paeans to scientific revolution all appeared in press releases over the past few months. With the revisions arriving at such a pace, it’s a wonder that textbooks aren’t recalled the moment they are printed.
‘Rewriting the textbooks’ is one of those clichés that is liberally misapplied in science writing. But it might be appropriate for two recent examples. The first is about slime, the mixture of borax and poly(vinyl alcohol) beloved of science festivals and feared by parents with deep-pile carpets. The second example – rather more highbrow – concerns the mechanism of nucleophilic aromatic substitution reactions. That’s unlikely to fire up the science fair enthusiasts, I admit, but it’s certainly useful in pharmaceutical synthesis.
In both cases, the widely accepted explanations of the chemistry involved have turned out to be wrong – perhaps not radically so, but nevertheless demonstrably incorrect. Although there’s no urgent need to pulp thousands of books, it does seem entirely reasonable to update our guides at the next opportunity.
But should the revision go further than simply replacing an old fact with a new one? Cases like these provide an opportunity to show how the transition happened – and understanding that process should itself be a core part of science education....
MORE: https://www.chemistryworld.com/opinion/t...71.article
https://www.fetzer-franklin-fund.org/med...man-video/
INTRO: The literature on Bell’s theorem includes much discussion of different definitions of locality, e.g., Bell’s locality vs. signal locality, or parameter independence vs. outcome independence. In contrast, Bell’s reviews of the topic identify “locality” with “local causality,” which is a mathematical condition representing the causal arrow of time. Elsewhere, the role of an arrow of time as an assumption leading to Bell’s theorem is downplayed, or completely omitted. An exception is the work of Huw Price, which requires complete time-reversal symmetry. It is argued that the time is ripe to seek mathematical theories in which neither the causal arrow of time nor time-reversal symmetry hold in a strict manner. As an example, the possibility that time-reversal symmetry is broken by a low-entropy-in-the-past condition is considered. For classical theories, those in which the state of the system at one time determines the state at other times, such symmetry-breaking leads to a strict causal arrow of time. For stochastic theories, the situation is less clear, but the emergence of an arrow of time for information is an intriguing possibility. The conclusion is that candidates for a “deeper-level theory” for Quantum Mechanics can only be stochastic theories with a “lenient” causal arrow of time.
MORE (video): https://www.fetzer-franklin-fund.org/med...man-video/
Time to rewrite the textbooks (chemistry)
https://www.chemistryworld.com/opinion/t...71.article
EXCERPT: ‘Scientists are looking to rewrite the textbook’, ‘these results are going to require rewriting the textbooks’, ‘this is textbook-changing stuff’. These paeans to scientific revolution all appeared in press releases over the past few months. With the revisions arriving at such a pace, it’s a wonder that textbooks aren’t recalled the moment they are printed.
‘Rewriting the textbooks’ is one of those clichés that is liberally misapplied in science writing. But it might be appropriate for two recent examples. The first is about slime, the mixture of borax and poly(vinyl alcohol) beloved of science festivals and feared by parents with deep-pile carpets. The second example – rather more highbrow – concerns the mechanism of nucleophilic aromatic substitution reactions. That’s unlikely to fire up the science fair enthusiasts, I admit, but it’s certainly useful in pharmaceutical synthesis.
In both cases, the widely accepted explanations of the chemistry involved have turned out to be wrong – perhaps not radically so, but nevertheless demonstrably incorrect. Although there’s no urgent need to pulp thousands of books, it does seem entirely reasonable to update our guides at the next opportunity.
But should the revision go further than simply replacing an old fact with a new one? Cases like these provide an opportunity to show how the transition happened – and understanding that process should itself be a core part of science education....
MORE: https://www.chemistryworld.com/opinion/t...71.article