tingilinde

eye strain and blue light filtering glasses

They probably don't work, but there are other tricks.

 

interesting signs

 

a tip of the hat to Sarah

 

cheering on an american senator

 

 

how invars work

This has bothered me for some time.  Why don't some alloys (specifically invars) expand when heated?  Now a neat potential answer.

snip

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"It's almost unheard of to find metals that don't expand," says Stefan Lohaus, a graduate student in materials science and lead author of the new paper. "But in 1895, a physicist discovered by accident that if you combine iron and nickel, each of which has positive thermal expansion, in a certain proportion, you get this material with very unusual behavior."

That anomalous behavior makes these alloys useful in applications where extreme precision is required, such as in the manufacture of parts for clocks, telescopes, and other fine instruments. Until now, no one knew why Invars behave this way. In a new paper published in Nature Physics, researchers from the lab of Brent Fultz, the Barbara and Stanley R. Rawn, Jr., Professor of Materials Science and Applied Physics, say they have figured out the secret to at least one Invar's steadiness.

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runners and drafting

The power required to overcome air resistance goes as the cube of the speed relative to the wind.  At fast running paces it's appreciable and for things like 100 meter sprits, the limiting factor.  Drafting is common in marathons and a few papers have been written on strategies.  The good studies are doing in wind tunnels as it's far too difficult computationally given the wildly changing area and coefficient of drag of the main runner and the wake of the pacers. Greg points to a new one .. sadly paywalled. 

from the abstract

Drafting is a strategy in marathon running races that reduces the drag force acting on a designated runner. Drafting involves a formation of athletes, called pacers, running in front of (and sometimes behind) the designated runner. The present experiments evaluated complex formations involving up to seven pacers with the aim of enhancing the performances of an elite marathoner. Wind tunnel measurements with 1/10 scale articulated runner manikins were carried out. First, simple formations with one or two pacers were examined and the results were compared with previous investigations. Second, the runner formations of the Nike Breaking2 and INEOS 1:59 Challenge events whose goal was to break the 2 h marathon barrier were studied. The main finding was the identification of three complex formations of six and seven pacers that allow a drag-force reduction of about 60% with respect to a solo runner and an estimated time saving of 262 s. These results point to how it may be possible to run the fastest marathon ever.

 

a strike victim

Amazon cancels Peripheral despite having renewed it. Many others, particularly the expensive ones, will probably follow.

a tip of the hat to John

 

 

 

intellectual rigor

Not a strong suit of many rightwing judges.

There is a strong hate for the idea of women as people.

 

 

p vs np and on to meta-complexity

Believe it or not, a well-written non-specialist piece on meta-complexity.

sno[

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t seems that proving that computational problems are hard to solve is itself a hard task. But why is it so hard? And just how hard is it? Carmosino and other researchers in the subfield of meta-complexity reformulate questions like this as computational problems, propelling the field forward by turning the lens of complexity theory back on itself.

“You might think, ‘OK, that’s kind of cool. Maybe the complexity theorists have gone crazy,’” said Rahul Ilango, a graduate student at MIT who has produced some of the most exciting recent results in the field.

By studying these inward-looking questions, researchers have learned that the hardness of proving computational hardness is intimately tied to fundamental questions that may at first seem unrelated. How hard is it to spot hidden patterns in apparently random data? And if truly hard problems do exist, how often are they hard?

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a segmentation of the gop

Segmentations are always tricky, but here's one from the NY Times. 

I worry that it mostly ignores the authoritarianism buy-in.

 

 

 

going beyond teaching just the science part of science

Science has a large impact on society, but you wouldn't know it from how it's taught.  Comments on the subject as well as noting perhaps the only country in the world that tries to get it right. 

snip

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We live in a time when misinformation, including scientific misinformation, is deliberately constructed and circulated. The age of misinformation is coupled with substantial present and future societal challenges such as environmental pollution and more jobs being at risk of automation with the advent of artificial intelligence. The COVID-19 pandemic has taught us in no subtle terms that to protect ourselves and others, we need to understand who produces, validates, and shares scientific knowledge in the community, and how the solutions to problems proposed by scientists may be mediated by economic and political dynamics. When scientific evidence is beyond the grasp of the public—which is very often the case—deciphering whose science to believe in and why necessitates that students appreciate the personal, the social, and the institutional dynamics of science.

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