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New clarity in visualizing quantum realm + Toxic tide of ship breaking + Cracks in GR

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In search of cracks in Albert Einstein’s theory of gravity
https://www.quantamagazine.org/in-mexico...-20220223/

INTRO: During a solar eclipse in 1919, Arthur Eddington observed light bending around the sun just as predicted by general relativity, Albert Einstein’s new theory of gravity. Since then, general relativity, which says that massive objects like stars warp the fabric of space-time around them, has passed increasingly precise tests. A year rarely goes by without a new experiment or observation confirming Einstein’s theory. But there’s a hitch.

Invisible substances known as dark matter and dark energy seem to make up some 95% of the content of the universe. The working assumption is that dark matter consists of nonluminous elementary particles, and that dark energy is the energy of space itself. But it’s also possible that they are illusions that appear because gravity works differently from how Einstein thought about it. “We’re invoking these mysterious things,” said the cosmologist Celia Escamilla-Rivera.“I am strongly convinced that alternative theories of gravity are needed.”

Escamilla-Rivera is searching for another, more complete theory. A bewildering array of alternatives to general relativity have been put forward over time, from “teleparallel gravity” to “complex quintessence” and “negative-mass cosmology,” but they long seemed like theoretical fancies. With cosmologists unable to create experiments that can distinguish these theories from general relativity, the ideas have gathered dust.

According to Escamilla-Rivera, that’s beginning to change in this new era of precision cosmology, a field she is pioneering in her home country of Mexico. Precision cosmology combines large and diverse data sets with new statistical methods, machine learning and supercomputers. “Thanks to this data you can open a door and classify all these theories and say which ones work and which ones don’t,” she said.

By scouring the early universe and the extreme environments of black holes, Escamilla-Rivera thinks we can find cracks in general relativity, which will make way for something else. This isn’t conventional wisdom among cosmologists, but Escamilla-Rivera’s path to becoming a cosmologist hasn’t been conventional either... (MORE - details)


Princeton scientists achieve new clarity in visualizing the quantum realm
https://www.princeton.edu/news/2022/02/2...ntum-realm

RELEASE: Princeton physicists have peered deeper than ever before into the quantum realm of electrons — and what they are seeing is providing greater insight into how electrons behave collectively.

In a paper recently published in Science, a team led by Ali Yazdani describes how the strong interactions between electrons in graphene, a material with a single layer of carbon atoms, drive them to form a crystal structure with a complex pattern determined by what’s known as quantum superposition — electrons residing at multiple atomic sites at the same time.

“Previous studies have shown that graphene demonstrates novel electrical properties,” said Yazdani, the Class of 1909 Professor of Physics and director of the Center for Complex Materials at Princeton University. “But never before have researchers been able to peer so deeply and with such spatial resolution into the nature of quantum states.”

This pattern corresponds to a structure first recognized in the 1860s by chemist August Kekulé, with alternating single and double bonds. In a single bond, one electron from each atom binds with its neighbor electron; in a double bond, two electrons from each atom participate.

The experiment also shows that this novel quantum crystal hosts exotic deformations that correspond to the twisting and winding of electrons’ wavefunction.

In one remarkable finding, “they found a ‘vortex’ in the Kekulé pattern, which is like a hurricane around which the phase-angle winds around by 12 hours [as on a clock],” said Michael Zaletel of the University of California, Berkeley, a co-author on the paper. “When making predictions about such quantum, nanoscale, objects, you rarely think you’ll have the pleasure to really ‘see’ a picture of them, but the group has been able to do just that.”

This item has been abridged from the full story available on the Dean for Research website.


ship breaking (wikipedia): Ship-breaking (also known as ship recycling, ship demolition, ship dismantling, or ship cracking) is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap.
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The toxic tide of ship breaking (chemistry)
https://www.chemistryworld.com/features/...58.article

EXCERPT: . . . Alang, and other harbours like it in Gadani, Pakistan, and Chittagong, Bangladesh, is home to shipbreakers. Although such recycling should be a green activity, the International Labour Office considers it one of the most dangerous jobs in the world, fraught with chemical peril – and one whose pollutants are damaging both the local environment and the communities living nearby.

The scale of the operation is massive, explains Ingvild Jenssen, executive director of Shipbreaking Platform, a non-governmental organisation that polices ship recycling. ‘Every year, around 800 large ocean-going vessels get broken down. About 75% of them end up in one of the three beaches in South Asia,’ Jenssen explains. In terms of tonnage being scrapped, however, the three countries deal with 90% of the world total.

These ships bring a host of dangers. Workers are routinely exposed to carcinogens including polychlorinated biphenyls (PCBs), polyvinyl chloride, polyaromatic hydrocarbons (PAHs), tributyltin compounds, mercury, lead, isocyanates and sulfuric acid. Asbestos is another major risk: on average, each ship contains seven tonnes of the material – all of which ends up being removed by hand. In 2015, a study from Taiwan looked at population data from 4427 shipbreaking workers and found that, from 1985 to 2008, 940 had died of cancer, with 436 more developing various forms of the disease; those with the highest exposure to asbestos were more likely than the general population to develop cancer overall, particularly of the oesophagus, liver, trachea and lungs.

‘When you’re torch-cutting a vessel, the anti-fouling paints, which contain large amounts of heavy metals, will also heat up and release toxic fumes,’ Jenssen adds. ‘You’ve got PCBs, ozone-depleting substances, and many residue oils that may cause gases to explode. You’ll have people torch-cutting in a vessel that catches fire, and workers being trapped in areas that they can’t escape.’

These dangers don’t just affect the dockworkers themselves, says Soumya Haldar, senior principal scientist at the Central Salt & Marine Chemicals Research Institute in Bhavnagar, India, who is responsible for independent environmental assessments of Alang’s ship recycling. Before he started work in 2001, there had been no baseline measurements to determine the industry’s impact. ‘The main pollutants are residual oil, oxyacetylene gas from cutting, as well as iron and other metals,’ he says. As the crafts are beached – flooding the hulls at high tide – these substances are washed into the surrounding area. ‘Another important issue is ballast water, which the ships take on from other countries,’ Haldar explains. Although this is released before the ship is broken up, there may be sediment containing exotic species that could affect the local ecology. His studies of ballast sediments have yet to find any invasive species.

The ships themselves are only part of the problem. ‘The pollution is not only coming from the recycling facilities,’ says Jenssen. ‘It’s also from the steel mills that are rewelding the steel afterwards, without proper filters to reduce emissions. The downstream waste management infrastructure is also sorely lacking in these areas – even the asbestos will be resold.’ Bangladesh, Jenssen adds, has no capacity in the entire country to manage the hazardous materials its shipyards work with on a daily basis.

This combination of activities can have a severe impact on air quality.... (MORE - missing details)
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