An enormous randomized trial of communities in Bangladesh seems to provide the clearest evidence yet that regular mask-wearing can impede the spread of the covid-19 pandemic. The study found that villages where masks were highly promoted and became more popular experienced noticeably lower rates of covid-like symptoms and confirmed past infections than villages where mask-wearing remained low. These improvements were even more pronounced for villages given free surgical masks over cloth masks.

Plenty of data has emerged over the last year and a half to support the use of masks during the covid-19 pandemic, both in the real world and in the lab. But it’s less clear exactly how much of a benefit these masks can provide wearers (and their communities), and there are at least some studies that have been inconclusive in showing a noticeable benefit.

[…]

Last late year, however, dozens of scientists teamed up with public health advocacy organizations and the Bangladesh government to conduct a massive randomized trial of masks—often seen as the gold standard of evidence. And on Wednesday, they released the results of their research in a working paper through the research nonprofit Innovations for Poverty Action.

The study involved 600 villages in a single region of the country with over 350,000 adult residents combined. Similarly matched villages were randomly assigned to two conditions (a pair of villages with similar population density, for instance, would go to one condition or the other). In one condition, the researchers and their partners promoted the use of masks through various incentives between November 2020 and January 2021. These incentives included free masks, endorsements by local leaders, and sometimes financial prizes for villages that achieved widespread mask usage. In two-thirds of the intervention villages, the free masks given were surgical, while one-third were given free cloth masks. In the second condition, the researchers simply observed the villages and did nothing to encourage masks during that time.

Residents in the villages where masks were encouraged did start wearing them more, though no individual nudge or incentive seemed to do better than the others. By the end, about 42% of residents in these villages wore masks regularly, compared to 13% of those in the control group. And in these communities, the odds of people reporting symptoms that may have been covid or testing positive for antibodies to the virus declined.

Overall, the average proportion of people who reported symptoms in the weeks following the mask promotions went down by 11% in these villages compared to the control group, and the average number of people having antibodies went down by over 9%. These differences were larger for surgical mask-wearing villages (12% vs 5% for reducing symptoms) and for residents over 60 (35% for reducing infections for older residents in surgical mask-wearing villages).

Some of this effect might not have come directly from the ability of masks to block transmission of the virus. Those who used masks, the study found, were also more likely to practice social distancing. That’s a relevant finding, the authors note, since some people who have argued against mask mandates do so by claiming that masks will only make people act more carelessly. This study suggests that the opposite is true—that masks make us more, not less, conscientious of others.

[…]

Source: Masks Lead to Less Covid-19, Massive Study Finds

Reddit has finally cracked down on COVID-19 misinformation following growing calls to act, although it probably won’t satisfy many of its critics. The social site has banned r/NoNewNormal and quarantined 54 other COVID-19 denial subreddits, but not over the false claims themselves. Instead, it’s for abuse — NoNewNormal was caught brigading en masse (that is, flooding other subreddits) despite warnings, while the other communities violated a rule forbidding harassment and bullying.

The company didn’t, however, relent on its approach to tackling the misinformation itself. Reddit said it clamps down on posts that encourage a “significant risk of physical harm” or are manipulations intended to mislead others, but made no mention of purging posts or subreddits merely for making demonstrably false claims about COVID-19 or vaccines.

Reddit previously defended its position by arguing its platform was meant to foster “open and authentic” conversations, even if they disagree with a widely established consensus. However, that stance hasn’t satisfied many of Reddit’s users. Business Insider noted 135 subreddits went “dark” (that is, went private) in protest over Reddit’s seeming tolerance of COVID-19 misinformation, including major communities like r/TIFU.

Critics among those groups contended that Reddit let these groups blossom through “inaction and malice,” and that Reddit wasn’t consistent in enforcing its own policies on misinformation and abuse. As one redditor pointed out, Reddit’s claims about allowing dissenting ideas don’t carry much weight — the COVID-19 denial groups are presenting false statements, not just contrary opinions.

[…]

Source: Reddit offers a non-response to uproar over COVID-19 misinformation | Engadget

“It occurred to us that actually a clock is a thermal machine,”[…]Like an engine, a clock harnesses the flow of energy to do work, producing exhaust in the process. Engines use energy to propel; clocks use it to tick.

Over the past five years, through studies of the simplest conceivable clocks, the researchers have discovered the fundamental limits of timekeeping. They’ve mapped out new relationships between accuracy, information, complexity, energy and entropy — the quantity whose incessant rise in the universe is closely associated with the arrow of time.

These relationships were purely theoretical until this spring, when the experimental physicist Natalia Ares and her team at the University of Oxford reported measurements of a nanoscale clock that strongly support the new thermodynamic theory.

[…]

The first thing to note is that pretty much everything is a clock. Garbage announces the days with its worsening smell. Wrinkles mark the years. “You could tell time by measuring how cold your coffee has gotten on your coffee table,”

[…]

Huber, Erker and their colleagues realized that a clock is anything that undergoes irreversible changes: changes in which energy spreads out among more particles or into a broader area. Energy tends to dissipate — and entropy, a measure of its dissipation, tends to increase — simply because there are far, far more ways for energy to be spread out than for it to be highly concentrated. This numerical asymmetry, and the curious fact that energy started out ultra-concentrated at the beginning of the universe, are why energy now moves toward increasingly dispersed arrangements, one cooling coffee cup at a time.

Not only do energy’s strong spreading tendency and entropy’s resulting irreversible rise seem to account for time’s arrow, but according to Huber and company, it also accounts for clocks. “The irreversibility is really fundamental,” Huber said. “This shift in perspective is what we wanted to explore.”

Coffee doesn’t make a great clock. As with most irreversible processes, its interactions with the surrounding air happen stochastically. This means you have to average over long stretches of time, encompassing many random collisions between coffee and air molecules, in order to accurately estimate a time interval. This is why we don’t refer to coffee, or garbage or wrinkles, as clocks.

We reserve that name, the clock thermodynamicists realized, for objects whose timekeeping ability is enhanced by periodicity: some mechanism that spaces out the intervals between the moments when irreversible processes occur. A good clock doesn’t just change. It ticks.

The more regular the ticks, the more accurate the clock. In their first paper, published in Physical Review X in 2017, Erker, Huber and co-authors showed that better timekeeping comes at a cost: The greater a clock’s accuracy, the more energy it dissipates and the more entropy it produces in the course of ticking.

“A clock is a flow meter for entropy,” said Milburn.

They found that an ideal clock — one that ticks with perfect periodicity — would burn an infinite amount of energy and produce infinite entropy, which isn’t possible. Thus, the accuracy of clocks is fundamentally limited.

Indeed, in their paper, Erker and company studied the accuracy of the simplest clock they could think of: a quantum system consisting of three atoms. A “hot” atom connects to a heat source, a “cold” atom couples to the surrounding environment, and a third atom that’s linked to both of the others “ticks” by undergoing excitations and decays. Energy enters the system from the heat source, driving the ticks, and entropy is produced when waste energy gets released into the environment.

The researchers calculated that the ticks of this three-atom clock become more regular the more entropy the clock produces. This relationship between clock accuracy and entropy “intuitively made sense to us,” Huber said, in light of the known connection between entropy and information.

In precise terms, entropy is a measure of the number of possible arrangements that a system of particles can be in. These possibilities grow when energy is spread more evenly among more particles, which is why entropy rises as energy disperses. Moreover, in his 1948 paper that founded information theory, the American mathematician Claude Shannon showed that entropy also inversely tracks with information: The less information you have about, say, a data set, the higher its entropy, since there are more possible states the data can be in.

“There’s this deep connection between entropy and information,” Huber said, and so any limit on a clock’s entropy production should naturally correspond to a limit of information — including, he said, “information about the time that has passed.”

In another paper published in Physical Review X earlier this year, the theorists expanded on their three-atom clock model by adding complexity — essentially extra hot and cold atoms connected to the ticking atom. They showed that this additional complexity enables a clock to concentrate the probability of a tick happening into narrower and narrower windows of time, thereby increasing the regularity and accuracy of the clock.

In short, it’s the irreversible rise of entropy that makes timekeeping possible, while both periodicity and complexity enhance clock performance. But until 2019, it wasn’t clear how to verify the team’s equations, or what, if anything, simple quantum clocks had to do with the ones on our walls.

[…]

The vibrating membrane isn’t a quantum system, but it’s small and simple enough to allow precise tracking of its motion and energy use. “We can tell from the energy dissipation in the circuit itself how much the entropy changes,” Ares said.

She and her team set out to test the key prediction from Erker and company’s 2017 paper: That there should be a linear relationship between entropy production and accuracy. It was unclear whether the relationship would hold for a larger, classical clock, like the vibrating membrane. But when the data rolled in, “we saw the first plots [and] we thought, wow, there is this linear relationship,” Huber said.

The regularity of the membrane clock’s vibrations directly tracked with how much energy entered the system and how much entropy it produced. The findings suggest that the thermodynamic equations the theorists derived may hold universally for timekeeping devices.

[…]

One major aspect of the mystery of time is the fact that it doesn’t play the same role in quantum mechanics as other quantities, like position or momentum; physicists say there are no “time observables” — no exact, intrinsic time stamps on quantum particles that can be read off by measurements. Instead, time is a smoothly varying parameter in the equations of quantum mechanics, a reference against which to gauge the evolution of other observables.

Physicists have struggled to understand how the time of quantum mechanics can be reconciled with the notion of time as the fourth dimension in Einstein’s general theory of relativity, the current description of gravity. Modern attempts to reconcile quantum mechanics and general relativity often treat the four-dimensional space-time fabric of Einstein’s theory as emergent, a kind of hologram cooked up by more abstract quantum information. If so, both time and space ought to be approximate concepts.

The clock studies are suggestive, in showing that time can only ever be measured imperfectly. The “big question,” said Huber, is whether the fundamental limit on the accuracy of clocks reflects a fundamental limit on the smooth flow of time itself — in other words, whether stochastic events like collisions of coffee and air molecules are what time ultimately is.

[…]

Source: The New Science of Clocks Prompts Questions About the Nature of Time | Quanta Magazine

Pfizer’s COVID-19 vaccine is now not only approved for everyone over 16 years old, it’s recommended.

On Monday, an independent advisory committee to the Centers for Disease Control and Prevention voted unanimously to support recommending the vaccine.

The decision of those 14 experts was based on overwhelming evidence that Pfizer’s 2-shot immunization, named Comirnaty, which was fully approved by the Food and Drug Administration last week, is not only safe but also works very well at preventing disease.

The independent experts on the CDC panel cheered on the creation of the COVID-19 vaccines in the midst of a pandemic, calling it a “miraculous accomplishment” and “a moment of incredible scientific innovation.”

Here are eight charts and graphs that lay out why Pfizer’s vaccine was given a big thumbs up:

COVID-19 vaccines are doing a great job keeping people healthy, alive, and out of the hospital.

The CDC committee looked at data from across the US showing unvaccinated adults are being hospitalized for COVID-19 at rates roughly 16 times higher than the vaccinated.

As of August 23, 0.006% of vaccinated Americans (fewer than 9,000 people) have had a severe enough case of COVID-19 to be hospitalized, according to CDC data.

The number of vaccinated people who’ve died from COVID-19 is even smaller. Of the 636,015 American COVID-19 deaths, just 2,063, or 0.3% have been in vaccinated people, a tiny fraction when you consider that more than 174 million people are fully vaccinated in the US.

Unvaccinated people under age 50 are getting hospitalized at especially high rates this year.

The CDC tracks these rates of COVID-19 hospitalizations through COVID-NET, a system which collects data from 250 hospitals across 14 states (located in different areas of the country) every week.

It’s true that more vaccinated people are now catching COVID-19, due to the Delta variant. But their cases are generally mild and the vaccines are still preventing severe disease well.

[…]

Source: CDC shares 8 new charts that show how powerful Pfizer’s vaccine is against COVID-19 and the Delta variant

Over 135 subreddits have gone dark this week in protest of Reddit’s refusal to ban communities that spread misinformation about the COVID pandemic and vaccines.

Subreddits that went private include two with 10 million or more subscribers, namely r/Futurology and r/TIFU. The PokemonGo community is one of 15 other subreddits with at least 1 million subscribers that went private; another 15 subreddits with at least 500,000 subscribers also went private. They’re all listed in a post on r/VaxxHappened which has been coordinating opposition to Reddit management’s stance on pandemic misinformation. More subreddits are being added as they join the protest.

“Futurology has gone private to protest Reddit’s inaction on COVID-19 misinformation,” a message on that subreddit says. “Reddit won’t enforce their policies against misinformation, brigading, and spamming. Misinformation subreddits such as NoNewNormal and r/conspiracy must be shut down. People are dying from misinformation.”

[…]

Last week, the moderators of over 450 subreddits joined an open letter urging Reddit to “take action against the rampant Coronavirus misinformation on their website,” saying that subreddits existing “solely to spread medical disinformation and undermine efforts to combat the global pandemic should be banned.”

Reddit published a response defending its stance, saying it will continue to allow “debate” and “dissent” on vaccines and other COVID-related matters, even when it “challenge[s] consensus views.”

“We appreciate that not everyone agrees with the current approach to getting us all through the pandemic, and some are still wary of vaccinations. Dissent is a part of Reddit and the foundation of democracy,” the company said.

Reddit does draw a line somewhere, as it said it will continue to take action against communities “dedicated to fraud (e.g. fake vaccine cards) or encouraging harm (e.g. consuming bleach).” But in general, Reddit said, “we believe it is best to enable communities to engage in debate and dissent, and for us to link to the CDC wherever appropriate.”

[…]

Source: Reddit’s teach-the-controversy stance on COVID vaccines sparks wider protest | Ars Technica

Encouraging anti-vaxxers would definitely fall under the category of encouraging harm.