During the flyby, Parker Solar Probe passed into and out of the corona several times. This is proved what some had predicted — that the Alfvén critical surface isn’t shaped like a smooth ball. Rather, it has spikes and valleys that wrinkle the surface. Discovering where these protrusions line up with solar activity coming from the surface can help scientists learn how events on the Sun affect the atmosphere and solar wind.
Six panels of images taken from inside a coronal streamer. They appear grayish with white streaks showing particles in the solar wind.
At one point, as Parker Solar Probe dipped to just beneath 15 solar radii (around 6.5 million miles) from the Sun’s surface, it transited a feature in the corona called a pseudostreamer. Pseudostreamers are massive structures that rise above the Sun’s surface and can be seen from Earth during solar eclipses.
Passing through the pseudostreamer was like flying into the eye of a storm. Inside the pseudostreamer, the conditions quieted, particles slowed, and number of switchbacks dropped — a dramatic change from the busy barrage of particles the spacecraft usually encounters in the solar wind.
For the first time, the spacecraft found itself in a region where the magnetic fields were strong enough to dominate the movement of particles there. These conditions were the definitive proof the spacecraft had passed the Alfvén critical surface and entered the solar atmosphere where magnetic fields shape the movement of everything in the region.
The first passage through the corona, which lasted only a few hours, is one of many planned for the mission. Parker will continue to spiral closer to the Sun, eventually reaching as close as 8.86 solar radii (3.83 million miles) from the surface. Upcoming flybys, the next of which is happening in January 2022, will likely bring Parker Solar Probe through the corona again.
The video above provides a great overview of the origins, objectives, and motivations for the mission.
The YouTube channel Two Minute Papers enthusiastically shares the findings from scientific papers about technology: computing, graphics, AI, robotics, etc. Recently they reviewed this paper on simulating the growth of large-scale plant ecosystems based on real-world forestry and botany research. From the paper’s abstract:
In this paper we describe a multi-scale method to design large-scale ecosystems with individual plants that are realistically modeled and faithfully capture biological features, such as growth, plant interactions, different types of tropism, and the competition for resources. Our approach is based on leveraging inter- and intra-plant self-similarities for efficiently modeling plant geometry. We focus on the interactive design of plant ecosystems of up to 500K plants, while adhering to biological priors known in forestry and botany research.
What that means, as they show in the video, is that you can watch these incredibly detailed time lapse videos of forests developing over time in a realistic way. So cool. This kind of thing always reminds me of favorite childhood thing, Al Jarnow’s Cosmic Clock. (via waxy)
Mathematics isn’t the most obviously cinematic academic discipline out there, but it is one that the movies (and to a lesser extent television) have repeatedly tried to understand, or in some cases, used to goose up a vaguely science-y story. Unsurprisingly, mathematicians often become sticklers for detail in such high-profile depictions of what they do, and a good or bad portrayal can become famous or infamous.
My friend Jordan Ellenberg, a math professor at the University of Wisconsin-Madison, is also an expert in translating math to popular audiences, in his books and sometimes on screen. In this video, he takes a look at some popular representations of math in TV and the movies, and tries to explain what’s going on, including what the filmmakers do well or not so well.
Good Will Hunting’s use of math is famously bad, and Ellenberg unsurprisingly agrees (although, surprisingly, he had never before seen the movie or even the math scenes in question). Portrayals that get a perhaps-surprisingly high score include The Simpsons (which includes several former mathematicians among its writers) and Jurassic Park — Jeff Goldblum pulls off a passable explanation of chaos theory while also eerily accurately capturing the slightly-creepy vibe of a neurotic academic asked to describe what he studies to a layperson. “He was the one who I most felt might have spent a long time studying mathematicians and truly trying to give off a mathematician vibe,” says Ellenberg.
One thing I love is Ellenberg’s attention to how each of the on-screen mathematicians write (if they do any writing themselves at all, rather than ponder something that’s already been written by a character offscreen) — the connection between math and writing is so powerful, and math is one of the great remaining repositories of manuscript culture (even as it’s also taken on computers and machines, like everything else).
Ellenberg also adds that the most important thing a movie about mathematics can do is to convey to the audience that being a mathematician is something real, ordinary people still do, rather than being just a bunch of old dead men wearing robes.
How do you steer a bike? You turn the handlebars to the left to go left, correct? Actually, you don’t: you turn the handlebars to the right to go left…at least at first. And also? Bikes don’t even need riders to remain upright…they are designed to steer themselves.
Last week, a worrisome variant of SARS-CoV-2 burst into the public consciousness: the Omicron variant. The concern among scientists and the public at large is substantial, but it is unfortunately going to take a few weeks to figure out whether those concerns are warranted. For a measured take on what we know now and what we can expect, read thesetwo posts by epidemiologist Dr. Katelyn Jetelina (as well as this one on vaccines).
B.1.1.529 has 32 mutations on the spike protein alone. This is an insane amount of change. As a comparison, Delta had 9 changes on the spike protein. We know that B.1.1.529 is not a “Delta plus” variant. The figure below shows a really long line, with no previous Delta ancestors. So this likely means it mutated over time in one, likely immunocompromised, individual.
Of these, some mutations have properties to escape antibody protection (i.e. outsmart our vaccines and vaccine-induced immunity). There are several mutations association with increased transmissibility. There is a mutation associated with increased infectivity.
That sounds bad but again, we presently do not have enough information to know for sure about any of this. As Jetelina concludes in one of the posts:
We still have more questions than answers. But we will get them soon. Do not take Omicron lightly, but don’t abandon hope either. Our immune systems are incredible.
None of this changes what you can to do right now: Ventilate spaces. Use masks. Test if you have symptoms. Isolate if positive. Get vaccinated. Get boosted.
Whether or not Omicron turns out to be another pandemic gamechanger, the lesson we should take from it (but probably won’t) is that grave danger is lurking in that virus and we need to get *everyone* *everywhere* vaccinated, we need free and ubiquitous rapid testing *everywhere*, we need to focus on indoor ventilation, we need to continue to use measures like distancing and mask-wearing, and we need to keep doing all of the other things in the Swiss cheese model of pandemic defense. Anything else is just continuing our idiotic streak with this virus of fucking around and then finding out. (via jodi ettenberg & eric topol)
In this video, whale scientist Nan Hauser tells the story about how a humpback whale she was swimming with saved her from what she calls “the largest tiger shark I’ve ever seen”. It turns out this is not atypical behavior for humpbacks — they’re one of the nicest animals in the sea or on land and have been known to rescue animals from other species from predators.
First-person accounts of animals saving other animals are rare. Robert Pitman, a marine ecologist with the US National Oceanic and Atmospheric Administration, describes a pivotal encounter he witnessed in Antarctica in 2009. A group of killer whales washed a Weddell seal they were attacking off an ice floe. The seal swam frantically toward a pair of humpbacks that had inserted themselves into the action. One of the huge humpbacks rolled over on its back and the 180-kilogram seal was swept up onto its chest between the whale’s massive flippers. When the killer whales moved in closer, the humpback arched its chest, lifting the seal out of the water. And when the seal started slipping off, the humpback, according to Pitman, “gave the seal a gentle nudge with its flipper, back to the middle of its chest. Moments later, the seal scrambled off and swam to the safety of a nearby ice floe.”
Is this behavior in humpbacks altruistic or even compassionate? Or is it “just” instinct?
So are humpbacks compassionate? Scientists, Sharpe tells me, shy away from using the same descriptors we use for humans. “What is exciting about humpbacks is that they are directing their behavior for the benefit of other species,” he says. “But there’s no doubt there are important differences between human compassion and animal compassion.” When I pose the same question to Pitman he concurs. “No editor is going to let me use the word compassion. When a human protects an imperiled individual of another species, we call it compassion. If a humpback whale does so, we call it instinct. But sometimes the distinction isn’t all that clear.”
Somehow, I missed the teaser trailer for Don’t Look Up a couple months back, but the official trailer just came out yesterday. Directed by Adam McKay (The Big Short, Vice) and starring Leonardo DiCaprio & Jennifer Lawrence (and Meryl Streep, Jonah Hill, Mark Rylance, Cate Blanchett, Tyler Perry, and Timothée Chalamet), Don’t Look Up is a comedy about what happens when scientific fact (in the form of a planet-killing comet) slams into the fantasy worlds of politics and entertainment media. Just because you can’t spin Newton’s laws of motion doesn’t mean you can’t try!
Nothing, absolutely nothing whatsoever, about this movie is related to current events, nope, no sir. *sobbing intensifies* (I love disaster movies and will 100% see this even though it will probably be completely enraging.)
I have been a fan of how things are made videos since my Mister Rogers and Sesame Street days, so I was not expecting to be so surprised watching the video above about how bowling balls are made. It’s a ball — how complicated could it be? Well, it turns out that modern bowling balls contain an asymmetric weight block in the middle that looks a little like a car’s starter. Weird, right?
As I started to wonder why it would be advantageous to include such a lopsided core in a ball you want to roll predictably down a lane, I noticed YouTube’s algorithm doing its job in recommending that I watch Veritasium’s recent video on How Hidden Technology Transformed Bowling, which totally explains the wonky weight block thing:
The weight blocks are wonky in a precise way. They’re designed to cause the ball to contact the lane over more of the surface of the ball, giving it more traction once it hits the unoiled part of the lane, which is desirable for expert bowlers looking for a wicked hook. So cool! (thx, mick)
Update: Brendan Koerner wrote a piece for Wired several months ago about Mo Pinel, who revolutionized bowling with the asymmetric cores described in the video above.
Pinel toured Faball’s factory and examined a freshly made core that the company used in its Hammer brand. It had a symmetrical and unexciting shape — the center looked like a lemon, and there were two convex caps of equal size on either side. In a moment that has now passed into ball-design legend, Pinel grabbed the core, which was still soft because the polyester had yet to cure, and sliced off the ends with a palette knife. Then he smooshed the caps back on into positions that were slightly askew, so that the contraption now looked like a Y-wing fighter from Star Wars.
The ball that contained this revamped core, the Hammer 3D Offset, would become Pinel’s signature achievement. “That ball sold like hotcakes for three years, where the average life span of a ball was about six months,” says Del Warren, a former ball designer who now works as a coach in Florida. “They literally couldn’t build enough of them.” In addition to flaring like few other balls on the market, the 3D Offset was idiot-proof: The core was designed in such a way that it would be hard for a pro shop to muck up its action by drilling a customer’s finger holes incorrectly, an innovation that made bowlers less nervous about plunking down $200 for a ball.
The result is a highly entertaining, tongue-in-cheek short paper in the journal Travel Medicine and Infectious Disease. The paper details 007’s exposure risk to infectious agents during his global travels, covering everything from foodborne pathogens to ticks and mites, hangovers and dehydration from all those martinis, parasites, and unsafe sex.
Some of the findings include that 007 should wash his hands more often, frequently risks dehydration and heatstroke due to improper hydration, often engages in unsafe sex with partners whose sexual histories are unknown to him, and endangers his sexual partners (“27.1% of them died shortly after sex”). My favorite finding is the speculation that Bond contracted Toxoplasmosis1 from a cat in From Russia With Love and that’s why he engages in risky behavior all the time:
The biggest stretch in Graumans et al.’s analysis is that of feline-borne Toxoplasmosis, a parasite carried by cats. Those who contract the parasite tend to exhibit reckless behavior, such as mice losing their fear of cats. Bond engages in all manner of reckless behavior, and the authors suggest he may have contracted the parasite from Ernst Stavro Blofeld’s fluffy white Persian cat (featured in both From Russia With Love and Spectre). The possibility is admittedly far-fetched, but isn’t that the essence of a good Bond film?
I will take any opportunity to remind you of one of my favorite things I’ve ever posted: a short talk by Kevin Slavin about how the Toxoplasma gondii may be responsible for viral videos.↩
A team of scientists looked at wood found at the L’Anse aux Meadows Viking site. In three cases the trees had been physically cut down, and moreover, they were clearly cut with metal tools — Vikings had metal implements at the time, but indigenous people did not. The wood was all from different trees (one was fir, and another juniper, for example). The key parts here are that the wood was all from trees that had been alive for many decades, and all had their waney edge intact as well.
The scientists extracted 127 samples from the wood, and 83 rings were examined. They used two methods to secure dates. The first was to compare the amount of carbon-14 in each ring with known atmospheric amounts from the time. This gives a rough date for the waney edge of the wood. They also then looked for an anomalous spike in carbon-14 in an inner ring, knowing this would have come from the 993 A.D. event, and then simply counted the rings outward from there to get the date of the waney edge.
In all three samples the waney edge was dated to the same year: 1021 A.D. This would be incredibly unlikely to occur at random.
Outstanding science. It’s incredible how much of a time machine these analysis tools are. There’s so much we don’t know about people who lived 1000 years ago, but it’s astounding that we know anything at all, particularly precise dates like this.
Based on the development stages of certain cells in the waney layer, Dee, Kuitems, and their colleagues say that one of the trees was cut down in the spring, while another was cut down in the summer or fall. The third tree’s final season couldn’t be identified because the cells had been damaged by a conservation treatment, but the results suggest that the Norse cut down these trees within a few months of each other in 1021.
That lends additional support to the other evidence that the Norse only stayed in Newfoundland for a few years.
“One would imagine the dates would have been different if the occupation period of the site was very long,” Dee told Ars. “However, the fact all three of our samples produced the same date does not, of course, mean the site was only occupied for one year. It may indeed have been occupied longer. But I think it is true to say our results support a short occupation.”
For the last nine months, NASA’s Perseverance rover has been rolling around on Mars taking photos and doing science. It’s also been recording audio of its environment with a pair of microphones and in this video, a pair of NASA scientists share some of those recordings and what we might learn about Mars from them.
This is one of my absolute favorite sounds. This is the sound of a helicopter flying on Mars. We used this sound to actually understand the propagation of sound in general through the Martian atmosphere, and it turns out that we were totally wrong with our models. The Martian atmosphere can propagate sound a lot further than we thought it could.
And surprisingly for me, that’s my friend Nina in the video! (We eclipse-chased together in 2017.) I knew she was working on the rovers but didn’t know she was going to pop up in this video I found on Twitter this morning. Fun!
The fossil record has provided us with so much information about plants, animals, and organisms that lived hundreds, thousands, millions, and even billions of years ago. But we are actually only seeing evidence of a tiny fraction of the species that lived then and even for those we do know about, there’s often much we still don’t know. Traditionally, dinosaurs have been depicted as drab and often terrible lizards but recent finds of soft tissues (skin, feathers, etc.) and an increased sense of imagination based on our current vibrant biodiversity has people thinking differently about how they looked and behaved.
In trying to explain what you’re about to see here, I cannot improve upon the Dr. Adrian Smith’s narration at the beginning of this video:
But sometimes I think the most useful thing I can do as a scientist is to point the fancy science cameras at some moths flapping their wings in front of a purple backdrop. I mean, whose day isn’t going to be better after watching a pink and purple rosy maple moth flying in super slow motion? This is a polyphemus moth, a gigantic species of silk moth. What you are seeing, like all the rest of the clips in this video, was filmed at 6,000 frames per second.
Most of the moths in the video are delightfully fuzzy and chonky — if these moths were birds, they’d be birbs. Shall we call them mopfs?
From 2019 to 2021, a small Spanish football team was renamed Flat Earth FC, both as a publicity stunt and because club president Javi Poves couldn’t understand how water “curves”.
“Football is the most popular sport and has the most impact worldwide, so creating a club dedicated to the flat earth movement is the best way to have a constant presence in the media,” said Poves earlier this year. “Flat Earth FC is the first football club whose followers are united by the most important thing, which is an idea.”
The club’s crest is now a circular image of the earth, pressed flat on to all kits, and fans are encouraged to spark regular conversations in their pursuit of answers from the powers that be. The team mascot? An astronaut. It’s a radical move, but the club is bringing in supporters from afar. “It’s really amazing to be part of this amazing movement,” says Flat Earth player Mario Cardete. “I think it’s more than a club.”
During the pandemic, the club also became anti-mask and anti-vax — because conspiracy theories come in price-saving 3-packs, I guess? Poves resigned in late 2020 and the club was renamed and then purchased by a larger club to become their reserve team. The Earth remains round.
So let’s say, for the sake of argument and against all scientific evidence to the contrary, the Earth was flat instead of being an oblate spheroid. What would life on a flat Earth be like? Well for one thing, gravity would present some challenges. From a 2018 piece by Doug Main at the Columbia Climate School:
People who believe in a flat Earth assume that gravity would pull straight down, but there’s no evidence to suggest it would work that way. What we know about gravity suggests it would pull toward the center of the disk. That means it would only pull straight down at one point on the center of the disk. As you got increasingly far from the center, gravity would tug more and more horizontally. This would have some strange impacts, like sucking all the water toward the center of the world, and making trees and plants grow diagonally, since they develop in the opposite direction of gravity’s pull.
And even more than that, gravity would tend to pull a flat disc shape back into a spheroid, so absent an intense spinning force (for which there is zero evidence) or some other completely unknown effect, a flat Earth couldn’t even exist:
For Earth to take the shape of a flat disk in the first place, gravity — as we know it — must be having no effect. If it did, it would soon pull the planet back into a spheroid.
A flat Earth would also likely not have a magnetic field (or at least one that is scientifically possible), meaning no atmosphere:
Deep below ground, the solid core of the Earth generates the planet’s magnetic field. But in a flat planet, that would have to be replaced by something else. Perhaps a flat sheet of liquid metal. That, however, wouldn’t rotate in a way that creates a magnetic field. Without a magnetic field, charged particles from the sun would fry the planet. They could strip away the atmosphere, as they did after Mars lost its magnetic field, and the air and oceans would escape into space.
Oh and no tectonic plates, volcanos, mountains, etc. Or GPS. Or weather. Or satellites. Or different night skies in, say, South Africa and Denmark. Or the Sun behaving the way it does in respect to the Earth. Or air travel. Or plant and animal life as it exists presently. To suppose a flat Earth also supposes that physics doesn’t explain our observable universe the way in which it reliably and comprehensively does. The simplest, best evidence for a round Earth is that we’re here living on it in the manner in which we are living on it.
Train wheels do not sit completely flat on the tracks — they’re designed with a slight taper that increases the stability of the train and allows the train to go around curves without any of the wheels skidding. In this short video, Tadashi Tokieda explains how those conical wheels keep trains on track.
Ed Yong: We’re Already Barreling Toward the Next Pandemic. The US is throwing too little money at high-tech, ultimately private sector solutions but much of the problem comes down to our underfunded public health system and “profoundly unequal society”.
“To be ready for the next pandemic, we need to make sure that there’s an even footing in our societal structures,” Seema Mohapatra, a health-law expert at Indiana University, told me. That vision of preparedness is closer to what 19th-century thinkers lobbied for, and what the 20th century swept aside. It means shifting the spotlight away from pathogens themselves and onto the living and working conditions that allow pathogens to flourish. It means measuring preparedness not just in terms of syringes, sequencers, and supply chains but also in terms of paid sick leave, safe public housing, eviction moratoriums, decarceration, food assistance, and universal health care. It means accompanying mandates for social distancing and the like with financial assistance for those who might lose work, or free accommodation where exposed people can quarantine from their family. It means rebuilding the health policies that Reagan began shredding in the 1980s and that later administrations further frayed. It means restoring trust in government and community through public services. “It’s very hard to achieve effective containment when the people you’re working with don’t think you care about them,” Arrianna Marie Planey, a medical geographer at the University of North Carolina at Chapel Hill, told me.
Within the past 50 years, the global community has solved two huge problems that had the potential to harm every person on Earth. Smallpox once killed 30% of the people who contracted the disease but through the invention of an effective, safe vaccine and an intense effort that began in the 1960s, smallpox was completely eradicated by 1980. In the 1980s, scientists discovered a hole in the ozone layer that protects the Earth from UV radiation; further depletion would have caused major problems with the world’s food supply and an epidemic of skin cancer. Forty years later, we’ve virtually eliminated the chemicals causing the depletion and ozone losses have stabilized and have recently shown improvement.
So how did we do it? The short video above talks through each of challenges, how they were met (science + politics + a bit of luck), and how we might apply these lessons to the big problems of today (climate emergency, the pandemic).
In one of their most popular videos in awhile, kottke.org favorite Kurzgesagt tells us about something I’d never heard of before: giruses. These giant viruses have only been discovered within the last 20 years and are so large and contain so much genetic material that maybe they are actually alive?
Hidden in the microverse all around you, there is a merciless war being fought by the true rulers of this planet, microorganisms. Amoebae, protists, bacteria, archaea and fungi compete for resources and space. And then there are the strange horrors that are viruses, hunting everyone else. Not even being alive, they are the tiniest, most abundant and deadliest beings on earth, killing trillions every day. Not interested in resources, only in living things to take over. Or so we thought.
It turns out that there are giant viruses that blur the line between life and death — and other viruses hunting them.
It may seem like sometimes that with the pandemic, we’re back to square one. With the much more contagious Delta variant in play and an increasing number of breakthrough infections, the efficacy of these vaccines that we thought were amazing maybe aren’t? (Or maybe we just need to readjust our expectations?) But in terms of what these vaccines were specifically developed for — reducing & preventing severe disease and death — they are still very much doing their job. Just take a look at this graph from a White House Covid-19 press briefing yesterday:
Even with Delta endemic in the country, the vaccines are providing extraordinary protection against infections severe enough to land folks in the hospital. In a recent CDC study of infections and hospitalizations in Los Angeles County, they report that on July 25, the hospitalization rate of unvaccinated people was 29.2 times that of fully vaccinated persons. 29 times the protection is astounding for a medical intervention. These vaccines work, we’re lucky to have them, and we need to get as many people worldwide as we can vaccinated as quickly as we can. Period.
I love this post from the NYPL comparing astronomical drawings by E.L. Trouvelot done in the 1870s to contemporary NASA images.
Trouvelot was a French immigrant to the US in the 1800s, and his job was to create sketches of astronomical observations at Harvard College’s observatory. Building off of this sketch work, Trouvelot decided to do large pastel drawings of “the celestial phenomena as they appear…through the great modern telescopes.”
He made drawings of Saturn, Jupiter, aurora borealis, the Milky Way, and more. Here’s his incredible drawing of sun spots compared to a recent image of the Sun’s surface:
And his drawing of a solar eclipse compared to a recent image:
Unfortunately, communal benefit is harder to define, harder to quantify, and harder to describe than individual protection, because “it’s not the way Americans are used to thinking about things,” Neil Lewis, a behavioral scientist and communications expert at Cornell, told me. That’s in part because communal risk isn’t characteristic of the health perils people in wealthy countries are accustomed to facing: heart disease, stroke, diabetes, cancer. Maybe that’s part of why we gravitate toward individual-focused comparisons. Slipping into a pandemic-compatible, population-based frame of mind is a big shift. In the age of COVID-19, “there’s been a lot of focus on the individual,” Lewis told me. That’s pretty at odds “with how infection works.”
As someone who has struggled with analogizing the virus & vaccines, I was nodding my head a lot while reading this. Something I’ve noticed in recent years that Wu didn’t get into is that readers desire precision in metaphors and analogies, even though metaphor is — by definition! — not supposed to be taken literally. People seem much more interested in taking analogies apart, identifying what doesn’t work, and discarding them rather than — more generously and constructively IMO — using them as the author intended to better understand the subject matter. The perfect metaphor doesn’t exist because then it wouldn’t be a metaphor.
One of the many effects of human-driven climate change is that, on average, the bodies of animals are getting smaller — birds, fish, deer, frogs, rodents, insects. And these changes could have large and unpredictable consequences.
“That’s the problem with human-driven climate change. It’s the rate of change that’s just orders of magnitude faster than what the natural world has had to deal with in the past. Size is really important to survival, and you can’t just change that indefinitely without consequence. For one thing, I don’t think it’s feasible that species are going to be able to continue to get smaller and maintain things like a migration from one hemisphere to another.”
And since smaller bodies can hold fewer eggs, they result in fewer offspring, and a lower population size in the long run. For amphibians who need to keep their skin wet in order to breathe, shrinking can mean higher chances of drying out in a drought because their bodies absorb and hold smaller quantities of water.
But the more concerning consequences have to do with how this could destabilize relationships between species. Because shrinking plays out at different rates for different species, predators might have to eat more and more of shrinking prey, for example, throwing a finely-tuned ecosystem off balance.
I’m just going to go ahead and say it right up front here: if you had certain expectations in May/June about how the pandemic was going to end in the US (or was even thinking it was over), you need to throw much of that mindset in the trash and start again because the Delta variant of SARS-CoV-2 has changed the game. I know this sucks to hear,1 but Delta is sufficiently different that we need to reset and stop assuming we can solely rely on the vaccines to stop Covid-19 from spreading. Ed Yong’s typically excellent piece on how delta has changed the pandemic’s endgame is helping me wrap my head around this.
But something is different now — the virus. “The models in late spring were pretty consistent that we were going to have a ‘normal’ summer,” Samuel Scarpino of the Rockefeller Foundation, who studies infectious-disease dynamics, told me. “Obviously, that’s not where we are.” In part, he says, people underestimated how transmissible Delta is, or what that would mean. The original SARS-CoV-2 virus had a basic reproduction number, or R0, of 2 to 3, meaning that each infected person spreads it to two or three people. Those are average figures: In practice, the virus spread in uneven bursts, with relatively few people infecting large clusters in super-spreading events. But the CDC estimates that Delta’s R0 lies between 5 and 9, which “is shockingly high,” Eleanor Murray, an epidemiologist at Boston University, told me. At that level, “its reliance on super-spreading events basically goes away,” Scarpino said.
In simple terms, many people who caught the original virus didn’t pass it to anyone, but most people who catch Delta create clusters of infection. That partly explains why cases have risen so explosively. It also means that the virus will almost certainly be a permanent part of our lives, even as vaccines blunt its ability to cause death and severe disease.
And a reminder, as we “argue over small measures” here in the US, that most of the world is in a much worse place:
Pandemics end. But this one is not yet over, and especially not globally. Just 16 percent of the world’s population is fully vaccinated. Many countries, where barely 1 percent of people have received a single dose, are “in for a tough year of either lockdowns or catastrophic epidemics,” Adam Kucharski, the infectious-disease modeler, told me. The U.S. and the U.K. are further along the path to endemicity, “but they’re not there yet, and that last slog is often the toughest,” he added. “I have limited sympathy for people who are arguing over small measures in rich countries when we have uncontrolled epidemics in large parts of the world.”
Where I think Yong’s piece stumbles a little is in its emphasis of the current vaccines’ protection against infection from Delta. As David Wallace-Wells explains in his piece Don’t Panic, But Breakthrough Cases May Be a Bigger Problem Than You’ve Been Told, vaccines still offer excellent protection against severe infection, hospitalization, and death, but there is evidence that breakthrough infections are more common than many public health officials are saying. The problem lies with the use of statistics from before vaccines and Delta were prevalent:
Almost all of these calculations about the share of breakthrough cases have been made using year-to-date 2021 data, which include several months before mass vaccination (when by definition vanishingly few breakthrough cases could have occurred) during which time the vast majority of the year’s total cases and deaths took place (during the winter surge). This is a corollary to the reassuring principle you might’ve heard, over the last few weeks, that as vaccination levels grow we would expect the percentage of vaccinated cases will, too — the implication being that we shouldn’t worry too much over panicked headlines about the relative share of vaccinated cases in a state or ICU but instead focus on the absolute number of those cases in making a judgment about vaccine protection across a population. This is true. But it also means that when vaccination levels were very low, there were inevitably very few breakthrough cases, too. That means that to calculate a prevalence ratio for cases or deaths using the full year’s data requires you to effectively divide a numerator of four months of data by a denominator of seven months of data. And because those first few brutal months of the year were exceptional ones that do not reflect anything like the present state of vaccination or the disease, they throw off the ratios even further. Two-thirds of 2021 cases and 80 percent of deaths came before April 1, when only 15 percent of the country was fully vaccinated, which means calculating year-to-date ratios means possibly underestimating the prevalence of breakthrough cases by a factor of three and breakthrough deaths by a factor of five. And if the ratios are calculated using data sets that end before the Delta surge, as many have been, that adds an additional distortion, since both breakthrough cases and severe illness among the vaccinated appear to be significantly more common with this variant than with previous ones.
Vaccines are still the best way to protect yourself and your community from Covid-19. The vaccines are still really good, better than we could have hoped for. But they’re not magic and with the rise of Delta (and potentially worse variants on the horizon if the virus is allowed to continue to spread unchecked and mutate), we need to keep doing the other things (masking, distancing, ventilation, etc.) in order to keep the virus in check and avoid lockdowns, school closings, outbreaks, and mass death. We’ve got the tools; we just need to summon the will and be in the right mindset.
In a tweet introducing his piece, Yong says “Many folks are upset & confused by the last month” and that’s right where I am with this. Maybe you are too. I’m expecting to get angry email about this post, calling it alarmist. But Covid is different now and thinking our same March 2021 thoughts about it isn’t going to help ourselves, our families, or our communities. The sooner we can regroup, the better.↩
In the first part of a multi-video series on how the human immune system works, Kurzgesagt describes how the system’s first lines of defense work when your body is invaded by microorganisms.
The human immune system is the most complex biological system we know, after the human brain, and yet, most of us never learn how it works. Or what it is. Your immune System consists of hundreds of tiny and two large organs, it has its own transport network spread throughout your body. Every day it makes hundreds of billions of fresh cells.
It is not some sort of abstract entity. Your immune system is YOU. Your biology protecting you from the billions of microorganisms that want to consume you and from your own perverted cells that turn into cancer.
Black holes are the largest single objects in the universe, many times larger than even the biggest stars, and have no upper limit to their size. But practically, how big is the biggest, heaviest black hole in the universe? (A: More massive than the entire Milky Way.)
The largest things in the universe are black holes. In contrast to things like planets or stars they have no physical size limit, and can literally grow endlessly. Although in reality specific things need to happen to create different kinds of black holes, from really tiny ones to the largest single things in the universe. So how do black holes grow and how large is the largest of them all?
Videos about space are where Kurzgesagt really shines. I’ve seen all their videos about black holes and related objects, and I always pick up something I never knew whenever a new one comes out. This time around, it was quasistars and the surprisingly small mass of supermassive black holes located at galactic centers compared to the galaxies themselves.
As I’ve written before, in the history of astronomy and astrophysics, women have made major discoveries and played a significant role in advancing our understanding of the universe but have often not gotten the recognition their male peers enjoy. In 1967, while she was working on her doctoral research with her advisor Antony Hewish, Jocelyn Bell Burnell (then Jocelyn Bell) discovered a new and unusual kind of object, the pulsar. In this short documentary, Bell Burnell shares her story — how she got interested in radio astronomy, the prejudice with which she was treated as the only woman in her university program, how she discovered the first pulsar and persisted (more than once) through Hewish’s assertions that the object was “interference”, and how she was passed over for the Nobel Prize for her discovery.
In 2018, Bell Burnell was awarded the Special Breakthrough Prize in Fundamental Physics “for fundamental contributions to the discovery of pulsars, and a lifetime of inspiring leadership in the scientific community”, joining past honorees like the LIGO team, Stephen Hawking, and the team that discovered the Higgs boson. She donated the entire $3 million prize to the Institute of Physics to help support “PhD physics students from under-represented groups” with their educations.
This piece by Susan Matthews is really helpful for those of us who are vaccinated and trying to figure out what their risks are regarding the much more transmissible delta variant of SARS-CoV-2. Covid-19 is endemic now — how do we live with that? What reasonable actions should we take to keep ourselves, our communities, and our loved ones safe?
All of this is making people — yes, probably mostly vaccinated people — rethink the basic questions they thought their vaccine had answered for them: Can I go to restaurants and bars unmasked? Can I go back to the office? Can I see my grandma? Can I go on vacation? Can I unmask at my people-facing job? Can I have a wedding, or a party? The answer to those questions is not quite as easy as “yes, if you’re vaccinated.” It depends partly on how many in your group are vaccinated, but the actual answer is basically the same as it’s been all pandemic: It depends on your risk tolerance, it depends on what is happening with case counts locally (though, as more people travel, this might become a less reliable tool), and it depends on any unique risk factors in your group. Kass’ perspective felt novel to me: She said she suspects that in the end, a lot of people are going to end up boosting their immunity by suffering through a mild case of COVID. So no one should feel that bad about getting sick after they’re vaxxed. What matters is getting the order right: “If everyone who gets vaccinated still gets COVID but doesn’t die, that’s a success,” she said. The issue is that it doesn’t feel like a success for vaccinated people. Plus, “if you get infected after you’re vaxxed, it’s all you talk about,” she said. And right now, that’s understandably freaking out a lot of vaccinated people who thought they were in the clear.
Well, this is really quite odd. A group of scientists discovered that if they cool ordinary oily droplets floating in water down to around 2-8°C, they change shape, grow tentacles, and propel themselves around like tiny little sci-fi creatures.
Some of the particles’ facets grow while other shrink, producing a variety of geometrical forms such as kites, isosceles triangles and spiked tetrahedra. Then, from some of the sharp corners emerge tentacle-like strands, as if being extruded from a nozzle. As they grow, the strands bend into undulating shapes — and the droplets start to swim, propelled through the fluid by the tentacles’ extension.
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