Here is the hypothesis: Not so long ago, the very nature of planet Earth suffered a devastating rupture. The break was sudden, global, and irreversible. It happened on a Sunday within living memory. Mick Jagger, Meryl Streep, and Caitlyn Jenner were all born before this crack in time. Vladimir Putin, Liam Neeson, and Mr. T were all born after it.

That idea might soon carry the weight of scientific fact. Later this month, a committee of researchers from around the world will decide whether the Earth sprang into the Anthropocene, a new chapter of its history, in the year 1950. If accepted, this delineation will signal a new reality, that human activities, not natural processes, are now the dominant driver of change on Earth’s surface—that carbon pollution, climate change, deforestation, factory farms, mass die-offs, and enormous road networks have made a greater imprint on the planet than any other force in the past 12,000 years.

In the early 2000s Terry Mitchell’s dentist retired. For a while, Mitchell, an electrician in his 50s, stopped seeking dental care altogether. But when one of his wisdom teeth began to ache, he started looking for someone new. An acquaintance recommended John Roger Lund, whose practice was a convenient 10-minute walk from Mitchell’s home, in San Jose, California. Lund’s practice was situated in a one-story building with clay roof tiles that housed several dental offices. The interior was a little dated, but not dingy. The waiting room was small and the decor minimal: some plants and photos, no fish. Lund was a good-looking middle-aged guy with arched eyebrows, round glasses, and graying hair that framed a youthful face. He was charming, chatty, and upbeat. At the time, Mitchell and Lund both owned Chevrolet Chevelles, and they bonded over their mutual love of classic cars.

Of all the questions that will be answered by the 2020 election, one matters above the others: Is Trumpism a temporary aberration or a long-term phenomenon? Put another way: Will the changes brought about by Donald Trump and today’s Republican Party fade away, or will they become entrenched?

Trump’s reelection seems implausible to many people, as implausible as his election did before November 2016. But despite the scandals and chaos of his presidency, and despite his party’s midterm losses, he approaches 2020 with two factors in his favor. One is incumbency: Since 1980, voters have only once denied an incumbent a second term. The other is a relatively strong economy (at least as of now). Alan Abramowitz, a political scientist at Emory University who weights both of those factors heavily in his election-forecasting model, gives Trump close to an even chance of reelection, based on a projected 2 percent GDP growth rate for the first half of 2020.

Attorney General William Barr released Special Counsel Robert Mueller’s full report on Thursday. Contained therein were the summaries Mueller’s team prepared for the nearly 450-page-long document—presumably, the details he felt were most important for the public to know.

The report details Russian efforts to influence the 2016 election and details 10 episodes the special counsel examined related to obstruction of justice. According to Barr, four types of information have been redacted, related to grand-jury material, the intelligence community’s sources and methods, ongoing cases, and the privacy of “peripheral third parties.”

Below, the summaries as written by the special counsel.

Executive Summary to Volume I

SAN FRANCISCO—The thought I had when the $100 chicken nugget hit my expectant tongue was the one cartoon villains have when they entrap a foreign critter and roast him over a spit: It tastes like chicken.

That’s because it was chicken—albeit chicken that had never laid an egg, sprouted a feather, or been swept through an electrified-water bath for slaughter. This chicken began life as a primordial mush in a bioreactor whose dimensions and brand I’m not allowed to describe to you, for intellectual-property reasons. Before that, it was a collection of cells swirling calmly in a red-hued, nutrient-rich “media,” with a glass flask for an eggshell. The chicken is definitely real, and technically animal flesh, but it left the world as it entered it—a mass of meat, ready for human consumption, with no brain or wings or feet.

What possible reason did Attorney General William Barr have to hold a press conference about Special Counsel Robert Mueller’s report before the report was released?

It was not, based on his brief remarks Thursday morning, to instill public faith in the process, for he did little of that. Nor was it to answer questions from the press, for he did little of that as well—bristling at a few reporters’ questions before tersely exiting the stage.

Instead, Barr seemed most interested in painting President Donald Trump as a victim. Although, as has been endlessly noted, there’s no crime of “collusion,” the attorney general repeatedly used that phrase, echoing the president’s own tweets, both before and during the press conference: “The Special Counsel found no ‘collusion’ by any Americans in the IRA’s illegal activity”; “there was no evidence of Trump campaign ‘collusion’ with the Russian government’s hacking”; “after finding no underlying collusion with Russia.”

In Rwanda, we know what can happen when political leaders and media outlets single out certain groups of people as less than human.

Twenty-five years ago this month, all hell broke loose in my country, which is tucked away in the Great Lakes region of Africa. Hordes of members of the Hutu ethnic majority, armed with machetes, spears, nail-studded clubs, and other rudimentary weapons, moved house to house in villages, hunting for Tutsis, the second largest of Rwanda’s three ethnic groups. The radio station RTLM, allied with leaders of the government, had been inciting Hutus against the Tutsi minority, repeatedly describing the latter as inyenzi, or “cockroaches,” and as inzoka, or “snakes.” The station, unfortunately, had many listeners.

A common, low-stakes living-room scenario: A couple is trying to decide on a movie to watch. There’s an option one-half of the relationship is thrilled about, but the other has already seen it. On those grounds, it’s ruled out.

But a new study suggests that this notion that having already seen it—or read it, done it, visited it—automatically precludes a second go-around might be mistaken. Repeating something, it turns out, “may turn out to be less dull than people think,” writes Ed O’Brien, the author of the study and a behavioral-science professor at the University of Chicago’s Booth School of Business.

In one experiment, O’Brien and his research team approached people near an exhibit on genetics at Chicago’s Museum of Science and Industry, asking them to rate how much they enjoyed the exhibit and how much they think they’d enjoy perusing it again. While the subjects tended to predict that the exhibit would be less fun the second time around, the ones who did another walkthrough at the researchers’ request rated it roughly as enjoyable as the first. In other words, the museumgoers, as a group, underestimated how much they would like doing the same thing twice.

In recent years, some of society’s gender norms have begun to stretch and soften, while others cling fast. For many young boys, there continues to be a very small space that they can occupy to be considered traditionally “masculine,” and that small space can be restricting, forcing boys to lose what doesn’t fit inside it.

In his new book, How to Raise a Boy, Michael Reichert calls that space the “man box.” Reichert is a psychologist who specializes in boys and men, and the founding director of the Center for the Study of Boys’ and Girls’ Lives at the University of Pennsylvania. His book is written as a guide to parents who want to create more space for their boys to express themselves. The key, he writes is “a relationship in which a boy can tell that he matters … A young man’s self confidence is not accidental or serendipitous but derives from experiences of being accurately understood, loved, and supported.”

The brain, supposedly, cannot long survive without blood. Within seconds, oxygen supplies deplete, electrical activity fades, and unconsciousness sets in. If blood flow is not restored, within minutes, neurons start to die in a rapid, irreversible, and ultimately fatal wave.

But maybe not? According to a team of scientists led by Nenad Sestan at Yale School of Medicine, this process might play out over a much longer time frame, and perhaps isn’t as inevitable or irreparable as commonly believed. Sestan and his colleagues showed this in dramatic fashion—by preserving and restoring signs of activity in the isolated brains of pigs that had been decapitated four hours earlier.

The team sourced 32 pig brains from a slaughterhouse, placed them in spherical chambers, and infused them with nutrients and protective chemicals, using pumps that mimicked the beats of a heart. This system, dubbed BrainEx, preserved the overall architecture of the brains, preventing them from degrading. It restored flow in their blood vessels, which once again became sensitive to dilating drugs. It stopped many neurons and other cells from dying, and reinstated their ability to consume sugar and oxygen. Some of these rescued neurons even started to fire. “Everything was surprising,” says Zvonimir Vrselja, who performed most of the experiments along with Stefano Daniele.