Month: November 2022

Enlarge / Where the action happens inside the National Ignition Facility. (credit: Damien Jemison/LLNL)

On Monday, a paper was released that describes some confusing results from the National Ignition Facility, which uses a lot of very energetic lasers focused on a small target to begin a fusion reaction. Over the past few years, the facility has passed some key milestones, including ignition of fusion and creating what's termed a burning plasma.

Now, researchers have analyzed the properties of the plasma as it experiences these high-energy states. And to their surprise, they found that burning plasmas appear to behave differently from those that have experienced ignition. At the moment, there's no obvious explanation for the difference.

Ignition vs. burning

In the experiments at issue here, the material being used for fusion is a mix of tritium and deuterium, two heavier isotopes of hydrogen. These combine to produce a helium atom, leaving a spare neutron that's emitted; the energy of the fusion reaction is released in the form of a gamma ray.

Enlarge / The house wren (Troglodytes aedon ) is a small brown bird found throughout the Americas. A study conducted in Costa Rica revealed that these birds change their song in the city to counteract the effects of noise produced by humans. (credit: Larry Keller, Lititz Pa./Getty Images)

Dawn breaks in San Jose, the capital of Costa Rica. The city is still asleep, but the early risers are greeted by a beautiful symphony: Hummingbirds, corn-eaters, yigüirros (clay-colored thrushes), yellow-breasted grosbeaks, blue tanagers, house wrens, warblers and other birds announce that a new day has arrived.

Soon the incessant noise of vehicles and their horns, construction, street vendors and more take over, shaping the soundscape of the frenetic routine of hundreds of thousands of people who travel and live in this city. Then, the birds’ songs will slip into the background.

“The act of birdsong has two main functions in males: It is to attract females and also to defend their territory from other males,” says Luis Andrés Sandoval Vargas, an ornithologist at the University of Costa Rica. For females in the tropics, he adds, the primary role of their song is to defend territory. Thus, in order to communicate in cities, to keep their territory safe and find mates, birds must find ways to counteract the effects of anthropogenic noise—that is, the noise produced by humans.

Enlarge (credit: Aurich Lawson)

Elon Musk has sent an ultimatum to all Twitter staff—commit to an "extremely hardcore" approach to work or quit your job by Thursday.

"Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore. This will mean working long hours at high intensity. Only exceptional performance will constitute a passing grade," Musk wrote in the all-staff email.

The email's subject line was, "A Fork in the Road."