Author: easyfilo

Enlarge (credit: NASA/STSci)

Today, NASA shared an image indicating that it had successfully completed the image alignment stage of commissioning the James Webb Space Telescope. The Webb’s primary mirror is composed of 18 individual segments, and, as of today’s update, all of those segments are aligned so that a single star shows up as a single object. While there are still several more focusing steps required, the path to commissioning the telescope keeps getting shorter.

Immediately after launch, the focus was on unfolding all the pieces of the telescope that had to be held in a compact configuration to fit inside the launch vehicle. This process included reorienting and extending the primary mirror, lowering the secondary mirror into place, and stretching out the multi-layered sunscreen that helps keep the imaging hardware cold.

To the surprise and delight of many people, that all went incredibly smoothly. Since then, the focus has shifted to… well, focus. The Webb’s primary mirror consists of 18 separate mirrors in a hexagonal array, each of which can be controlled separately. Initially, when the mirror was first unfolded, these produced 18 individual smears scattered across the secondary mirror.

Enlarge / Caltech researchers conducted a study on how the body responds to threats in conjunction with The 17th Door haunted house experience in Orange County, California. (credit: YouTube/17th Door)

The 17th Door haunted house experience has become a fixture of the annual Halloween fright scene in Orange County, California, attracting thousands of scare seekers since it opened in 2014. And now it’s contributing to science, specifically our understanding of how the human body responds to threats differently depending on certain factors, according to a recent paper published in the journal Psychological Science.

As we’ve reported previously, human beings tend to seek out scary movies, horror novels, or haunted houses—and not just during the Halloween season. This tendency has been dubbed “recreational fear” in the academic literature: a “mixed emotional experience of fear and enjoyment.” This new study focuses less on recreational fear specifically and more on gaining a better understanding of the biological systems that are involved with different fear responses in humans, according to lead author Sarah Tashjian, a postdoc in psychology at Caltech.

Mathias Clasen of Aarhus University, author of Why Horror Seduces, conducted his own investigation of two different fear-regulation strategies employed by subjects participating in a Danish haunted house: “adrenaline junkies,” who lean into the fear; and “white-knucklers,” who try to tamp down their fear. A 2020 study from Clasen’s lab found that the scare factor has to be just right in order to achieve that crucial mixed stated (a “Goldilocks zone” or “sweet spot” of subjective enjoyment). Clasen’s core hypothesis is that horror exploits the evolved fear system.

Enlarge / The new standards place most of the country in a state where mask use is optional. (credit: CDC)

In a widely expected move, the Centers for Disease Control and Prevention announced new guidelines for the use of masks and other precautions to limit the spread of COVID-19. While the precautions people should take—vaccinations and mask use—are largely unchanged, the metrics that will trigger changes in suggested precautions will shift from being focused purely on case counts to including information on the severity of cases and hospital capacity.

The move had been hinted at for weeks, and it comes in response to a wide range of pressures. These include the rapidly falling numbers of new cases following the peak of omicron infections earlier this year, changes made in policies at the state level, and a general fatigue regarding pandemic precautions among the public. During a press call announcing the changes, however, CDC head Rochelle Walensky said the agency had been considering the changes for some time.

What’s new

Walensky announced the changes by saying, “We’re in a stronger place today,” before elaborating that this is because, “with widespread population immunity, the overall risk of severe disease is lower.” Given that situation, the CDC has decided to shift the focus of its advice to cases of severe illness and the strain those put on the health care system.

Enlarge / The Reddit iOS app icon. (credit: Getty Images | Yuriko Nakao )

The Reddit mobile app doesn’t often get big updates, but this week was an exception, with the company adding a new “Discover Tab” and menus for managing subscriptions.

In a blog post announcing the feature, Reddit says that one in five users joined at least one new community after using the Discover Tab. Jason Costa, Reddit’s director of product for content and communities, offered the following statement in the blog post:

We’re ushering in a new era of discovery on Reddit, with images and video top of mind. We’re making discovering relevant content and communities more intuitive with the Discover Tab. It’s a great new way for people to explore and engage with hundreds of thousands of communities around the world.

The Discover Tab is now in the top-level app navigation, replacing the communities and subscriptions tab. Tapping it brings you to a scrollable grid list of Reddit content from a variety of subreddits you may not already be following.