TikTok is an app for making and sharing short videos. The videos are tall, not square, like on Snapchat or Instagram’s stories, but you navigate through（浏览)videos by scrolling up and down, like a feed, not by tapping or swiping side to side. Video creators have all sorts of tools at their disposal: filters as on Snapchat (and later, everyone else); the ability to search for sounds to score your video. Users are also strongly encouraged to engage with other users, through “response” videos or by means of “duets” — users can duplicate videos and add themselves alongside.

Hashtags play a surprisingly large role on TikTok. In more innocent times, Twitter hoped its users might congregate around hashtags in a never-ending series of productive pop-up mini-discourses. On TikTok, hashtags(话题标签)actually exist as a real, functional organizing principle: not for news, or even really anything trending anywhere else than TikTok, but for various “challenges,” or jokes, or repeating formats, or other discernible blobs of activity.

TikTok is, however, a free-for-all. It’s easy to make a video on TikTok, not just because of the tools it gives users, but because of extensive reasons and prompts it provides for you. You can select from an enormous range of sounds, from popular song clips to short moments from TV shows, YouTube videos or other TikToks. You can join a dare-like challenge, or participate in a dance meme, or make a joke. Or you can make fun of all of these things.

TikTok assertively answers anyone’s what should I watch with a flood. In the same way, the app provides plenty of answers for the paralyzing what should I post? The result is an endless unspooling of material that people, many very young, might be too self-conscious to post on Instagram, or that they never would have come up with in the first place without a nudge. It can be hard to watch. It can be charming. It can be very, very funny. It is frequently, in the language widely applied outside the platform, from people on other platforms, extremely “cringe”.

Time to unfriend Facebook?

For the past 18 months, communicating the findings of science to the world has hit what sometimes seems like an all-time low. Never mind the years of failure in convincing much of the public about climate change; the pandemic has revealed shocking ineptness(拙劣)by the scientific establishment at conveying messages about masks, vaccination, or the dangers of consuming horse drugs and aquarium cleaners—even in the face of a rising death toll from COVID-19. One puzzling element of this crisis is how social media has been skillfully exploited by antiscience forces. Given all of this, what is the right move for science communication as it relates to social media? Unfriend Facebook or beat it at its own game?

A few months ago, New York Times reporters Cecilia Kang and Sheera Frenkel published An Ugly Truth: Inside Facebook’s Battle for Domination, in which they explored how the world’s largest social network, Facebook, fills its coffers by exploiting the viral spread of misinformation while trying to convince everyone of its noble mission to connect the world. Kang told me that she believes the algorithms and business practices of Facebook and other social media companies that encourage misinformation erect huge barriers, keeping people from paying attention to authoritative scientific information. Her ideas for combating this begin with understanding two kinds of misinformation that propagate through these powerful social networks. One is the news that is blatantly wrong. These posts are sometimes taken down but mostly flagged by Facebook’s algorithms with a disclaimer, which most people ignore. This has only a minor effect on stopping their spread. Kang sees an even bigger problem: the misinformation that arises from conversational posts among individuals. This kind of informal misinformation is frustrating because it’s not easy to police the people you know from saying crazy things on Facebook. The result is that both kinds of misinformation tend to rise to the top of Facebook’s news feeds because they get more engagement than posts about recent research findings reported in scholarly scientific articles or even in the mainstream press.

Communicating about research in real time is hard because science is always a work in progress, with caveats and answers that are not always definitive. That doesn’t translate well to social media or Facebook’s algorithms that determine which posts to promote. “Oftentimes that kind of content just does not work well in terms of engagement,” Kang said, “because it’s not the kind of stuff that people will immediately try to share.” The antiscience opposition doesn’t care about the caveats. Kang pointed out that “super figures” on social media, such as Ben Shapiro and Dan Bongino, have built up a loyal following of people who will believe them no matter what.

As tempting as it may be for frustrated scientists to simply delete their Facebook accounts and avoid this dreck, Kang believes that a better approach for them is to engage more aggressively by being “out there,” competing for people’s attention by the same rules. Refusing to play hardball on the social media field is not serving science or society well. The pandemic has seen the rise of numerous scientists on Twitter who have amassed relatively large followings, but their presence on Facebook is much smaller. Although Twitter is a powerful platform for political messages that get liked and retweeted, people tend to trust individuals they know on Facebook, making it powerful for changing hearts and minds. To do battle in this arena, science will need to find its own super figures who can compete directly with the Shapiros and Bonginos of the antiscience world. Some of these new figures might be practicing scientists, and some might be science communicators. What is crucial is a knack for cutting through the caveats and conditions and forcefully conveying the bottom line. Like their opponents, they need to be adept at strategically exploiting the algorithms that can push a post to the forefront or bury it in the never-ending racket.

Since the end of World War II, scientists have stick to the idea that if they stay objective and state the science, then the rest of the world will follow. As the pandemic cycles on, it’s time to face the fact that this old notion is naive.

Revealing the source of Jupiter’s x-ray auroral flares

Abstract

Jupiter’s rapidly rotating, strong magnetic field provides a natural laboratory that is key to understanding the dynamics (动力学) of high-energy plasmas (等离子体). Spectacular auroral (极光的) X-ray flares (耀斑) are diagnostic of the most energetic processes governing magnetospheres but seemingly unique to Jupiter. Since their discovery 40 years ago, the processes that produce Jupiter’s X-ray flares have remained unknown. Here, we report simultaneous (同时的) in situ satellite and space-based telescope observations that reveal the processes that produce Jupiter’s X-ray flares, showing surprising similarities to terrestrial ion aurora. Planetary-scale electromagnetic waves are observed to modulate (调节) electromagnetic ion cyclotron waves, periodically causing heavy ions to precipitate and produce Jupiter’s X-ray pulses. Our findings show that ion aurorae share common mechanisms across planetary systems, despite temporal, spatial, and energetic scales varying by orders of magnitude.

INTRODUCTION

Aurorae, observed from planetary polar regions across the solar system, are displays of light that are produced when energetic particles precipitate along magnetic field lines and transfer their energy to the atmosphere. Jupiter’s soft x-ray aurorae are produced by energetic [~ (MeV) (电子伏)] heavy ions (S and O), originally from the moon Io’s (木卫一的) volcanic activities. The dynamic X-ray emissions often pulse with a regular beat of a few tens of minutes. The spectacular quasi-periodic (准周期性的) auroral pulsations at Jupiter have also been observed in ultraviolet (UV), infrared, and radio emissions. The X-ray aurorae are predominately confined (主要局限于) to the region poleward of Jupiter’s main aurora, connecting to Jupiter’s outer magnetosphere via magnetic field lines. The mapping of the emissions leads to the suggestion that the particle precipitations were driven by magnetic reconnection. However, observations show that the x-ray pulsations last for several Jupiter days or longer, evidencing that the driver may not be a transient process like magnetic reconnection.

To date, 40 years after their discovery, the mechanisms that cause these X-ray aurorae remain unknown. Simultaneous measurements of the magnetospheric environment and the auroral emissions are critical to revealing their driving mechanisms. Here, we present observations of Jupiter’s unique x-ray aurorae with simultaneous in situ measurements from the magnetosphere. In this study, we reveal the physical driver for Jupiter’s pulsating x-ray emissions by analyzing simultaneous in situ measurements from Juno and remote spectroscopic imaging by XMM-Newton telescope (XMM，牛顿卫星) during 16 and 17 July 2017. XMM’s European Photon Imaging Camera (EPIC-pn and MOS) instruments provided spatial, spectral, and timing data of Jupiter for a continuous 26-hour (~2.6 Jupiter rotations) observation from 18:26 UT on 16 July to 22:13 UT on 17 July, which was shifted to account for the ~46-min light travel time between Jupiter and Earth. This XMM observation was planned to coincide with the time when NASA’s Juno spacecraft was moving from 62 to 68 RJ (1 RJ = 71 492 km) radially away from the planet in the Southern Hemisphere in the predawn sector between ~0400 and 0430 magnetospheric local time (MLT).

Ionosphere-magnetosphere (电离层) mapping from previous observations suggested that the origins of Jupiter’s X-ray auroral pulsations occurred at these distances from the planet. Juno provided contemporaneous (同时发生的) in situ measurements from the plasma sheet only when Jupiter’s north magnetic pole tilted to Earth. Therefore, we focus on the northern aurora, for which Juno’s in situ measurements detail what was happening in the plasma sheet during the X-ray pulses. At Jupiter, the analysis of these comparisons between in situ and remote sensing observations is more complex than at Earth. At Earth, during the time scale of an auroral event, typically tens of minutes, a spacecraft in the terrestrial magnetosphere usually travels little (e.g., hundreds of kilometers) in comparison to the spatial scale of a magnetospheric event (e.g., several Earth radii) that would cause a large auroral brightening so that this in situ spacecraft could be magnetically connected to the aurora region over the full auroral lifetime. This is not true for Jupiter, because the footprint of the aurora (which is rotating with Jupiter) with respect to Juno’s location changes substantially during an observation. There are also substantial travel times (a few tens of minutes) along the magnetic field expected from the outer magnetosphere to the Jovian aurora. Therefore, the correlation between a single outer magnetosphere event in Jupiter’s in situ measurements and a single auroral pulse cannot be expected on a one-to-one level basis. Instead, a series of successive events are required to draw reliable careful correlations, with the regular periodicity of the x-ray flares, providing an invaluable diagnostic signature of the source process.

(Adapted from an essay on Science.)