When the pandemic hit, Kirsten Banks missed speaking to audiences. A physics PhD student at the University of New South Wales in Australia, she was used to giving educational astronomy talks regularly at elementary and secondary schools and at public events. When those engagements were canceled, she turned to social media to continue her science outreach.
“I started doing science communication on social media by joining Twitter and making a Facebook page and an Instagram page,” Banks says. Then her partner introduced her to TikTok.
TikTok launched internationally in 2017. In contrast to Twitter, which features mostly written text, and Instagram, which consists primarily of images, TikTok users can post only short videos. If Twitter is like writing a pithy summary, TikTok is akin to giving a short, catchy talk with audiovisual aids. The platform is most popular with teenagers and young adults; in a survey conducted earlier this year, nearly half of US adults ages 18–29 reported using the service, compared with 22% of those 30–49 and 4% of people 65 and over.
TikTok features a wide variety of content, largely jokes and viral trends in which a video template is copied by many users. There are also educational videos, including about science. An array of filters enables users to add various visual effects; they can also add a soundtrack, such as a popular song or audio they create themselves. TikTok’s green-screen feature allows them to create their own backgrounds as well.
One distinguishing feature of TikTok is the way viewers discover content. Unlike Facebook and Twitter, where users see posts made, liked, or commented on by the people they follow or friend, TikTok is constantly recommending new content to its users. When a user watches or interacts with a video, TikTok puts similar content into their feed. As a result, TikTok viewers are continually being introduced to new creators. “The great thing with TikTok versus other platforms like Twitter and Instagram is your video can really go to anyone,” Banks says. “The possibilities to really take off are highest on TikTok.”
Motivated to join because of the dearth of science content, Banks created a TikTok account and began posting videos shortly after. Now she has more than 300 000 followers, and her content is available to audiences across the globe who probably would not have come across it on other social media platforms. Her videos regularly get tens of thousands of “likes” from viewers.
“My absolute favorite video that I made is the one . . . [where] I’m holding up pictures of the planets, one by one, and spinning,” Banks says, “slowly for the rocky planets and then fast for the gas giant planets,” to represent each planet’s rate of rotation. “Then, when it comes to Uranus, because its rotation is actually tilted, I roll on the floor. I really enjoyed making that one.”
@astrokirstenThe spinning of the Earth really makes my day 😜 #planets #solarsystem #spinmeround #spinmerightround #astronomy #dizzy #spacethings #learnfromme♬ You Spin Me Round – Reflections
Clara Nellist, a particle physicist at Radboud University in the Netherlands and at CERN, launched a TikTok account in January because she didn’t see many particle physicists or anyone from CERN on the platform. Nellist’s account gained popularity after she made a casual video introducing herself. “I think I got 50 000 followers in about three days,” she says. “Part of the reason that video took off,” she came to realize, “is because [TikTok users] like authenticity.” Today she has about 130 000 followers. “What I’ve learned is that the platform likes just peeking into people’s worlds and finding out things in a short way,” she says. Her goal is to help her followers “know a little bit more than they did before.”
Originally the platform limited videos to a minute in length; it now allows posts up to three minutes long. Although that extra time enables communicators to better explain their concepts, TikTok users still expect brevity; a longer video risks people scrolling away before it is over. “If you can take the most important and simple bits of information that you can about a topic and put it in a one-minute video, you’re going to get the most viewers,” says Sophia Gad-Nasr, a physics PhD student at the University of California, Irvine, who has about 1600 followers on TikTok and more than 65 000 on Twitter. “The audiences that you get on TikTok have very short attention spans, so you’re probably not going to get that many people watching your entire three-minute video.”
TikTok creators can reply to comments made on their videos with a new video, which allows more personal interactions with viewers than a simple text-based reply. Science communicators often use that feature to address questions that require in-depth answers. For example, in Banks’s recent video showing how Jupiter looks in different wavelengths of light, a TikTok user asked if Jupiter is considered a failed star. Banks made a response video, linked to that comment, in which she answered the question (no) and discussed brown dwarfs.
Memes—joke templates that are repeatedly used and slightly altered to fit a wide variety of situations—are another effective way to connect with audiences. On other social media platforms, memes generally take the form of images or phrases, but on TikTok they are sounds or video effects. “The reason memes are popular is because it’s shared knowledge,” Nellist says. “It feels like an inside joke with millions of people.”
One of Nellist’s recent posts employs a trending visual effect (it’s been used in more than 150 000 videos) of a creature running from an eagle. Nellist captioned her video “POV: protons in the Large Hadron Collider at #CERN.” Many of the comments on that post include laughing emojis. Banks hopped aboard a trend that uses a line from the superhero movie The Incredibles to promote the accomplishments of women creators. A soundtrack of the character Elastigirl saying “Girls, come on. Leave the saving of the world to the men? I don’t think so. I don’t think so” accompanies images of Banks using telescopes, speaking on a science panel, and appearing on a magazine cover.
Science communicators on TikTok face the same challenge as those on other platforms: fighting widespread misinformation. When Nellist joined, she encountered conspiracy-theory videos about CERN, including those created by popular accounts. In a now-deleted video, a TikTok user with more than 3.5 million followers said that “the Large Hadron Collider could destroy the world any day now!” To refute those claims, Nellist made two one-minute response videos in which she “stitches” the original content: Her videos start with a clip of the misleading video, followed by an explanation of why the high-energy collisions at CERN don’t create black holes or rip apart spacetime.
Nellist says that a global community has formed among the scientists on TikTok. They support one another’s work by sharing videos and pointing their viewers to others’ accounts. Furthermore, the creators can learn from one another. Nellist says she gets “inspiration and understanding from the great work they’re doing.”