In July 2023, Adam Kucharski asked his Twitter followers: What platform do you think you will be spending the most time on a year from now? Like many scientists on Twitter, Kucharski, a mathematical modeler of infectious diseases, was increasingly frustrated with changes to the platform since Elon Musk bought it in October 2022. But of the more than 1300 people who responded to his poll, the vast majority expected to keep posting on Twitter, which was renamed X just 2 weeks later. About one-quarter were banking on Threads, Meta’s Twitter rival. Only about 7% chose Bluesky.
Now, that has changed, in a big way. Although academics mostly stuck with X in the year after the poll, Bluesky has rapidly emerged as the new online gathering place for researchers, Kucharski among them. They are drawn by its Twitter-like feel, welcoming features, and, increasingly, the critical mass of scientists in many fields who have already made the move. “The majority has spoken, and researchers are moving en masse” to Bluesky, says De-Shaine Murray, a neuroscientist at Yale University who has also migrated to Bluesky.
“It’s just gone completely crazy,” says Mike Young, a science communicator in Denmark who gives social media workshops to scientists. He and his colleague Lasse Hjorth Madsen did an analysis in August mapping science communities on Bluesky. They found more than 20,000 influential scientists—people on the platform who were followed by at least 30 other scientists in the same network. When they repeated the analysis last week with an increased threshold of 40 scientist followers, the new number of influential scientists was almost 40,000. It is likely to be many times that now, Young says.
Bluesky started as a research project at Twitter, but after Musk’s takeover it severed all ties with the company and launched as a social app in February 2023. At first, it could only be joined by invitation and growth was slow. When it opened to the public this February, Bluesky had 3 million users. But by 5 November, the day of the U.S. elections, the platform had nearly 14 million users. Two weeks later it has passed 20 million. (X has more than 500 million.)
For scientists the network is starting to look like home. Academic institutions, scientific journals and conferences, and international organizations such as the World Health Organization have established a presence there in recent days. The platform has become so popular that on Monday, Altmetric, a company that tracks where published research is mentioned online, urged publishers to implement a “share to Bluesky” button like those to share content to Facebook, X, or LinkedIn that many websites feature. Many researchers say the atmosphere on Bluesky so far is less polarized than on X, partly because there is more content moderation and the user base is, for now, much smaller and more homogenous. “There is this pent-up demand among scientists for what is essentially the old Twitter,” Young says.
“Old Twitter” refers to the platform’s earlier role as a hub where scientists could talk to one another, distribute and discuss preprints and published papers, post job openings and conference invitations, and communicate their research to the public. “I could go on there for 15 minutes and I would know what the trending papers in infectious diseases and virology were just by looking at the timeline,” says Emory University virologist Boghuma Titanji.
But that all changed with Musk’s takeover of Twitter. “It was obvious within 2 months of his purchase that the algorithm was already skewing against people who post factual, accurate information on climate,” says Katharine Hayhoe, a climate researcher at Texas Tech University. Many researchers say interesting interactions were increasingly obscured by misinformation and hate. “Over the last few years, the experience on Twitter has just become worse and worse,” says Ilan Schwartz, a researcher studying fungal diseases at Duke University.
And yet the shift was slow. Researchers studying online migration emphasize how hard it is for entire communities to move. It usually takes both a push and a pull. In X’s case, there is no shortage of push factors: Among other things, Musk scaled back moderation and fired people charged with making the platform safer, abolished the old system of verification, shuttered researchers’ access to data, and tweaked the algorithm to amplify his own often false and conspiracy-filled tweets. Lies and misinformation about the U.S. elections and major scientific topics including climate change, misinformation research, and infectious diseases flourished on the platform.
Yet other platforms appeared to exert little pull for many researchers. Many scientists tried and abandoned Mastodon, LinkedIn, and Threads. In a preprint published earlier this year, Pennsylvania State University data scientist Sarah Rajtmajer and her colleagues followed more than 7500 academics who used Mastodon from just after Musk acquired Twitter until 1 year later. They found that every month between 10% and 20% of the scholars stopped using the platform. X, with its vast network of researchers, exerted a gravitational pull that drew them back. “In the end you just didn’t want to miss out, you didn’t want to actually leave Twitter,” she says. As a result, “The migration failed.”
But some things may now be working to Bluesky’s advantage versus other platforms. For one, many researchers with huge followings on X had already established a similar presence on Bluesky without using it much, a recently published paper found, possibly because of the similarities in the two platforms, according to Ujun Jeong, a computer scientist at Arizona State University and one of the study’s authors. “Interestingly, people with more influence actually wanted to migrate more,” he says. And the ones who established a presence on Bluesky were more likely to keep it and X going at the same time. That may have resulted in a large community of researchers ready to shift.
Anastasia Bizyaeva, an engineer at Cornell University, says the trend reminded her of the dynamics she studies, called behavioral cascades, where a system that has reached a certain threshold can suddenly shift. In a school of fish, for example, a few individuals might notice a predator and change their behavior, “and then suddenly, there’s this really fast transition where the whole network reacts.”
Bluesky has eased migration by offering hundreds of “starter packs,” curated lists of people to follow in different fields. For instance, it took Titanji 5 to 6 years to find the people she really wanted to follow on Twitter, she says. But on Bluesky, she has found three-quarters of them in about 1 week.
Some early adopters of the platform also laid the groundwork for specific communities to thrive, Murray says. One user, Rudy Fraser, started blacksky, a collection of Black-centered feeds that uses volunteer and automated moderation to filter out racist posts, for instance, and neuropharmacologist Monica Javidnia helped build the neuroscience community on Bluesky. “Many of us are getting to reap the benefits of [such] work,” Murray says.
Not everyone supports the flight to bluer skies. “Some people feel like we’re ceding ground to disinformation and we’re abandoning the people that need to have voices countering misinformation,” Schwartz says. Tulio de Oliveira, an infectious disease researcher based in South Africa, is staying put. “I am staying on X, because I believe that it is important to still have scientific views and information on the platform.”
Chanda Prescod-Weinstein, a particle physicist and writer at the University of New Hampshire, understands that concern. “I do see why some people focused on public health and the environment might feel they have to stay and try,” she says. But with X’s changing algorithms, “It is pretty difficult to challenge disinformation and get in front of the eyes of people who are susceptible to it.”
Most researchers leaving X are keeping their accounts there for now, in part to keep their usernames from being taken up by others and used to spread more misinformation. Hayhoe says she occasionally logs into X, mostly to invite some remaining colleagues to move to Bluesky. The last time she checked, half her messages were from people saying they had abandoned ship, she says. “It’s a ghost town.”
More: https://www.science.org/content/article/old-twitter-scientific-community-finds-new-home-bluesky
