The day US president Donald Trump was sworn into office, an article from Motherboard about the scrubbing of all references to climate change on the White House website made its way onto Reddit. The story, posted to the subreddit for US politics, swiftly garnered more than 76,000 points as the upvotes rolled in.

“I’m starting to think I should get together with some colleagues and see if we can get some letter written and signed,” commented a Reddit user with the handle retardcharzard, who said he worked in a lab where a colleague was studying global warming’s effect on frogs, and near others studying the effects on butterflies. “This isn’t just about jobs to us, if we cared about money we wouldn’t be in this field in the first place. This is about the future of every organism on earth, many that haven’t even been born yet. We have to fight.”

The first reply to that comment came from a user called beaverteeth92: “There needs to be a Scientists’ March on Washington.”

User after user concurred, pleading for someone with organizational skills follow through on the idea.

The movement took off like subatomic particles in the Large Hadron Collider. As the Washington Post recounted in January (paywall), Jonathan Berman, a postdoctoral fellow at the University of Texas Health Science Center San Antonio, was among the scientists on the Reddit thread inspired to take their own internet action. Through social media, Berman, a microbiologist who studies cell signaling, connected with Caroline Weinberg, a physician with a masters in public health, and Valorie Aquino, an anthropology doctoral candidate at the University of New Mexico, to organize their fellow science devotees. Together they created a private Facebook group and Twitter presence focused on the cause, along with an official website for the march and a Google form for volunteers.

For a group stereotyped as infinitely objective and unflappable, scientists have been notably impassioned in their response to Trump’s election, fueled by anger over the new administration’s promise of funding cutbacks, pollution-promoting policies, and political interference with research findings. Even before Trump took office, scientists were taking to the streets, marching in San Francisco in December, for instance, to support climate research.

Trump’s anti-science rhetoric has continued in his first months in office. He has proposed massive cuts to federal research budgets and put a climate change-denier, Scott Pruitt, in charge of the Environmental Protection Agency (EPA). Trump also pushed for an immigration ban that caused foreign scientists working in the US to question their place in the country and prompted European labs to open their doors for stranded scientists.

Meanwhile, the private Facebook group sparked by that first Reddit thread allowed members to invite their friends, and the page exploded. In early February, administrators created a public page for the march. Three weeks later, the march organizers announced that they had received support from over 50,000 volunteers who coordinated almost 300 marches in total—a number that would rise further—with the support of 27 partner groups. The partners included the American Association for the Advancement of Science (AAAS), the largest scientific society in the world, with 120,000 members in 91 countries. Other heavy hitters, such as the Union of Concerned Scientists, a nonprofit in support of science-supported policy, joined in. The number of organizations lending support skyrocketed to over 250, including groups not primarily focused on science, like the Hindu American Foundation, the National Association of Social Workers, and the National Association for Transgender Equality.

Just three months after the initial suggestion on Reddit, thousands of scientists, teachers, journalists, and prominent science advocates like Bill Nye the “Science Guy” will attend more than 600 Marches for Science scheduled to take place globally on April 22—Earth Day.

Though the protests may appear political in nature—and the planned participation of partisan groups has caused disagreements among organizers and potential attendees who worry the march will be too political—the point being made by many of those who will be marching is that science should be a non-partisan issue, with research supported and facts accepted no matter who occupies the oval office.

Marches on the Mall

The similarities to the Women’s March on Washington—and its sister marches globally—are hard to miss. Demonstrators for the women’s marches, held in the day after Trump’s inauguration in January, showed up in massive numbers (paywall) following a call that originated on social media (on a spontaneous, election-night Facebook page created by a woman in Hawaii) for the largest political march in US history. Women organized themselves to march in favor of gender equality, but also human rights in general, which many felt were under threat by the Trump administration.

The Women’s March drew veteran protestors, but it also featured a lot of first-time marchers—many of whom have said they plan to stay involved, and possibly run for office. Scientists, it seems, have been similarly inspired. Estimates suggest that the March for Science will draw thousands of participants, many of whom have never ventured into advocacy. And already there are new groups dedicated to helping scientists break into politics.

Scientists are typically reticent to become involved in a political movements; they tend to prefer evidence-based work over partisanship. Historically, that wasn’t a problem. The objective value of research was one thing that both Democrats and Republicans generally agreed on, especially when viewed in the context of infrastructure. But federal support for scientific endeavors have increasingly come under threat. That’s not just because of Trump—US president George W. Bush tended to ignore scientific evidence (paywall), too—but the new administration’s disregard for expert opinion and loose handle on the truth (remember “alternative facts?”) has lent a new sense of urgency to the problem.

From the first days of Trump’s presidency, scientists have proven surprisingly spunky, organizing takeovers of government social media accounts or rescuing data they feared would be wiped from government web pages, for instance. But the April 22 protests will mark their biggest action yet. In Washington, the rally will begin at 9am ET on the Mall east of the Washington Monument. At 2pm, marchers will proceed along Constitution Avenue, and to the front of the Capitol building.

It’s safe to assume that coverage of the event, and the hundreds of satellite protests planned, will be all over the internet, where the whole idea for the march began.