(Jia Naqvi/The Washington Post)

Tens of thousands of people across the planet marched for science on Saturday. The first-ever March for Science was a pro-science and political event, according to the march organizers, but not a partisan one. But in Washington, as the crowd streamed down Constitution Avenue, several marchers broke away from the pack. They clustered by a plaque that read, “United States Environmental Protection Agency,” snapping smiling photos. As the march passed the EPA headquarters, some began to chant, “Ho, ho, hey, hey, I support the EPA.” Other chanters took up a briefer slogan, announcing to the world that EPA administrator Scott Pruitt “sucks.”

The Washington march was one of some 600 rallies held in the United States and across the globe. Regina McCarthy, Pruitt's predecessor who worked under the Obama administration, addressed a rally at Boston Common. “As Americans, as New Englanders, as Boston Strong — we care about our natural world!” McCarthy said, the Boston Globe reported. “Now is the time to speak truth to power!”

A thousand miles to the west, in Chicago, more than 40,000 people marched, Chicago authorities told NBC 5. The crowd was so large that, at around 12 p.m., police asked those who had not yet joined the rally to turn back and not attend.

Once the marching ended in Los Angeles, the science demonstrations broke out. California Institute of Technology graduate students taught onlookers how to improvise a solar panel out of blackberries and sunblock. “The blackberry juice absorbs sunlight,” the Los Angeles Times reported, “while the titanium dioxide in the sunscreen converts the sun's photons to electrons.”

Not all marches took place in metropolitan hubs like San Francisco or New York. In one far-flung corner of the nation, Atka Island, Alaska, (population less than 100, according to the 2000 Census), ecology researcher Bruce Wright held up a small sign: “Science Is Truth.”

And, off Wake Island, the tiny Pacific atoll that houses a U.S. airstrip, three divers posed at the bottom of the sea. (Their signs fared better than many of those caught in the rain in Washington.)

Science icons from pop culture made cameos: There was plenty of love for Bill Nye, an honorary co-chair of the Washington march. “We are marching today to remind people everywhere, our lawmakers especially, of the significance of science for our health and prosperity,” Nye told the crowd on the Mall, as The Washington Post reported. (“DON'T DE-NYE TRUTH!” read one sign.)

Nye was not the only TV personality to show up. Across the Atlantic, Peter Capaldi, who plays the titular Time Lord on the television show  “Doctor Who,” marched in London.

Several Ms. Frizzles, of “The Magic School Bus,” attended, some in costume and others reimagined as the Statue of Liberty.

(Rick, the alcoholic mad scientist from the cartoon “Rick and Morty,” was a popular motif, too, if a questionable scientific role model.)

The march went far beyond a U.S. phenomenon. Marchers took to the streets in Berlin, London, Munich, Paris, Rio de Janeiro, Sydney and Tokyo.

In Dublin, Eamon Ryan, leader of the Irish Green Party, rode his bicycle to an event where the 600-strong crowd hoisted posters criticizing President Trump. “The denial of science happening at the moment with President Trump and others can’t be ignored, and has to be fought,” Ryan said, according to the Irish Times.

Part celebration, part protest, the march stretched from the equator to the poles. In Uganda, marchers sported signs like “Science Rocks!” and “Science Is Nature.” Three days before the march, climate researchers held a March for Science banner aloft at the North Pole.

Scientists at Antarctica's Neumayer Station, a German-operated meteorological observatory, posed in the snow while holding a poster. “Nothing in life is to be feared,” the sign read, quoting the pioneering scientist Marie Curie. “It is only to be understood. Now is the time to understand more so that we may fear less.”

Some signs were nerdy or clever; the best were both.

And then there were those who marched for the animals, like the staff of the Cincinnati Zoo.

A few animals — dogs, mostly — tagged along with their marching owners.

#sciencemarch #Dublin #march4science

A post shared by Andrew Flood (@andrewanarchist) on

California's Monterey Bay Aquarium, though, had two-legged marchers of a different species: a waddling band of African penguins.

It's the March of the Penguins for Science! #MarchForScience

Posted by Monterey Bay Aquarium on Saturday, April 22, 2017

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The scene at the March for Science in D.C.