Ordinarily, Geoffrey Rojas doesn't think of himself as a rabble rouser.
As a physicist, he spends his days in a University of Minnesota lab, using high-tech gadgets to analyze how surface materials interact.
But in his spare time, he's laying the groundwork for a mass rally in St. Paul on Saturday as part of a global event called the March for Science.
So far, 13 rallies are planned across Minnesota, from New Ulm to Grand Marais, in concert with the national march in Washington, D.C., and more than 500 satellite marches around the world.
Rojas, the vice president of the Minnesota march, says the event is a grass-roots effort to protect science from what he calls an unprecedented assault — including threats to slash government funding and attempts to censor research on climate change.
"More and more people are coming to grips with the fact that they need to speak up," he said. And that includes scientists like him, who normally might prefer to stay in the background.
As the organizers in Grand Rapids, Minn., posted on Facebook: "On April 22, 2017, we walk out of the lab and into the streets."
Nationally, plans for the March for Science started taking shape shortly after the Jan. 20 Women's March, which drew millions of protesters against President Donald Trump the day after his inauguration.