Science lovers across the country took to the streets on Saturday to protest President Trump’s policies, which critics say show an alarming disregard for science and research. The March for Science, held for the first time this year with events throughout the world, was timed to coincide with Earth Day. Demonstrations in the U.S. took aim at Trump’s stance on climate change and his proposed cuts to science and research budgets, with many protesters carrying signs that openly mocked the president. “Keep your tiny hands off my science,” read one sign carried by a demonstrator in New York. Rush Holt, chief executive of the American Association for the Advancement of Science, told Reuters ahead of the demonstrations that protesters had simply realized “it is time to speak up.” “I wouldn't say that it is fundamentally because of Donald Trump, but there's no question that there's been concern in recent months about all sorts of things,” Holt said. Rally organizers said the event is also meant to be a celebration of science and an appeal to the public to support the scientific community. The demonstration in Washington, which kicked off at 10 a.m. with tens of thousands expected to attend, was also due to feature popular speakers, including Bill Nye “the Science Guy,” former White House technology aide Megan Smith, and Dr. Mona Hanna-Attisha, a doctor who brought attention to the Flint water crisis.