Big names in science turned out for the March for Science rally in D.C. on Saturday, including educator Bill Nye, “The Science Guy.” The rallies, which coincide with Earth Day celebrations, are being held worldwide.

Marchers gathered from coast to coast to promote the understanding of science and defend it from budget cuts.

Earth Day Network live-streamed the “teach-in” rally ahead of the march on YouTube. A march was expected to follow the “teach-in” event at 2 p.m.