Update with Trump tweet President Donald Trump, while not mentioning today’s worldwide marches, tweeted an Earth Day message: “We stand committed to preserving the natural beauty of our nation.”  See the full tweet below.

Previous Bill Nye the Science Guy, the current Doctor Who, a Star Trek original, the creator of Mystery Science Theater and other celebrities joined the March for Science on ground and in the internet ether today as thousands gathered in New York, Washington D.C., Los Angeles and hundreds of cities around the world.

“Thank you for standing up for TRUTH,” tweeted Scandal‘s Kerry Washington, while Joel Hodgson, creator of Mystery Science Theater 3000, skipped his show’s trademark snark for a straightforward “Science is important – Don’t ignore it.”

The March for Science – marches, actually – is happening in more than 600 cities worldwide, with organizers dismissing partisanship and calling for what the March’s website says is recognition of the “vital role science plays in our democracy.”

Though climate change is the primary topic, the March for Science and its supporters have addressed “integrity” in all forms of science, including forensics, gun violence research and the Flint water crisis.

Still, politics wasn’t far from the surface. As Marchers walked past Trump Tower in New York City, the chant morphed into a simple “Dump Trump.”

Here is a sample of today’s celebrity statements, including Star Trek‘s original Hulu George Takei and the current Doctor Who Peter Capaldi.