Over the weekend, some 400,000 Americans took to the streets of New York City to demand action on climate change, but as Jon Stewart pointed out on Monday night’s “Daily Show,” too many members of Congress continue to deny the science.

Last week, the House Committee on Science, Space and Technology interrogated Presidential Science Advisor John Holdren — or, as Stewart called him, the hearing’s Sisyphus “charged with the impossible task of pushing a million pounds of idiot up a mountain.”

Holdren faced questions about “global wobbling,” comments from a congressman who refuses to read scientific journals because he doesn’t believe them, and gems like this one:

“I mean think about it, if your ice cube melts in your glass it doesn’t overflow, it’s displacement,” Rep. Steve Stockman (R-Texas) said. “This is the thing, some of the things they’re talking about, mathematically and scientifically don’t make sense.”

That got Stewart burning.

“Are you fucking kidding me? Are you fucking kidding me? I don’t even know what to do with that,” Stewart said. “How far back to the elementary school core curriculum do we have to go to get someone on the House Committee on Science, Space and Technology caught up?”

And with that, Stewart broke out some ice and some water and did an experiment that even a congressman could understand.

Then again, maybe not.