Wil Wheaton isn’t here to make science cool. Science is already cool, and vitally important. He’s just here to remind people of that.

Wheaton — who made his big debut in “Stand by Me,” made his mark in “Star Trek: The Next Generation” and now makes his living both as an actor (he plays an “evil” version of himself on “The Big Bang Theory”) and as a geek-about-town, speaking, blogging and hosting a gaming show on YouTube called “Tabletop” — will be appearing at this weekend’s fourth biennial USA Science and Engineering Festival. The event targets kids with Q-and-As featuring actual scientists, interactive demonstrations of the “don’t try this at home” variety, performances from They Might Be Giants and talks from other stars in the nerd universe.

“The STEM [science, technology, engineering and math] field is really important for people just to grow as humans, as a species, but especially for us, as Americans — [we need] to really think about where we are encouraging our young people to put their time and their energy,” Wheaton says. “It seems more and more, especially with the reality of climate change, science seems to run against the political agenda of a large number of people in Congress. I feel like we’ve got to do something.”

Key to that, Wheaton says, is refuting the idea that science is scary, or too difficult.

“When you hear people talk about being intimidated by science, that’s because you look at the entire field of science and it is intimidating,” says Wheaton, who will take the stage at noon Sunday for a talk. “But one of the things that’s really great about science — physics and astronomy and biology and chemistry — is that all of it can be reduced down to very simple concepts that all hold up and all can be understood, from very broad concepts to extraordinarily specific levels of detail.”

It’s also a matter of dispelling the myth that science isn’t for everyone, especially when it comes to schools.

“Kids get excited about what the kids around them are getting excited about,” Wheaton says. “If a group says, ‘Hey, we’re going to watch the SpaceX launch’ the way my generation watched the shuttle launches, more kids will be excited by that. That leads to a curiosity that isn’t going to take root in everyone, but is going to take root in a lot of people. And we need that.”

Walter E. Washington Convention Center; Sat., 10 a.m.-6 p.m. & Sun., 10 a.m.-4 p.m., free.

More interviews from Kristen Page-Kirby