Weber State University physics professor Adam Johnston says there’s that one moment at the annual Physics Open House that makes it all worth it.

“There’s always a moment, and it’s not the physics part of it,” Johnston said.

Rather, it’s usually something that Sir Isaac Newton seemed to allude to in his well-known laws of motion — the reaction to an action.

For example, Johnston says that at one point during the open house, he and physics colleague Colin Inglefield levitate a beach ball, moving it around the room above the crowd. The look on the children’s faces is priceless.

“I can see that look on their faces as they’re looking at a beach ball floating above their head,” he said. “Their eyes and mouth are all the same size. I remember that look, it’s the same look I have on my face.

“And that,” Johnston concludes, “is why we do it — to get that look of awe and wonder.”

This year’s annual shock-and-awe-and-wonder campaign will take place from 6-9 p.m. Friday, Oct. 11, in the Tracy Hall Science Center at WSU, 3848 Harrison Blvd., Ogden. Admission to the Physics Open House is free.

The 13th annual event will feature demonstrations, exhibits, hands-on activities, mini lectures and much more.

“I think of it as a giant carnival of science,” Johnston said. “There will be rooms you can walk into and play with stuff — see how magnets work, peer through a microscope or telescope — all sorts of interactive things.”

Johnston says the open house will offer both the practical and the whimsical. On the practical side, for example, associate professor Michelle Arnold is able to take any household object and determine what elements it contains.

“That’s practical, because there could be lead in it,” Johnston said. “So you could bring in your jewelry, or a toy that your child might be chewing on, and find out what’s in it.”

On the impractical side, each year Johnston and Inglefield present their Circus of Physics demonstration, which at some point involves one of the physicist’s smashing a cinderblock on the other’s chest.

“Colin usually gets the hammer side of the demo,” Johnston jokes. “That is definitely a terrible idea, and while there are some learning moments, people should not see any practical application in it.”

It’s a fairly even 50-50 split between popular returning features and new demonstrations and activities, according to Johnston. For example, he says a graduate of the physics department returns year after year to demonstrate rocket launching to the crowds.

“That is definitely a greatest hits,” Johnston said. “There are kids who will spend an hour just paying with the rockets.”

The open house has grown in popularity over the years, and Johnston admits the event “gets packed.” But at the same time, the move into a bigger, better science building a few years ago has allowed organizers to spread activities out a bit more.

“This has given us more opportunities in the last few years to have more departments open up their doors,” Johnston said. “And this year we’re doing that — it’s continuing to build.”

Earth and environmental sciences will be opening up four of its labs this year, and botany is also offering a few labs, according to Johnston.

“It has gotten crowded, but what we think will happen is now that we have more labs open it will spread things out more,” he said.

In conjunction with the open house, new this year will be a free concert in the Ott Planetarium. The band Conquer Monster will present their unique brand of electro-scifi music beginning at 7 p.m.

All tickets have been distributed for the Conquer Monster show, but others will be seated on a first-come, first-served basis as space allows, according to organizers.

Seeing as it’s an open house, Johnston said visitors can come and go as they please, enjoying those things that catch their attention. He stresses that they’re not looking to ram science down anyone’s throats.

“We’re not here to grab people by the shoulders and tell them how important science is,” he said. “This is just what we do as a society, this is what your tax dollars contribute to, and we want you to be a part of it.”

In the end, he says the event is all about highlighting the wonders of natural exploration.

“Ultimately, we just want to share what we do with the public,” he said. “There’s a spirit to science that we think is important — not just as scientists, but as people.”