A scale model of a satellite that will soon rocket into space. Colored glasses that enable you to see things otherwise invisible. Vegetables dipped in liquid hydrogen that you can shatter with a hammer. Even "Star Wars" paraphernalia.
That's just a sample of what kids — more specifically, "budding scientists" — got to enjoy at Saturday's 14th annual Physics Fair, sponsored by the Johns Hopkins University's department of physics and astronomy.
The daylong event, held inside and on the grounds near the university's Bloomberg Center for Physics and Astronomy on the Homewood campus, featured all sorts of exhibits and equipment, offering looks at the solar system, the properties of light and other scientific wonders.
But for 8-year-old Finn Ratchford, the coolest thing at the fair was probably the most basic. He loved the 2-liter plastic soda bottles that were being shot into the air via hand pumps and water pressure. On a plaza outside the center, kids were using pumps attached to water basins to propel those bottles high into the air, the launches accompanied by loud bangs.
Obviously, young Finn, whose parents are both Hopkins physicians, loved learning about water pressure, probably enjoyed tracking the arc of the bottles as they soared into the air, doubtless could explain the physical properties behind the demonstration.
But the real attraction: "It's cool when they explode," the Gilman School second-grader said.
And what kid, no matter how scientifically inclined, doesn't appreciate loud noises? But while the outdoor rocket launch was a crowd-pleaser, the more cerebral pursuits going on inside the center might have better reflected the true spirit of the day.
Take 10-year-old Natalie LaBrique. The Hampton Elementary School fourth-grader proudly carried the third-place trophy she won in a Science Bowl quiz competition for first- through fourth-graders. Over the course of the day, she also got to sit on a hovercraft, but that didn't give her any hardware to take home and display.
Her mother, Kim, a former high school science teacher, said the fair offered a perfect opportunity to stoke her daughter's nascent interest in science.
"As a family, we like to bring our kids to participate in as many science exhibits as possible," she said.
That sort of attitude is good news for people like Elena Sabbi, an astronomer at the Space Telescope Science Institute — responsible for the Hubble Space Telescope — who was at the fair to show off some of the wonders of infrared photography. She was also looking to generate enthusiasm for the James Webb Space Telescope, a successor to Hubble that is scheduled to be launched into space in October 2018.
"They can be the future astronomers and engineers," she said of the youngsters who spent the day trying on different-colored glasses, each of which revealed objects invisible to the naked eye. "We need people with brilliant ideas to create the new telescopes; we need people with vision.
"When Hubble was getting old and broken," Sabbi said, "and we had to replace the instruments, and NASA wasn't sure it was a good idea to do it ... the entire world started writing letters to NASA saying, 'Please save Hubble.'"
Just maybe, Sabbi said, some future letter-writers "might be right here."