Pouring liquid nitrogen into a plastic bottle sandwiched between two bricks and wrapped in duct tape, Western Kentucky University geology and geography professor Margaret Crowder sealed the bottle and dropped the contraption into a trash can filled with water.
The explosion that occurred seconds later sent gallons of water - and the trash can - into the air, to the delight of the girls who had gathered to watch.
“I actually jumped when it erupted,” said Mackenzie Evans, 11, of Kuttawa.
Evans and nearly 150 other girls from the region visited WKU Saturday for the university’s annual Girls in Science Day.
Funded by a grant and currently in its ninth year, the program gives girls in fourth through seventh grade an opportunity to meet scientists at WKU, take part in three classes and learn many different applications of science.
Crowder taught a class about volcanoes, and the liquid nitrogen trash can experiment demonstrated how volcanoes erupt due to pressure that builds up underground.
Other classes taught girls about beekeeping, the answers behind optical illusions, forensic anthropology and building a lunar rover.
“We want to give girls an opportunity to talk to scientists in the field and learn from them, and we also want to take some girls who don’t know a lot about science and give them the idea that science is fun, interactive and something they can become actively involved in,” said Rachel Campbell, observatory education scientist for WKU and head of the Girls in Science program.
Registration forms were sent to local schools and Girl Scout troops several weeks in advance, but word of mouth spread to the extent that several dozen girls registered in the last few days and on Saturday morning, Campbell said.
Mackenzie was attending the Girls in Science Day for the second time, and also attended the forensic anthropology and archaeology classes.
“I’d tell my friends that they definitely need to come to this,” said Mackenzie, who wants to study forensic anthropology when she grows up. “It’s totally awesome.”
Alexis Alvey, 10, of Leitchfield, was attending her first Girls in Science Day.
In the beekeeping class, Alexis wore WKU biology assistant Cassandra Cantrell’s beekeeping suit, while her classmates played the roles of the different types of bees in a hive community.
“It’s been a fun thing to do, you get to learn a lot of different things,” Alexis said.
Her friend, 12-year-old Jacquie Sanders, of Leitchfield, said she came back for her second Girls in Science Day because she got to learn about new things in a fun way.
Campbell said the opportunity for girls to apply their knowledge is a key component of the program and what attracts girls to come back year after year.
“There are a lot of hands-on activities, and the girls can take that home with them and show their friends and families what they learned here,” Campbell said.