Carl Brodersen wanted to know if a catapult used in the 13th century could be made so powerful that enemy archers couldn't reach it.
Nellie Olsen wondered if an insect that defoliates spruce trees was more likely to occur on trees facing the south or west. And Tally Teal questioned whether students will do better on tests if there are rewards and punishments.
Those students' curiosity and the way they tried to answer those questions won them the "gold" awards at the 10th annual Capital City High School Science Fair on Saturday. They will go on to a state science fair in Anchorage.
About 114 students competed in the privately sponsored fair at the Marie Drake gym. Nearly all of them were Juneau-Douglas High School freshmen and sophomores enrolled in advanced physical science or biology classes taught by Jonathan Smith.
"The thing I'm most proud of is every one of these students worked with a mentor in the community," Smith said. The students had to find an expert in the field and strike up a relationship with an adult who isn't a teacher, he said.
Brodersen, a junior, is a past science fair winner at local and state levels, and he placed fourth in his category at an international fair last year.
He has been playing around with trebuchets a medieval catapult since the eighth grade as a good way to learn carpentry, he said.
"I've always been interested in history, and I've been reading a lot about the Welsh. I've read that nothing matches an English longbow" for range and accuracy, Brodersen said.
He wondered if a trebuchet could fling a missile farther than defenders' arrows, putting the catapult out of reach. Sometimes medieval catapults shot rocks. Other times they sent back a hapless messenger, or fired a fetid dead horse into a castle to spread disease.
"If you can sit outside the range of a castle and knock down the walls, it's yours, basically," Brodersen said.
Brodersen concluded that a trebuchet could be built that would fire farther than arrows, but it would be so large and unwieldy it wouldn't be worth using.
Teal, a freshman, considered a potentially less brutal competition, that of school tests.
She gave math tests to three groups of elementary school students. She told students in one group that they would get candy bars for doing well, and told children in another group that they would get more homework if they did poorly. Kids in the third group were told there were no consequences for their performance.
"The 'positive' and the 'negative' scored better on the test than the 'no consequences,' " Teal said. "I think it has to do with the motivation. If you have a reason to take the test, you're going to do better."
Olsen, a sophomore, rated 482 Sitka spruce near beaches around Juneau for the amount of defoliation caused by the spruce needle aphid. She found that locations with southern through western aspects would have more defoliation than trees open to the north or east.
The information could help foresters decide which trees to treat for the insect, she said in her report.
Judges were "looking for some originality in thought in so far as how they approach the project," said Mike Sakarias, one of the fair's organizers.
The goal of the fair "is to give these young people the idea that science is interesting," he said. "It's a fascinating way to look at the things around you."
A future edition of the Empire will print a complete list of winners of the science fair and of a balsa bridge contest held at the same time.
Eric Fry can be reached at email@example.com.