Science came alive on Thursday for high schoolers at the Park Avenue Alternative Education site in Grass Valley when they wrestled with the angles, trajectories, force and resistance of a medieval weapon of war - catapults.

The students learned to use mills, lathes, drills and other tools to make the catapults during the training session, offered through the Sierra College Tech-Explorer program.

"The program, which is offered to junior high and high school students, gives students hands-on experience to get them all excited about science and math and, we hope, encourage them to pursue a career in those areas," said Dean Neal Allbee, of the Sierra College Nevada County campus.

The Alternative Education site is located at 140 Park Ave., Grass Valley.

To contact Soumitro Sen, e-mail ssen@theunion.com or call 477-4229.