Abstract
Zero-G is a concept that people think they know but usually misunderstand. To illustrate the effects that happen in free-fall, the proper term, NASA developed two different demonstration units based on drop towers it uses in microgravity research, and associated education materials. While highly valuable, their efficacy has never been tested to show that they lead to proper student understanding of gravity and free-fall rather than providing a classroom diversion. In preparation for employing the free-fall demonstrator in a museum, an informal education setting, I developed and tested an activity in which students are challenged to explain what is happening in free-fall and the apparent 0g of space, and lead them to discover that the "awful truth" that true 0g does not exist. The activity is targeted for grades 5–9, consistent with New Mexico education standards, but is applicable to a broad range of audiences. I describe common misperceptions, the apparatus used, and results of the activity with teachers and then with students in an after-school program.
