Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion in these demonstrations is not actually diffusion, but rather convection. Yet teachers, textbooks, and workbooks continue to cite these as examples of diffusion, despite having been adequately refuted. In order to reaffirm the refutations and promote greater awareness of the continued existence of these misconceptions among teachers, the authors designed an experiment to test the premise that typical classroom diffusion experiments are, in fact, examples of convection. Taking advantage of the free-fall environment through NASA's Teaching from Space Microgravity Experience, we were able to show that the great majority of dispersion patterns depicted in these demonstrations are due to convection. Subsequently, we propose classroom activities that serve as more accurate demonstrations of diffusion. Results J J J Sustaining Members share NABT's mission to promote biology and life science education.Call NABT at (888) 501-NABT or visit www.NABT.org to learn more.

Astronomy is one of the oldest STEM enterprises today. It is a discipline through which technology has been advanced, as well as our understanding of the universe. Further, astronomy is a gateway science that inspires the imagination of young learners, and can be used to promote STEM careers. In order to advance the astronomy enterprise, we must maintain an informed citizenry. The practice of astronomy has changed over time; astronomy today is much different than it was 50 years ago. In an effort to identify the current practice of astronomy, or what it is that today's astronomers do, 478 U.S. astronomers participated in the study focusing on their engagement in three areas of scientific practice; science attitudes, tools and techniques, and social interactions. In addition, astronomers' perceptions about career choice, work-related activities they engage in, motivations for doing astronomy, and changes needed in education were also explored. Data were collected over a 3-month time period via an online survey and telephone interviews. Data provided by survey participants provides a solid foundation from which findings and conclusions are drawn. Today's population of astronomers is largely white, male, and older, however moving toward gender balance. The population as a whole places great importance on the practice of attitudes such as thinking critically, respecting the evidence, honesty, and objectivity. Unlike many might think, astronomers spend little time at the telescope collecting data, but rather the vast majority of their time is spent working at a computer. Further, engaging in administrative duties, writing, use of mathematics, searching for funding, mentoring others, and collaborating with colleagues are all critical tools/techniques and social skills in the practice of astronomy today. Finally, pop culture and personal experience plays a significant role in attracting individuals to a career in astronomy, and exploration and uncovering that which is unknown, the thrill of discovery, is what keeps them motivated. This study identified and quantified the activities in which professional astronomers engage, and the findings can be used to design formal and informal learning experiences K through adult to more closely reflect the science of astronomy and the people who engage in the practice. iii DEDICATION This dissertation is dedicated to my father Charles W. Spuck, and mother Melda R. Spuck. My father grew up in a time when few people finished high school, he made it to the 8 th grade. However, he was the true example of a lifelong learner, always pushing to educate himself. It was rare that I did not see him in the evening at the kitchen table without a book in his hand. In his mid 50's he walked across the stage to receive his GED. That was one of his proudest moments in life. My mother too had a passion for learning, she was the first in her family to graduate high school. They both have been, and continue to be, inspirations in my life. Then there is Dr. Patricia Obenauf, Pat. What an amazing perso...

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