Successful teaching and learning occurs in venues where the faculty and students are fully engaged in the endeavor, and the discovery of scientific principles and theory occurs in an active learning environment. In FTE-based universities the design and implementation of such learning experiences is challenging because science courses tend to be highly enrolled, frequently with student to faculty ratios exceeding 100 to 1. If laboratory exercises exist, they are taught by well-intentioned graduate students who are usually distanced from the real intent of the course, and sometimes the laboratory objectives are not well sequenced with the lecture. If the course is demonstration based the students may be more entertained, but they are still distanced from understanding that experimental evaluations form the basis of scientific principles. All participantsfaculty, teaching assistants, and studentsreceive limited or minimal fulfillment from such endeavors. Is it surprising that student achievement is frequently less than desired in this factory teaching environment?

In an effort to engage the students and faculty, to teach fundamentals of scientific principles, and to demonstrate that science cannot be organized into disciplines as isolated domains, a new course entitled "Our Microscopic Universe" was created at Temple University. Its objectives were modest: to illustrate classical theories of geology, chemistry, and physics, with a greater integration of discovery or active learning exercises. The target population was elementary education majors, but the course is open to all students as partial fulfillment of a core requirement in the sciences.

From the first meeting, the class is immersed in the local geology. Supplied with a compass, students orient themselves relative to landmarks and hike through the Wissahickon Valley, counting contours on topographic maps and estimating heights and distances. The effect of geological cycles on creek bed formation and a brief introduction to rock formations are presented. Then the students return to the laboratory for a "breakdown" session to review the major points. The lecture follows the field and laboratory experiences, reinforcing them with important theories.

Just two weeks later, out to the field again. Now the focus is on rock formation and composition, and sedimentation. Back in the classroom, observations on the structure of rocks and minerals are reinforced: first from a chemical view of bonding in minerals at an atomic level, then analyzing the relationship of the elements and ions to the morphological structure, through analysis of crystal form and cleavage planes, to the development of rock types. Minerals analyzed include aluminosilicates and carbonates.

Again, out to the field. Students venture to a nearby site where they can analyze sedimentary rock formation and then stop at the local limestone quarry. At the quarry they follow the geological path of dolomite from its prehistoric formation to its packaging as limestone and lime. They witness a blast, the collection of rock, and grinding, kilning and chemical processing. Geological features leading to the formation of the quarry are discussed by the engineers at the quarry; chemical factors such as pH, chemical composition, and environmental damage are discussed by the quarry chemist. Students collect rock and water samples and processed materials for analysis. Back at the university, physics becomes important. Spectroscopic analysis is introduced as a means to determine metal content. Collected samples are analyzed for Ca and Mg by atomic spectroscopy. The data are used to define the mineral origin of the carbonate - is it from dolomite or calcite? Density determinations of dolomite and calcite are made to underscore ideas about chemical structure. The acid­base properties of lime and limestone are measured to explain the chemical processing that produces the basic oxide from the carbonate. Water samples collected from the quarry are tested for Ca and Mg. Students learn that the solubility of the carbonates is significantly different.

Now the students view the bigger picture: from their local environment they travel through the solar system. They take a trip to the planetarium and discuss the chemical composition of the stars against an analysis of spectral data. They study planetary motion. Gravity as a primary force is discussed as it relates to large bodies. But how big is an atom? How big is a molecule? In the physics lab, students determine the gravitational constant. In the chemistry lab, they measure the density of a metal. With assistance from their instructors they determine crystal structure and unit cell size. They measure the size of a molecule and compare its mass and dimensions to basic objects. It becomes obvious that gravity cannot be a significant force for small particles. A discussion follows on atomic structure. If gravity does not hold an atom or molecule together, what does? Again a microscopic view - is it chemistry or physics? Finally, kinetic energy and temperature are introduced. Students calculate escape velocities for a variety of atomic and molecular species, using many of the chemical and physical ideas presented to answer simple questions concerning, for example, Freon and the ozone layer.

At the end of the semester, two class periods are left for discussion. Our geologist asks the students "what is structure?" - a loaded question that instigates considerable discussion.

In its present version, the class can accommodate approximately 70 students and is team-taught by geology, chemistry, and physics faculty. All our field trips are within the local area with driving times of 20­35 minutes.

Acknowledgment

This work was partially supported by the National Science Foundation, Division of Undergraduate Education, Collaboratives for Excellence in Teacher Preparation Program, award no. 9354034.