about the big objectives of the field and why it is worthy of attention from fellow scientists and programmatic focus by funding agencies. The second goal is to assess current work using that framework and to point out some of the more promising opportunities for future efforts, such as research that could significantly benefit society. The third and final goal of the report is to set out strategies for realizing those benefits—ways to enable and enhance collaboration so that the United States can take full advantage of the opportunities at this intersection.

Any attempt to provide an all-inclusive framework for this work will inevitably leave out research that belongs within it. With that caveat, a good way to think of research at this intersection is that it turns ways of looking at things—both figuratively and literally—from their original purpose and uses them to tackle new problems, often in ways far removed from when they were first conceived.

Most—but not all—of the new problems being addressed at this intersection are biological ones, largely because of the incredible richness of this field. The realm of biology is immense, involving complicated structures as small as molecules and as large as the biosphere and timescales that range from submicroseconds to eons. Answers to these problems seek not only to describe how the individual structures, in their immense complexity and diversity, work but also how they interplay. A very rich source of potential questions indeed.

The ways of looking often come from the physical sciences. Those ways might be conceptual—approaches for looking at and solving problems—or analytical—methods for extracting understanding from data—or technical—tools for collecting information needed to address the problem at hand. But it is this intermingling of problems from one arena and ways of looking at them from another arena that makes this intersectional area between the biological and physical sciences so rich and offers many of the opportunities that reside there. The committee expects that ideas will emerge from such studies that will go well beyond the intersection and transform both the biological and physical sciences.

What, then, are some of the areas being explored at this intersection? Interestingly, many share common conceptual themes, several of which are discussed in this report. Interactions appear in both branches, albeit with much different content and contexts. Describing how individual particles interact—what forces and energy exchanges cause crystalline materials to form, and matter in all phases to display characteristic behavior and to undergo phase changes—are mainstays of the world of physics. However, these ways of thinking about and discussing how inanimate