MOST OF US are familiar with the observation that house plants placed near a window have branches that grow toward the incoming light. This response, called phototropism, is an example of how plants alter their growth patterns in response to the direction of incident radiation. This response to light is intrinsically different from light trapping by photosynthesis. In photosynthesis, plants harness light and convert it into chemical energy (see Chapters 7 and 8). In contrast, phototropism is an example of the use of light as an environmental signal.
Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs.
Biophotonics is revolutionizing the field of medicine, biology and
chemistry and creating a new breed of medical engineers while at the
same time getting engineers a taste of medicine. From an engineer's
perspective, biophotonics is the application of photonics - the technology
of generating and harnessing packet of light energy called photons - to
image, detect and manipulate biological materials. In biology the
understanding of molecular mechanisms, function of proteins and
molecules has seen great new advances.