Scope and ideas of the workshop The workshop which took place at the University of Giessen from Oct. 3 to Oct. 7, 2002 and whose proceedings are collected in this volume started from the idea to convene a number of scientists with the aim to outline their "visions" for the future of radiation research on the basis of their expertise. As radiation research is a very wide field restrictions were unavoidable. It was decided to concentrate this time mainly on molecular and cellular biology because it was felt that here action is par-ticularly needed. This did not exclude contributions from neighbouring fields as may be seen from the table of contents. It was clearly not planned to have a c- prehensive account of the present scientif fic achievements but the results presented should only serve as a starting point for the discussion of future lines of research, with the emphasis on the "outreach" to other parts of life sciences. If you are interested in the future ask the young - we attempted, therefore, to invite mainly younger colleagues (with a few exceptions) who had, however, already left their marks in the field. They were asked to describe what they felt is important in radiation research and may have significant influences on other branches of life sciences. They were given the task to demonstrate what is lost for science "if we do no longer exist."

Scope and ideas of the workshop The workshop which took place at the University of Giessen from Oct. 3 to Oct. 7, 2002 and whose proceedings are collected in this volume started from the idea to convene a number of scientists with the aim to outline their "visions" for the future of radiation research on the basis of their expertise. As radiation research is a very wide field restrictions were unavoidable. It was decided to concentrate this time mainly on molecular and cellular biology because it was felt that here action is par-ticularly needed. This did not exclude contributions from neighbouring fields as may be seen from the table of contents. It was clearly not planned to have a c- prehensive account of the present scientif fic achievements but the results presented should only serve as a starting point for the discussion of future lines of research, with the emphasis on the "outreach" to other parts of life sciences. If you are interested in the future ask the young - we attempted, therefore, to invite mainly younger colleagues (with a few exceptions) who had, however, already left their marks in the field. They were asked to describe what they felt is important in radiation research and may have significant influences on other branches of life sciences. They were given the task to demonstrate what is lost for science "if we do no longer exist".

The biological action of radiation undoubtedly constitutes an issue of actual con cern, particularly after incidences like those in Harrisburg or Chernobyl. These considerations, however, were not the reason for writing this book although it is hoped that it will also be helpful in this respect. The interaction of radiation with biological systems is such an interesting research objective that to my mind no special justification is needed to pursue these problems. The combination of physics, chemistry and biology presents on one hand a fascinating challenge to the student, on the other, it may lead to insights which are not possible if the dif ferent subjects remain clearly separated. Special problems of radiation biology have quite often led to new approaches in physics (or vice versa), a recent example is "microdosimetry" (chapter 4). Biological radiation a9tion comprises all levels of biological organization. It starts with the absorption in essential atoms and molecules and ends with the development of cancer and genetic hazards to future generations. The structure of the book reflects this. Beginning with physical and chemical fundamentals, it then turns to a description of chemical and subcellular systems. Cellular effects form a large part since they are the basis for understanding all further responses. Reactions of the whole organism, concentrating on mammals and especially humans, are subsequently treated. The book concludes with a short discussion of problems in radiation protection and the application of radiation in medical therapy. These last points are necessarily short and somewhat superficial."

Radiation is the one agent among all environmental factors which may damage biological systems that is not only easily quantifiable but can also be measured with unsurpassed resolution. Its primary effects on atoms and molecules are well understood, and the secondary processes can be followed by sophisticated experimental techniques. The quantum nature of interactions and the importance of stochastic variations call for an exact mathematical description. This task is by no means simple, and presents a challenge both to the experimentalist and to the theoretician. It is hoped that a generally acceptable formalism will help to quantify radiation responses, both in radiation protection and radiation therapy, and make it possible to move from a purely empirical approach with all its fallacies to real understanding.