Physics now: Reviews by leading physicists in the International Union of Pure and Applied Physics

This collection of reviews of the state of the art in physics is an updated version of a collection edited by Paul Black, Gordon Drake and Leonard Jossem , to mark the beginning of the new millennium. Several years on, physics has moved forward and it is time once again to take stock and to look a little into the future.

The first collection arose out of discussions at a meeting of the Council of the International Union of Pure and Applied Physics in 1998. The Commission on Physics Education, C14, had raised the question of whether IUPAP would arrange any special activity to celebrate the millennium. It was decided to ask the chair of each IUPAP commission to contribute a short article to explain recent major advances
in their field, and suggest how it might develop in the next few years.

The authors were asked to write for physicists who are not specialists in their commission's field, aiming at physicists – including high school teachers – who might use the material to enliven their classes. Many of the contributions rise nobly to this difficult challenge. Browse amongst them to see which appeal to you and your students. However, the special strength of the collection is that each piece is authoritative — written by recognised international experts in the field with a passion for their particular part of it. Thanks are due to the original authors for their willingness to contribute to the collection, and to those in the new commissions who undertook the revisions.

The pieces are presented in the order in which the IUPAP commissions happen to be numbered. There are many links between these fields, and sometimes some overlap. As editor, it has been my privilege to read each contribution several times, and this has led me to note a number of trends across the various commissions, which give a hint of how physics as a whole is changing and developing.

One such trend is towards increasing interdisciplinarity. More and more, physicists are working with others to develop ideas at the boundaries of different fields, including chemistry and biology. In the work described by several commissions there is also a trend to tackle more complex and realistic systems, evidenced for example by the interest in 'soft matter'. Going along with this is a widespread theoretical interest in non-linearity, in complexity, critical phenomena, and the renormalisation group.

Several commissions report the growing importance of miniaturisation, of manipulation of matter at the nano-scale, together with recognition of the importance of phenomena at the meso-scale. Instruments and sensors are rapidly getting smaller, as well as more accurate.

It is notable, in m any reports, how optics ha s regained its importance and value for a range of new applications in many areas of physics.

Finally, the computer now plays a central role in the work of most physicists. It has become an indispensable tool of research, both experimental and theoretical. Computational modelling of physical systems, allied to the rapid growth in computer power and speed, thrives in very many areas. Sophisticated image processing is vital in many areas of both fundamental and applied physics. It seem s safe to predict that uses of computing in physics will grow in the future, notably in those areas such as astrophysics, statistical physics and particle physics that already make heavy demands on computing.

Such changes in character of physics deserve to be brought to the attention of students, amongst whom is the next generation of physicists. In particular, it is important that high school physics courses reflect these changes, so that students can make better informed choices of the subjects they will study.

Reading and editing these pieces has been a pleasure. Taken together, they expand ones vision of physics and show that the subject is very much alive, still full of intriguing surprises, worthwhile problems and fascinating promise.