Science communication, whether internally or to the general public depends on trust, both trust in the source and trust in the medium of communication. With the new 'ecology of communication' this trust is endangered. On the one hand the very term of science communication has been captured by many different actors (e.g., governments, PR experts, universities and research institutions, science journalists, and bloggers) apart from scientists themselves to whom science communication means different things and whose communication is tainted by special interests. Some of these actors are probably more trusted by the general public than others. On the other hand, the channels that are used to communicate science are also not trusted equally. Particularly the widespread use of social media raises doubts about the credibility of the communication spread through them.

In considering the ethos of science, Robert Merton [1973] posited that openness and secrecy reflect opposing values in the accomplishment of science. According to Merton, scientific inquiry required that all interested parties have access to and freely share scientific information. In our current epoch, this importance of openness in science seems even more widely accepted. It is a given nowadays that scientists are expected to work as part of a team, not only within their own department, but also with other departments different disciplines. To work interdisciplinary scientists must become more communicative and critically talk about difference, which asks maximum transparency and open communication of the participants. However, against the adage that openness and participation in science is an inherent good, one easily forgets that the actual practice of collaborating may also require things are not said. Navigating everyday interactional challenges may depend on postponing issues to keep the process going, for instance because scientists still have to figure out what they find important in the collaboration with others. But also issues like, withholding sensitive problems or not critiquing each other's options viewpoints, leaving points shrewdly of the agenda, and excluding relevant actors from the meeting table. Despite the idea of open innovation, shared visions, beliefs and knowledge we must focus on silence for the good and the bad as well.

The twenty-first century has witnessed a shift in science communication ideals from one-way science popularization activities towards more reflexive, participatory approaches to public engagement with science. Yet our longue duéee histories of science communication's antecedents focus on the former and have neglected the latter. In this paper I identify parallels between modern science communication ideals and an iconic Enlightenment text, Condorcet's Sketch for a Historical Picture of the Progress of the Human Mind (1795). I show that Condorcet's carefully negotiated balance between scientific reason and radical principles of democracy has much in common with twenty-first century debates about science communication.

The letter compares and contrasts thinking about making science accessible and relevant to children in science centres and museums with thinking about communication in social history museums.

As a result of the large number of media used and a variety of objectives pursued by the various Public Communication of Science (PCS) activities, their evaluation turns into a daunting task. Therefore, a general taxonomy for all the approaches used by PCS could be helpful in order to differentiate their effects and to measure their results. A general format is proposed for a fast and easy evaluation of PCS efforts and to share a common language with all science communicators, who need to easily compare the results of this growing activity.

Citizen science is one of the most dramatic developments in science communication in the last generation. But analyses of citizen science, of what it means for science and especially for science communication, have just begun to appear. Articles in this first of two special issues of JCOM address three intertwined concerns in this emerging field: The motivation of citizen science participants, the relationship of citizen science with education, and the implications of participation for creation of democratic engagement in science-linked issues. Ultimately these articles contribute to answering the core question: What does citizen science mean?