The division of labor in the interdisciplinary planetary science group, I argue, is best understood as complementary collaboration—an ongoing, open-ended collaboration in the course of which group members cooperate inter pares in order to complement their respective expertise in the pursuit of a cluster of differentially shared research interests. In the following, I will characterize the practices by which members of the planetary science group collaborate and divide labor among themselves, namely by shared planning and framing, deference and witnessing, and iterative deliberation. All three of these practices enable group members to draw on their mutually complementary expertise, weaving their distinct individual research interests together.
Two types of experiments are central to joint activity in the planetary science group: experiments with the simulation tunnels in the group’s large basement laboratory, and so-called “tumbling experiments," upon which I will draw to illustrate the group’s division of labor. In tumbling experiments, small samples of quartz sand or similar material are bottled and mounted onto an experimental device that the group’s technician built to Laurits’s specification. The device, powered by a washing machine motor, spins bottled samples in circles to simulate erosion processes caused by wind. It is a shared assumption among group members that processes similar to the tumbling of grains take place on planetary surfaces and that these processes change the geomorphology of planets.
To provide a vivid illustration of the experimental practices I have observed in the group, I refer to parts of a particular experiment in the following. The experiment in question addresses whether and to what degree hydrogen peroxide is produced when tumbled quartz comes into contact with water. The presence of hydrogen peroxide is of biological interest because it is known to have toxic effects on cells, though it is also known that some, supposedly “old," micro-organisms have developed mechanisms to cope with its presence. Moreover, hydrogen peroxide is a rather unstable compound that can trigger various geochemical reactions.
The decision to conduct these experiments was taken more than a year before they actually happened. It was also decided that these measurements would form part of a dissertation project in microbiology, which would be supervised by Victor. The measurements have eventually been delegated to Lucas, a newly started PhD student. With the help of Christoffer’s chemical expertise, Lucas has been developing a protocol for the measurements needed during the past few months.
It is a November morning and the group meets as usual in the same small meeting room with the large round table. All core group members are present today—Laurits, Adam, Christoffer, Rasmus, Victor with his PhD student Lucas, and Nikolaj, the group’s dedicated technician. When everyone is seated, Laurits reports that two glass flasks with quartz have been heated up to 110 degrees and are now sterilized. Laurits goes quickly through a number of other things (a student, an application, an invoice, a computer system, a new instrument), but then abruptly comes back to the two flasks: “What to do with them now? They have been cooling down.”
It had been agreed earlier that the flasks have to be closed, one of them will be vacuum pumped and both will be tumbled for the same period of time, so that Lucas will be able to perform his hydrogen peroxide measurements on them. Adam and Nikolaj discuss briefly how actually to pump the air out of one of the flasks. Then, the conversation suddenly turns away from experimental details.
As Lucas has begun drafting an article about his envisioned measurements during the last week, he mentions that they need to talk about the focus that the article should have. The subsequent discussion becomes contentious. While some group members prefer a focus on the physical details of the experiment and the chemical mechanisms which can be measured by Lucas, others argue that an article with the character of a report would not “sell” and they propose to interpret measurements with regard to geomorphological processes which might have taken place on early Earth. Lucas’s findings could be used, they argue, for a “back-of-the-envelope” calculation supporting the formulation of a rough quantitative hypothesis about the production of oxygen on Earth. Phrasing the article in this manner, they may be able to place it in a high-profile journal. Christoffer argues enthusiastically for this option. Other group members, however, are rather skeptical of these suggestions and doubt that there is sufficient reliable background literature to support any hypothesis about the role of hydrogen peroxide in oxygen production on early Earth. Finally, Victor suggests to include considerations of the early Earth’s geomorphological processes, albeit with the proviso that “the story might actually be more complicated.” The meeting comes to a close.
After the meeting, they all gather in the lab opposite Laurits’s office. With Nikolaj’s advice, Lucas takes two quartz flasks cautiously out of an oven. The flasks are still very hot, and they transport them down to the basement laboratory where they plan to vacuum pump them. Adam and Nikolajprepare the vacuum pumping and explain the process to Nikolaj. Christoffer is also present. They talk loosely. Christoffer wants to know: “Why did we actually never tumble in water?” Adam agrees: “That would be very interesting. We could do that at some point. We should put it on the list.”
Then, the vacuum pump is switched on. You can see the flask vibrating lightly. Lucas takes pictures. They discuss the best way to switch off the pump and disconnect it from the flask. The latter task will be taken care of by the glass-blower who has just come over from his workplace in the chemistry department and is now preparing for the task. Adam slowly switches off the pump while the glass-blower carefully seals the flask just above the base of its neck. Then they disconnect the pump and Christoffer labels the two flasks. Nikolajmeasures them. Lucas tells me: “After so many days of work I’m so happy that we finally have the samples ready.” (field note, group meeting, groupl)
This field note describes a phase of close collaboration in the planetary science group in which the respective research interests and the expertise of group members—biological, geochemical and physical—are tightly integrated. However, the field note also exemplifies that, since the planetary science group is interdisciplinary, it is often not obvious to group members how experiments should be conducted and how experimental results should be framed for publication. Therefore, group members are forced to discuss the planning and framing of experiments that they jointly carry out at their weekly meetings in great detail, and sometimes controversially. Not only do they discuss possible experiments, their design and the outcome oftheir respective disciplinary viewpoints, it is also important for them to discuss the framework of interpretation, that is, from which perspective should they argue for the relevance of their experimental results. The framing of conducted experiments concerns decisions about “which story to sell.” For which geomorphological, geophysical or biochemical phenomena are the tumbling experiments relevant? After all, what do these experiments reveal? How would different scientific communities interpret them? What broader theoretical context is of primary concern here? What journals should the authors target for submission? Which narrative would be appropriate for such an article? To which phenomena of general interest should a possible article relate? And taking these things into account, which further measurements and calculations are needed, and which experimental standards have to be met?
Right from the start of experimentation, planning discussions and framing negotiations are important for the planetary science group to define, assign and coordinate experimental work. Apparent differences in expertise between group members force them to rely upon each other, to step back and defer experimental work to their collaborators. Nonetheless, group members take an active interest in each other’s work. Deferring labor to a collaborator is seldom an act of indifferent outsourcing. Rather, when group members have a shared interest in experimental results, deference is often complemented by enthusiastic witnessing, particularly in the group’s dedicated lab facilities. Group members appreciate the opportunity to witness and share experimental experience even though, for pragmatic reasons, only one or two group members will actually carry out particular experimental steps.
Iterative deliberation accompanies all steps of joint experimentation in the planetary science group. The interpretation of ultimate, interim and envisioned results, as well as the question as to when results are actually definite and publishable—all this is a matter of open-ended discussion, in the course of which a common vision of joint experimentation (and jointly authored publication) is continuously negotiated. While single experiments or experimental steps are clearly endorsed with varying enthusiasm by different group members, methods and results should eventually be acceptable to all participating senior core group members. This acceptance evolves gradually in joint discussion in the course of which different group members at different points in time offer both their critical objections and their arguments for developing the experiment in question further. Here, a lack of agreement does not lead to dissent but ultimately reinforces group members’ collaborative search for experimental results whose reliability, validity and interpretation can be accepted by all core group members. In fact, the planetary science group has established a continuous mode of collaboration in which one experiment, whether successful or not, leads to another experiment in the future.
Through shared, open-ended discussions, deference and witnessing, the planetary science group has adopted a pattern of division of labor that reflects the interdisciplinary character of its research. Senior group members possess complementary expertise, and they do not aspire to acquire the expertise that their colleagues possess—“we try not to step on each others’ toes," as one member told me (Adam, interview, groupl). Each senior member seeks to carve out his or her niche within the group’s research in a way that fosters collaboration with other members but allows the pursuit of distinct, individual research interests at the same time, continuously balancing research collaboration with professional individuation and interweaving individual research interests into a shared experimental practice.