The lunar eclipse yesterday (July 27, 2018) provided an excellent opportunity to take pictures and to study the color of Earth’s shadow. I snapped some images with my smartphone (Huwai Mate 10 Pro, Leica camera) through a 130mm Newton telescope. The moon was pretty low and within the city barely visible. Just after leaving the central shadow cone, the bluish color of the umbra/penumbra region became very noticeable. Today, I analyzed the picture a bit and drew the relative red/green/blue components along the shadow. Indeed blue wins within a narrow stripe bordering the penumbra. According to the literature, this is a signature of the ozone layer (which absorbs orange and red light, while blue passes and arrives at the moon).
I was lucky to witness the total eclipse under perfect weather conditions in Salem, Oregon. Salem was very accessible with public transport (Amtrak trains arriving before the eclipse, special stop to accommodate people getting off to viewing locations). While this picture does little justice to the real impression of the “inverted Sun” (dark disk with bright corona around it), it shows the irregular “triangular” shape of the corona with three rays poking out. From Earth it is normally impossible to see the corona due to scattered light in the atmosphere, but solar satellites monitor the Sun constantly. I followed NASA’s example and overlaid a space satellite image with my image (after rotating it such that the ecliptic plane [conveniently indicated by Venus] aligns horizontally). If you want to try something similar yourself, I recommend the helioviewer website for easy selection and download of the solar satellite imagery. To match the scales on your pictures: Venus is 34.3 degrees away from the Sun, corresponding to about 130 solar radii. We are presently close to a minimum of solar activity and thus the corona less roundish.
I will resume posting about algorithm development for computational physics. To put these efforts in a more general context, I start with some observation about the current publication ranking model and explore alternatives and supplements in the next posts.
Working in academic institutions involves being part of hiring committees as well as being assessed by colleagues to measure the impact of my own and other’s scientific contributions.
In the internet age it has become common practice to look at various performance indices, such as the h-index, number of “first author” and “senior author” articles. Often it is the responsibility of the applicant to submit this data in electronic spreadsheet format suitable for an easy ranking of all candidates. The indices are only one consideration for the final decision, albeit in my experience an important one due to their perceived unbiased and statistical nature. Funding of whole university departments and the careers of young scientists are tied to the performance indices.
I did reflect about the usefulness of impact factors while I collected them for various reports, here are some personal observations:
A high h-index can be a sign of a narrow research field, since the h-index is best built up by sticking to the same specialized topic for a long time and this encourages serialised publications. I find it interesting that on the other hand important contributions have been made by people working outside the field to which they contributed. The discovery of three-dimensional quasicrystals discussed here provides a good example. The canonical condensed matter theory did not envision this paradigmatic change, rather the study of group theoretical methods in nuclear physics provided the seeds.
The full-text search provided by the search engines offers fascinating options to scan through previously forgotten chapters and books, but it also bypasses the systematic classification schemes previously developed and curated by colleagues in mathematics and theoretical physics. It is interesting to note that for instance the AMS short reviews are not done anonymously and most often are of excellent quality. The non-curated search on the other hand leads to a down-ranking of books and review articles, which contain a broader and deeper exposition of a scientific topic. Libraries with real books grouped by topics are deserted these days, and online services and expert reviews did in general not gain a larger audience or expert community to write reports. One exception might be the public discussion of possible scientific misconduct and retracted publications.
Another side effect: searching the internet for specific topics diminishes the opportunity to accidentally stumble upon an interesting article lacking these keywords, for instance by scanning through a paper volume of a journal while searching for a specific article. I recall that many faculty members went every monday to the library and looked at all the incoming journals to stay up-to-date about the general developments in physics and chemistry. Today we get email alerts about citation counts or specific subfields, but no alert contains a suggestion what other article might pick our intellectual curiosity – and looking at the rather stupid shopping recommendations generated by online-warehouses I don’t expect this to happen anytime soon.
On a positive note: since all text sources are treated equally, no “high-impact journals” are preferred. In my experience as a referee for journals of all sorts of impact numbers, the interesting contributions are not necessarily published or submitted to highly ranked journals.
To sum up, the assessment of manuscripts, contribution of colleagues, and of my own articles requires humans to read them and to process them carefully – all of this takes a lot of time and consideration. It can take decades before publications become alive and well cited. Citation counts of the last 10 years can be poor indicators for the long-term importance of a contribution. Counting statistics provides some gratification by showing immediate interest and are the (less personal) substitute for the old-fashioned postcards requesting reprints. People working in theoretical physics are often closely related by collaboration distance, which provides yet another (much more fun!) factor. You can check your Erdos number (mine is 4) or Einstein number (3, thanks to working with Marcos Moshinsky) at the AMS website.
How to improve the current situation and maintain a well curated and relevant library of scientific contributions – in particular involving numerical results and methods? One possibility is to make a larger portion of the materials surrounding a publication available. In computational physics it is of interest to test and recalculate published results shown in journals. The nanohub.org platform is in my view a best practice case for providing supplemental information on demand and to ensure a long-term availability and usefulness of scientific results by keeping the computational tools running and updated. It is for me a pleasure and excellent experience to work with the team around nanohub to maintain our open quantum dynamics tool. Another way is to provide and test background materials in research blogs. I will try out different approaches with the next posts.