EISCAT, the European Incoherent SCATter system, was an advanced research radar system established in northern Scandinavia in the mid-1970s for studies of the aurora and the earth's plasma environment. This paper describes the operation, development, problems and successes of the system during its first 2 decades, as recalled by its former deputy director.

In this article, I trace the history of the models of ice ages during the period between the nineteenth and twentieth century. Some previous versions of ice age models were briefly discussed. I present a bird’s-eye view of the scientific collaboration in developing a model and of the reasons behind the success of the Milankovitch model as well.

For a long time, human beings have lived with the idea of cycles, as attested by many ancient traditions. This perception led our way of observing and interpreting the most diverse types of phenomena. In the Earth sciences, cyclicity has crucial epistemological value. It offers simple solutions for cause and consequence analysis in time and space. The intention here is to review how such ideas emerged in the geosciences, supporting current stratigraphic principles and practices.

We present the history of how and why a high-power radio wave transmitter facility with large antenna arrays was built in northern Norway in the 1970s with the aim of injecting radio waves into the auroral ionosphere. The facility has conducted fundamental research on plasmas, by heating electrons and exciting plasma waves in the ionosphere; the effects of these experiments have been measured using a host of other instruments, such as incoherent scatter radars, radio receivers, and cameras.

The road to success for Danish seismologist Inge Lehmann (1888–1993) – known for her 1936 discovery of the Earth's inner core – was difficult and full of challenges. While she herself refused to accept any notion of gender difference ascribed, society at large was less open-minded. Using newly discovered, unpublished historical documents, this article examines to what degree her gender played a decisive role in her graduate and postgraduate experiences.