Global and local geospace modeling in ISTP

The objective of the University of Maryland ISTP theory project is the development of the analytical and computational tools, which, combined with the data collected by the space and ground-based ISTP sensors, will lead to the construction of the first causal and predictive global geospace model. To attain this objective a research project composed of four complementary parts is conducted. First the global interaction of the solar wind-magnetosphe re system is studied using three-dimensional MHD simulations. Appropriate results of these simulations are made available to other ISTP investigators through the Central Data Handling Facility (CDHF) in a format suitable for comparison with the observations from the ISTP spacecrafts and ground instruments. Second, simulations of local processes are performed using a variety of non-MHD codes (hybrid, particle and multifluid) to study critical magnetospheric boundary layers, such as the magnetopause and the magnetotail. Third, a strong analytic effort using recently developed methods of nonlinear dynamics is conducted, to provide a complementary semi-empirical understanding of the nonlinear response of the magnetosphere and its parts to the solar wind input. The fourth part will be conducted during and following the data retrieval and its objective is to utilize the data base in conjunction with the above models to produce the next generation of global and local magnetospheric models. Special emphasis is paid to the development of advanced visualization packages that allow for interactive real time comparison of the experimental and computational data. Examples of the computational tools and of the ongoing investigations are presented.     

A language based on the fundamental facts of science

The problem of how to communicate with the members of an alien society has been discussed by many authors but only one, Hans Freudenthal, has constructed a language for this purpose. Freudenthal assumes nothing other than the ability to reason as humans do and, because he assumes so little, it is necessary to communicate a great deal about the language itself before being able to communicate any interesting information. The problem is here approached differently. Since it is likely that contact between our civilization and an alien one would be via radio, potential correspondents would have a basic knowledge of science. Such beings should therefore be able to learn a language based on fundamental science. It is assumed, more specifically, that our correspondents can count, understand chemical elements, are familiar with the melting and boiling behaviour of a pure substance and understand the properties of the gaseous state. All this should be known to any society capable of developing the radio telescope. By systematically using this common knowledge one can communicate notation for numbers and chemical elements and then communicate our basic physical units; i.e., the gram, the calorie, the degree (Kelvin), etc. Once this is done more interesting information can be exchanged.