Max Planck Institutes and Experts

Light microscopy has continually played a key role in science, but diffraction has limited the imaging of details that are smaller than about half the wavelength of light. For the important contrast mode of fluorescence, which is crucial to modern cell and molecular biology, the diffraction barrier has now been broken. In spite of relying on focused visible light, stimulated emission depletion (STED) microscopy is not limited by diffraction. To date, current schemes of STED-microscopy have delivered 50 nm (1/12 of the wavelength) resolution on cell membranes.

Scientists at the Max-Planck Institute for Astrophysics have carried out the worldwide largest cosmological simulation of structure formation and used it to make accurate theoretical predictions for the growth of galaxies and supermassive black holes. For the first time, the model allows a detailed comparison of the theory of hierarchical galaxy formation to observations in a volume comparable to that of the largest spectroscopic redshift surveys, including rare objects such as the first quasars or massive galaxy clusters.

Researchers at the Max-Planck-Institute for Astrophysics have developed new relativistic models which allow predictions of so far unknown properties of short gamma-ray bursts. Their simulations will come under scrutiny by the Swift Gamma-Ray Burst Explorer, a NASA mission that was launched on November 20, 2004.

In theory as well as in practice the relationship between experience, experiment and theory has changed over time. The studies concentrate on the period between the 18th and the early decades of the 20th century. Around 1800 we observe the complex interplay of practical knowledge traditions (mechanical arts, crafts) and their impact on the formation of the physical sciences. Around 1900 new experimental techniques werde developed within experimental physics, evoking a fundamental discussion about the potentials and limits of sensory experience in the sciences.

Modern spin-electronics defines high requirements for the design and fabrication of new materials. Dilute magnetic semiconductors take an important position among the materials that can fulfill these requirements. Here we report on the results of some of our first-principles studies on these materials. We show that partially filled electronic bands play an important role in the magnetism of these systems. The long-range exchange interaction appears as a compromise between the delocalization of the hole states from the 3d impurities and the strength of the 3d-hole interaction. The properties of this compromise depend strongly on the system studied and can be determined only within the framework of the realistic first-principles density-functional-theory calculations