Measuring the Stars, by J. Davis in Sky and Telescope , Vol. The Quest for High Resolution, by J. Davis in Sky and Telescope , Vol. Long-Baseline Optical and Infrared Stellar Interferometry, by M. Shao and M. M. Colavita in Annual Review of Astronomy and Astrophysics , Vol. Stephen T. Ridgway is a visiting scientist at the Center for High Angular Resolution Astronomy at Georgia State University. To study faint stars and galaxies, large telescopes are required for their light-gathering power.
Large telescopes are also valuable for their ability to measure fine detail.
Yet for many purposes, this resolution is still not sufficient. A resolution 100 times better is required, for example, to resolve spots on a typical solar-type star. Fortunately, it isn't necessary. Still, the simplicity of geometric optics hides the complexity of electromagnetic-wave propagation. This method is difficult and has severe limitations, but it allows us to achieve 'aperture synthesis' and greatly exceed the resolution of any telescope.