Cooled infrared filters and dichroics for the James Webb Space Telescope Mid-Infrared Instrument

The cooled infrared filters and dichroic beam splitters manufactured for the Mid-Infrared Instrument are key optical components for the selection and isolation of wavelengths in the study of astrophysical properties of stars, galaxies, and other planetary objects. We describe the spectral design and manufacture of the precision cooled filter coatings for the spectrometer (7 K) and imager (9 K). Details of the design methods used to achieve the spectral requirements, selection of thin film materials, deposition technique, and testing are presented together with the optical layout of the instrument. (C) 2008 Optical Society of America.

Lewis Fry Richardson's forecast factory - for real

The idea that supercomputers are an important part of making forecasts of the weather and climate is well known amongst the general population. However, the details of their use are somewhat mysterious. A concept used to illustrate many undergraduate numerical weather prediction courses is the idea of a giant 'forecast factory,' conceived by Lewis Fry Richardson in 1922. In this article, a way of using the same idea to communicate key ideas in numerical weather prediction to the general public is outlined and tested amongst children from local schools.