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The study of nature and how things work ranging from the smallest subatomic and atomic scales, through intermediate scales describing matter in its various forms, up to the largest astrophysical scales.
Exhibit from the American Institute of Physics. The IDEAS section includes Greek scientists/philosophers, Copernicus, Newton, as well as lesser known figures of the 20th century. The TOOLS section combines observation, ideas, and technology: naked eye to early telescopes, through space telescopes, spectroscopy, and nonoptical cosmology. Includes biographies.