The electron microscope works much like an optical microscope except for one main difference. The optical microscope uses glass to bend light to focus an image to increase magnification where an electron microscope uses magnetic coils to bend streams of electrons to focus an image. The resolving power of microscopes is limited by the wavelength of the light used to illuminate the sample. Visible light microscopes are limited to resolving powers of the order of 1000x. The wavelength of electrons allows for resolving powers on the order of 1,000,000x. This device opened a new era of study of the microscopic world and earned Ruska half the 1986 Nobel Prize in Physics and a place in science history.
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