English: Some Applications of electromagnetic radiation: Mobile payment (top left), x-ray scanning (top right), microwave oven (bottom left) and radio astronomy (bottom right)

English: The 30-meter telescope on Pico Veleta in the Spanish Sierra Nevada is one of the two radio astronomy facilities operated by IRAM. Built in only four years (1980 to 1984) at an elevation of 2850 meters, it is one of today’s largest and most sensitive radio telescopes for tracing millimeter waves. The telescope is a classic single dish parabolic antenna, which allows the exploration of extended cosmic objects such as nearby galaxies and interstellar clouds. Due to its large surface, the 30-meter telescope is unrivalled in its sensitivity and is well adapted to detect weak sources. By pointing the telescope towards a celestial source, and then by scanning and tracking the source, one can build up radio images – whether of complete galaxies or regions of star formation in the Milky Way. With its ability to observe simultaneously at several wavelengths, the telescope can produce multiple images.

English: Mobile payment terminal, in Fornebu, Norway. Operated by NFC technology. Telenor.

English: matlåda, mikro, mikrovågsugn