Visible-light astronomy  Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes). Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves. Visible light ranges from 380 to 750 nanometers in wavelength. Visible-light astronomy has existed as long as people have been looking up at the night sky, although it has since improved in its observational capabilities since the invention of the telescope, which is commonly credited to Hans Lippershey, a German-Dutch spectacle-maker, although Galileo played a large role in the development and creation of telescopes. Visible-light astronomy continues to get better in the modern day, with projects such as the James Webb Telescope being projected for launch in the next few years. Since visible-light astronomy is restricted to only visible light, no equipment is necessary for simply star gazing. This means that it's the most commonly participated in type of astronomy, as well as the oldest. Before the advent of telescopes, astronomy was limited solely to unaided eyesight. Humans have been gazing at stars and other objects in the night sky for thousands of years, as is evident in the naming of many constellations, notably the largely Greek names used today. Hans Lippershey, a German-Dutch spectacle maker, is commonly credited as being the first to invent the optical telescope. Lippershey is the first recorded person to apply for a patent for a telescope; however, it is unclear if Lippershey was the first to build a telescope. Based only on uncertain descriptions of the telescope for which Lippershey tried to obtain a patent, Galileo Galilei made a telescope with about 3× magnification in the following year. Galileo later made improved versions with up to 30× magnification. With a Galilean telescope, the observer could see magnified, upright images on Earth; it was what is commonly known as a terrestrial telescope or a spyglass. Galileo could also use it to observe the sky, and for a time was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, Galileo demonstrated one of his early telescopes, with a magnification of up to 8 or 9, to Venetian lawmakers. Galileo's telescopes were also a profitable sideline, selling them to merchants who found them useful both at sea and as items of trade.