400 Years of the Telescope
A Journey of Science, Technology and Thought



 
400 Years of the Telescope
A Journey of Science, Technology and Thought

 
The word telescope now refers to a wide range of instruments detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.

Based only on uncertain descriptions of the first practical telescope, invented by Hans Lippershey in the Netherlands in 1608, Galileo, in the following year, made a telescope with about 3x magnification.

He later made improved versions with up to about 30x magnification.

With a Galilean telescope the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass.


Beautifully photographed in 4K digital cinematography, the film is a visually stunning chronicle of the history of the telescope from the time of Galileo, its profound impact upon the science of astronomy, and how both shape the way we view ourselves in the midst of an infinite universe.

The film features interviews with leading astrophysicists and cosmologists from the world's renowned universities and observatories, who explain concepts ranging from Galileo's act of revealing the cosmos with a simple telescope, to the latest discoveries in space, including startling new ideas about life on other planets and dark energy — a mysterious vacuum energy that is accelerating the expansion of the universe.


The earliest evidence of working telescopes were the refracting telescopes that appeared in the Netherlands in 1608.

Their development is credited to three individuals: Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, and Jacob Metius of Alkmaar.

Galileo greatly improved upon these designs the following year. The idea that the objective, or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope.

The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs and several attempts to build reflecting telescopes.

In 1668, Isaac Newton built the first practical reflecting telescope, which bears his name, the Newtonian reflector.

The invention of the achromatic lens in 1733 partially corrected color aberrations present in the simple lens and enabled the construction of shorter, more functional refracting telescopes.

Reflecting telescopes, though not limited by the color problems seen in refractors, were hampered by the use of fast tarnishing speculum metal mirrors employed during the 18th and early 19th century—a problem alleviated by the introduction of silver coated glass mirrors in 1857, and aluminized mirrors in 1932.

The maximum physical size limit for refracting telescopes is about 1 meter (40 inches), dictating that the vast majority of large optical researching telescopes built since the turn of the 20th century have been reflectors.

The largest reflecting telescopes currently have objectives larger than 10 m (33 feet). The 20th century also saw the development of telescopes that worked in a wide range of wavelengths from radio to gamma-rays. The first purpose built radio telescope went into operation in 1937. Since then, a tremendous variety of complex astronomical instruments have been developed.