Who Invented the Telescope?

Ask any child, "Who invented the telescope," and you will probably be met with the same answer: Galileo. While this answer has been widely discredited, another incorrect answer-Hans Lippershey-is being propagated as the ultimate truth. However, as with much of history, the invention of the telescope was more of a process than a sudden creation by one astute inventor that can be nailed down to a specific time and place. This article describes the progression of the telescope's invention during the 16th and 17th centuries in Europe, as summarized in the table below.

Progression of Early Telescope Magnification

The Very First Telescope? Historian Colin Ronan has put forth convincing evidence that Leonard Digges created a telescope sometime in the mid 16^th century. Although the device was likely crude and unable to be mass-produced, the presence of lenses capable of basic magnification and written testimony that "perspective lenses" existed prior to the 17^th century imply that, if not Digges, someone around this time created something very close to the telescopes popularized during the following century.

The First Telescope Patent: Many pundits like to debunk the myth that Galileo invented the telescope in 1609 by pointing out that Hans Lippershey requested a patent for a telescope an entire year earlier, but creating a new myth that Lippershey himself "invented" the telescope goes a bit far in revising history. Lippershey's patent application preceded Jacob Metius's patent for the same technology by just a few weeks, and historical evidence points to Zacharias Janssen and others using telescopes around the same time. Lippershey was perhaps the most entrepreneurial of the bunch, but not necessarily the most groundbreaking.

The Myth Of Galileo: In contrast, many of Galileo's achievements were quite groundbreaking, and, although he did not "invent" the telescope, his enhancements and uses of the telescope can probably be considered more original than anything Lippershey, Metius or Janssen did. He was the first to add both convex and concave lenses, and he increased magnification of the telescope considerably. He also was the first to use the telescope for astronomical, rather than military or novelty, purposes.

Newtonian Telescope: Galileo's telescope was refractive, which creates images that suffer from chromatic aberration. Although not the first aware of this challenge, Isaac Newton was the first to successfully address it through the creation of a reflective telescope in 1669. This telescope used a design similar to that of Leonard Digges, and, though perhaps less crudely designed, it was no more practical for replication. Reflective telescopes were not popularized until the next century.

We will likely never know exactly when someone first employed a pair of lenses to magnify and see distant objects; it very well might have been before even Leonard Digges did so in the mid 16th century. However, it is clear that the importance of telescopes as tools for military use and astronomical study escalated in the early 17th century, leading to patent applications and rapid development of this important technology.