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Period: 470 BCE to 390 BCE
Pre-Telescope: First Observation of Optics
Chinese philosopher Mozi recorded observations that showed how concave mirrors could focus rays from the Sun. -
Period: 900 to 1100
Book of Optics Emerges
Ibn al-Haytham’s “Book of Optics” focuses on the properties of light, mirrors, and lenses. It arrives in Europe and becomes the foundation of the modern European study of lenses. -
Period: 1250 to 1300
First Spectacles
The first spectacles were invented. It was unknown who invented it and the invention itself had only a frame with lenses. -
Dawn of the Telescope
Hans Lippershey, a spectacle-maker, applies his patent on what would be known today as a telescope. He patented it before two other Dutch scientists, Jacob Metius and Zacharias Janssen. -
Galileo's Innovations
Galileo improves Hans’s design to make astronomical discoveries. He called it, “perspicillum.” (Spectacles or glasses in Latin.) -
The Ritchey-Chrétien Telescope
One of the most important and popular telescope designs is created, it is called the Ritchey-Chrétien telescope. They are reflector telescopes that use 2 mirrors to focus on an image. -
The Gamma Ray Telescope
The first gamma-ray telescope is carried into space by the American satellite Explorer 11. It was launched April 27, 1961. The gamma ray detector weighed 30 lbs compared to the total weight of the spacecraft’s 82 lbs. -
Hubble Space Telescope
The Hubble Telescope is launched into Earth’s orbit. It was put into space because scientists wanted to observe the universe without the images being filtered through the Earth’s atmosphere. -
Kepler Space Telescope
The Kepler Space Telescope is launched into space. It has a 2.4m diameter mirror. It uses the Schmidt telescope design which involves using a curved mirror to focus light onto a curved film plane that then reflects the image back to what we see. -
James Webb Space Telescope
On December 25, 2021, the James Webb Space Telescope is launched into space. Instead of seeing optical and ultraviolet light like the Hubble Space Telescope, this telescope will mainly be looking at the universe in infrared. It also has a much bigger mirror than Hubble’s. (6.5m vs 2.4m)
