Astronomical observation, tracing back to 1608, relies significantly on astronomical telescopes. It's no overstatement to claim that the birth and evolution of telescopes are foundational to modern astronomy.
As telescopic capabilities continue improving, astronomy undergoes a monumental leap, rapidly advancing humanity's comprehension of the cosmos.
Astronomy, an ancient yet continually evolving natural science, focuses on understanding the laws governing the universe. It primarily involves observing and interpreting celestial bodies' material conditions and events.
Its main research areas encompass the distribution, movement, positions, status, structures, compositions, properties, origins, and evolution of celestial entities. Differing from other natural sciences, astronomy predominantly relies on observation to gather diverse information about celestial bodies. Therefore, studying observation methods and instruments represents a crucial pursuit for astronomers. Constant enhancement and diversification of observational techniques serve as an endless quest and mission for astronomers and enthusiasts alike, propelling astronomical advancements.
Traditionally, the telescope is credited to Dutch spectacle maker Hans Lippershey in 1608. In 1609, Italian astronomer Galileo Galilei fashioned a telescope with a 4.4cm convex objective lens, a 1.2m focal length, and a concave eyepiece, magnifying objects by 33 times. Galileo utilized it to observe the moon, sun, stars, and Milky Way, discovering Jupiter's moons and determining sunspot cycles.
In 1611, German astronomer Johannes Kepler invented the Keplerian telescope, differing from Galileo's by placing the eyepiece behind the focal point with a convex lens, producing inverted images. Its advantage lies in placing crosshairs at the focal point as aiming references.
The birth of the first reflective telescope occurred in 1668. After multiple unsuccessful attempts to grind non-spherical lenses, Isaac Newton ingeniously invented the reflective telescope, replacing refractive mirrors. This marked a significant achievement due to its numerous advantages and relative ease of construction compared to refractive telescopes, despite inherent limitations.
The catadioptric telescope appeared in 1814. By 1931, German optician Bernhard Schmidt combined a nearly parallel plate non-spherical thin lens with a spherical mirror, creating a catadioptric telescope. Known for its strong light-gathering ability, large field of view, and minimal aberrations, it excelled in capturing extensive sky photographs, particularly highlighting faint nebulae.
This type of telescope became an indispensable tool for astronomical observation, blending the advantages of refractive and reflective telescopes, ideal for unprofessional astronomy and photography.
For over three centuries, optical telescopes have remained astronomy's foremost tools. In 1932, Karl Jansky detected radio emissions from the Milky Way's center using a radio antenna, marking humanity's first window for observations beyond traditional optical wavelengths. In the 1960s, astronomy witnessed four significant discoveries—quasars, pulsars, interstellar molecules, and cosmic microwave background radiation—achieved through observations with radio telescopes.
Astronomy stands as humanity's forefront in comprehending the universe, occupying a foundational position in national scientific development. The innovative level of astronomy reflects a country's, especially major powers', comprehensive technological prowess and significant benchmark.
