How They Built the World's Largest Telescope (1936-1948) - Palomar Observatory

Discover how Palomar Observatory and the legendary 200-inch Hale Telescope were built—an engineering project that took more than 20 years and pushed glassmaking, precision optics, structural engineering, and telescope construction beyond anything attempted before. In this AI-powered historical reconstruction, we rebuild Palomar Observatory from an empty mountaintop in the 1930s to the moment Edwin Hubble finally used the completed telescope in 1949. Using historical engineering records, construction documentation, technical drawings, archival photographs, and contemporary accounts, this documentary follows the extraordinary process of creating what would become the world's most powerful optical telescope. See how George Ellery Hale secured $6 million for a telescope that had no site, no mirror, and no proven method of construction. Follow the failed attempt to create an enormous fused-quartz mirror before Corning Glass Works turned to Pyrex and successfully cast a 20-ton, 200-inch glass disc. Watch as the mirror survives a flood and power failure during its ten-month cooling process, then travels across America by special train at just 25 miles per hour. Inside Caltech's optical shop, the enormous blank was transformed into a precision astronomical mirror. Tons of glass were ground away as opticians worked toward a surface accurate to approximately two millionths of an inch. Meanwhile, on Palomar Mountain, workers built the roads, water systems, electrical infrastructure, foundations, rotating dome, and the 530-ton telescope that would eventually carry it. See how engineers used pressurized oil bearings to make hundreds of tons of steel move precisely enough to track a star, how the 1,000-ton rotating dome could be moved by just two small motors, and how the mirror was transported up the specially engineered Highway to the Stars. World War II stopped the project with the mirror nearly finished, leaving the completed telescope waiting for years while its optics