The Master Key on Instagram: "Ten people who could have changed everything. Ten names most people have never heard. Ten inventors, scientists, and visionaries who either disappeared, died mysteriously, or had their work buried. Thomas Ogle built an engine that ran 100 kilometers on just one gallon of fuel. Imagine what that would do to the oil industry. He died under suspicious circumstances. Nikola Tesla developed technology for free wireless energy accessible to everyone on the planet. His lab

History Facts & Stories on Instagram: "In 1939, inventor William E. Urschel created the world’s first 3 D printed building behind a small warehouse in Valparaiso, Indiana. The experimental structure was produced using a custom built mechanical system that continuously extruded layers of concrete to form walls directly on site, reducing the need for traditional formwork and manual labor. The following year he would file a series of patents for a Wall Building Machine, describing a method for auto