I think that glass is under-appreciated. Without it we would not have telescopes and microscopes (and all the scientific (and later engineering) that came from

I think that glass is under-appreciated. Without it we would not have telescopes and microscopes (and all the scientific (and later engineering) that came from them), and later movies and photography—the latter also led to photolithography. * https://en.wikipedia.org/wiki/Glass https://en.wikipedia.org/wiki/Glass * https://en.wikipedia.org/wiki/Telescope https://en.wikipedia.org/wiki/Telescope * https://en.wikipedia.org/wiki/Microscope https://en.wikipedia.org/wiki/Microscope * https://en.wikipedia.org/wiki/Photolithography https://en.wikipedia.org/wiki/Photolithography Nevermind the day-to-day quality of life improvements of eye glasses. Also: * https://en.wikipedia.org/wiki/Optical_fiber https://en.wikipedia.org/wiki/Optical_fiber Would also need laters: modern communications would be much different if we still had to use copper cable (esp. over long distances), or microwave relays.