Ocular, the lens also known as the eyepiece in a refracting telescope and in a microscope.
Whether they're sorting out scrap metal or helping us unlock the secrets of the universe, electromagnets are pretty nifty devices. What's so great about magnetism on demand? We'll electrify you with the details in these videos.
Who made it possible to light up your home at night? Thomas Edison, right? Yes, but without the work of Nikola Tesla, we would be living in a different world.