Another familiar trope in both the Star Trek and Star Wars universes, deflector shields are forever being powered up to ward off pesky Klingons, TIE fighters, what-have-you. NASA has done some research toward using plasma-based force fields to protect spacecraft in orbit from radiation, and more recently, Portuguese scientists have proposed a deflector shield made of plasma contained in a magnetic field. The inspiration for the Portuguese plan? Earth's own magnetic field, which acts as a giant deflector shield, diverting charged particles from the Sun that would otherwise fry the planet. At 3.45 billion years, Earth's built-in deflector shield is the oldest example of sci-fi reality on the list.