Here are some examples of technologies that were considered impossible, magic, legendary, or miraculous in medieval times, but are now achievable thanks to advances in science and technology:
Remote viewing : Satellite, Google Maps, video call, IP camera
Levitation : Magnet, sound levitation
Healing : Medical technology, treatments
Invisibility : Advanced materials, optical technologies
Teleportation : Quantum teleportation
Weather control : Weather satellite, radar, supercomputer
Flight : Airplane, jetpack
Golems : Robots
Fire magic : Flame-thrower, napalm, lighter
Magic mirror : Smartphone, computer
Telekinesis : Robotics, artificial intelligence
Shape-shifting : Virtual and augmented reality
Communication with the dead : Speech recognition, natural language processing
Immortality : Medical technologies, organ transplantation, gene editing
Clairvoyance : Telescope, camera, satellite
Transmutation : Chemical reactions, particle accelerator
Resurrection : Defibrillation, organ transplantation
Precognition : Machine learning, data analysis
Divination : Machine learning, data analysis
Telepathy : Brain-computer interface, neural implants
Can you think of anything else? Please post in comments, I'll be upvoting best finds!