A screwdriver, pen, lipstick and gun – sonic technology has always been in the firm grip of the Doctor, her friends and enemies. At the press of a button, the Doctor can disarm a Silurian solider, sever a suspended rope and crack any lock… as long as it’s not made of wood. The power of the sonic screwdriver is not merely the product of mechanical make-believe but follows the logic of high-kinetic sonic waves. The physical abilities of sonic technology can be demonstrated in acoustic levitation. Using a sound-emitting transducer, sound waves are sent upwards to an overhanging reflector, which reflects the waves back down. At a specific wavelength this sound pressure can hold an object in its grasp and appear to make it levitate. However, these sound waves can do much more than hold a ball in mid-air.
Sound waves, such as ultrasound, can be used to see inside the body, used at high frequencies to vibrate the dirt away when cleaning tanks, while infrasound can even be weaponised to affect hearing, balance and induce headaches.