Who's appliances of science

Doctor Who was full of mental technology, some of which bears no resemblance to any possible science...

Cybermen

This race inhabited Earth's twin planet, Mondas. As it moved farther away from the Sun, its inhabitants took drastic measures in order to survive; their bodies became old and diseased, and were replaced with plastic and metal. Finally, computers replaced their brains. They desire Earth both for its mineral resources and for its people - captured humans are converted into Cybermen.

Daleks

Encased in their pepperpot-shaped travel machines, each Dalek is a mutant monstrosity from the planet Skaro. One of the galaxy's most feared races, they are interested only in conquest.

K9

Constructed by Professor Marius of the medical Bi-Al Foundation, K9 is a huge database of information and is equipped with a laser in his nose. In his first encounter, K9 helped defeat the Swarm that was attacking not only the Bi-Al Foundation but the Doctor's own brain.

TARDIS

The Time And Relative Dimensions In Space vessel is what Time Lords travel in. It exists outside of normal space and time, and is not limited by standard geometry and physics (it's bigger on the inside than outside). There is a telepathic link between the Doctor and his ship and they share a kind of symbiotic relationship.