TARDIS force field
From Tardis Wiki, the free Doctor Who reference
The TARDIS force field was a force field surrounding the outer plasmic shell of the craft. It was designed to protect the occupant(s) both from harm (though it was far from invulnerable) and from the Time Vortex and other environments dangerous to its pilot.
- See real world interface.
On one occasion during his fourth incarnation, the Doctor was able to reconfigure the force field of his TARDIS, a Type 40, into a corridor through which he could safely traverse a vacuum. (DW: The Horns of Nimon)
After the Last Great Time War, the force field was non-default, and a tribophysical waveform macro-kinetic extrapolator was required for the TARDIS to work instead. (DW: The Parting of the Ways)
