A stasis or stasis field, in science fiction, is a confined area of space in which time has been stopped or the contents have been rendered motionless.
Overview
A stasis field is imagined to be a region in which a stasis process is in effect. Stasis fields in fictional settings often have several common characteristics. These include infinite or nearly infinite rigidity, making them "unbreakable objects" and a perfect or nearly-perfect reflective surface. Most science fiction plots rely on a physical device to establish this region. When the device is deactivated, the stasis field collapses, and the stasis effect ends.
Time is often suspended in stasis fields. Such fields thus have the additional property of protecting non-living materials from deterioration. This time dilation can be, from an in-universe perspective, absolute; something thrown into the field, has the field triggered and then reactivated, would fly out as if nothing had happened. Storylines using such fields often have materials as well as living beings surviving thousands or millions of years beyond their normal lifetimes. The property also allows for such plot devices as booby traps, containing, for instance, a nuclear bomb. Once out of the stasis field, the trap is sprung. In such a situation, to avoid the protagonist from seeing what is in the field, the story line would not allow normal beings to see something protected by a stasis field.
One use of stasis fields is as a form of suspended animation: to let passengers and cargoes (normally of spacecraft or sleeper ships) avoid having to experience extremely long periods of time by "skipping over" large sections of it. They may also be used, such as in The Night's Dawn Trilogy, as protection against the effects of extreme acceleration.
There are real phenomena that cause time dilation similar that of a stasis field. Extremely high velocities approaching light speed or immensely powerful gravitational fields such as those existing near the event horizons of black holes will cause time to progress more slowly. However, there is no known theoretical way of causing such time dilation independently of such conditions.
Examples
The Dune series of novels refers to "nullentropy" containers, where food is preserved indefinitely, as well as entropy-free "no-chambers" or "no-ships" which are undetectable to prescience.
The noted science fiction author Larry Niven used the concept of stasis fields and stasis boxes to a great extent directly or indirectly throughout his many novels and short stories set in the Known Space series. Niven's stasis fields followed conductive surfaces when established, and the resulting frozen space became a completely invulnerable and perfectly reflective object. They were often used as emergency protective devices. They could also be used to create a weapon called a variable sword, a length of extremely fine wire in a stasis field that makes it able to easily cut through normal matter. For more information, see Slaver stasis field.
A more limited form of stasis field is the "bobble", found in Vernor Vinge's Peace Authority setting. A bobble is always perfectly spherical and exists for a fixed period of time that is set when the bobble is first created. The duration of a bobble effect cannot be changed. Bobble generators were initially used as weapons, removing their targets from the field of combat.
Another example of a stasis field exists in Joe Haldeman's The Forever War, where stasis field generators are carried by troops to create conditions where melee weapons become the only viable means of combat. Inside the field, no object can travel faster than 16.3 m/s, which includes electrons, photons, and the field itself. Soldiers inside the field must be wearing suits with a special coating, or all electrical activity within their body would stop and the soldiers would die. In the novel, the main character defeats an enemy army, which has besieged a small remaining contingent of human troops on a moon, by arming a nuclear bomb inside the field and then moving the field away from the bomb. Once the bomb is revealed, its electrical activity resumes, and it promptly detonates. That vaporises the surrounding army, and a large chunk of the ground beneath the field. The soldiers emerge some days later to see if their trick worked and find themselves alone at the bottom of a large crater, their enemy destroyed.
In Peter F. Hamilton's The Night’s Dawn trilogy (1996-1999), “zero-tau pods” — powered containers inside which time halts — are an important narrative device.