what was the force field? why …

In physics a force field is a vector field that describes a non-contact force acting on a particle at various positions in space. Specifically, a force field is a vector field {\displaystyle {\vec {F}}}{\vec {F}}, where {\displaystyle {\vec {F}}({\vec {x}})}{\vec  {F}}({\vec  {x}}) is the force that a particle would feel if it were at the point {\displaystyle {\vec {x}}}{\vec {x}}. In speculative fiction, a force field, sometimes known as an energy shield, force shield, force bubble, defence shield or deflector shield, is a barrier made of energy, plasma, or particles. It protects a person, area, or object from attacks or intrusions. This fictional technology is created as a field of energy without mass that acts as a wall, so that objects affected by the particular force relating to the field are unable to pass through the field and reach the other side. This concept has become a staple of many science-fiction works, so much that authors frequently do not even bother to explain or justify them to their readers, treating them almost as established fact and attributing whatever capabilities the plot requires.