The Death Star is referred to in
the
movie as a moon sized space station. Inside the Death Star there are
many different rooms such as living quarters, command section, and
dining areas. You see people walking around the Death Star just as they
would on any other planet, but there's a problem. Where is the gravity
coming from that is holding everyone down? 
Now taking into a fact Newton's Law of Gravitation, that
every particle attracts any other particle with a gravitational force
of magnitude. The Death Star was indeed very big, but it was mostly
empty space with all the rooms and hanger bays it had. So the Death
Star did have some gravitational force acting on everything and
everybody, but that force was no greater than the gravitational force
of the moon. Now because they were a technologically advanced society
they might of had some type of gravity well mechanism to generate
artificial gravity, but that would take a tremendous amount of energy
to
create that type of force. So throwing that out the window there is
only one other way to generate a type of artificial gravity, using
centripetal force. Now even though centripetal force is not a new kind
of force, it's just the direction of the force by using uniform
circular motion.
We can use Newton's 2nd law of F=ma and rewrite it as F=m(v^2/R). If the Death Star was rotating at a constant speed it would contain a force outward that would act as artificial gravity. Instead of walking on the floors, you would be walking on the walls. So when the Death Star was built they would just make the hallways and everything else in this rotation of the floors being the walls and the walls being the floor.
Now taking into a fact Newton's Law of Gravitation, that
every particle attracts any other particle with a gravitational force
of magnitude. The Death Star was indeed very big, but it was mostly
empty space with all the rooms and hanger bays it had. So the Death
Star did have some gravitational force acting on everything and
everybody, but that force was no greater than the gravitational force
of the moon. Now because they were a technologically advanced society
they might of had some type of gravity well mechanism to generate
artificial gravity, but that would take a tremendous amount of energy
to
create that type of force. So throwing that out the window there is
only one other way to generate a type of artificial gravity, using
centripetal force. Now even though centripetal force is not a new kind
of force, it's just the direction of the force by using uniform
circular motion. We can use Newton's 2nd law of F=ma and rewrite it as F=m(v^2/R). If the Death Star was rotating at a constant speed it would contain a force outward that would act as artificial gravity. Instead of walking on the floors, you would be walking on the walls. So when the Death Star was built they would just make the hallways and everything else in this rotation of the floors being the walls and the walls being the floor.