Can you have zero gravity conditions on Earth?

Answer 1

Gravity declines as a function of the square of the distance from a mass. Earth's gravity is less and less as one goes further away, but is never zero. A quarter of a million miles from earth, gravity is still strong enough to hold the moon. Earth has very tiny affects on the orbits of Mars and Venus, millions of miles away.

About four million miles away from earth, gravity is about one millionth that at the surface. A 200 pound man would feel a weight of just 1/5000 pound or about the weight of a grain of sand at the surface.

There are areas of space near the Earth (and every gravitationally significant object in the solar system, such as other planets and significant moons) in which the effects of Earth's Gravity are balanced against and neutralized by (and equivelantly neutralizing) the effect of the Sun's gravity, enabling an object to 'hover' at a fixed point relative to earth instead of having to maintain an orbit. These are called Lagrangian points.

Answer 2

No. That's the simple answer. You can simulate zero gravity in a couple of ways. One is unrestricted free fall. Astronauts are trained in an airplane which plunges toward the ground as if in complete free fall. They get just seconds of free fall time per flight. A second way is to immerse the subject in fluid that provides buoyancy.

Answer 3

Gravity will always be there, but you can set up an arrangement where you will appear to be weightless. Such an arrangement is in a plane that flies up and swoops down so that its path is a circle standing on edge. You will hang in the plane and appear to be weightless. What is actually happening is that for a few seconds the plane is falling at the same speed as you are so if you measured your weight on scales in the plane, you would appear to weigh zero.