You might be surprised to read that we don not know exactly what is gravity. We feel it’s influence and we can determine how it operates in the universe. Some scientists think that this force is made up of particles called gravitons that travel at the speed of light. However, if we are to be honest, we do not know what gravity "is" in any fundamental way - we only know how it behaves.
We can define gravity is a force of attraction that exists between any two masses, any two bodies, any two particles.This force is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe. The effect of gravity extends from each object out into space in all directions, and for an infinite distance. However, the strength of the gravitational force reduces quickly with distance. Humans are never aware of the Sun's gravity pulling them, because the pull is so small at the distance between the Earth and Sun. Yet, it is the Sun's gravity that keeps the Earth in its orbit! Neither are we aware of the pull of lunar gravity on our bodies, but the Moon's gravity is responsible for the ocean tides on Earth.
Is there gravity in space? Yes but it's very, very small and it’s called "microgravity". Gravity affects everything, everywhere, although in space it is usually such a small effect that it can be ignored.
s gravity the same all over the surface of the Earth? NO!
Recent measurements done by JPL and NASA proved that in some places you will feel slightly heavier than others. The above relief map shows in exaggerated highs and lows where the gravitational field of Earth is relatively strong and weak. A low spot can be seen just off the coast of India, while a relative high occurs in the South Pacific Ocean. The cause of these irregularities is unknown since present surface features do not appear dominant. Scientists hypothesize that factors that are more important lay in deep underground structures and may be related to the Earth’s appearance in the distant past.
What is the influence of the microgravity over plants and animals? How about the effects of an increased gravity force over living specimens from our planet?