Scientists are acutely aware of the attraction force inherent in gravity, as are folks in general. The babe learns about this early, while taking his first few steps. Oops. Ouch! It is assumed that gravity has only an attractive force, and that the planets, in orbit around the Sun, are held in place by their momentum. Does this make sense? What caused the momentum in the first place? Children play with a ball on the end of a string, swinging it around and around their head. As long as the arm is tugging, the ball maintains its orbit, else stops. Why would the planets not drift into the Sun? Are the orbits all that swift so that centrifugal force is extreme?
The reason Mankind is Unaware of a repulsive force, also inherent in gravity, is that for this to become evident there must be a semblance of equality in size and weight, i.e. the mass of the objects, and freedom of movement such as exists in space, and lack of undue influence from other nearby objects. Objects on the surface of the Earth have none of these. They are infinitesimal in proportion to the Earth itself, and thus any repulsion the Earth may have toward a tiny speck on its surface is also infinitesimal. Proportionally, its all gravity, a one way trip. The object on the surface, pushing away, is overwhelmed by the Earth's gravitational pull, the attraction. The repulsion force is generated as a result of two bodies exerting a gravitational force on each other. In the case of a tiny object on the surface of the Earth, its gravitational pull on the Earth is scarcely noticed by the Earth. A gnat or mite. A nothing. Where the repulsion force has not been invoked within the Earth by any objects placed on the surface of the Earth, this is in play between the Earth and her Moon. The repulsion force is invoked between objects on the surface of the Earth, incessantly, but this is masked by the intense force of gravity the Earth presents and other factors such as surface tension or friction or chemical bonding so that the repulsion force cannot be recognized.
The gravitational force exists first. It is the static condition. The repulsion phenomena only manifests when, as we said, the objects are of equal size, are free to move, and dominate the immediate environment. Where the repulsion force comes to equal the force of gravity by the time the objects in play would make contact, it builds at a rate that differs from gravity. Humans have calculated the force of gravity, which at first they assumed was equal for all objects but lately have come to understand is stronger for larger objects. They have formulas for the force of gravity which have proved accurate on the face of their home planet. These formulas are incomplete, and would not work as expected elsewhere, however. The repulsion force is infinitesimally smaller than the force of gravity, but has a sharper curve so that it equals the force of gravity at the point of contact. For experimental purposes, one would have to be almost at the point of contact for it to come into play at all, and this in an environment where other factors are eliminated or negated. To examine the phenomena, Earth scientists would have to set up a lab in space, far enough away from any planetary body so that free movement is possible. Place two balls in a cage. Put one in motion toward another. Microscopically examine the interchange. They do not touch. They do not bounce off one another. They do not touch.