Gravity is Love.
— Brian Swimme
The principle of attraction and its opposite repulsion is pervasive throughout the conceptualization of modern physics. Even ancient Empedocles, of the four elements fame, thought that in all nature the force of attraction and combination was Love or Philia, and that the force of repulsion and separation was Strife or Neikos. These forces have now been depersonalized and mathematized, but still inhabit natural laws which must be obeyed. (See the Four Fundamental Forces of Physics.)
At all levels of matter and energy, from the lowest atomic interactions to the highest cosmic forces, the duality of attraction and repulsion are everywhere. In atoms, there is the strong force and the weak force that respectively pull nuclei together or push them apart. In and between atoms and molecules, covalent bonds, magnetic polarities, electric charges, hydrogen bonds, salt bridges, and hydrophobic effects gather and scatter and even make life possible. In the large-scale macro world, electromagnetism and gravity extend their influence. And in the cosmic arena, the mysterious effects of dark matter and dark energy perform without our current understanding.
In the biological world, attraction and repulsion are seen in the action of plants and animals. The plant is attracted to light and moisture, and repulsed by darkness and dryness. The animal is attracted to food and safety, and repulsed by lack and danger. Plants and animals are also attracted to their kin, and repulsed by their non-kin, because there is strength in commonality. However, too much sameness becomes toxic. It is the dynamic between attraction and repulsion that creates much of the living world and its richness.
In the human world, culture and language enable the forces of attraction and repulsion. Known culture and language is attractive; unknown culture and language is repulsive. But the human mind also craves newness. Interactions between the same and the different have been a great source of the creative drive which fuels the human spirit.
The sums of attractions are combinations. The sums of repulsions are separations.