Complex sentence: In 1690 Pierre Varignon assumed that all bodies are exposed to pushes by aether particles from all directions, and that there is some sort of limitation at a certain distance from the Earth's surface which cannot be passed by the particles.
Split into simpler sentences: In 1690 Pierre Varignon assumed that all bodies are exposed to pushes by aether particles from all directions. He assumed that there is some sort of limitation at a certain distance from the Earth's surface, which cannot passed by the particles.