1. Newton's Law of Universal Gravitation: This law states that every particle in the Universe attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This law explains why objects fall to the ground, why the planets orbit the Sun, and why galaxies hold together.

2. The Law of Conservation of Energy: This law states that energy cannot be created or destroyed, only transformed from one form to another. This law is fundamental to physics and explains why energy is always conserved in a closed system, even when it appears to be lost or gained.

These laws are examples of fundamental principles in science. They have been rigorously tested and confirmed through countless experiments and observations, making them extremely reliable. They also have wide applications in various fields of science and engineering.