# 13 Examples of Natural Laws

The laws of nature are propositions that state constant phenomena. They are considered constant because they have been found to recur in a variety of circumstances and conditions.

The formulation of the laws is based on empirical observations of natural phenomena, which allow drawing conclusions about their invariance and predictability.

The characteristics of natural laws are:

• Universal. As long as the conditions described by law are met, the phenomenon will occur.
• Objectives. Natural laws are objective, that is, they can be verified by anyone.
• Predictive. Since they are universal, they allow us to foresee that certain phenomena will occur under certain conditions.

Some laws are named after the scientist who discovered the phenomenon, such as Newton, Kepler, or Mendel.

### Examples of natural laws

1. Newton’s First Law. Law of inertia. Isaac Newton was a physicist, inventor, and mathematician. He discovered the laws that govern classical physics. Its first law is: “Every body perseveres in its state of rest or uniform or rectilinear motion, unless it is forced to change its state, by forces impressed on it.”
2. Second law of Newton. Fundamental law of dynamics. “The change in the acceleration of a movement is directly proportional to the printed motive force and occurs according to the straight line along which that force is printed.”
3. Newton’s third law. Principle of action and reaction. “To every action corresponds a reaction”; “With every action an equal and opposite reaction always occurs, that is, the mutual actions of two bodies are always equal and directed in the opposite direction.”
4. Zero principle of thermodynamics. Formulated by Ralph Fowler, it states that two bodies that are at the same temperature do not exchange heat. Another way to express this law: if two separate bodies are each in thermal equilibrium with a third body, then they are in thermal equilibrium with each other.
5. First Law of Thermodynamics. Principle of conservation of energy. “Energy is neither created nor destroyed, it only transforms.”
6. Second law of thermodynamics. In a state of equilibrium, the values ​​taken by the characteristic parameters of a closed thermodynamic system are such that they maximize the value of a certain magnitude that is a function of said parameters, called entropy.
7. Third law of thermodynamics. Nernst’s postulate. It postulates two phenomena: when reaching absolute zero (zero Kelvin) any process in a physical system stops. Upon reaching absolute zero, the entropy reaches a minimum and constant value.
8. Law of conservation of matter. Lamonosov Lavoisier’s Law. “The sum of the masses of all the reactants that take part in a reaction is equal to the sum of the masses of all the products that are obtained.”
9. Mendel’s First Law. Law of the uniformity of first-generation heterozygotes. Gregor Mendel was a naturalist who discovered the way genes are passed from one generation to another through the observation of plants. Its first law indicates that from the crossing of two pure races, the result will be descendants with identical characteristics, both phenotypically and genotypically between them and they will be phenotypically the same as one of the parents.
10. Mendel’s Second Law. Law of segregation of characters in the second generation. During the formation of gametes, each allele of a pair is separated from the other allele of the same pair, to give rise to the genetics of the filial gamete.
11. Mendel’s third law. Law of independence of hereditary characters: traits are inherited independently of each other. This means that the fact of having inherited a trait from one of the parents does not mean that others are also inherited.
12. Kepler’s First Law. Johannes Kepler was an astronomer and mathematician who discovered invariable phenomena in the motion of the planets. His first law states that all planets move around the sun in elliptical orbits. Every ellipse has two foci. The sun is in one of them.
13. Kepler’s Second Law. Velocity of the planets: “The radius vector that joins a planet and the sun sweeps equal areas in equal times.”