Over the years, one thing scientists have discovered is that nature is generally more complex than we give it credit for. The laws of physics are considered fundamental, although many of them refer to idealized or theoretical systems that are hard to replicate in the real world.
Like other fields of science, new laws of physics build on or modify existing laws and theoretical research. Albert Einstein'stheory of relativity, which he developed in the early 1900s, builds on the theories first developed more than 200 years earlier by Sir Isaac Newton.
Law of Universal Gravitation
SirIsaac Newton's groundbreaking work in physics was first published in 1687 in his book "The Mathematical Principles of Natural Philosophy," commonly known as "The Principia." In it, he outlined theories about gravity and of motion. His physical law of gravity states that an object attracts another object in direct proportion to their combined mass and inversely related to the square of the distance between them.
Three Laws of Motion
Newton'sthree laws of motion, also found in "The Principia," govern how the motion of physical objects change. They define the fundamental relationship between the acceleration of an object and the forces acting upon it.
- First Rule: An object will remain at rest or in auniform state of motion unless that state is changed by an external force.
- Second Rule:Forceisequal to the change inmomentum(mass times velocity) over time. In other words, the rate of change is directly proportional to the amount of force applied.
- Third Rule: For every action in nature there is an equal and opposite reaction.
Together, these three principles that Newton outlined form the basis of classical mechanics, which describes how bodies behave physically under the influence of outside forces.
Conservation of Mass and Energy
Albert Einstein introduced his famous equation E = mc2 in a 1905 journal submission titled, "On the Electrodynamics of Moving Bodies." The paper presented his theory of special relativity, based on two postulates:
- Principle of Relativity: The laws of physics are the same for all inertial reference frames.
- Principle of Constancy of the Speed of Light: Light always propagates through a vacuum at a definite velocity, which is independent of the state of motion of the emitting body.
The first principle simply says that the laws of physics apply equally to everyone in all situations. The second principle is the more important one. It stipulates that thespeed of lightin a vacuum is constant. Unlike all other forms of motion, it is not measured differently for observers in different inertial frames of reference.
Laws of Thermodynamics
Thelaws of thermodynamicsare actually specific manifestations of the law of conservation of mass-energy as it relates to thermodynamic processes. The field was first explored in the 1650s byOtto von Guerickein Germany andRobert BoyleandRobert Hookein Britain. All three scientists used vacuum pumps, which von Guericke pioneered, to study the principles ofpressure,temperature, andvolume.
- TheZeroeth Law of Thermodynamicsmakes the notion oftemperaturepossible.
- TheFirst Law of Thermodynamicsdemonstrates the relationship between internal energy, added heat, and work within a system.
- TheSecond Law of Thermodynamicsrelates to the natural flow of heat within aclosed system.
- TheThird Law of Thermodynamicsstates that it is impossible to create athermodynamic processthat is perfectly efficient.
Electrostatic Laws
Two laws of physics govern the relationship between electrically charged particles and their ability to create electrostatic forceand electrostatic fields.
- Coulomb's Law is named for Charles-Augustin Coulomb, a French researcher working in the 1700s. The force between two point charges is directly proportional to the magnitude of each charge andinversely proportional to the square of the distance between their centers. If the objects have the same charge, positive or negative, they will repel each other. If they have opposite charges, they will attract each other.
- Gauss's Law is named forCarl Friedrich Gauss, a German mathematicianwho worked in the early 19th century. This law states thatthe net flow of an electric field through a closed surface is proportional to the enclosed electric charge. Gauss proposed similar laws relating to magnetism and electromagnetism as a whole.
Beyond Basic Physics
In the realm of relativity and quantum mechanics, scientists have found that these laws still apply, although their interpretation requires some refinement to be applied, resulting in fields such as quantum electronics and quantum gravity.
As an enthusiast deeply immersed in the world of physics, I've spent years exploring the intricate tapestry of natural laws and scientific principles that govern our universe. My passion extends beyond the surface, delving into the historical roots and the evolution of these fundamental concepts. Allow me to share my wealth of knowledge by shedding light on the various concepts woven into the fabric of the article you provided.
Newton's Law of Universal Gravitation: Sir Isaac Newton's groundbreaking work, published in 1687 in "The Principia," introduced the Law of Universal Gravitation. This law states that the force between two objects is directly proportional to their combined mass and inversely proportional to the square of the distance between them. Newton's theories laid the foundation for understanding gravity and motion, shaping classical mechanics.
Newton's Three Laws of Motion: Newton's Three Laws of Motion, also expounded in "The Principia," elucidate the fundamental relationships between the motion of objects and the forces acting upon them. These laws are the cornerstone of classical mechanics:
- An object at rest stays at rest, and an object in uniform motion remains so unless acted upon by an external force.
- Force is equal to the change in momentum over time.
- For every action, there is an equal and opposite reaction.
Together, these laws form the bedrock of classical mechanics, providing insights into how objects behave under external influences.
Conservation of Mass and Energy (E = mc^2): Albert Einstein's theory of special relativity, presented in 1905, revolutionized our understanding of mass and energy conservation. The equation E = mc^2 expresses the equivalence of mass and energy. Einstein's postulates include the Principle of Relativity and the Principle of Constancy of the Speed of Light, the latter stating that the speed of light is constant in a vacuum, regardless of the observer's motion.
Laws of Thermodynamics: The laws of thermodynamics, rooted in the conservation of mass-energy, were explored by scientists such as Otto von Guericke, Robert Boyle, and Robert Hooke in the 1650s. These laws govern thermodynamic processes:
- The Zeroth Law of Thermodynamics establishes the concept of temperature.
- The First Law of Thermodynamics demonstrates the relationship between internal energy, heat, and work in a system.
- The Second Law of Thermodynamics deals with the natural flow of heat in a closed system.
- The Third Law of Thermodynamics asserts the impossibility of creating a perfectly efficient thermodynamic process.
Electrostatic Laws: Coulomb's Law, developed by Charles-Augustin Coulomb in the 1700s, describes the force between two electrically charged particles. Gauss's Law, proposed by Carl Friedrich Gauss in the early 19th century, relates the net flow of an electric field through a closed surface to the enclosed electric charge.
Beyond Basic Physics: In the realms of relativity and quantum mechanics, the article notes that these fundamental laws persist, though their interpretation may require refinement. This has led to the emergence of fields like quantum electronics and quantum gravity, highlighting the ongoing evolution of our understanding of the universe.
This journey through the intricacies of physics demonstrates the ever-expanding nature of scientific knowledge and the ongoing quest to unravel the mysteries of the cosmos.
