Modern Physics

Physics is a natural science that is based on experiments, measurements, and mathematical analysis. Its purpose is to find the quantitative physical laws for everything from the Nanoworld to the planets. A branch of science which is dealing with the interaction of matter and energy is popularly known as physics. There are two major branches of Physics. These are Classical Physics and Modern Physics.

Modern physics is that branch of physics that deals with the post-Newtonian concepts in the areas of physics. It is having its base on the two major breakthroughs of the twentieth century. These are Relativity and Quantum Mechanics. Modern physics mainly involves the advanced description of nature through some theories which were different from classical Physics. These are involving the elements of quantum mechanics and Einsteinian relativity. Albert Einstein is popular as the father of modern physics.

Introduction to Modern Physics

Modern physics is based on the two major inventions of the early 20th century. These are relativity and quantum mechanics. This kind of Physics is based on what was known before then, i.e. Newton’s laws, Maxwell’s equations, thermodynamics and termed as classical physics.

Modern physics is presenting the foundations and frontiers of today’s physics. It is focusing on the domains like quantum mechanics; applications in atomic, nuclear, particle, and also the condensed-matter physics. Mainly it includes the special relativity, relativistic quantum mechanics, Dirac equation and the Feynman diagrams, quantum fields with general relativity. The aim of modern physics is to cover these topics in sufficient depth.

Topics in Modern Physics

Various topics which form the core to the foundation of modern physics are:

• Atomic theory and atomic model
• Black-body radiation
• Franck–Hertz experiment
• Geiger–Marsden experiment i.e. Rutherford’s experiment
• Gravitational lensing
• Michelson–Morley experiment
• Photoelectric effect
• Quantum thermodynamics
• Radioactive phenomena in general
• Perihelion precession of Mercury
• Stern–Gerlach experiment
• Wave-particle duality
• Thermodynamics. Heat and temperature.
• Vibrations and Waves Phenomena
• Quantum Mechanics.

Important Discoveries in Modern Physics

Several experiments have marked the history and development of Modern Physics. Among these, we may mention those who provided us with a deeper understanding of the structure of matter and atoms. Some such examples of these important discoveries are as given below:

• In the year 1895, Wilhelm Röntgen discovered the existence of X-rays. It is an invisible type of extremely penetrating radiation.
• After a few years in the year 1900, the German physicist Max Planck proposed that the energy-charged by the electromagnetic field and having quantized values. It is the integer multiples of a minimum and constant amount.
• In the year 1905, through his theory of relativity, Albert Einstein explained and showed that references which move at very high speeds. This speed was close to the speed of light propagation, experience the passage of time and the measurement of distances in different ways.
• In the year 1913, Niels Bohr proposed that the energy levels of electrons scattered around atomic nuclei are quantized. It means, their energy is given by an integer multiple of a minimum value.
• In the year 1924, the wave-particle duality, which was established by physicist Louis De’Broglie, showed that anybody can behave like a wave.
• In the year 1926, Quantum Mechanics appeared. It was the result of the work of physicists like Werner Heisenberg and Erwin Schröedinger.

Thus, modern physics was able to explore the nature of the microscopic world and the great relativistic speeds. It also provides valuable explanations for various physical phenomena that were, until then, misunderstood.

FAQs about Modern Physics

Q.1: Why is modern physics such important?

Answer: The term Physics describes how the natural world works with the applied mathematical formulas. Chemistry is essentially being applied to physics as well as biology is essentially applied chemistry. Physical theories are responsible for the changes in electronics giving advances in modern computers as well as electronic media.

Q.2: What is the most difficult in physics?

Answer: The most difficult concept in physics is undoubtedly the unification of the theory of gravity with the theories concerning matter and the other three fundamental forces. These forces are like electromagnetism and nuclear forces. At the later stage, it is constituting the Standard Model.