Modern Physics - Timeline Of The Study In This Domain

Introduction to Modern Physics

Modern Physics is the branch of physics that deals with the study of the fundamental particles and their interactions.
It emerged in the early 20th century with the discovery of the quantum nature of light and the atomic structure of matter.
Modern Physics theories go beyond classical mechanics and electromagnetism, providing a deeper understanding of the universe.
Modern Physics includes theories such as Quantum Mechanics, Special and General Relativity, and Nuclear Physics.

J.J. Thomson discovered electrons while studying Cathode Rays.
He proposed the “Plum Pudding Model” of the atom, which suggested electrons were embedded in a positively charged sphere.

Max Planck introduced the revolutionary idea that energy is quantized.
He proposed that energy could only be emitted or absorbed in discrete packets called “quanta.”
This theory laid the foundation for Quantum Mechanics.

Albert Einstein’s theory of Special Relativity introduced the concept of time dilation and the equivalence of mass and energy.
It also gave rise to the famous equation E=mc^2, which shows the relationship between energy, mass, and the speed of light.

Ernest Rutherford conducted the famous gold foil experiment, leading to the discovery of the atomic nucleus.
He proposed that atoms have a small, dense, positively charged nucleus at the center, with electrons orbiting around it.

Louis de Broglie proposed that matter particles, such as electrons, have wave-like properties.
This wave-particle duality concept laid the foundation for understanding the behavior of particles in Quantum Mechanics.

Erwin Schrödinger developed the Schrödinger Wave Equation, a fundamental equation in Quantum Mechanics.
This equation describes the wave function of a particle and how it evolves over time.

James Chadwick discovered the neutron, a neutral subatomic particle in the atomic nucleus.
This discovery helped to better understand atomic stability and nuclear reactions.

Enrico Fermi built the world’s first nuclear reactor, initiating the field of nuclear energy.
This significant achievement opened doors to harnessing the power of nuclear reactions for practical purposes.

The first atomic bomb was successfully detonated during the Second World War.
This event marked the beginning of the Atomic Age and raised awareness about the immense power and destructive capabilities of nuclear weapons.

The world’s first nuclear power reactor was developed by the Soviet Union in 1954.
This marked a significant milestone in the utilization of nuclear energy for generating electricity.
Nuclear power reactors provide a reliable source of energy with reduced greenhouse gas emissions.
Examples of nuclear power reactors include pressurized water reactors (PWR) and boiling water reactors (BWR).
Equation: E = mc^2, where E is the energy obtained from converting mass (m) into energy (E) using the speed of light (c).

Quantum Mechanics describes the behavior of particles at the atomic and subatomic levels.
The wave-particle duality suggests that particles can exhibit both wave-like and particle-like properties.
Examples: The double-slit experiment, where electrons show interference patterns, revealing their wave nature.
Equation: λ = h/p, where λ is the wavelength, h is Planck’s constant, and p is the momentum of the particle.

Heisenberg’s Uncertainty Principle states that it is impossible to simultaneously know the exact position and momentum of a particle.
The more accurately the position is known, the less accurately the momentum can be known, and vice versa.
Equation: ∆x ∆p ≥ h/2π, where ∆x represents the uncertainty in position, ∆p represents the uncertainty in momentum, and h is Planck’s constant.

Quantum Tunneling is the phenomenon where particles can pass through energy barriers that would be classically impassable.
This occurs due to the wave-like nature of particles and their ability to exist in a superposition of states.
Quantum tunneling is important in various fields, including electronics, where it enables the operation of transistors.
Example: Scanning Tunneling Microscope (STM) allows researchers to visualize individual atoms on a surface.

The Special Theory of Relativity describes the behavior of objects moving at constant speeds relative to each other.
It introduces concepts of time dilation, length contraction, and the invariance of the speed of light in all inertial frames.
Equation: t’ = γ(t - vx/c^2), where t’ is the time measured in the moving frame, t is the time measured in the rest frame, v is the velocity of the moving frame, c is the speed of light, and γ is the Lorentz factor.

The General Theory of Relativity describes the behavior of objects in the presence of gravitational forces.
It introduces the concept of spacetime curvature caused by mass and energy, resulting in the bending of light and the warping of space.
Example: Gravitational waves, which were predicted by Einstein and discovered in 2015, provide evidence for the General Theory of Relativity.

Nuclear Fission is the process of splitting an atomic nucleus into two or more smaller nuclei.
This process releases a large amount of energy and is the basis for nuclear power reactors and nuclear weapons.
Example: The splitting of a uranium-235 nucleus into two smaller nuclei and the release of neutrons and energy.

Nuclear Fusion is the process of combining two or more atomic nuclei to form a larger nucleus.
This process releases a tremendous amount of energy and powers the Sun and other stars.
Example: The fusion of hydrogen nuclei to form helium in the Sun’s core, releasing energy in the process.

Radioactive Decay is the spontaneous disintegration of an atomic nucleus, emitting particles or electromagnetic radiation.
It is a random process that cannot be influenced by external factors.
Example: The decay of a radioactive isotope, such as uranium-238, into thorium-234 through a series of alpha and beta decays.

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Introduction to Modern Physics
Timeline of the Study in this Domain
1897: Discovery of Electron by J.J. Thomson
- Cathode ray experiments
- Plum pudding model of the atom
1900: Planck’s Quantum Theory
- Energy quantization
- Introduction of quanta
1905: Einstein’s Theory of Special Relativity
- Time dilation
- Mass-energy equivalence
1911: Discovery of Atomic Nucleus by Ernest Rutherford
- Gold foil experiment
- Nuclear model of the atom
1924: de Broglie’s Wave-Particle Duality
- Wave-like behavior of matter particles
- Dual nature of particles
1926: Schrödinger’s Wave Equation
- Mathematics of Quantum Mechanics
- Describes behavior of quantum particles
1932: Discovery of Neutron by James Chadwick
- Neutral subatomic particle
- Importance in atomic stability
1938: Fermi’s Nuclear Reactor
- First controlled nuclear chain reaction
- Utilization of nuclear energy
1945: Atomic Bomb - Dawn of the Atomic Age
- Invention and use of atomic bombs
- Impact on science and society
1954: Development of the First Nuclear Power Reactor
- Utilization of nuclear energy for electricity generation
- Advancements in nuclear technology

`` Note: Slide 31 and beyond have been excluded to keep within the 30-slide limit.