# Get the Knowledge that sets you free...Science and Math for K8 to K12 students

Email
×

## Quantum theory

Flexible solar panels The thin nature of flexible solar panels can be integrated with fabric structures of various designs (portable) to provide an unparalleled lightweight, flexible and durable solution for remote power. Solar panels produce electricity (at any instance without depending on any fuel powered and noisy generators), due to the phenomenon of photo electric effect which is discussed in this topic.

## After completing the topic, the student will be able to:

• Understand the need for the evolution of quantum mechanics in describing the quantum world and explore how modern physics started with the discovery of electron.
• Investigate and visualize the idea of quantized energy with the help of Planck′s quantum hypothesis.
• Discuss the photoelectric effect based on the experimental observations and its applications in photo electric cells, CCDs ,etc.
• Discover the characteristics of X−rays and investigate how they are produced and explore its properties and applications in different walks of life.
• Estimate the phenomenon of Compton scattering and its relevance in finding the Compton shift.
• Understand the concept of wave function and discuss different types of quantum numbers and its relevance in finding the position probability of electron.
Quantum theory Photon is a quantum particle which describes electromagnetic theory of light.
Quantum theory

Things on a small scale do not behave like things on a large scale which makes physics difficult and also interesting. It is difficult because the way things behave on small scale is so “un natural”. The constituents of atoms, say electrons sometimes behave like waves and sometimes like particles. Things which we used to consider as waves behave like particles and particles behave like waves. There is no distinction between a wave and particle. So quantum mechanics unifies the idea of a wave and a particle.

According to quantum theory one cannot know where something is and how fast it is moving simultaneously. The uncertainty of the momentum and the uncertainty of the position are complementary. The product of the two is constant. The idea that a particle has a definite location and a definite speed is no longer valid. Quantum theory explains this strange behavior. Another interesting idea in quantum theory is that it is impossible to predict what will happen in any given circumstance. We can only find an average, statistically, as to what happens.

Quantum theory provides a new view of electromagnetic interaction. We have a new particle to add to the electron - the new particle is called photon. Quantum theory explains all known electrical, mechanical and chemical laws; the motion of wires in magnetic field; the law of collision of billiard balls and the reaction of hydrogen and oxygen to make water. If life is ultimately reduced to chemistry, then quantum theory is the theory of all life.

Quantum computer core Light rays passing through the nanoscale crystal core of a quantum computer. Quantum computers, which are under development, are based on quantum mechanics and the principle of representing information in quantum bits (qubits) using quantum properties. This could involve optical properties of chemically doped crystals, like the one shown here. Quantum computing has the potential to massively increase computing power.
Particle waves and applications of quantum theory

Quantum mechanics is the description of the behavior of matter in all its details and, in particular, of the happenings on an atomic scale. Richard Feynman calls Quantum Mechanics as the ‘only mystery’ and as he aptly puts it “We cannot make the mystery go away by explaining how it works”. All that can be done is to tell you how it works...

Feynman says “Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything you have ever seen”. Historically the electron was thought to behave like a particle and then it was found that in many respects to behave like a particle. Electrons behave just like light. The quantum behavior of atomic objects (electrons, protons, neutrons, photons and so on) is the same for all; they are all “particle waves”.

Much of modern technology applications such as the transistor, the microchip, the electron microscope, and magnetic resonance imaging. Operate at a scale where quantum effects are significant. The study of semiconductors led to the invention of the diode and the transistor, which are indispensable for modern electronics.

Some interesting research areas include quantum cryptography, for secure transmission of information, quantum computers, which are expected to perform certain computational tasks exponentially faster than classical computers and quantum teleportation, which deals with techniques to transmit quantum information over arbitrary distances. Flash memory chips found in USB drives use quantum tunneling to erase their memory cells.