# Video:What is Quantum Physics?

with John McGinityQuantum physics is the branch of physics that deals with matter and energy working on an atomic and subatomic level. This About.com video will go over some key concepts of quantum physics.See Transcript

## Transcript:What is Quantum Physics?

Hi, I'm John for About.com. Today I am going to be highlighting some of the key concepts of quantum physics.

### Meaning of Quantum Physics

Quantum Physics is the branch of physics concerned with the principles that describe the interaction of matter and energy on the atomic and subatomic levels. The term "quantum mechanics" was coined by Max Born in 1924, and derives from the Latin *quanta*, meaning "how much."

J.J. Thompson's discovery of the electron in 1897 demonstrated that the laws of classical (Newtonian) physics break down and cannot be applied at the atomic level. New equations and principles were developed to mathematically describe the behavior of matter and energy on a quantum scale.

Some important historical figures and concepts of quantum mechanics are:

### Wave-Particle Duality

Wave-particle duality is the principle that states that matter and light can act as either waves or particles depending on the circumstance of its observation.

### Heisenberg's Uncertainty Principle

This states that the exact position and the exact momentum of an object cannot be obtained simultaneously. This ties into the concept that the position of a moving object is difficult to delineate. As such, their location can only be predicted statistically.

### Max Planck

Max Planck's research on Black Body radiation led to the discovery of the Planck constant. The Planck Constant is the relationship between the energy of a photon and the frequency of its electromagnetic wave.

### Albert Einstein

Albert Einstein explained the Photoelectric Effect by introducing his photon theory of light. That is, electromagnetic energy, or light, can be quantized into packets called photons.

### Schrodinger

Developed the equations that describe the probability of finding an electron at a certain distance from the nucleus of an atom.

In conclusion, the study of quantum physics has led to unprecedented technological breakthroughs such as lasers and semiconductors, a better understanding of natural phenomena at an atomic scale, and the advancement of science as a whole.

Thank you for watching. For more information on quantum physics and other related topics, please visit About.com.