Difference Between Quantum Physics and Particle Physics

The key difference between quantum physics and particle physics is that quantum physics deals with the smallest scales of energy levels of atoms whereas particle physics deals with particles that constitute matter and radiation.

Quantum physics and particle physics are two major branches of physics. However, they are different from each other. Nevertheless, quantum physics is often applied in particle physics. In fact, we call particle physics “high energy physics” because it explains the behaviour of particles at high energies.

CONTENTS

1. Overview and Key Difference
2. What is Quantum Physics
3. What is Particle Physics
4. Side by Side Comparison – Quantum Physics vs Particle Physics in Tabular Form
5. Summary

What is Quantum Physics?

Quantum physics is a branch of physics in which we study the nature of small scale energy levels of atoms. Another common name for this term is quantum mechanics because it describes the mechanical properties of atoms. According to quantum physics, energy and momentum are quantized, objects show wave-particle duality, and there are limits to the precision with which quantities can be measured.

In history, the concept of quantum mechanics arose with the findings and theories of Max Planck (black body radiation) and Einstein (photoelectric effect). However, the early quantum mechanics came to fame in 1920 with the work of  Erwin Schrödinger, Werner Heisenberg, Max Born and others.

The important fields where we need to apply quantum theory include quantum chemistry, quantum optics, quantum computing, superconducting magnets, light-emitting diodes, laser, transistors, semiconductors such as the microprocessor, medical and research imaging such as magnetic resonance imaging, and electron microscopy.

What is Particle Physics?

Particle physics is a branch of physics in which we study the nature of particles that constitute matter and radiation. The term particle may refer to different objects, but in particle physics, we usually talk about smallest detectable particles; subatomic particles.

Subatomic particles include protons, neutrons, electrons, etc. that form from radioactive processes and scattering processes. Moreover, particle physics deal with the dynamics of these particles such as the wave-particle duality. They are useful concepts in studying the particles. The standard model presents the dynamics of the subatomic particles.

That is; the standard model describes the classification of all subatomic particles and the strong, weak and electromagnetic fundamental interactions of these particles.

What is the Difference Between Quantum Physics and Particle Physics?

Quantum physics is also called quantum mechanics; it is a major branch of physics as well as chemistry. The key difference between quantum physics and particle physics is that quantum physics deals with the smallest scales of energy levels of atoms whereas particle physics deals with particles that constitute matter and radiation.

Furthermore, quantum physics discuss energy, momentum, angular momentum, etc. while particle physics discuss subatomic particles such as elementary particles. When considering the theory of quantum physics and particle physics, the theory behind quantum physics says that energy and momentum are quantized, objects show wave-particle duality, and there are limits to the precision with which quantities can be measured, while particle physics deals with the properties and dynamics of subatomic particles.

The below infographic summarizes the difference between quantum physics and particle physics.

Summary – Quantum Physics vs Particle Physics

Quantum physics and particle physics are two major branches of physics. The key difference between quantum physics and particle physics is that quantum physics deals with the smallest scales of energy levels of atoms, whereas particle physics deals with particles that constitute matter and radiation.

Reference:

1. “Quantum Mechanics.” Wikipedia, Wikimedia Foundation, 15 June 2019, Available here.

Image Courtesy:

1. “Max Planck (1858-1947)” By Unknown, credited to Transocean Berlin – (Public Domain) via Commons Wikimedia
2. “Standard Model of Elementary Particles” By MissMJ – Own work by uploader, PBS NOVA [1], Fermilab, Office of Science, United States Department of Energy, Particle Data Group (Public Domain) via Commons Wikimedia