# Quantum Mechanics | 01: What is Quantum Mechanics?

This is the first video of our series 'Introduction to Quantum Mechanics'

In the first video, I have given a brief introduction to what is quantum mechanics and how is it different from classical mechanics and statistical mechanics. While classical physics is based on the idea that the future is deterministic, quantum mechanics is based on the assumption that the world is probabilistic and events take place at random chances.

I have also given an overview of how quantum mechanics began. At the beginning of the 20th century, classical physics was challenged on two fronts: The relativistic domain and the microscopic domain. In 1905, Albert Einstein found that Newton's laws of motion are no longer valid at velocities close to that of light. Then, in the first quarter of the 20th century, a series of experiments such as the black body radiation, the photoelectric effect, and the Compton effect showed that classical physics cannot event explain the behavior of light and the subatomic particles.

Historically, there are two representations of quantum mechanics: The Heisenberg picture in which the dynamical quantities are represented by matrice, and the Schrodinger picture, in which differential equations are used.