What type of physics deals with the quantization of energy and light?

The focus of this question is on the quantization of energy and light, which is a key concept within quantum physics. Quantum physics, also known as quantum mechanics, describes the behavior of matter and energy on very small scales, such as atoms and subatomic particles. It introduces the idea that energy is not continuous but rather comes in discrete units called quanta. This is particularly evident in phenomena like the photoelectric effect and the emission or absorption of light by atoms, which cannot be explained by classical physics.

In quantum physics, concepts such as wave-particle duality and the uncertainty principle are fundamental. For instance, light can exhibit properties of both waves and particles (photons) depending on the context of observation. This quantization is crucial in understanding various modern technologies, including lasers and semiconductors.

Other areas mentioned, such as classical physics and thermal physics, deal with macroscopic phenomena that do not account for the discrete nature of energy. Astrophysics, while it may involve concepts from quantum physics when studying the universe, primarily focuses on the properties and behavior of celestial bodies rather than on the fundamental quantization principles themselves. Thus, quantum physics is the appropriate field that encompasses the quantization of energy and light.