Vaisheshika, a philosophical school within Hinduism, is known for its atomistic realism, which holds that the ultimate reality is made up of discrete, indivisible particles called atoms. This concept of atoms as the building blocks of reality also extends to the understanding of change and impermanence in the Vaisheshika philosophy.

According to Vaisheshika, all objects and phenomena in the world are composed of atoms, which are constantly in motion and interact with each other to form different combinations and configurations. This constant motion of atoms is what gives rise to the ever-changing nature of the world. Therefore, change is seen as an inherent quality of reality, rather than an illusion or a temporary state.

The Vaisheshika philosophy also recognizes the concept of impermanence, or the idea that all things in the world are subject to decay and eventual dissolution. This is because the atoms that make up objects are in a constant state of motion and interaction, leading to their eventual disintegration. This understanding of impermanence is in line with the larger Hindu concept of the cyclical nature of time, where everything in the world goes through a cycle of creation, sustenance, and destruction.

However, Vaisheshika also acknowledges that while objects and phenomena may be impermanent, there is a permanent substratum that remains unchanged throughout the cycles of creation and destruction. This substratum, known as the dharmas or universal qualities, is seen as the underlying reality that gives rise to the changing world of objects. These dharmas are considered to be eternal and unchanging, providing a sense of stability and permanence amidst the ever-changing nature of reality.

Furthermore, Vaisheshika also emphasizes the concept of cause and effect in understanding change and impermanence. According to this philosophy, every effect has a cause, and every cause will eventually result in an effect. This understanding of causation is seen as a fundamental principle that governs the changes and transformations in the world.

In conclusion, Vaisheshika's philosophy of atomistic realism provides a comprehensive understanding of change and impermanence in the world. It recognizes the constant motion and interaction of atoms as the source of change, while also acknowledging the permanent substratum of dharmas. Through its emphasis on causation, Vaisheshika offers a logical and systematic approach to understanding the ever-changing nature of reality.