Vaisheshika is a school of Indian philosophy that is based on the concept of atomistic realism. This means that it believes in the existence of discrete, indivisible particles as the fundamental building blocks of reality. According to Vaisheshika, these particles, known as atoms, combine and interact to create the physical world and its various phenomena.

The Vaisheshika philosophy explains the existence of the physical world through its theory of causation. It states that all objects and phenomena in the world are the result of a cause and effect relationship. This means that every effect has a cause, and every cause has an effect. In other words, the physical world is a manifestation of the interplay between causes and their corresponding effects.

The school of Vaisheshika also believes in the concept of substance (dravya), which refers to the material basis of all things. According to this philosophy, there are six fundamental substances that make up the physical world - earth, water, fire, air, ether, and time. These substances are considered eternal and unchanging, and they combine to form the different objects and phenomena that we experience in the world.

In addition to substances, Vaisheshika also recognizes qualities (guna) and actions (karma) as essential aspects of the physical world. Qualities refer to the attributes or properties of substances, such as color, taste, and smell. Actions, on the other hand, are the movements or changes that occur in substances.

The Vaisheshika philosophy also explains the existence of the physical world through its theory of atoms (anu). According to this theory, atoms are the smallest, indivisible particles that make up all substances. These atoms have specific characteristics, such as size, shape, and weight, which determine their interactions and combinations with other atoms to form substances.

Furthermore, Vaisheshika also recognizes the role of a supreme being, known as Ishvara, in the creation and maintenance of the physical world. Ishvara is seen as the ultimate cause and controller of the universe, and all objects and phenomena are believed to be a result of its will.

In conclusion, Vaisheshika explains the existence of the physical world and its various phenomena through its theories of causation, substance, qualities, actions, atoms, and the role of Ishvara. It sees the physical world as a complex interplay of these elements, with atoms being the fundamental building blocks that combine to form all objects and phenomena. Overall, Vaisheshika offers a unique perspective on the nature of reality, emphasizing the role of causation and the underlying unity of the physical world.