According to Samkhya philosophy, the origin of the universe can be explained through the concept of Purusha and Prakriti. Purusha is the eternal, conscious, and unchanging spirit, while Prakriti is the material world, made up of the three gunas (qualities) of sattva, rajas, and tamas.

In Samkhya, it is believed that the universe is created when Purusha and Prakriti come into contact with each other. This contact is known as the cosmic dance of Shiva and Shakti, where Shiva represents Purusha and Shakti represents Prakriti. This dance creates a vibration which leads to the manifestation of the material world.

Prakriti is considered to be the source of all material existence and is made up of the three gunas. Sattva represents purity and intelligence, rajas represents activity and passion, and tamas represents inertia and ignorance. These three gunas are constantly interacting with each other, creating the diversity and complexity of the material world.

At the same time, Purusha remains untouched and unaffected by the material world. It is the pure consciousness that observes and experiences the material world but is not influenced by it. This duality between Purusha and Prakriti is the basis of the dualistic realism in Samkhya.

The interaction between Purusha and Prakriti is not a one-time event, but a continuous process. This process is known as evolution and involution. Evolution is the process of the material world coming into existence, while involution is the process of the material world dissolving back into its original state.

According to Samkhya, the material world goes through cycles of creation, preservation, and destruction, known as the cosmic cycles. These cycles are driven by the interaction between Purusha and Prakriti, with Purusha remaining unchanged throughout the process.

In conclusion, Samkhya explains the origin of the universe as the result of the interaction between Purusha and Prakriti, with Purusha being the eternal and unchanging spirit and Prakriti being the material world, constantly evolving and dissolving. This dualistic realism provides a unique perspective on the creation and existence of the universe, highlighting the importance of both the spiritual and material aspects of our existence.