The question of how the universe came into existence is a topic of ongoing scientific research and philosophical debate. While there are several theories and hypotheses, including the Big Bang theory, none of them conclusively prove that the universe came from "nothing" in the strict sense of the term.
The idea you mentioned about matter and antimatter canceling each other out is related to the concept of particle-antiparticle annihilation. In particle physics, when a particle collides with its corresponding antiparticle, they can annihilate each other, resulting in the production of energy. This process is well understood and has been observed in laboratory experiments.
Regarding the Big Bang theory, it describes the early stages of the universe's evolution from an extremely dense and hot state. According to this theory, the universe underwent a rapid expansion and cooling, leading to the formation of matter as we know it today. However, the precise details of what triggered the Big Bang or what existed before it are still open questions.
It is important to note that the concept of "nothing" in the context of the universe's origin is a challenging concept to define and understand. It is an area where scientific understanding is limited, and different philosophical perspectives exist.
Scientists continue to investigate the origins of the universe through fields such as cosmology, quantum physics, and theoretical physics. These efforts involve exploring ideas such as inflationary cosmology, quantum fluctuations, and the nature of space and time.
In summary, while scientific theories like the Big Bang provide explanations for the early stages of the universe's development, they do not definitively prove that the universe originated from "nothing." The question of the universe's ultimate origin remains a subject of ongoing scientific exploration and philosophical contemplation.