The concept of entropy and its relationship to the beginning of the universe is a complex topic in cosmology and physics. While it is true that entropy tends to increase in isolated systems, the exact nature of entropy and its behavior in the early universe is still a subject of scientific investigation and debate.
According to our current understanding, the universe began with a state of extremely low entropy. This initial state is often referred to as the "low-entropy initial condition" or the "cosmological arrow of time." However, the precise mechanism by which the universe originated and its initial low-entropy state emerged are still open questions.
One proposed explanation is based on the concept of cosmic inflation. According to the inflationary theory, the universe underwent an extremely rapid expansion in its earliest moments. This inflationary period could account for the uniformity and low entropy observed in the cosmic microwave background radiation, which is the afterglow of the Big Bang.
The exact cause of the low-entropy initial condition or the origins of the universe itself are areas of active research. Some theories suggest that the universe could be part of a larger multiverse system, where the laws of physics and the arrow of time may vary between different regions or universes.
It's important to note that our current understanding of the universe's origins and the behavior of entropy is based on theoretical models and observational data. As scientific knowledge advances, our understanding of these concepts may evolve, leading to new insights and explanations.