The question of whether time is infinite in the past or how it began is still a topic of active scientific investigation and philosophical debate. There are different perspectives and theories that attempt to address this question, but no definitive consensus has been reached.
In classical physics, time is often considered to be infinite in both the past and the future, without a specific beginning or end. This view suggests that time extends infinitely into the past, implying that the universe has always existed in some form.
However, with the advent of modern cosmology and our improved understanding of the universe, theories such as the Big Bang have gained prominence. According to the Big Bang theory, the universe originated from a singularity—an extremely hot and dense state—approximately 13.8 billion years ago. This theory suggests that time, as we understand it, began at the moment of the Big Bang.
While the Big Bang theory provides a framework for understanding the evolution of the universe from a particular moment in the past, it does not address the ultimate origin of time itself. The concept of what came before the Big Bang or how time might have emerged from a pre-existing state remains an area of ongoing scientific inquiry and speculation.
Additionally, certain theoretical frameworks, such as loop quantum gravity and some cosmological models involving multiverses or cyclic universes, propose alternative ideas about the nature of time and its origins. These theories suggest the possibility of cyclical or non-singular universes, but they are still highly speculative and require further empirical evidence to support them.
It's important to note that our understanding of the origin and nature of time is limited by our current scientific knowledge, and the subject remains an active area of research and exploration.