The question of whether the universe had a beginning or not is a topic of ongoing scientific and philosophical debate. Different perspectives exist, and no consensus has been reached thus far. Let's explore two prominent viewpoints:
Big Bang and the Beginning of the Universe: The prevailing scientific model, supported by various lines of evidence, including the cosmic microwave background radiation and the expansion of the universe, suggests that our universe originated from a hot, dense state known as the Big Bang approximately 13.8 billion years ago. According to this model, the universe as we know it began with a singularity—a point of infinite density and temperature—followed by rapid expansion. In this sense, the universe had a starting point.
Eternal Universe and Cyclic Models: Some theories propose that the universe undergoes cycles of expansion and contraction, with each cycle potentially leading to a new "Big Bang" event. These cyclic models suggest that the universe has no ultimate beginning or end but goes through an eternal series of cycles. However, it's important to note that these cyclic models are still speculative and face challenges in terms of explaining certain observations, such as the second law of thermodynamics.
It's essential to recognize that our understanding of the universe's origin is limited by the availability of empirical evidence and the current state of scientific knowledge. New observations and advancements in theoretical physics may provide additional insights into the nature of the universe and its origins in the future.
Ultimately, the question of whether the universe had a beginning or is eternal remains an open topic of scientific investigation and philosophical contemplation.