Final answer:
The unobserved past does not distinctly exist in a quantum superposition state like particles in quantum mechanics. However, the early universe and theories such as superstring theory, alternate universes, and dark energy contribute to our evolving understanding of cosmology, which remains subject to change with new evidence.
Step-by-step explanation:
The question at hand contemplates whether the unobserved past may exist in a superposition of states, akin to principles found in quantum mechanics, and wonders if, until observed, various historical events, such as the Big Bang or alternate universe origins, may similarly exist in untold states. This ties into foundational elements of quantum mechanics and the concept of superposition, which posits that particles can exist in multiple states simultaneously until measured.
Superstring theory, which is in the early stages of development and deals with dimensions significantly smaller than what we've observed, suggests a multitude of theoretical possibilities. This leads to a degree of subjectivity in theorizing due to a current lack of direct experimental evidence. Speculations rise about alternate universes and differing sets of physical laws coming into existence with different Big Bang events. However, the uniqueness of our universe and the observable phenomena suggest a specific history and set of laws that have led to the current state.
Considering theories of the early universe such as the oscillating theory, which suggested an infinite cycle of Big Bangs and big crunches, or the recent findings around dark energy pointing away from this model, we understand the complexities in describing the universe's origins. These theories continuously evolve with new discoveries and observations, indicating the ever-changing nature of our understanding of cosmology.
While quantum mechanics has not been directly applied to the macroscopic past, it provides insights into particle behavior and the very nature of reality on smaller scales. As for cosmological events like the Big Bang, while they do not fit neatly into the framework of quantum superposition, understanding and exploring these concepts remain vital to the advancement of physics and our understanding of the universe.