The current understanding of the Big Bang, based on scientific theories and observations, suggests that the concept of spacetime and elemental particles as we know them today emerged from the singularity that initiated the universe. The singularity is a point of infinite density and temperature from which the expansion of the universe began.
According to the prevailing cosmological model, spacetime, elemental particles, and the energy associated with them all came into existence simultaneously during the early moments of the Big Bang. At extremely high temperatures and densities, the fundamental forces that govern the universe were unified into a single force. As the universe expanded and cooled down, these forces separated, leading to the formation of spacetime and the subsequent emergence of elementary particles.
It's important to note that our understanding of the early moments of the universe is based on theoretical models and observations, such as the cosmic microwave background radiation and the abundance of light elements. However, these models have limitations, and there are still open questions and ongoing research to further explore and refine our understanding of the origins of the universe.
As for whether there was something before the Big Bang, this remains a subject of speculation and intense scientific inquiry. The concept of what, if anything, existed before the Big Bang is still an area of active research and debate within cosmology. Some theoretical models propose the existence of a multiverse or cyclical universe scenarios, while others suggest that the question itself may be beyond the scope of scientific investigation.
Ultimately, our current knowledge and understanding of the early universe are limited, and further scientific advancements and discoveries are needed to unravel the mysteries of cosmic origins more definitively.