alkuräjähdysmalli

The Big Bang model, or alkuräjähdysmalli in Finnish, is the prevailing cosmological model for the observable universe. It describes the early development of the universe from a state of extremely high density and temperature. According to this model, the universe began approximately 13.8 billion years ago and has been expanding ever since.

Key evidence supporting the Big Bang model includes the cosmic microwave background radiation, which is faint radiation left over from the early universe. The observed abundance of light elements, such as hydrogen and helium, also aligns with predictions made by the model. Furthermore, the expansion of the universe, evidenced by the redshift of distant galaxies, is a cornerstone of the Big Bang theory.

The model posits that in its initial moments, the universe was a singularity, a point of infinite density and temperature. Following this initial event, a rapid expansion, known as inflation, is thought to have occurred. As the universe expanded and cooled, fundamental forces separated, and subatomic particles formed. These particles eventually coalesced into atoms, which then gravitationally attracted to form stars and galaxies.

While the Big Bang model successfully explains many observed phenomena, certain aspects, such as the nature of dark matter and dark energy, remain active areas of research. Scientists continue to refine the model and explore its implications through observations and theoretical work.