The discussion centers on how to calculate the number of atoms in the universe, particularly following the Big Bang. It explores theoretical aspects, observational data, and the implications of an infinite universe.
Participants express differing views on the feasibility of calculating the total number of atoms, with some suggesting that the infinite nature of the universe complicates this calculation. There is no consensus on a definitive method or answer.
The discussion highlights limitations in defining terms such as "number" versus "number density," and the implications of an infinite universe on such calculations remain unresolved.
Technically, atoms couldn't form and remain stable until the recombination epoch, about 380,000 years after the Big Bang. Some of the best evidence for the Big Bang theory itself, comes from the analysis of the expected proportion of light elements during this initial phase of nucleosynthesis.zaman786 said:TL;DR Summary: how do we calculated the number of atoms at the start , after big bang?
hi, how do we calculated the number of atoms at the start of universe i.e, after big bang?
Wikipedia says 0.25 per cubic meter in the observable universe.Vanadium 50 said:Are you sure?
Their references areIn the observable universe, atoms have an average density of 0.25 atoms/m³. According to the Big Bang model (Lambda-CDM model), they make up around 4.9 percent of the total energy density. The remaining 95.1 percent, whose nature is still largely unclear, is composed of about 27 percent dark matter and 68 percent dark energy, as well as small contributions from neutrinos and electromagnetic radiation.