Formula for dating age range
The first observation that one can make from this formula is that it is the Hubble parameter that controls that age of the universe, with a correction arising from the matter and energy content.So a rough estimate of the age of the universe comes from the Hubble time, the inverse of the Hubble parameter.In contrast, theories of the origin of the primordial state remain very speculative.If one extrapolates the Lambda-CDM model backward from the earliest well-understood state, it quickly (within a small fraction of a second) reaches a singularity called the "Big Bang singularity".Assuming an extra background of relativistic particles, for example, can enlarge the error bars of the WMAP constraint by one order of magnitude.This measurement is made by using the location of the first acoustic peak in the microwave background power spectrum to determine the size of the decoupling surface (size of the universe at the time of recombination).If one has accurate measurements of these parameters, then the age of the universe can be determined by using the Friedmann equation.This equation relates the rate of change in the scale factor a(t) to the matter content of the universe.
CMB measurements are very good at constraining the matter content Ω come from Type Ia supernovae.
Combining these measurements leads to the generally accepted value for the age of the universe quoted above.
The cosmological constant makes the universe "older" for fixed values of the other parameters.
The light travel time to this surface (depending on the geometry used) yields a reliable age for the universe.
Assuming the validity of the models used to determine this age, the residual accuracy yields a margin of error near one percent.