How many galaxies are there estimated to be in the known universe? Some say about 100 billion, and others even say up to 1 trillion. Which estimate would be closer to the actual number?
Firstly, these are scientific
Approximations to a few significant digits (2-sd or 3-sd), in great
unit like billion, are based on other scientific surmises.
Different sources might use different models.
The estimating process is based on surmises on the extent of
universe and average density of population of galaxies, taking unit
area as great as
Despite all these reasons that give relative error in the estimates as
1 in 10, it is possible to have a consensus estimate, if a specialist,
who is conversant in Numerical analysis and Statistics, is included in
the team of astronomers in the observatories.