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?

1 Answer
Feb 3, 2017

See explanation.


Firstly, these are scientific #surmises#.

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 #our#

universe and average density of population of galaxies, taking unit

area as great as # 1 million (light year)^2#.

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.