Comprehending how large the observable universe is

The observable universe is a region of space where all matter that we can observe exists. The reason it is limited is because light from beyond the 46 billion ly radius has yet to reach our home planet. It is estimated that there are approximately 2,000,000,000,000 galaxies in the observable universe (2 trillion!), each galaxy containing billions of stars. The stars in total outnumber the number of grains of sand on the earth.

The spherical region that the observable universe occupies

Volume of the observable universe

The volume of a sphere is given by the formula :

where r is the radius, in this case the radius is that of the observable universe, measured in metres. 46,000,000,000 ly converts to roughly 4.35*10^26m. Plugging in that value in the equation gives the volume to be 3.5*10^80 m^3. It is now relatively simple to calculate how many of some astronomical objects would fit in the observable universe, listed in the table below.

Object	Volume (m^3)	Quantity of object
A person	0.07	5*10^81
The earth	10^21	3.5*10^59
The sun	1.4*10^27	2.5*10^53
The Milky Way	6.65*10^60	5.3*10^19
Boötes void	6.93*10^72	50,724,637

For clarification purposes, the Boötes void is a region of space containing a relatively few amount of galaxies, about 315 million ly in diameter. Over 50m of those could fit in the observable universe.