How many atoms in the univearse?

Answer 1

There is an infinite number of atoms in the universe. This is because the universe never ends, it is always expanding. So, since you can't measure how large the universe is, as it is ever-expanding, you cannot determine how many atoms are in the universe.

alternate view. Though the universe may be infinite, that is not the same thing as boundless. And of course most of the universe is space without matter in it.

Astrophysicist Arthur Eddington estimated the number of hydrogen atoms in the Universe to be about 10^73, and even with knowledge of 'Dark matter' that would only add a few digits to the exponent. Today's best guess along those lines is around 10^80. (Also known as the Dirac large number hypothesis.)

This is a long way from infinite, and even a long way from a Googol or a Googolplex.

Answer 2

It is estimated that there are around 10^80 atoms in the observable universe. This number is derived from the estimated number of stars and galaxies in the universe, each of which is made up of a vast number of atoms.