How big is the universe? Can we guesstimate it?

How old is the universe? A 2013 map of the background radiation left over from the Big Bang, taken by the ESA's Planck spacecraft, captured the oldest light in the universe. This information helps astronomers determine the age of the universe. Credit: ESA and the Planck Collaboration.          Do you know how old is the universe? Some people may know a little about how old is the universe and some might not. Those little people who know might have some doubts. This information was used by astronomers to determine the age of the universe i.e. how old is the universe? Age may only be a number, but when it comes to the age of the universe, it's a pretty important one.           As per research, the universe is approximately 13.8 billion years old. We know age is just a number but when we talk about the age of the universe, it becomes hard to guess. As per the research  till now, the universe is 13.8 billion years ol...

Stars in the Universe?  Which Is Greater, the Number of Sand Grains in the world's deserts and beaches, Or stars in the universe?                   Here's an old question— which are there more grains of sand in the world's deserts and beaches, or stars in the Universe? American astrophysicist Carl Edward Sagan had told that there are much more and more stars in the universe than the sand grains in the world's deserts and beaches. Is he right in his claim? Can the stars in the Universe be counted?                                                                           Obviously, grains and stars can't be counted, but you can estimate. Being well-versed in all these things, Gerry Gilmore , professor of astronomy at Cambridge U...