Stars in Billions and Billions of Galaxies
Take a good look at this picture. Go ahead, embiggen it. Check it out. I’ll wait.
What you’re looking at are galaxies. There are 7,500 of them in this image, which covers a very small angular area of space. The most distant galaxies lie more than 13 billion light-years away. That means the light captured in this image of those galaxies was shining a few hundred million years AFTER the Big Bang — the event that resulted in the birth of the universe. The closest galaxies in this image emitted their light about a billion years ago.
When you look at this image, you’re gazing at a slice of cosmic time, a snapshot of galaxies in nearly every stage of formation and evolution. If you looked in every direction, across the entire sky, the view would be similar to this — galaxies as far as we can detect. Billions and billions of galaxies, each one comprised of anywhere from a few hundred million stars to hundreds of billions of stars.
Think about that as you gaze at this picture.
That’s a lot of stars. And, you have to wonder if we really are the only ones out here in this vast cosmos to appreciate that fact. Are we the only life capable of looking up and wondering if any of those other stars have planets and life? I often think about that concept — as I wonder what the future of the cosmos will be; and think about the glories of past histories in other galaxies — glories we can only appreciate as a dim glow from a galaxy long, long ago and far, far away.
I always wondered how do we determine the distance. How can we say certain light traveled 12 billion light years.
Hi Carolyn:)
Nice post! It’s still hard to fathom what a rich field of galaxies really means.
You and were on same wavelength with our new posts.
See http://bit.ly/a9pTc0
-Jeff
You have the same thoughts as myself Carolyn, and I guess a majority of those reading this wonderful post.
Of course what you so eloquently describe is just the visible universe! How much more of it is there from which light has not had time to travel in the 13.7 billion years since the Big Bang? And are there other universes as postulated by some proponents of string theory such as Michio Kaku?
My own view is in line with the Principle of Mediocrity/Copernican Principle… although as human beings we may be unique (assuming that the universe is not infinite in which case there would be an infinite number of instances where human beings have independently evolved), other intelligent life is bound to have evolved somewhere else. After all, the laws of physics, as far as we can tell are the same throughout the 200 billion galaxies, each of which contain a similar number of stars.
It’s just a good job we don’t live in the seventeenth century. Giordano Bruno was burned at the stake for making public such views!!!