Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level..
Astronomers have calculated that the universe is 13.8 billion years old.
The Hubble Space Telescope has seen back to about 500 million years after the big bang, revealing galaxies with much less defined and more compact structures, very different than those close to us in space and time..
Imagine light leaving the first stars and galaxies nearly 13.6 billion years ago and traveling through space and time to reach our telescopes.
We're essentially seeing these objects as they were when the light first left them 13.6 billion years ago..
Anaximander, (born 610 bc, Miletus—died 546/545 bc), Greek philosopher, often called the founder of astronomy.
He apparently wrote treatises on geography, astronomy, and cosmology that survived for several centuries and made a map of the known world.
He was the first thinker to develop a cosmology..
The universe began 13.8 billion years ago, and in its early years, it looked completely different than it does now.
For nearly 400,000 years, the entire cosmos was opaque, which means we have no direct observations of anything that happened during that time.
Despite those problems, the early epochs of cosmic history are essential for everything that came after, leading researchers to find ways to figure out exactly what happened when our universe was in its infancy.
Center for Astrophysics | Harvard & Smithsonian scientists study the early universe in a variety of ways:.
