As technology has evolved, astronomers are able to look back in time to the moments just after the Big Bang. This might seem to imply that the entire universe lies within our view. But the size of the universe depends on a number of things, including its shape and expansion. Just how big is the universe? The truth is, scientists can’t put a number on it.

The observable universe

Astronomers have measured the age of the universe to be approximately 13.8 billion years old. Because of the connection between distance and the speed of light, this means they can look at a region of space that lies 13.8 billion light-years away. Like a ship in the empty ocean, astronomers on Earth can turn their telescopes to peer 13.8 billion light-years in every direction, which puts Earth inside of an observable sphere with a radius of 13.8 billion light-years. The word “observable” is key; the sphere limits what scientists can see but not what is there.

But though the sphere appears almost 28 billion light-years in diameter, it is far larger. Scientists know that the universe is expanding. Thus, while scientists might see a spot that lay 13.8 billion light-years from Earth at the time of the Big Bang, the universe has continued to expand over its lifetime. Today, that same spot is 46 billion light-years away, making the diameter of the observable universe a sphere around 92 billion light-years. [VIDEO: Oldest Light in the Universe: How it Traveled to Us]

Interesting Read…

See Also:

Cosmic Discoveries Fuel a Fight Over the Universe’s Beginnings

Stunning Hubble images reveal the brightest galaxies in the universe

The Milky Way exists in a giant hole of the universe that may have helped life on Earth to develop

Seeing double

Potential building block of life is found in young star system similar to our own

Einstein was right!

Russian billionaire’s plans for a floating nation in SPACE called Asgardia take a step closer

Self-Replicating 3D Printers Could Build Moon Bases, Fight Global Warming

Mars missions in crisis as study finds astronauts face DOUBLE the cancer risk previously predicted

Mars Has Many Faces, Including Some That Look Like Earth (Video)

Astronomers Are About to Get a Look at Pluto Probe’s Next Flyby Target

Surprise! Giant Exoplanet ‘Cousins’ Have Different Atmospheres

Spot the moon!

Hottest planet EVER found

(Visited 5 times, 1 visits today)