The observable universe is just a fraction of the vast cosmos, ... we delve into five intriguing scientific theories that attempt to explain what exists outside the observable universe.

Beyond the observable universe lie “unknown unknowns”: the subject of speculation rather than direct observation. 1 The 45.7 billion light-year radius includes only light sources.

Astronomers think space outside of the observable universe might be an infinite expanse of what we see in the cosmos around us, distributed pretty much the same as it is in the observable universe ...

The “outside the universe” question gets tricky right off the bat, because first you have to define the universe. One common answer is called the observable universe, and it’s defined by the ...

So for all we know, just outside the observable universe there is a big bad wall. Or a brane-type singularity. Or fire-breathing pink unicorns preventing us from going any further.

The observable universe is still huge, but it has limits. That’s because we know the universe isn’t infinitely old — we know the Big Bang occurred some 13.8 billion years ago.

And that’s just within the observable universe. Because the cosmos emerged some 13.8 billion years ago, we’re only able to observe objects up to a certain distance from Earth.

That’s because we know the universe isn’t infinitely old — we know the Big Bang occurred some 13.8 billion years ago. That means that light has had “only” 13.8 billion years to travel. That’s a lot of ...

Assuming the universe is bigger than the observable universe, we could also be able to detect the influence of objects outside our observable universe on objects towards our observable universe's ...