OriginsExplainer
What Happened in the First Second After the Big Bang?
From the first atomic nuclei back to a possible burst of inflation, here is what scientists have tested about the first second, and where knowledge runs out.
SECTION
Origins.
Where did it all begin?
The Big Bang, the first second, the size of the cosmos and where our atoms came from: what is established, what is debated, and what is still open.
OriginsExplainer
How Big Is the Universe, and Does It Have an Edge?
The part we can see is about 93 billion light-years wide, but whether the whole universe ends, loops back or goes on forever is still unknown.
OriginsExplainer
Can a Telescope See the Beginning of the Universe?
Distant light lets us look far into the past. But the earliest light we can receive arrived after the universe had already been changing for a long time.
OriginsExplainer
How Could We Test an Extra Dimension?
An unseen direction in space is a serious possibility in some models. What would it change in a detector, and what would count as evidence?
OriginsExplainer
How Did We “Hear” Gravitational Waves?
LIGO measured tiny changes in distance and opened another way to study the universe.
OriginsExplainer
Why Do Stars Shine—and Where Did Our Atoms Come From?
A star’s light comes from fusion. Its long history also helps explain the matter that makes planets and people.
OriginsExplainer
What Does the Big Bang Actually Explain?
The hot early universe has strong observational support; the ultimate beginning remains an open question.