The Universe

Universe [basics for beginners]

How big is the universe? No one knows, because we cannot see the edge of it—if there is one. 

All we do know is that the visible universe is at least 93 billion light-years across. 

Scientists believe that the universe was born in a huge fireball about 13.5 billion years ago; matter, energy, time and space came into being is what known as  The Big Bang.

The story of these fundamental features of our universe is called physics. 

Even in places far from stars and planets, space contains scattered particles of dust or a few hydrogen atoms. 

In photos taken from space, our planet is surrounded by blackness. 

This shows how empty outer space is. 

Planets like Earth shine because they reflect light from the Sun. 

Stars shine because they produce huge amounts of energy by burning fuel. 

Most of space looks black because there is nothing there to produce or reflect light.

We live on one tiny planet in the vast universe. 

Finding out what else is “out there” has been one of our biggest challenges, and it started with people simply staring at the sky.

[Facts:: We can see and measure three dimensions of space- height, width and depth. 

Time is a fourth dimension. Scientists believe the universe may have at least six other, hidden dimensions. These are all curled up on each other and are infinitely tiny.]

{image: google unknown}