Who or what made the Earth?

Earth, the planet we live on, is about 4.5 billion years old. At least, scientists think that’s how old it is because of some really, really ancient rocks in Australia that come from about that long ago.

Since there was no-one around 4.5 billion years ago, we don’t know for sure how the Earth and the other planets in our solar system were made. But scientists who study stars and planets millions of miles away in Space have been able to do experiments to learn about how other galaxies (enormous collections of stars and planets) are formed. And they think this must be how our planet was made, too.

So let’s find out more about how the Earth got started…!

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Why do we have hairy arms?

Hair is a normal and natural part of the human body. Many people have hair on their heads and it could be yellow (blonde), red/orange, brown, black or grey/white in colour. And you may choose to wear your head hair long or short or style it in different ways.

But have you thought about the hair on other parts of your body? Like your eyebrows or nose hairs or toe hairs? My friend’s daughter has and she wants to know why do people have hairy arms and why are grown-ups hairier than children? So let’s find out…

How does food give me energy?

Food is important for keeping us alive. Our bodies need nutrients from the foods we eat to keep our bodies working and healthy. And some of those nutrients give our bodies energy to keep working. Those nutrients are called ‘carbohydrates’. But what are they and how do they give us the energy we need?

Is it black inside a black hole?

Black holes are strange things in Space that scientists are still trying to understand. They were first thought of by Albert Einstein, a very famous scientist who did lots of thinking about maths and physics. Einstein’s ideas about how Space and time worked made him think that there might be ‘black holes’ in Space. But black holes weren’t actually discovered to be real until 55 years after Einstein first had the idea of them!

So what are they? Well, black holes are sort of made from old stars. So, we should start by thinking about what stars are made of, then figure out how they can turn into black holes. And then we can figure out why they are called black holes and whether they are actually black!