It’s super exciting because we actually can’t see anything left from the first 300,000 years of the universe! We can only see a very faint glow in space, little patches of warm and cool gas, that let us try and imagine what happened. This is called the microwave background radiation. We know that the big bang happened, and the universe is expanding, because the galaxies around us are all moving away- and the furthest ones are moving fastest.
About 14 million years ago, something happened that would change our lives forever- the big bang! Way back then, the universe was inside a tiny bubble, that was millions of times smaller than a ladybird’s spots. It was more hot and more dense (heavy and small) than anything we can imagine. Something caused the tiny bubble to shake and get angry and the bubble exploded! Everything happened so quickly that not even a second had passed before galaxies had grown from single atoms. Then, it just kept growing.
As soon as it was born it was too hot for anything to stick together and form planets or stars or solar systems, and it was a long time until it was cool enough for all the energetic atoms to start sticking. At this time, there was ‘matter’ and ‘antimatter’, and they were just destroying each other! But there was enough matter that survived to form the atoms we are made of today.
Inside an atom there is 99 % empty space, and a tiny clump at the middle where the mass is called the ‘protons and neutrons’. This centre (called a nucleus) is surrounded by little energetic electrons (charge carriers). Within minutes of the big bang the temperature had dropped by 1,000,000,000 C (!) and was cool enough to form these little protons, neutrons and electrons- they were still whizzing around super fast. It was only thousands of years later that the temperature had dropped to 3000 C, cool enough for the atoms to stick together to form neutral (no charge) atoms of hydrogen . After a while, huge clouds of these hydrogen atoms formed- this is the beginning of a galaxy!
In CERN, geneva, we’re using something called a particle accelerator to recreate the conditions that happened at the very beginning of time. We’re firing super energetic atoms at each other to try and understand more about what happened in the first few moments!