Causal sets

Causal sets are like a story book with a lot of different events that happen, but they are special because each event happens one after another in a certain order. The events are called "events of spacetime", which means they happen at a certain place and at a certain time.

Just like reading a story book from beginning to end, causal sets also have a beginning and an end. The beginning is called the "initial event" and the end is called the "final event".

But why are causal sets important? Well, just like how every event in a story book is linked to the events that happened before it and after it, every event in a causal set is also linked to the events that happened before it and after it. This means that every event is caused by the ones that came before it and it causes the ones that come after it.

Causal sets are used in physics to help us understand how the universe works. By studying the links between different events, scientists can learn about things like how gravity works or how particles interact with each other. It's kind of like solving a big puzzle - by putting together all the different events, scientists can learn more about how the universe works as a whole.