Wolfgang Pauli put forward the idea that similar particles cannot be in the same place as one another while moving in the same direction. They repel each other, meaning particles of the same kind will tend to move away from one another, giving the universe structure, rather than letting it all mix up into soup.
Pauli exclusion principle Term Timeline in A Brief History of Time
The timeline below shows where the term Pauli exclusion principle appears in A Brief History of Time. The colored dots and icons indicate which themes are associated with that appearance.
...exist in exactly the same space going at the same velocity. This is called the Pauli exclusion principle . The way particles inherently repel each other and spread out is what gives the... (full context)
...the velocity of this second matter particle. These force carrying particles do not obey the Pauli exclusion principle , so they can build up to become bigger forces. Their range depends on their... (full context)
...support itself against its own gravity after using up all its fuel. According to the Pauli exclusion principle , matter cannot be in exactly the same place, so nearby particles will repel each... (full context)