We know that life has arisen at least once in our universe. This simple fact testifies to an extraordinary feature of the building blocks of the universe – subatomic particles, atoms and molecules – the ability to aggregate to form immensely complex entities, which display a vast array of emergent structural properties. One of the pinnacles of this potential (on Earth) is the human brain, with the consciousness it engenders (see Chapter 17 for a detailed discussion).

When examining the building blocks of the early universe there is no indication whatsoever that these elements – initially hydrogen with some helium – would ever give rise to beings capable of reflecting on the nature of the universe and mulling over its origin and possible future. It would seem that all one needs are suitable conditions and enough time.