The examples I gave, superconductivity and ferromagnetism, are example of phase transitions, which only happen when there are large number of components interacting. I wouldn’t call phenomena that can be explained by one or few components as emergent. So, I wouldn’t call a black hole as emergent. I wouldn’t call an electron and a proton making up a hydrogen atom as emergent. I wouldn’t call two hydrogen atoms and an oxygen atom forming a water molecule as emergent. But liquid that is formed by a large number of water molecules is an emergent phenomenon to me. Jagadul’s example of traffic jam is also a good one.
“Tell me what it isn’t!”
The examples I gave, superconductivity and ferromagnetism, are example of phase transitions, which only happen when there are large number of components interacting. I wouldn’t call phenomena that can be explained by one or few components as emergent. So, I wouldn’t call a black hole as emergent. I wouldn’t call an electron and a proton making up a hydrogen atom as emergent. I wouldn’t call two hydrogen atoms and an oxygen atom forming a water molecule as emergent. But liquid that is formed by a large number of water molecules is an emergent phenomenon to me. Jagadul’s example of traffic jam is also a good one.