Fill a sealed room with “air”, consisting of a mixture (in our view) of hydrogen gas and oxygen gas. If a person were to enter such a room, he or she would find this mixture completely breathable, without any noticeable negative effects, at least if the person did not stay in the room for very long….Now light a match in the room. An explosion occurs, and the room is now damped. The “air” in the room has been replaced with water. That is, a tiny amount of one fundamental substance, fire, introduce into another fundamental element, air, has caused the air to be transformed – transubstantiated – into a third fundamental substance, water
According to quantum mechanics, there has been no change in “substance”. The number of hydrogen atoms and the number of oxygen atoms is unchanged. There has, however, been a change in the quantum coherence relations between the atoms. Before water was formed, the hydrogen atoms were bound in pairs to each other to form a hydrogen molecule, an the oxygen atoms were bound in pairs to form an oxygen molecule. These molecules individually were in a coherent quantum state. Further, the atoms were bound in such a molecule precisely to form a coherent quantum state, since being in such a state would minimize energy. But in a mixture of hydrogen and oxygen gas, there is a lower energy coherent state, the state in which the hydrogen and oxygen are bound into water molecules. The mixture would become water eventually even without the spark; spark merely speeds up the reaction rate.
This is exactly what [Tipler proposes] happens when the bread and wine are transubstantiated by the priest
Source: The Physics of Christianity, Frank J Tipler, 2007