“Dr Stapley found that if you pour milk into a hot tea, the milk will heat unevenly which will cause the proteins in your milk to alter their natural quality.
This is the main cause of floaty bits that sometimes appear at the top of your cup.”
No, the main cause of those floaty bits is that the milk is starting to go off.
Over in Blighty there is a whole debate over whether you put the milk or tea in first.