This note is a part of my Zettelkasten. What is below might not be complete or accurate. It is also likely to change often.
A Tipping point is a threshold beyond which the the elasticity of any stable system breaks.
Any system which is pushed beyond the tipping point, will not return to the equilibrium it occupied previously. At the tipping point, the external force which was changing the system overcomes the resistance of the system to change. This allows the force to change the system much faster till the force assimilates into the system and a new equilibrium is found.