We have definitely reached the tipping point. Quantifying the exact temperature change for which this tipping point is crossed remains controversial. The interview proved to be the tipping point. Mike later catches Archie by tipping over a trash can and trapping him. Darwin devised the steering system because he experienced injury during a carriage tipping over. Such distinctions underlie research into a possible global cascade of tipping points. Richard believes someone is tipping them off. In the cases of systems which involve tipping points, effects may be irreversible. The pilot quickly buried the helicopter's nose to keep it from tipping over. Economists have varies opinions on the issue of mandatory tipping. He demands food and begins tipping extensively. There is only limited information available on levels of tipping. Journalist Jake Steelhammer believes the American urban myth of cow tipping originated in the 1970s. The wooden pieces had none, often resulting in pieces tipping over. Each type of customer has different degrees of patience and tipping habits.