Quantum mechanics/Casimir effect in one dimension. Abstract The Casimir effect is interesting because it introduces the concept of Ramanujan summation of the divergent series, 1+2+3+4+..., and because it offers experimental evidence that empty space is not truly empty. Every step in this derivation of the Casimir effect uses straight-forward and familiar mathematics.
Man's Kidney Failure Linked To Massive Tea Consumption. The puzzling case of a 56-year-old U.S. man who suddenly developed weakness, fatigue and body aches is leading doctors to warn that massive consumption of tea may be responsible.
The poor woman in the NEJM study is not alone. There are a few other cases of people who have damaged their bones through too much tea. But she (like those in other studies) was drinking excessive amounts: 100-150 tea bags a day to make 12 cups of tea. A litre of tea can contain up to 9mg of fluoride, which in excess can cause skeletal fluorosis, reducing bone quality and causing pain and stiffening of the ligaments. Other studies show you generally need to drink a gallon a day for three decades to develop this condition.