B R Sitaram Here are the answers to last month’s questions! Q 1. Which of the following is the most important cause of stomach ulcers? i. Eating spicy food ii. Drinking excessive coffee iii. Infection by a bacterium iv. Less exercise v. Excessive use of oil A. The surprising answer is (iii). It was thought that bacteria cannot survive in the harsh environment of the stomach, but the bacterium Helicobacter pylori does survive and causes gastric ulcers! Q 2. In 1828, the German chemist Friedrich Wohler synthesized urea. Why is this considered to be such an important event in the history of science? A. Before this event, scientists distinguished between organic chemicals, which came from living organisms and inorganic chemicals, which were found in non-living objects. Urea is clearly organic but Wohler managed to synthesize it from inorganic substances, showing that there was nothing “living” about organic chemicals. Q 3. Worcester, Leicester, Cholmondeley and Warwick are the names of cities in England. In addition to this, however, these cities have something else in common. What is it? Hint: it has to do with the names of the cities. A. All these words have pronunciations very different from their spellings! Their phonetic spellings would be Wooster, Lester, Chumley and Warick! Q 4. Epimendes, the Cretan, said “All Cretans are liars”. Why is this statement so important in logic? A. This is a very early example of a self-referential statement, a statement that refers to itself. To see why it creates problems, imagine that the statement is true. Then Epimendes, being a Cretan, is lying, hence the statement is a lie. But that means that Epimendes is telling the truth, which means that the statement is true! So, was Epimendes right or wrong? You decide! Questions for this month How come we do not have 4 seasons (summer, autumn, winter and spring) in the tropics? Which months would be the hottest near the Equator? If someone tells you that a particular product is not made up of chemicals, what would your response be? Vehicle tyres, as you would have seen, have lots of treads. Obviously, treads increase friction. But you do not need fancy treads to do this, all you need is a rough surface. Why do tyres have such treads then? The other day, I was using an elevator when I caught sight of a notice, “Maximum 8 passengers, 544 kg”. Why this strange number, 544? Why not 550, 500 or 600 kg? Send in your