On the move: While watching this year鈥檚 rugby union world cup, I became intrigued by the issues of power output relating to the New Zealand winger, Jonah Lomu. Lomu is 6 feet 4 inches (193 centimetres) and weighs 18 stones (114 kilograms), and can run 100 metres in about 10.6 seconds. Of course, the athlete Linford Christie can run faster than this but he doesn鈥檛 have 18 stones to shift. Is it possible to eliminate all the variables such as wind resistance, energy requirements for body function and so on, and compare the power requirements of the two feats? Does the greater speed of Linford Christie require vastly more energy or is mass the main factor? Is there a physiological limit on power output for humans?
Family line: Why is it that so many pregnant women of all races should develop a straight and vertical pigmented brown line over the bulge of their pregnancies (the line referred to as the linea nigra)? What is the evolutionary purpose of this line and how do the pigmented skin cells know how to grow in a straight line?
Wee problem: It is well-known that if a bitch urinates on your lawn, you鈥檒l get a brown circle of dead grass, whereas a dog鈥檚 urine does no visible harm. What is the chemical involved and why do only bitches excrete it? Does the same apply to the male and female of other animals (including humans)?
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