Life at the Extremes: The Science of Survival
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What causes mountain sickness? How is it possible to reach the top of Everest without supplementary oxygen, when passengers in an airplane that depressurized at the same altitude would lose consciousness in seconds? Why do divers get the bends but sperm whales do not? How long you can survive immersion in freezing water? Why don't penguins get frostbite? Will men always be faster runners than women? How far into deep space can a body travel?
As she considers these questions, Ashcroft introduces a cast of extraordinary scientific personalities—inventors and explorers who have charted the limits of human survival. She describes many intriguing experiments and shows how scientific knowledge has enabled us to venture toward and beyond ever greater limits. Life at the Extremes also considers what happens when athletes push their bodies to the edge, and tells of the remarkable adaptations that enable some organisms to live in boiling water, in highly acidic lakes, or deep in the middle of rocks.
Anyone who flies in an airplane, sails the high seas, goes skiing or walking in the mountains, or simply weathers subzero winters or sweltering summers will be captivated by this book. Full of scientific information, beautifully written, and packed with many fascinating digressions, Life at the Extremes lures us to the very edge of human survival.
rate to the concentration of the gas in the body. Hence, carbon dioxide acts as the main controller of breathing. Flying High At the summit of Everest a person can only survive without oxygen if they are very fit and have taken time to adapt. Even then, they move slowly and with difficulty. In contrast, birds such as the bar-headed goose (Anser indicus) regularly migrate across the Himalayas flying at the same or higher altitudes. Moreover, they may begin their flight at sea-level and
entangled in a transatlantic cable. Elephant seals are even more prodigious divers, for the deepest dive that has been recorded is a staggering 1570 metres, where the pressure is more than 150 times that at the surface. This is way beyond the limit for humans. Moreover, seals may dive repeatedly without ill effect. Indeed, the elephant seal should more correctly be called a surfacing animal than a diving animal, for it spends more than 90 per cent of its time at sea underwater; one animal was
among myriad clouds of brilliantly coloured fishes; where animals were inquisitive rather than fearful; where treasure lay scattered on the sea-bed for all to find; and where few had ever explored before. Many desired to it see for themselves, fuelling the development of a scuba-diving industry that now supports a large number of recreational divers. Yet, as we have already seen, for all its beauty, the underwater world is not without its dangers, and would-be scuba-divers are well advised to
in some partes than in others and rather to those which mount from the sea, than from the plaines.’ This passage has been taken to indicate that Father Acosta was aware that people who had become acclimatized to high altitude by spending time on the high plains, such as the Altiplano plateau, succumbed less readily to mountain sickness than those who ascended directly from sea-level. Scholars now suggest that this is probably not the case, as the original Spanish text appears to have been
time you can run before stopping from exhaustion, for example, more than doubles after only three to four weeks of regular exercise, and endurance improves even more markedly with intensive training. Sprint performance is also enhanced by training but this is mainly due to the ability to run fast for longer, rather than an improvement in absolute speed. The effect of training on the heart can be dramatic. A trained Olympic cross-country skier has a maximum cardiac output more than double that of