Bill Bryson - A short history of nearly everything

Здесь есть возможность читать онлайн «Bill Bryson - A short history of nearly everything» весь текст электронной книги совершенно бесплатно (целиком полную версию без сокращений). В некоторых случаях можно слушать аудио, скачать через торрент в формате fb2 и присутствует краткое содержание. Жанр: Физика, на английском языке. Описание произведения, (предисловие) а так же отзывы посетителей доступны на портале библиотеки ЛибКат.

A short history of nearly everything: краткое содержание, описание и аннотация

Предлагаем к чтению аннотацию, описание, краткое содержание или предисловие (зависит от того, что написал сам автор книги «A short history of nearly everything»). Если вы не нашли необходимую информацию о книге — напишите в комментариях, мы постараемся отыскать её.

A Short History of Nearly Everything is a general science book by Bill Bryson, which explains some areas of science in ordinary language. It was the bestselling popular science book of 2005 in the UK, selling over 300,000 copies. A Short History deviates from Bryson's popular travel book genre, instead describing general sciences such as chemistry, paleontology, astronomy, and particle physics. In it, he explores time from the Big Bang to the discovery of quantum mechanics, via evolution and geology. Bryson tells the story of science through the stories of the people who made the discoveries, such as Edwin Hubble, Isaac Newton, and Albert Einstein. Bill Bryson wrote this book because he was dissatisfied with his scientific knowledge – that was, not much at all. He writes that science was a distant, unexplained subject at school. Textbooks and teachers alike did not ignite the passion for knowledge in him, mainly because they never delved in the whys, hows, and whens.

A short history of nearly everything — читать онлайн бесплатно полную книгу (весь текст) целиком

Ниже представлен текст книги, разбитый по страницам. Система сохранения места последней прочитанной страницы, позволяет с удобством читать онлайн бесплатно книгу «A short history of nearly everything», без необходимости каждый раз заново искать на чём Вы остановились. Поставьте закладку, и сможете в любой момент перейти на страницу, на которой закончили чтение.

Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

Much of our knowledge of what goes on up there is surprisingly recent. Jet streams, usually located about 30,000 to 35,000 feet up, can bowl along at up to 180 miles an hour and vastly influence weather systems over whole continents, yet their existence wasn’t suspected until pilots began to fly into them during the Second World War. Even now a great deal of atmospheric phenomena is barely understood. A form of wave motion popularly known as clear-air turbulence occasionally enlivens airplane flights. About twenty such incidents a year are serious enough to need reporting. They are not associated with cloud structures or anything else that can be detected visually or by radar. They are just pockets of startling turbulence in the middle of tranquil skies. In a typical incident, a plane en route from Singapore to Sydney was flying over central Australia in calm conditions when it suddenly fell three hundred feet-enough to fling unsecured people against the ceiling. Twelve people were injured, one seriously. No one knows what causes such disruptive cells of air.

The process that moves air around in the atmosphere is the same process that drives the internal engine of the planet, namely convection. Moist, warm air from the equatorial regions rises until it hits the barrier of the tropopause and spreads out. As it travels away from the equator and cools, it sinks. When it hits bottom, some of the sinking air looks for an area of low pressure to fill and heads back for the equator, completing the circuit.

At the equator the convection process is generally stable and the weather predictably fair, but in temperate zones the patterns are far more seasonal, localized, and random, which results in an endless battle between systems of high-pressure air and low. Low-pressure systems are created by rising air, which conveys water molecules into the sky, forming clouds and eventually rain. Warm air can hold more moisture than cool air, which is why tropical and summer storms tend to be the heaviest. Thus low areas tend to be associated with clouds and rain, and highs generally spell sunshine and fair weather. When two such systems meet, it often becomes manifest in the clouds. For instance, stratus clouds-those unlovable, featureless sprawls that give us our overcast skies-happen when moisture-bearing updrafts lack the oomph to break through a level of more stable air above, and instead spread out, like smoke hitting a ceiling. Indeed, if you watch a smoker sometime, you can get a very good idea of how things work by watching how smoke rises from a cigarette in a still room. At first, it goes straight up (this is called a laminar flow, if you need to impress anyone), and then it spreads out in a diffused, wavy layer. The greatest supercomputer in the world, taking measurements in the most carefully controlled environment, cannot tell you what forms these ripplings will take, so you can imagine the difficulties that confront meteorologists when they try to predict such motions in a spinning, windy, large-scale world.

What we do know is that because heat from the Sun is unevenly distributed, differences in air pressure arise on the planet. Air can’t abide this, so it rushes around trying to equalize things everywhere. Wind is simply the air’s way of trying to keep things in balance. Air always flows from areas of high pressure to areas of low pressure (as you would expect; think of anything with air under pressure-a balloon or an air tank-and think how insistently that pressured air wants to get someplace else), and the greater the discrepancy in pressures the faster the wind blows.

Incidentally, wind speeds, like most things that accumulate, grow exponentially, so a wind blowing at two hundred miles an hour is not simply ten times stronger than a wind blowing at twenty miles an hour, but a hundred times stronger-and hence that much more destructive. Introduce several million tons of air to this accelerator effect and the result can be exceedingly energetic. A tropical hurricane can release in twenty-four hours as much energy as a rich, medium-sized nation like Britain or France uses in a year.

The impulse of the atmosphere to seek equilibrium was first suspected by Edmond Halley-the man who was everywhere-and elaborated upon in the eighteenth century by his fellow Briton George Hadley, who saw that rising and falling columns of air tended to produce “cells” (known ever since as “Hadley cells”). Though a lawyer by profession, Hadley had a keen interest in the weather (he was, after all, English) and also suggested a link between his cells, the Earth’s spin, and the apparent deflections of air that give us our trade winds. However, it was an engineering professor at the École Polytechnique in Paris, Gustave-Gaspard de Coriolis, who worked out the details of these interactions in 1835, and thus we call it the Coriolis effect. (Coriolis’s other distinction at the school was to introduce watercoolers, which are still known there as Corios, apparently.) The Earth revolves at a brisk 1,041 miles an hour at the equator, though as you move toward the poles the rate slopes off considerably, to about 600 miles an hour in London or Paris, for instance. The reason for this is self-evident when you think about it. If you are on the equator the spinning Earth has to carry you quite a distance-about 40,000 kilometers-to get you back to the same spot. If you stand beside the North Pole, however, you may need travel only a few feet to complete a revolution, yet in both cases it takes twenty-four hours to get you back to where you began. Therefore, it follows that the closer you get to the equator the faster you must be spinning.

The Coriolis effect explains why anything moving through the air in a straight line laterally to the Earth’s spin will, given enough distance, seem to curve to the right in the northern hemisphere and to the left in the southern as the Earth revolves beneath it. The standard way to envision this is to imagine yourself at the center of a large carousel and tossing a ball to someone positioned on the edge. By the time the ball gets to the perimeter, the target person has moved on and the ball passes behind him. From his perspective, it looks as if it has curved away from him. That is the Coriolis effect, and it is what gives weather systems their curl and sends hurricanes spinning off like tops. The Coriolis effect is also why naval guns firing artillery shells have to adjust to left or right; a shell fired fifteen miles would otherwise deviate by about a hundred yards and plop harmlessly into the sea.

Considering the practical and psychological importance of the weather to nearly everyone, it’s surprising that meteorology didn’t really get going as a science until shortly before the turn of the nineteenth century (though the term meteorology itself had been around since 1626, when it was coined by a T. Granger in a book of logic).

Part of the problem was that successful meteorology requires the precise measurement of temperatures, and thermometers for a long time proved more difficult to make than you might expect. An accurate reading was dependent on getting a very even bore in a glass tube, and that wasn’t easy to do. The first person to crack the problem was Daniel Gabriel Fahrenheit, a Dutch maker of instruments, who produced an accurate thermometer in 1717. However, for reasons unknown he calibrated the instrument in a way that put freezing at 32 degrees and boiling at 212 degrees. From the outset this numeric eccentricity bothered some people, and in 1742 Anders Celsius, a Swedish astronomer, came up with a competing scale. In proof of the proposition that inventors seldom get matters entirely right, Celsius made boiling point zero and freezing point 100 on his scale, but that was soon reversed.

The person most frequently identified as the father of modern meteorology was an English pharmacist named Luke Howard, who came to prominence at the beginning of the nineteenth century. Howard is chiefly remembered now for giving cloud types their names in 1803. Although he was an active and respected member of the Linnaean Society and employed Linnaean principles in his new scheme, Howard chose the rather more obscure Askesian Society as the forum to announce his new system of classification. (The Askesian Society, you may just recall from an earlier chapter, was the body whose members were unusually devoted to the pleasures of nitrous oxide, so we can only hope they treated Howard’s presentation with the sober attention it deserved. It is a point on which Howard scholars are curiously silent.)

Читать дальше
Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

Похожие книги на «A short history of nearly everything»

Представляем Вашему вниманию похожие книги на «A short history of nearly everything» списком для выбора. Мы отобрали схожую по названию и смыслу литературу в надежде предоставить читателям больше вариантов отыскать новые, интересные, ещё непрочитанные произведения.


Отзывы о книге «A short history of nearly everything»

Обсуждение, отзывы о книге «A short history of nearly everything» и просто собственные мнения читателей. Оставьте ваши комментарии, напишите, что Вы думаете о произведении, его смысле или главных героях. Укажите что конкретно понравилось, а что нет, и почему Вы так считаете.

x