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Text 3. HEAT PENETRATES EVERY SUBSTANCE IN THE UNIVERSE
We all got used to the fact that one of the most fundamental laws of physics is that energy is neither created nor destroyed – it only changes from one form to another or moves from one place to another. Going back in time, the French mathematician Joseph Fourier was a pioneer in the study of heat. He was the first to explain how heat moves from warm places to cool places. The scientist was interested in both processes: how heat diffused through solids by conduction and how things cooled down by losing heat. Before Fourier, his colleague Jean-Baptiste Biot had imagined the spread of heat as “action at a distance,” where heat spreads by jumping from warm places to cool. He represented the flow of heat in a solid as a so-called series of slices, which gave him the opportunity to study the process with conventional equations showing the heat jumping from one slice to the next one.
Temperature gradients
Fourier considered heat flow in an entirely different way: the scientist focused on temperature gradients, i.e. continuous gradations between warm and cool places. The gradients could not be quantified with the conventional equations, so he had to devise new mathematical techniques. Fourier focused on the concept of waves, and made an effort to find a way to represent them by mathematical means. He found out that 9 every wavelike movement, i.e. a temperature gradient, can be approximated mathematically by adding together simpler waves. Those to be added together are sines and cosines, derived from trigonometry, so they can be expressed mathematically as a series. Such individual waves move uniformly from a peak to a trough. Thus, adding more and more of the simple waves together results in the increase of complexity that may approximate any other wave type. This is how was invented the infinite series we now know as the Fourier series.
Fourier published his idea in 1807, but it faced some criticism, so his work was finally accepted only in 1822. Continuing his research of heat, Fourier studied the existing difference between the heat that Earth gains from the Sun and the heat it loses to space. Within his research the scientist found out the reason why the Earth is pleasantly warm: this is due to the gases in its atmosphere trap heat and stop it from being radiated back into space. Modern physicists call it the greenhouse effect
Today, Fourier analysis is widely applied not only to heat transfer but also to a wide range of problems at the cutting edge of science, for instance, acoustics, electrical engineering, optics and even quantum mechanics as well.
Exercises
1. Give synonyms to the following words and expressions used in the text: Fundamental – to consider – to represent – a wide range of – as well – for instance
2. Find Russian equivalents to the following words and expressions:
A fundamental law of physics – a pioneer – to be interested in – to lose heat – the spread of heat – a gradient – to focus on – a conventional expression – complexity – research – for instance
3. Answer the following questions basing on the text:
• Who was a pioneer in the study of heat?
• What does one of the fundamental laws of physics say about energy?
• How did Jean-Baptiste Biot imagine the spread of heat?
• What was the problem Fourier faced while examining the temperature gradient?
• Where can we apply the results of Fourier’s analysis today?
• How did Fourier consider heat?
• How can temperature gradients be approximated by mathematical means?
• Were Fourier’s ideas accepted immediately? 10
4. Form adjectives from the following nouns:
Physics – France – mathematics – simplicity – complexity – criticism – difference – electricity
5. Write a brief summary of the text in English paying attention to the key ideas of the text (10 sentences)
6. Read the text again and translate it orally