Read the text, try to catch its essentials and be ready to do the tasks. Scientific research is a creative process that can involve a variety of techniques

HOW SCIENTISTS WORK

Scientific research is a creative process that can involve a variety of techniques. Important advances may result from patient hard work or sudden leaps of imagination. Even chance can play a role in the scientific process. For example, Sir Alexander Fleming, a British bacteriologist, discovered penicillin accidentally in 1928, when he noticed that a bit of mold of the genus Penicillium had contaminated a laboratory dish containing bacteria. Examining the dish, Fleming saw that the bacteria around the mold had been killed.

Scientists use a number of methods in making discoveries and in developing theories. These methods include (1) observing nature, (2) classifying data, (3) using logic, (4) conducting experiments, (5) forming a hypothesis, (6) expressing findings mathematically, and (7) modeling with computers. Most scientific research involves some or all of these steps.

Observing nature is one of the oldest scientific methods. For example, the ancient Egyptians and Babylonians studied the motions of heavenly bodies and so learned to predict the changes of seasons and the best times to plant and harvest crops. In the 1830s, Charles Darwin carefully observed plants and animals in many parts of the world while serving as a naturalist with a British scientific expedition aboard. Study of the specimens collected on the voyage helped Darwin develop his theory that modern species had evolved from a few earlier ones.

Classifying data can reveal the relationships among observed facts. In the mid-1800s, Dmitri Mendeleev, a Russian chemist, classified the elements into families or groups in a chart called the periodic table. On the table, elements with similar properties appeared at regular intervals. Gaps in the table indicated elements that were not yet known. Scientists later proved the importance of Mendeleev's systematic classification when they discovered the existence and chemical properties of new elements that filled the gaps.

Using logic enables scientists to draw conclusions from existing information. In the late 1800s, a German physicist named Wilhelm Wien studied the relationship between temperature and the energy radiated by heated solids and liquids. After studying many specific examples, he noted that multiplying the temperature of a heated solid or liquid by the wavelength of greatest intensity radiated at that temperature always produced the same number. Although Wien could not test all solids and liquids, he used inductive reasoning to conclude that this number was a universal constant which was the same for all heated solids and liquids, regardless of their physical or chemical makeup.

Conducting experiments is one of the most important tools in developing and testing scientific theories. The Italian astronomer and physicist Galileo was one of the first scientists to recognize that systematic experimentation could help reveal the laws of nature. During the late 1500s, Galileo began performing carefully designed experiments to study the basic properties of matter in motion. By rolling balls of different weights down inclined planes, Galileo discovered that all objects fall to the ground with the same acceleration (rate of increase in speed), unless air resistance or some other force slows them down.

In the early 1600s, William Harvey, an English physician, used the experimental method to learn how blood circulates through the body. He made careful studies of the human pulsebeat and heartbeat and dissected (cut up) human and animal corpses for examination. Harvey concluded that the heart pumps blood through the arteries to all parts of the body and that the blood returns to the heart through the veins.

Forming a hypothesis requires talent, skill, and creativity. Scientists base their proposed explanations on existing information. They strive to form hypotheses that help explain, order, or unify related facts. They then use experimentation and other means to test their hypotheses.

The discovery of the planet Neptune in the mid-1800s resulted from the formation of a hypothesis. Astronomers noticed that Uranus, which they thought was the most distant planet, was not always in the position predicted for it by the laws of gravitation and motion. Some Monomers concluded that the laws did not hold at such great distances from the sun. But other astronomers hypothesized that the force of gravity from an unknown planet might cause the variations in the orbit of Uranus. By calculating where such a planet would have to be located to affect the orbit, astronomers eventually discovered Neptune.

Expressing findings mathematically can yield valuable insights about how the world works. Galileo used mathematics to express the results of his experiments with falling bodies and to enable him to determine the distance an object would fall in a certain amount of time. The English scientist Sir Isaac Newton developed a mathematical theory of gravitation in the 1600s that explained many types of motion, both on the earth and throughout the universe. In the early 1900s, the German-born physicist Albert Einstein found that mass is related to energy by the mathematical equation E - me². The equation states that energy (E) is equivalent to mass (m) multiplied by the speed of light squared (c²). This equation later provided the basis for the development of nuclear energy.

Modeling with computers helps scientists quickly analyze large amounts of data. A model is a set of mathematical equations that describes relationships between data. In the past, scientists computed these equations on paper or with a calculator. Many models were too difficult or time-consuming to attempt. However, the development of highly powerful computers in the late 1970s enabled scientists to formulate complex models at great speeds.

Using computer models, scientists can easily vary data to test scientific hypotheses. This use of a model is known as simulation. Scientists commonly simulate experiments that would be impossible to carry out in a laboratory. For example, meteorologists simulate the development of thunderstorms to test ideas of how changes in atmospheric pressure affect cloud movement. An engineer may simulate an airplane's flight to find ways of improving its design. Simulations are also used to predict voting results, population growth, and stock market prices.

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Task 11

Дата добавления: 2015-10-24