Science

Today, "science" usually refers to a way of pursuing knowledge, not just the knowledge itself. It is mainly about the phenomena of the material world. The Greek works into Western Europe from the 6th to 7th century B.C. revived "Philosophy".^[5] In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature such as Newton's laws of motion. And during the 19th century, the word "science" became more and more associated with the scientific method itself. It was seen as a way to study the natural world, including physics, chemistry, geology and biology.

It was also in the 19th century that the term scientist was created by William Whewell. He meant it to tell the difference between those who looked for knowledge on nature from those who looked for other types of knowledge.^[6]

The scientific method is the name given to the methods used by scientists to find knowledge. The main features of the scientific method are:

1. Scientists identify a question or a problem about nature. Some problems are simple, such as "how many legs do flies have?" and some are very deep, such as "why do objects fall to the ground?"
2. Next, scientists investigate the problem. They work at it, and collect facts. Sometimes all it takes is to look carefully.
3. Some questions cannot be answered directly. Then scientists suggest ideas, and test them out. They do experiments and collect data.
4. Eventually, they find what they think is a good answer to the problem. Then they tell people about it.
5. Later, other scientists may agree or not agree. They may suggest another answer. They may do more experiments. Anything in science might be revised if we find out the previous solution was not good enough.

A famous example of science in action was the expedition led by Arthur Eddington to Principe Island in Africa in 1919. He went there to record where the stars were around the Sun during a solar eclipse. The observation of where the stars were shown that the apparent star positions close to the Sun were changed. In effect, the light passing the Sun was pulled towards the Sun by gravitation. This confirmed predictions of gravitational lensing made by Albert Einstein in the general theory of relativity, published in 1915. Eddington's observations were considered to be the first solid proof in favour of Einstein's theory.

Discoveries in fundamental science can be world-changing. For example:

Research	Impact
Static electricity and magnetism (1600) Electric current (18th century)	All electric appliances, dynamos, electric power stations, modern electronics, including electric lighting, television, electric heating, magnetic tape, loudspeaker, plus the compass and lightning rod.
Diffraction (1665)	Optics, hence fiber optic cable (1840s), cable TV and internet
Germ theory (1700)	Hygiene, leading to decreased transmission of infectious diseases; antibodies, leading to techniques for disease diagnosis and targeted anticancer therapies.
Vaccination (1798)	Leading to the elimination of most infectious diseases from developed countries and the worldwide eradication of smallpox.
Photovoltaics (1839)	Solar cells (1883), hence solar power, solar powered watches, calculators and other devices.
The strange orbit of Mercury (1859) and other research leading to special (1905) and general relativity (1916)	Satellite-based technology such as GPS (1973), satnav and communications satellites.[7]
Radio waves (1887)	Used in broadcast: radio (1906) and television (1927) entertainment. It is used in telephony, emergency services, radar (navigation and weather forecasting), medicine, astronomy, wireless communications, and networking. Radio research led to microwave cooking.
Radioactivity (1896) and antimatter (1932)	Cancer treatment (1896), Radiometric dating (1905), nuclear reactors (1942) and weapons (1945), PET scans (1961), and medical research (with isotopic labelling)
X-rays (1896)	Medical imaging, including computer tomography
Crystallography and quantum mechanics (1900)	Semiconductor devices (1906), hence modern computing and telecommunications including the integration with wireless devices: the mobile phone[7]
Plastics (1907)	Starting with bakelite, many types of artificial polymers for numerous applications in industry and daily life
Antibiotics (1880's, 1928)	Salvarsan, Penicillin, doxycycline. In 2018 Amoxicillin and amoxicillin/clavulanic acid were the most frequently used.[8]
Nuclear magnetic resonance (1930's)	Nuclear magnetic resonance spectroscopy (1946), magnetic resonance imaging (1971), functional magnetic resonance imaging (1990's).
Genomics (1990s)	Genomics = genetics + medicine. It is the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA (or RNA). This makes up its genes. Vaccines for viruses are built by genomics.

Not everyone completely agrees about how theories should be used or updated. Some philosophers and scientists say that scientific theories are only accepted for the time being. They last as long as they are the best explanation. When theories no longer explain the data, they are removed and replaced. Or, sometimes scientists will make a theory better rather than remove it, or they will keep on using the theory hoping that it will be made better eventually.

Science is a way to get knowledge by getting rid of what is not true.

Scientists must be very careful to make explanations that fit well with what they observe and measure. They compete to provide better explanations. An explanation might be interesting or pleasing, but if it does not agree with what other scientists really see and measure, they will try to find a better explanation.

Before a scientific article is published, other scientists read the article. They decide whether the explanations make sense from the data. This is called peer review. After articles are published, other scientists will also check to see if the same experiments, observations or tests produce the same data again. Peer review and repeating experiments are the only way to be sure the knowledge is correct.

Science makes models of nature, models of our universe, and medicine. There are many different sciences with their own names. However it is not right to say "science says" any one thing. Science is a process, not just the facts and rules believed at one time.

• History of science
• Philosophy of science
• Science tourism

• "How Do We Know What Is True?" (animated video; 2:52)

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