The Scientific Universe
The scale of the universe mapped to the branches of science.

Science is what we do to find out about the natural world. It is the total of physics, chemistry, biology, geology and astronomy. Science makes use of mathematics, and it makes observations and experiments. Science produces accurate facts, scientific laws and theories. 'Science' also refers to the large amount of knowledge that has been found using this process.

Research uses the scientific method. Scientific research uses hypotheses based on ideas or earlier knowledge. Then those hypotheses are tested by experiments.

People who study and research science and try to find out everything about it are called scientists. Scientists study things by looking at them very carefully, by measuring them, and by doing experiments and tests. Scientists try to explain why things act the way they do, and predict what will happen.

Scientific method

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. 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 over the course of the 19th century, the word "science" became increasingly associated with the scientific method itself, as a way to study the natural world, including physics, chemistry, geology and biology.

It is in the 19th century also that the term scientist was created by William Whewell. He meant it to distinguish those who sought knowledge on nature from those who sought other types of knowledge.

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, collecting 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 figure out 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.

Practical impacts of scientific research

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

Research Impact
Static electricity and magnetism (1600)
Electric current (18th century)
All electric appliances, dynamo's, 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 satellite communications.
Radio waves (1887) Radio had become used in innumerable ways beyond its better-known areas of telephony, and broadcast television (1927) and radio (1906) entertainment. Other uses included – emergency services, radar (navigation and weather forecasting), medicine, astronomy, wireless communications, and networking. Radio waves also led researchers to adjacent frequencies such as microwaves, used worldwide for heating and cooking food.
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
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 etc.
Nuclear magnetic resonance (1930's) Nuclear magnetic resonance spectroscopy (1946), magnetic resonance imaging (1971), functional magnetic resonance imaging (1990's).

Other features of science

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

Science is a way to get knowledge by discarding 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 and decide whether the explanations make sense from the data. This is called peer review. After articles are published, other scientists will also check 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.

Some types of science

Related pages


Science for Kids. Kiddle Encyclopedia.