Science

Science is a way to understand the world around us. It uses careful tests and watching to learn how things work. Scientists make guesses, called hypotheses, and then test them to see if they are true.

There are many areas of science. Some study nature, like plants, animals, and space. Others study people and how societies work.

The history of science goes back thousands of years. Early ideas about numbers, stars, and health came from places like Egypt and Mesopotamia. These ideas influenced thinkers in Greece and during the Middle Ages. In the 16th century, a big change happened during the Scientific Revolution, when new discoveries changed how people saw the world.

Today, scientists work together in teams at universities, research centers, and companies. They are driven by curiosity and the wish to solve problems. Their work helps improve our health, protect the environment, and create new technologies. Important discoveries are often honored with awards like the Nobel Prize. The knowledge we gain from science shapes how we live and make decisions about the future.

Etymology

The word science has been used in English since the 1300s. It comes from an old French word ending in ‑cience. This French word came from the Latin word scientia, meaning "knowledge."

Long ago, "science" meant any kind of knowledge or study. People who did scientific work were called "natural philosophers" or "men of science." In 1834, a writer named William Whewell first used the word scientist to describe someone who studies science.

History

Main article: History of science

Early history

Science didn’t start at one time. Thinking about science grew slowly over many thousands of years in different parts of the world. We don’t know much about the very beginnings. Women likely helped in early science, as did religious practices. Some people use the word “protoscience” to describe old activities that are a little like modern science but not exactly the same. But this word can be confusing because it makes us think only about today’s science.

We get clearer signs of scientific thinking when writing systems began in places like Ancient Egypt and Mesopotamia around 3000–1200 BCE. Even though they didn’t use the words “science” or “nature,” these ancient people made discoveries in math, astronomy, and medicine that later influenced Greek and medieval science.

The ancient Egyptians created a decimal system for numbers, used geometry to solve problems, and made a calendar. They used treatments like drugs and prayers for healing. Ancient Nubians were early experts in natural substances that act like medicine and developed ways to tell time using the sun.

The people of Mesopotamia studied natural materials to make things like pottery and glass. They looked at animals and the stars for understanding and for special meanings. They were very interested in medicine, and some of the earliest medical instructions come from Sumer around the Third Dynasty of Ur. They studied science mainly when it had useful or religious purposes, not just out of curiosity.

Classical antiquity

In ancient times, there wasn’t someone called a “scientist.” Instead, educated men—usually from wealthy families—looked into nature when they had the time. Before the idea of “nature” was invented by early Greek thinkers, people used the same words to talk about how plants grow and how groups of people worship gods. These early Greek thinkers were the first to try to explain the world without using magic or gods.

The Milesian school, started by Thales of Miletus and continued by Anaximander and Anaximenes, were the first to try to explain natural events without magic. The Pythagoreans loved numbers and helped develop math. The idea that everything is made of tiny pieces called atoms was created by Leucippus and Democritus. Later, Epicurus used this idea to explain the whole universe naturally. The Greek doctor Hippocrates started organized medical science and is called “The Father of Medicine.”

Socrates showed how to study human questions by talking and asking questions, a method later used by Plato. Aristotle created a big system for understanding the world. Aristarchus of Samos was the first to say the Sun was in the middle of the solar system, but most people didn’t agree. Archimedes made big steps in early math. Pliny the Elder wrote a major book called “Natural History.”

The way Indians wrote numbers made math easier and became the standard around the world.

Middle Ages

Main article: History of science § Middle Ages

When the Western Roman Empire fell apart in the 5th century, learning declined in Western Europe. But in the Byzantine Empire, learning continued. John Philoponus, a Byzantine scholar, questioned some of Aristotle’s ideas about physics and suggested new thoughts that later inspired others, even Galileo Galilei many years later.

During the early Middle Ages, people mainly studied nature using Aristotle’s ideas. Many Greek books were saved by the Byzantine Empire and translated into Arabic by Christian scholars. Under the Abbasid leaders, these translations were improved in Baghdad, Iraq. Ibn al-Haytham, also called Alhazen, did experiments to study light. Avicenna wrote a major medical book called “The Canon of Medicine,” which was used for many years.

By the 11th century, Europe became mostly Christian. In 1088, the University of Bologna opened as the first university in Europe. This led to more demand for old and new scientific books, helping start what is called the “Renaissance of the 12th century.” Scholars in Europe began doing experiments by watching, describing, and grouping things in nature. In the 13th century, medical teachers in Bologna started studying human bodies, leading to the first anatomy book based on human dissection by Mondino de Luzzi.

Renaissance

Further information: Printing press § Circulation of information and ideas, and Copernican heliocentrism

Around 1440 in Mainz, Germany, the printing press was invented. By the end of the 15th century, printing had spread to around 270 cities in Europe and produced over 20 million books. Printing made books easier to get, so researchers could read old texts and compare their own findings with others. This ended the old way of copying books by hand, where facts were hard to find, and started a time when facts became well-known and trusted.

In the 16th century, Nicolaus Copernicus suggested that the Sun, not Earth, was at the center of the solar system. This idea challenged the older belief that Earth was the center. Although Copernicus’s model wasn’t perfect, it was a big step forward.

Scientific Revolution

Main article: Scientific Revolution

Tycho Brahe’s very careful star watching in the late 1500s and Galileo Galilei’s telescope discoveries in the early 1600s helped make astronomy the first modern science. Galileo’s findings changed old ideas, and Johannes Kepler used Brahe’s data to show that planets move in oval paths, not circles. Because of Kepler, we began to see that the universe follows physical laws. By the late 1600s, a new way of thinking about science emerged, very different from older ideas. It was more practical, linked to math, and focused on gathering and understanding new information.

Age of Enlightenment

At the start of the Age of Enlightenment, Isaac Newton laid the groundwork for physics with his book Philosophiæ Naturalis Principia Mathematica. Gottfried Wilhelm Leibniz used ideas from Aristotle in new ways, thinking of objects as having no set goals. Leibniz believed all types of things followed the same basic rules of nature.

During this time, science aimed to create inventions that improved daily life, like better food and clothing. Scientists were encouraged to focus on useful discoveries rather than just abstract ideas.

Science was mainly supported by groups and academies instead of universities. These groups helped science grow as a profession. Science also began to be shared with more people as reading became common. Thinkers looked to scientists like Galileo, Kepler, Boyle, and Newton for guidance in many areas of life.

The 18th century brought big advances in medicine and physics. Carl Linnaeus created a system for naming living things. We learned more about magnetism, electricity, and chemistry. Ideas about human behavior, society, and money changed during this time. Adam Smith wrote The Wealth of Nations in 1776, which is considered the start of modern economics.

19th century

Main article: 19th century in science

The 19th century saw modern science take shape. Science became more organized, with tools used carefully, new words like “biologist” and “physicist,” and scientists gaining respect in society. Countries industrialized, and books about science for everyone became popular. Science journals also started.

Towards the end of the century, psychology became its own subject when Wilhelm Wundt opened the first psychology lab in 1879.

Charles Darwin and Alfred Russel Wallace separately came up with the idea of evolution by natural selection in 1858. Darwin’s book On the Origin of Species in 1859 explained this idea in detail. Gregor Mendel’s work on plants in 1865 became the foundation for genetics.

John Dalton suggested in the early 1800s that all matter is made of tiny, indivisible particles called atoms. Laws about energy and motion suggested a stable universe, but the Industrial Revolution showed that not all energy forms are equally useful. This led to the development of thermodynamics, showing that the energy in the universe slowly decreases over time.

The electromagnetic theory was developed in the 19th century by scientists like Hans Christian Ørsted, André-Marie Ampère, Michael Faraday, James Clerk Maxwell, Oliver Heaviside, and Heinrich Hertz. The discovery of X-rays led to the discovery of radioactivity by Henri Becquerel and Marie Curie in 1896. Marie Curie was the first person to win two Nobel Prizes. The next year, the first subatomic particle, the electron, was discovered.

20th century

Main article: 20th century in science

In the early 1900s, antibiotics and artificial fertilizers improved lives worldwide. Issues like ozone depletion, ocean acidification, eutrophication, and climate change became known to the public, leading to environmental studies.

Scientific experiments grew bigger and needed more money. Technology developed during World War I, World War II, and the Cold War led to competitions between countries, like the Space Race and nuclear arms race. Even with conflicts, many countries worked together.

In the late 1900s, more women became scientists, though differences still existed in some areas. In 1964, the cosmic microwave background was discovered, supporting the Big Bang theory over the steady-state model.

The century brought big changes in science. Evolution became a complete theory when it was combined with genetics. Albert Einstein’s theory of relativity and quantum mechanics added to classical physics. The use of integrated circuits and communication satellites led to advances in information technology, the internet, and mobile devices. New fields like systems theory and computer-assisted scientific modeling developed because of the need to understand complex chains of events and large amounts of data.

21st century

Main article: 21st century § Science and technology

The Human Genome Project finished in 2003, mapping all human genes. In 2006, scientists made the first induced pluripotent human stem cells, turning adult cells into stem cells that can become any cell in the body. In 2013, the Higgs boson, the last particle predicted by the Standard Model of particle physics, was confirmed. In 2015, gravitational waves, predicted by Einstein’s theory over 100 years earlier, were observed for the first time. In 2019, the Event Horizon Telescope showed the first direct image of a black hole’s accretion disc.

Branches

Main article: Branches of science

Science is mainly divided into three groups: natural science, social science, and formal science.

Natural science studies the world around us. It includes areas like life science and physical science, such as physics, chemistry, and astronomy.

Social science looks at how people behave and how societies work. It includes fields like anthropology, political science, and psychology.

Formal science uses logic to build knowledge, including theoretical computer science and mathematics.

All these groups help us understand the world in different ways. Natural and social sciences test ideas by watching the world, while formal sciences use reasoning to find answers. Both are important for learning new things.

Research

Scientific research has two main types: basic research and applied research. Basic research is about learning new things. Applied research uses that knowledge to solve real problems. Most of what we know comes from basic research. Applied research helps us create new technologies.

Scientists use the scientific method to study nature. This method means they make careful observations and do experiments to test ideas. They use math to help understand what they find. When a scientist makes a guess, called a hypothesis, they test it with experiments. If the guess is right, it might become part of a bigger idea that explains many things. Other scientists check the work to make sure it is correct. This careful process helps scientists solve problems and find new things.

Philosophy

Different ways of thinking about science exist, and they are studied in the philosophy of science. One popular idea is empiricism. This says we learn by watching and testing things.

Another idea is rationalism. This believes we can learn by thinking deeply. A famous thinker, Descartes, supported this view. Later, Karl Popper had a different idea. He said science tries to prove ideas wrong instead of just proving them right. This is called falsifiability.

Some people think science is a tool to explain and predict what happens. Others, like Thomas Kuhn, said science changes in big steps when old ideas stop working and new ones take over. These changes are influenced by what we see and by social factors.

Community

The scientific community is a group of people who work together to learn about the world. These scientists share their ideas and check each other's work to make sure research is done well.

Scientists

Scientists are people who study the world to learn new things. They may want to help people, protect nature, or just understand how things work. Many scientists work at schools or universities. Others work in businesses, government jobs, or non-profit groups.

Learned societies

Learned societies are groups that help scientists share their ideas. These groups have meetings where scientists talk about their newest discoveries and publish books called journals. Some of these groups also help make sure scientists follow good rules.

Many important science groups started a long time ago, like the British Royal Society in 1660 and the American National Academy of Sciences in 1863. There are also groups that help scientists from many countries work together.

Awards

Science awards are special prizes given to scientists for doing great work. Getting these awards is a big honor. One famous award is the Nobel Prize, given each year for important discoveries in medicine, physics, and chemistry.

Society

Science is taught in schools and supported by museums, online content, and magazines. It helps people understand how we learn new things by testing and watching closely. Learning about science includes studying topics like physics, chemistry, and biology.

Sometimes, people may not trust science because of misunderstandings or because new ideas are different from what they believe. It's important to look at evidence and talk about science openly to understand different views. Scientists work to make sure their research is honest and clear.