Science. Reading or hearing the word brings different images to mind. Depending on your life experience and level of understanding, you would associate science with white lab coats and test tubes, Einstein’s equations, human anatomy, rocket launches, or simply a fat textbook. While these are various aspects of science, they do not represent “science” as a whole. It is an incredibly vast topic and covers much more than people usually imagine.

What is science?
There is no single correct definition of the word. But, in general, it is described as both a body of knowledge (all the things humans have already discovered) and the process of gaining new knowledge through observation and experimentation.

As you may have already guessed from the definition, science is a topic with no end, which is fascinating. A seemingly small discovery can prompt more questions and new mysteries or be the beginning of something that revolutionizes the whole of humanity.

Main branches of science
The wide range of topics under science are typically divided into three main branches or types, namely physical science, life science, and earth science:

Physical science
It involves exploring natural, non-living objects and the laws governing them. Physical science is further divided into three main subtypes:

• Physics
  It is the study of energy and matter and the interactions between them. Physics explores and attempts to explain how and why the universe works by diving deeper into complex subjects like gravity, light, time, and atomic and subatomic particles. It also includes the study of sound (acoustics), the motion of air (aerodynamics), low temperatures and the behavior of matter at those temperatures (cryogenics), and a lot more.
• Chemistry
  This field of physical science examines the composition, properties, reactions, and structure of a matter, especially elements and compounds. Most things humans do in everyday life, including breathing, involve chemistry. So it is an integral part of science. There are different forms of chemistry, such as analytical chemistry, organic chemistry, inorganic chemistry, and thermochemistry.
• Astronomy
  It deals with celestial objects outside the earth, such as the moon, stars, planets, and galaxies. Astronomy uses both physics and chemistry to explore and understand celestial bodies, for example, identifying the constituents of stars and planets. It is a vast field involving astrobiology, astrochemistry, astrophysics, aeronautics, and astrodynamics.

Life science
Life science is concerned with the study of anything and everything that has life, including human beings, animals, plants, and tiny microorganisms. The sub-branches of life science are:

• Genetics
  It is the study of genes and heredity. Genetics focuses on understanding how certain qualities or traits of parents are passed to their offspring due to changes in DNA sequence. DNA, or deoxyribonucleic acid, is a long molecule that contains a genetic code.
• Botany
  This field of life science addresses everything related to plants, including their structure, properties, and biochemical processes. There are multiple specializations in botany, such as the study of woody plants (dendrology), pollen and spores (palynology), and algae (phycology).
• Zoology
  It is the study of animals. Zoology aims to understand how animals grow, develop, reproduce, and how long they live. It is further divided into sub-branches based on the category of animals, such as insects (entomology), reptiles and amphibians (herpetology), mammals (mammalogy), and birds (ornithology).
• Microbiology
  It involves the study of microorganisms or tiny organisms not usually visible to the naked eyes, such as bacteria, fungi, and viruses. Microbiology also helps us understand how microorganisms affect human health.

Earth science
Earth science focuses on studying the earth, its waters, the air surrounding it, and how these things are tied together. Some subsets of this field are:

• Geology
  It deals with the earth’s structure, evolution, and dynamics, along with its natural mineral and energy resources. Geology looks into the processes that have shaped the planet over millions of years.
• Oceanography
  This scientific domain focuses on the ocean’s physical, chemical, and biological features. It investigates the ocean’s ancient history, current condition, and future. Besides studying and researching oceans, oceanography helps leaders make choices that improve ocean health.
• Meteorology
  It studies the earth’s atmosphere and its effect on the weather. Meteorology involves the in-depth analysis of weather elements: temperature, humidity, precipitation amount and type, wind direction and strength, atmospheric pressure, and cloud cover.
• Paleontology
  It is the study of life that lived in prehistoric and geologic periods. Paleontology often uses fossils to learn about ancient animals, plants, and other living organisms. Fossils are remains or traces of plants, animals, fungi, bacteria, and single-celled living things that have been preserved by natural processes.