Physical science is generally considered to consist of four broad fields: physics, astronomy, chemistry, and biology. All of these are then further divided into smaller disciplines and subfields. This article briefly discusses the history of development of each of these and with special attention to its scope, key issues, and techniques of the last three fields. In addition, I discuss recent developments in physical science that are of note in the research literature as well as in the education arena.
The history of physics is basically the history of the universe and the laws governing its motion, size, composition, etc. Over time, physics has evolved into a solid science of macroscopy and has developed specific concepts that are at the foundation of all science, including classical mechanics and quantum mechanics. Classical mechanics postulates the existence of a universal law of nature that is governed by symmetries and special properties of unique entities such as particles and atoms. The study of such entities is further divided into two fields: Physics of the atomic and molecular domains and Physics of the cosmos or space-time. Quantum mechanics is a field of science that studies the behaviour of subatomic particles, those of very large unicellular organisms, and those of extremely high temperatures.
While classical mechanics has been widely used in the study of the atom and molecules, the earth sciences have relied mainly on observation to generate theories. For instance, all physical science theories about the evolution of the planets, stars, rocks, oceans, etc. rely on observational data to produce testable predictions about their surroundings. Astronomy is another of the earth sciences that has depended largely on observations to generate testable predictions about the properties of celestial bodies. The most famous example of this is the solar-system illustration in textbooks.
Astronomy is the application of astronomy to any non-galactic bodies in the entire universe. The most prominent example of this is the telescope used in the MRO (Million Year Radiometer) instrument on board the NASA’s Surveyor satellite. It is one of the tools used to study astrometry and physics. Astronomy also includes the study of very small objects like quasars and other small celestial bodies that are relatively close to the surface of the earth.
Astrophysics deals with the study of heavenly objects such as the stars and other celestial bodies. Many of the same processes that take place in the solar system can be observed in other solar-system bodies like the planets. Astronomy also involves the study of celestial objects in the Milky Way and other galaxies. This field is known as astrophysiology. The most prominent example of an astrometry instrument in this field is the Very Long Mission or VLM. It is a radio telescope designed to study extremely faint celestial radio emission.
Astronomy has given rise to many satellites as well as space probes that have been put into space to study celestial objects. Some of these include the Messenger and Spire satellites. The science team working on these satellites have made significant breakthroughs in understanding how planets formed, how they affect each other and how they travel through space. The Messenger probe is scheduled to launch again in late May of 2020 and Spire will fly by at the end of this year.