Astronomy is a broad term often misused by the average individual, that refers to the study of literally everything that takes place outside of the Earth’s atmosphere. It is one of the oldest forms of science that was ever developed, studied in some form by every civilization in recorded history. Most often, astronomy is confused with astrology, a nonsensical method of fortune telling that is loosely based on the position of the Earth in relation to the other planets and constellations. Astrophysics is a more specific branch of astronomy, that focuses on what it is exactly that astronomers are observing in the night sky, rather than where they are located and how they are moving through space.
Astrophysics is a complicated subject, and those who study it must be familiar with essentially every discipline in physics. It encompasses everything from quantum mechanics to thermodynamics, as a result of the sheer variety of phenomena that are being studied. Every single thing happening in the universe falls under the umbrella of astrophysics. This includes stars, galaxies, cosmic background radiation, and even the fabric of space itself. Because astrophysics is focused on things so far away from the scientists themselves, almost all of the work being done is theoretical in nature.
Astrophysicists such as Carl Sagan and Neil deGrasse Tyson have helped make the general public more aware of the things that they study, from the theory of General Relativity to the origins of the universe itself. As a result, in the last few decades, the field of astrophysics has experienced a renaissance of sorts, with more scientists choosing to study it, and new theories and experiments being developed than ever before. Particle accelerators have been built that allow scientists to simulate conditions that would never naturally occur on Earth, giving us unprecedented insights into the nature of the universe we live in. There are theories being developed that assume there are an infinite amount of parallel universes alongside our own, possibly even interacting with ours without our knowledge.
Astrophysics is arguably the most important field of physics being studied today, because the implications of discoveries in this field impact all of the others as well. By studying the stars, scientists were able to access the power held within an atom, with the creation of the hydrogen bomb and nuclear power plants. Einstein’s theories about the nature of the fabric of space and time changed the way scientists think about reality, proving that time literally moves more slowly on the surface of the Earth than it does when in orbit. Everything humanity knows about the universe and the way the world works is affected by our understanding of astrophysics.