Astrophysics
Most people may not have a practical use for astrophysics in their everyday lives. This scientific field will not be on the minds of many when they go to fill up their tanks as they go to the gas station, or as they go to the bagel shop in the morning to pick up breakfast for the office. In fact, it is somewhat of an esoteric topic, and you will likely only pursue advanced knowledge of the subject if you intend to be an astrophysicist. Nevertheless, it is important to at least have a general idea of what an astrophysicist does. There are a lot of terms that can get thrown together in the study of space and the stars, and wrongfully so; astrophysics and astrology are two completely different fields, in spite of the fact they share the common Greek prefix “astro”, which signifies a relation to the stars. Even you avoid this confusion, the study of astrophysics is one that, even if you don’t fully grasp, you can appreciate for the truly large scale of what it approaches. Astrophysics, a subset of astronomy, studies the physics of the universe, which is indeed quite a large undertaking. It is something that is distinct from cosmology, which deals with large-scale universal forces of change such as the Big Bang, and
makes of use of scientific principles important to terrestrial physics such as electromagnetism, thermodynamics and nuclear physics.
There are two major categories under which astrophysicists tend to fall. The majority of astrophysicists will tend to come to study observational astrophysics. An astrophysicist who deals with this classification of the field will be studying intergalactic phenomena that are observable using the physical visual spectrum or measurable in tangible, mathematical terms. Thus, while their name might imply a narrow focus on stars, astrophysicists must also understand stellar bodies in relation to other physical events. For instance, they must have a working knowledge of how radio waves can be emitted by galactic bodies and how that information can be used to determine their age and position. Aside from radio waves, observational astrophysics also governs the detection and measurement, in distant objects, of other forms of energy in what is known as the electromagnetic spectrum: X-rays, gamma rays, infrared and UV rays, etc. Probably the most accessible role of an astrophysicist would be the analysis of stars using telescopes. As well as using telescopes to detect the position of stars in the sky, astrophysicists use telescopes and compositional analyses to take account of what heavenly bodies are composed of.
The other major category of the field is theoretical astrophysics. A theoretical astrophysicist is more likely to deal with galactic processes and events that either happened before we had the tools to measure (such as, once again, the Big Bang) or objects so distant that they are not measurable by ordinary physical means and may not even be able to reached in our lifetimes. They also are more concerned with changes, evolutions and processes (e.g. the formation of a black hole) that occur over a longer period of time, rather than more immediately observable events such as chemical compositional analysis of a star cluster. Theoretical astrophysics, as one can imagine, makes use of models and theories for physics that may not even apply to life on Earth, such as the theory of relativity, quantum mechanics and light and dark matter.