What is cosmology really about? I am an undergraduate student studying computer engineering. I love programming, especially competitive programming, and I'm very interested in Artificial General Intelligence because I really like the idea of building something that is able to think. I'm also quite interested in physics, mainly cosmology. But before I get to this I want to provide some background because my question is a pretty vague one.
What I really like doing is thinking. For me, there is nothing quite like solving problems using my creative reasoning (which is not to say that I'm a genius or something, I just like thinking). So that's the main reason I love programming.
But, like I said, I have an interest for cosmology. I am fascinated with the deepest mysteries of the Universe. So I wonder if maybe a career in cosmology would be a more interesting.
On one hand, since I love thinking about basically anything, what can be better than thinking about thinking itself (which is where AGI comes in)? Well, maybe thinking about what is this Universe, how does it work and how did the Universe come from nothing.
So, I'm finally getting to my question. What is physics about? Because sometimes I feel like we don't know what the laws of nature really are. Sure, we know what their results are and we can measure them and find mathematical formulas but we don't really know how do they work. How come that the laws of nature are "programmed" into this Universe and every particle obeys them? Does physics study only their outcome, not how they really work, fundamentally? Or maybe we don't yet know enough or maybe we will never know enough to understand the fundamental nature of reality.
Finally, maybe I'm only interested in these questions from a philosophical point of view. After all, physics is our best bet to solve our greatest mysteries and if it's not enough then nothing is. No matter what I may end up doing I will always be fascinated with these questions, what I want to know is if as a career or as a hobby.
 A: Very briefly:
The overall program of physics is to gain quantitative understanding about how the universe works- well enough to account for the outcomes of experiments we perform on it. Occasionally, this process also leads to (perhaps qualitative) understanding of why it works the way it does.
That understanding is tentative and approximate, and subject to revision in face of new evidence. Broadly speaking, theoreticians work on the understanding, and experimentalists work on collecting the evidence.
As near as we can tell, physics is written in the language of mathematics- or at least, our models of it are well-described in that language, which means that to be a player in this field, you must be fluent in many different dialects of that language.
A: Well, a computer science analogy of what physicists do is reverse engineering. Unfortunately, the Universe is closed source. If we want to know how it works, we can't pull some repository and inspect its source code, but instead have to tinker around and experiment, and try to figure out what the source code could look like.
Mathematics can – in a way – be thought of as a programming language in which we write down our guess of what the "true source code of the Universe" looks like. We can then inspect our little program and play around with it, maybe finding behaviour we have not yet seen in nature. These predictions can in turn be tested in order to gradually improve our model.
When one has reverse engineered a program without access to its code, it is impossible to be sure that the original was programmed exactly like the model. The true source code might even have been written in a different programming language. The same is true for the Universe: Physics only develops better and better models. They might not have any physical truths on their own, but they allow us to replicate and predict the behaviour of the Universe.
In the end, only you can decide what you want to do professionally. However, I do want to make a remark: Maybe you can find a combination of the two topics you are most interested in – you should have a look at Computational Physics.
A: I remember an answer of a young Stephen Hawkings to his girlfriend, when she asked about his area of interest, in that film about him: cosmology is theology for the atheists.
It is always a temptation to get a deep understanding about  the origin and the possible ends of the universe. But at the same time we can not change anything on that big scale, it is pure theory.
