It’s a new semester and so I will be studying two new specialty electives (option modules). Last year I took Life in the Universe and Active Galaxies. I had the exam for those, as well as for Maths in January. The exams seemed to go okay, I get my results back for the Maths exam on the 26th of this month, but I think I have to wait until summer to find out how I did on the other two… sigh.
This semester I have chosen to study Cosmology and Elementary particles. I am over half way through cosmology, but I won’t start Elementary Particles until later (I will write a blog about how I found that too). Cosmology was one of the modules that I was most excited to see when I applied to Leicester. If you don’t know what cosmology is, it is the study of the universe as a whole. To fully appreciate the complexities in cosmology you have to learn Einstein theory of General Relativity. However, the mathematics of general relativity is extremely complicated, there are only very few physicists in the world you truly understand it. Luckily, I don’t have to learn all of this complex mathematics, because there are some cases where the mathematics drastically simplifies. However, even with this simplified model you can’t make some fairly accurate predictions about the evolution of the universe.
The most important equation in this course is the Friedmann equation named after the Russian physicist Alexander Friedmann. Using this equation you can create different models of the universe. For example you could model a universe with no matter in it at all, or one dominated by matter, or one with a force that causes the expansion of the universe to accelerate. The evolution and fate of the universe changes when you change these variables. Such universe may end in a Big Crunch, a Big Rip, or Big Freeze.
Later in this module you learn about the beginning of the universe including one of my favorite part of cosmology inflation.
All in all, cosmology, despite being one of the hardest specialty modules I have taken has been the one I have enjoyed the most (If you are interested my second favorite was Fractals and Chaos which was also pretty hard – I don’t know why it’s always the difficult ones I like). If you don’t know much about cosmology then I would recommend checking out both the videos above and their corresponding channels (Kurzgesagt and Sixty Symbols). I also casually mentioned the curvature of the universe in this video if you don’t know what that means I’d recommend checking out this video by minutephysics:
“Space is certainly something more complicated than the average person would probably realize. Space is not just an empty background in which things happen.”