shounakbhatta said:
Actually for me study of GR is a childhood dream that I am pursuing. For me, sometimes the maths part gets too difficult to handle, hence, I try to get over the conceptual part.
The math part of full GR is too difficult for most scientists to handle. What often happens is that someone who is a specialist in GR spends a few months figuring out the solution for one part of GR, and then people use that solution. Even the specialists don't completely understand GR, and there are a lot of open questions.
On the other hand, a basic understanding of GR is something that most college physics majors can have without too much trouble. One thing that makes it more difficult than it has to be is that people don't know exactly the best way to explain GR.
One irony is that most of my understanding of GR comes from knowing when to avoid GR. My background is supernova simulations. You have a limited amount of computer CPU, and if you can get a good simulation using Newtonian gravity you use that. It turns out that you can show through some basic algebra that the effects of GR aren't important for supernova.
And then there is the question of whether GR is in fact the right theory of gravity. One thing that happens is that GR is the standard comparison theory. For example, if you come up with a different theory of gravity (and there are hundreds), what you do when you write the paper is to compare your gravity theory with GR. This is useful because if your theory is very different for things within the solar system, then it's wrong.
Initially, how fluid is connected to GR and the stellar models became a bit difficult to understand. But now it is ok.
The one bit of math that you have to master is partial differential equations. This is usually a sophomore course in college for physics majors.
Imagine a pond of water. Now drop a rock in it. The rock creates a force. Where the force is high the water gets pushed away faster. Where it is low, the water doesn't move as much.
Now put numbers to all of this, and try to calculate what happens. You end up with a page full of greek letters. It takes about three months for a college sophomore or junior to understand the techniques to do the calculations.
Imagine a ball. It's round. How do you say "round" with numbers. Another three months of learning greek letters.