proginthebox
Joined 9 years ago
Joined 9 years ago
Also, unfortunately, its not the recommended order to learn them in.
But your advice has a point, just going through books mindlessly is not motivation enough/ can lead to wandering. And it is always good to have specific tasks at hand. Like, solving a particular ordinary differential equations numerically.
For example, (since I don't really have much time)
1. Topology (book by Munkres)
2. Real Analysis and Measure Theory (book series by Stein Shakarchi)
3. Algebra (book by Aluffi)
4. Linear Algebra (book by Friedberg Insel)
5. Measure Theoretic Probability (book by Cinlar)
6. Differential Geometry (book Smooth Manifolds by Lee)
7. Numerical Analysis (book by Quarteroni)
8. Set Theory and Propositional Logic (books by Goldrei)
This is what one will mainly learn in a strong undergrad/grad math program. Once this is done, then there are different tracks to follow.
Physical simulations need to preserve entropy, maximum principle, energy conservation and other kinds of conservation, preservation of consistent states, convergence in case of finer mesh.
There are multiple equations which model different forms of fluid: 1. Incompressible Euler (For liquid) 2. Compressible Euler (For non-viscous gases) 3. Navier Stokes Equations (For viscous liquids)
There are multiple solver methods: 1. Finite Difference 2. Finite Element 3. Discontiguous Galerkin Finite Element 4. Finite Volume Method
There are multiple equation methods: 1. equation splitting is just one of the many methods possible.
Just because the equation is unique does not mean that the solution is unique. Single equation provably have multiple and even infinite solution for the same initial condition. Computer graphics fluid simulation does not care (with a good reason) about this and hence, often their simulations even though they look kind of nice, are often incorrect since they do not demonstrate various physical characteristics that must be preserved.
In contrast, the qualitative/quantitative constraint in physical simulations are very strict. You need to know a lot of theoretical math to even understand if you are even computing the correct solution.
While I appreciate your brother's personal choice, to each their own after all. There is quite a lot of merit in your PhD advisor helping you in choosing a problem. That being said, good advisors provide students with an array of good problems out of which the student can choose one they are the most passionate about. This is what happened with me, I was provided with around 7 different choices to make. In the end, I chose 2 of them even though I wanted to chose 3 more but couldn't because of lack of time.