@corsair2014 First off, I want to say good luck on your journey toward a PhD in Aerospace! I completed my Aero PhD some time ago, in the gap between NASA and SpaceX, and occasionally wish I was starting fresh today. Needless to say, there was no Obsidian when I was in grad school and all my engineering notes are in handwritten notebooks more like @Lafarge describes. I would agree with him that a fair bit of how I think is on paper, in the form of sketches and handwritten math derivations.
I’m now an R&D engineer in industry, and I would say that one of the biggest things I’ve learned is that you don’t know where your future ideas are going to come from, but they will most likely be combinations of things you learn along the way in different courses and contexts. That is, you’ll take classes focused on particular subjects, but ultimately it’s the integration of these concepts in new an interesting ways that will enable you to maximize your impact on the world. This is aligned with Asimov’s notion of creativity, which I went into more detail on in another thread last year:
With regard to your specific question about how to organize notes, collect references, etc., the cheap answer is to say “you’ll figure it out as you go.” The longer answer is that Obsidian provides you with the opportunity to easily cross-reference notes, concepts, and ideas via links, while also enabling a simple, linear way of entering things. By that I mean that you can create a set of folders, one for each class, and drop class notes into each folder in sequential order. You’ll wind up with your notes naturally grouped by class, year, concept, which is how you think of them as a student.
But then you’ll get out into life and start working on some real problem and think to yourself: “I remember looking at a similar problem in class X” or “I know a math technique that was applied to a completely different problem but feels like it could be used here” and you link to it from your new project. I have had great success with this process, applying old methods to new problems, and wish it were as easy as poking through an old folder and linking to some notes as a refresher, rather than digging my class notes out of the basement!
With regard to @Lafarge’s comment about the challenge of trying to replace paper with a software tool, I agree with the sentiment but am working hard to find a way! I’ve found that Obsidian pushes me to create clean summary notes of stuff – what I think some here would consider “Evergreen” notes. When I write in my notebook, I sketch, I draw block diagrams, I do math, I write stream-of-consciousness dialogues to myself when I’m trying to work through a particularly hard problem. All these notes are valuable. But then I find the answer, and I want to capture the key insight. I find that the Zettelkasten idea pushes me to spend the time to properly summarize and capture key insights and link them appropriately. I literally will do screen-caps of handwritten notebook pages, add a pointer to a notebook page number, and include them in an Obsidian note. I link as appropriate and move on. This gives me the best of both world: traceability to my raw thoughts, and a concise, linkable summary going forward.
Still working on my workflow, but after almost a year with Obsidian, I’m very happy with where I’ve landed.