Physics PhD student here: stuff like this is awesome, but I also highly recommend the “bottom up approach” as well. Pick a little node in the vast physics network, something that interests you, and start digging deeper into the cluster connected to that curiosity.
I am wondering: I don't know much (if anything) about physics and I want to do a more basic/fundamental approach.
As far as I am aware there are two ways to approach physics: basic algebra based (simplified) as its typically taught in high school and calculus based (the proper way).
Since I do have a solid grasp on linear algebra and calculus, are there good calculus based physics books that don't assume any previous exposure to high school type physics and are suited for self learning?
The great thing about this is that it bridges the gap well between pop science and actual academic physics: certainly ideal for capable high school students. And it doesn’t skip important sections or neglect them either.
I (re-) developed a strong fascination for Physics last year after chancing upon Feynman's QED lectures. It was such mind-boggling stuff and I realized that that was just one level at which nature behaved in utterly magical ways (think - cosmological scales, the question of gravity, unified theory etc).
After trying to scour and even reading many books in this area, most that are either highly abstracted for the 'pop-sci' reader (like me, with no training in physics) or were all-out textbooks, I chanced upon Susskind's lectures and the Theoretical Minimum series. I started off right from the basics and IMHO, it has the right balance between introducing concepts and making sure you internalize them by having you actually work on problems (highly recommend that you don't skip these). I am nowhere near close to understanding any of this yet but it gave me at least an orientation for what to expect and how to prepare. Once I get a bit of time and the interest back again, I expect to go back to the other books in the series.
The lectures are also available for download as podcasts (with video!) so you don't need to watch them on youtube. At least in the Apple podcast app, but I'd imagine any podcast app will have them.
I went through the two courses on relativity and enjoyed them. They were super mathy, but I expected that going in. I had to stop them for a while and actually strengthen my math skills. I'd say my understanding is C+ at best, but like Isinlor's comment, I'm pretty sure all the relativity woo is out of my head.
The pop physics around relativity is particularly bad so I am happy that helped!
Relativity does not have to be super mathy, special relativity is kind of just a postulation that maybe there's a different sort of Doppler shift in the world. In the normal Doppler shift, clocks moving towards you appear to tick fast and clocks moving away from you appear to tick slow. Relativity adds a universal effect where if you accelerate towards a clock, it will also appear to tick faster, in proportion to both your acceleration and its coordinate along that acceleration line. So it's just an anomalous Doppler shift, to first order. (And all higher-order behavior can be derived from that.)
So like in the twin paradox, it is resolved because one of the twins accelerates towards the other twin, and when that acceleration is happening the other twin gets much much older very quickly because they are far away and the twin is accelerating towards them.
Furthermore this makes it much easier to understand some aspects of general relativity quite quickly. For example you get gravitational time dilation without much effort, once you postulate that the state of nature is freefall and we are actually accelerating against that, in a constant acceleration g upwards, which is why things in the natural state of freefall appear to accelerate downwards with acceleration g, you immediately predict that relativity will tell you that you see clocks in the upper atmosphere tick faster than they do down here. Furthermore you predict that if you could see through the Earth, at some surface below you you would hypothetically see clocks stand still, leading into a quick intuition for black holes.
Yeah I was able to handle Special Relativity fine without any need to re-dive into much math. But for the GR course I quickly realized I needed to restart from basic matrix math, haha.
To the physicist here, how much of "physics" you really get if you go through all this "minimal" courses?
To give it some context:
I watched classical mechanics a bit. Basically it's just math in the end, and to be honest after 50% of the lectures I had the feeling that the "practical" side or "intuition" is lacking. Especially in case of the conservation law's.
So maybe the question would be how much more do you get if you go through a true physics bachelor progamm?
Susskind's excellent lectures are very much a survey of physics. They're great for a lay person trying to get an initial grip on the subject matter. These lectures necessarily can't have the mathematical content that you would see even in an undergrad program. The lectures I've seen introduce the key mathematical ideas but don't exercise them in a way someone learning to be a practitioner would.
> how much more do you get if you go through a true physics bachelor program?
Every physics major will spend countless long nights working problems with pages and pages of algebraic manipulation and mathematical reasoning. It is (and must be) much more mathematical than what you see in the Susskind lectures. They're not intended to be an alternative to a traditional program, but IMHO, they do give a true understanding of the main concepts in physics.
Looking at Susskind's youtube, he has massive amount of content on Special Relativity (https://youtube.com/playlist?list=PLD9DDFBDC338226CA). Content-wise, it's the same as what a physics major would see, but without the many, many hours of problem solving exercises. The wonderful thing about Special Relativity is that it takes not a whole lot more than careful reasoning, a fair amount of algebra, and a little calculus to understand. The Susskind lectures actually go a bit farther, applying Special Relativity to Electro-Magnetism
One of the issues that Physics has (as a field) that others do not suffer, is a proliferation of cranks. I suspect that Susskind intends, in part, to counteract the cranks by providing solid, correct informational resources to the general public.
Physics is really a working knowledge, like computer programming. You have to be able to solve problems. All the 'practical' and 'intuitive' aspects of theoretical physics are built by working on problem sheets. A lot of progress in understanding (both personally and for the field!) is in tackling apparent paradoxes.
Susskind's courses are very much overviews / appreciations. For each of these areas (GR, StatMech, Quantum etc.) you would expect several 30-hr lecturer courses + problem sheets (or equivalent working through a textbook) to gain a deep knowledge.
I went trough Quantum Mechanics course and it really helped me understand Quantum Mechanics on mathematical level. I had my head full of Quantum woo from popular science programs and I barely could make heads or tails out of it. Knowing basic mathematics behind it helped a lot.
I am not a physicist but I have gone through most of the courses. It is aimed at preparing you to be able to read theorethical phisics research papers. It is not supposed to be practical and is ignoring engineering physics and history of phsics for the most part.
I think you can learn here the core concepts in theorethical phisics even at the masters program level, but you will not go through the same "math muscle training" that college students go through, so you will have to supplement that from elsewhere.
Thanks a lot for the answer! Sounds good. Guess I would have to combine it a bit with Engineering Physics (or at least experimental physics) to get the most out of it, since had really some difficulties to undestand, why core concepts, like conservation of momentum for example are important.
If you want to understand physics, then you need to build physical models and demonstrations, or perform experiments. If you want to get correct answers and make predictions, or you want to build a virtual model, then you need to study math a lot.
I would personally recommend Susskind’s videos on cosmology. Seems like the main ideas are surprisingly simple and I walked away feeling like I had learned something.
Recently stumbled upon this quite good YT channel, which also brands itself as aimed towards beginners, although in my opinion both the Susskind lectures and these 'physics mini lessons' would be best appreciated with at least some prior knowledge of undergrad physics.
I hope that I'll have time to go through this lectures. I didn't have any physics classes after the high school. It would be nice to refresh my knowledge and to learn something new :)
