Almost anyone can learn about the special theory of relativity from these lectures. I actually can't believe that I studied from a professor who teaches in the USA and in so simple way. I am grateful.
It was wonderful experience to know the special theory of relativity from Larry, who has presented the course in very simple way to understand. Thanks a lot to Larry for providing such a good session.
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I’ve enjoyed this course, which I’ve been following during the UK’s Covid 19 lockdown. It’s kept me happily occupied and, thanks to Larry Lagestrom’s generally careful and enthusiastic exposition, I’ve finally got my head round the relativity of simultaneity and its role in explaining the ‘pole in the barn’ paradox - something I never quite managed when introduced to special relativity as a physic’s undergraduate more than 50 years ago. So, a big thank you to Prof Lagerstrom.
I’ve a few reservations. First, the treatment of Einstein’s second postulate seems to be needlessly confusing. Starting in week 3, and then repeatedly throughout the course, the lecturer maintains that, by the phrase ‘the constancy of light’, used to describe the second postulate, Einstein means that light is a wave, implying, drawing an analogy with, say, sound waves, the the existence of a ‘supporting’ transmission medium - the luminiferous ether. It’s then maintained that, somehow - I can’t follow the argument - Einstein combined this interpretation of the constancy of light with the principle of relativity to deduce that the velocity of light is constant for all observers. I’ve read the relevant bit of Einstein’s 1905 paper several times, and I just don’t think this is what Einstein is saying at all. What it actually says is: ‘Llght is always propagated through empty space with a definite velocity c, which is independent of the motion of the observer’. There’s no recourse to any sort of argument, instead, it’s simply stated as a fact - just what you’d expect for a postulate. From some of the posts in the discussion forum, it would appear I’m not the only one having difficulties with this issue.
My second reservation - following on from the first - is that there’s too much time and effort devoted to the Michelson-Morley experiment. There’s no ether, the experiment was doomed to failure and all that time and effort deriving expressions for possible phase shifts - using highly questionable assumptions about the speed of the local ‘ether wind’ - could have been better spent.
It’s a small point, but my last reservation is with the derivation of length contraction, which I found hard to follow. The alternative approach - using a light clock sending pulses longitudinally along a train - seems much more straightforward and follows on nicely from the transverse clock used to explain time dilation.
Where I think the course really scores is in the derivation of the Lorentz transforms and the use of space-time diagrams. If you can work your way past possible early confusions and press on to these key topics,; you'll be amply rewarded for your troubles.
Alongside the course I’ve read Larry Lagestrom’s book, ‘Young Einstein: From the Doxel Affair to the Miracle Year’. It’s a good read and is particularly good at explaining the content of all Einstein’s 1905 papers.
by Richard E•
Lecture delivery: Very engaging, in general. I do appreciate the historical background material. Difficulty: Way too easy. The professor seems to assume that the audience is weak in Math & Physics. The prerequisites for the course should include at least elementary Mechanics and Vector Algebra. Near the end, one problem should have been presented in 3D [t, x, y, z] to reinforce that the the previous problems were based on holding 2 of the 3 space dimensions constant. Leaving the details of the vector algebra as an exercise for the student to verify is justified with a change in the prerequisites. There was way too much explanation of algebra manipulation. Much should have been left as an exercise to the student! The mass/energy issue with respect to the speed of light should have been presented. This was skipped and could have been presented in a general sense with accompanying Internet GR references for derivations (E.g. DrPhysicsA on YouTube.com). Problem sets should not be optional! These are good student reinforcement opportunities. A presentation which needs to be revisited IMO: "The Twin Paradox" part 3.
by John R•
Excellent presentation, clearly explained in generic language some of the esoteric concepts of the Special Theory of Relativity. In my Physics IV class, fifty years ago, we called this "Science Fiction I." I enjoyed the course. Only downside, I would think that a University with the standing of Stanford would produce a presentation that would use digital graphics instead of a white board and dry erase marker. With the capabilities of computer programming, this course could be greatly enhanced in the audio/visual area.
by Bhushan J•
In my view the course was a great exposure to Special Theory of Relativity and superbly conducted by Prof. Lagerstrom. I think some more rigor could be brought into as 'optional modules' and in the optional problem sets. There are some places where explanation could be elaborated or made clearer further in my view. Nonetheless for anyone who wants to know something about Special Theory (and vet intellectual appetite further), I would recommend this is a good place to start. Thank you!
by prasad s•
At first, it really seems to be very slow paced, but latter you realize that those initial concepts were so key to the analysis and concepts in during latter lectures. The professor seemed to be very dedicated, and taught everything from the ground-up; which was really a help and thus, there does not arises a moment when you seriously struggle about the topic being discussed. HATS OFF to the professor for teaching in such a simplistic and conceivable fashion.
by Michele S•
This was mind-expanding. I had forgotten most everything I had learned on this subject in college (40-odd years ago). Dr. Lagerstrom did an excellent job of describing the concepts of Special Relativity. The English language is not very good, however, at expressing things like "clocks lagging" or "running fast". But Dr. Lagerstrom rendered the material understandable, and my brain hsa gotten a much-needed jolt from the torpor of the everyday.
by Ameya K•
Pros: Everything is explained very well, to the point that even middle schoolers should be able to get it. It makes a university topic seem easy, which is impressive.
Cons: The course is very very long, and often feels very repetitive. A lot of videos don't seem necessary, and could have been shortened to half their length. Also, Week 1 is completely skippable because it doesn't actually teach anything about SR, just about Einstein's life.
by Lior S•
This was a great course which is taught by a passionate and patient lecturer. The whole 8 weeks covers the first half of Einstein's famous paper in detail. The pace can be slow, but of course you can always speed up the videos. The mathematics is very approachable - school level algebra is all you need. The only other prerequisite is a basic understanding of light and electromagnetic waves.
by Kelly S•
Good content, but too much focus on Einstein himself and philosophy. Could do with a little bit more of the math side of things, but I'm biased in that regard as already having finished my bachelors in aeronautical engineering. Spent too much time going over the examples, but they were well constructed and yielded a lot of insight.
by Floris v d P•
A comprehensive introduction to the subject, somewhat spoiled by the unrelenting reiteration of the most basics concepts in the earlier parts of the course. A bit of a pity, since the lecturer is a fairly engaging speaker when he is not busy interrupting the flow of his argument with mind–numbing repetition.
by Deleted A•
The content is really good. The quality of the content is excellent. The instructor's pedagogical skills are excellent as well.
The only criticism I have is with the length of the videos. I feel they could be shortened. Other than that, one of the best introductory courses for Special Relativity.
by Mitchell D•
I think very highly of the course, and the professor, with one quibble: The professor had some difficulty talking in full sentences, which I found frustrating and annoying. Nonetheless, I enjoyed the experience, and believe that my understanding of Einstein's theories is certainly improved.
by Mahesh U•
Not much of mathematical inclination. But the Prof. is really of high standard and he makes sure that you understand everything by the end of any topic as he will run by each topic more than once. Its an introductory course but induces a great amount of interest to learn more!
by Anthony B•
Very good introductory course, clear and well designed, with a nice emphasis on the key concepts of the special theory of relativity. The mathematical background required is very light, hence the quantitative analysis of various examples and situations is limited.
by Felix M•
A brilliant course. I got everything I wanted to out of it by the end, but one thing I would say is that it started off a little slow, particularly in weeks 2 and 3. All things considered, a great way to build a better understanding of special relativity.