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Feynman Lectures on Physics now free online (caltech.edu)
749 points by silenteh on Aug 23, 2014 | hide | past | favorite | 93 comments

I have to disable safety mode to watch these? WTF?

Physics is a dangerous thing.

I don't know what "safety mode" is, but I didn't need to disable anything to watch the videos.

Feynman is known to enjoy looking at titties while working, just warning the prudes.

Great! This part kind of surprises me though:

> However, we want to be clear that this edition is only free to read online, and this posting does not transfer any right to download all or any portion of The Feynman Lectures on Physics for any purpose.

I know it doesn't actually mean anything in practice, but still, I'm shaking my head in disbelief that there's still people out there clinging to this mentality. Aside from the fact that it's fundamentally technically impossible to read something online without downloading it first.

Lawmakers redefined the meaning of download to "download and permanently store". They don't see "download and only hold in application cache for a limited time" as download.

Unless it's child porn, I think.

So we cannot not scrape this to see how many words are in each chapter, how the technical vocabulary changes over topics, or perform an analysis on connected keywords...

Well, If you're going on the definition of download as mentioned above you could write a javascript program to do it and run it on the webpages while they're still in browser.

I was thinking of making up vocabulary lists, and creating a "learn physics in English" course.

Guess not...

Yes, but isn't that basically the same thing as most streaming services? Netflix? To me, 'clinging' makes it sound like the idea has gone away.

Wonderful news but particularly sickening for me as I fished out £130 for the hardback volumes last year!

Absolutely great books however!

I've learned a lot already from those books.

Also, the "For the Practical Man" (algebra, geometry, trig, arithemtic) series of books on mathematics that Feynman started his career with. They are hard to get hold of and expensive but the calculus book is wonderful if incredibly dense and written in an early 1900's style!

Those, a cheap Casio calculator, a box of pencils and some school exercise books have taught me more than a university degree and years of industry experience.

Edit: found a legitimate PDF of "Calculus for the practical man" http://physsocyork.co.uk/notes/J.%20E.%20Thopmson--Calculus%...

I do not regret buying the hardcover copies for one second. I prefer reading stuff ilke this on paper - digital makes a good reference for quick checking of facts but I get a better, deeper understanding of it when I sit down and read it on paper at a desk.

I'd love to buy the PDFs, but they're DRMed and I refuse to rent ebooks.

I guess I could buy them and then download the "pirate" versions from somewhere.

Instead, I'll stick with my hardcopy edition.

Wow - this is awesome. Anybody interested in helping me map out a dependency graph of the concepts in the Feynman Lectures?

Probably not exactly the dependency map you are looking for, but perhaps still very useful. http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html

If you did that it'd be super awesome. Maybe something like http://www.metacademy.org/about but for physics?

Is this worth reading for someone without a particular need to understand physics in depth? What I mean is if I take the time to read these will I learn anything useful to someone not pursuing a career in physics or related field?

I don't know about useful -- physics is not currently as useful to a programmer as, say, probability theory -- but I'd recommend volume 1 to anyone ready to follow it, just for the mind-stretching. Volume 2 is longer, harder, and less different in its approach to its main topic, electromagnetism. Volume 3 is short, unique, and doesn't depend too much on Volume 2 -- I was able to profit from it without mastering volume 2. (Nowadays there probably are better intros to quantum mechanics, though. I don't think there was any one really good intro when I studied it back in the 80s. The most enlightening were Feynman vol. 3, Dirac's Principles, and another whose authors I've forgotten.)

Added: There's only one other introductory physics text by a historically first-rank physicist, and that was Maxwell in the 19th century. (Maybe there were earlier ones, like Euler's books on mechanics, which I haven't read. Einstein's Relativity was a popularization like Feynman's QED or The Character of Physical Law rather than like the Feynman lectures. Newton's Principia has also been used as an intro text, which seems hilariously inappropriate.) The lectures are also unusually full of the this-is-how-a-physicist-thinks thing which is hard to pin down.

The honest answer is, unless your profession is in the physical sciences or hardware engineering, learning physics from this or other sources will probably not be useful.

Whether it's worthwhile is to at least some extent a value judgment, and also as I see it, depends to some extent on what else you would have done with the time. If you have a block of time allocated for work, and you're thinking of spending it reading about physics instead of reading documentation on something you do actually need, that's probably suboptimal. If you've finished work for the day, you have a block of time allocated for intellectual leisure and you're trying to decide between reading about physics versus, say, the latest Dungeons & Dragons rules, in my opinion the former is more worthwhile.

I feel quantum computing will become a critical field, starting a decade or so from now.

Since it's still in its infancy, higher level abstractions won't be engineered for atleast another 2-3 decades.

So the first few engineers who get into it - even software engineers - will have to grapple with fundamental quantum mechanical concepts, in the same way computer engineers in the 1940s-60s had to grapple with fundamental electrical engineering concepts.

Feynman's Volume 3 is an especially useful introduction to these fundamental concepts, and I feel a good investment for the future.

> Is this worth reading for someone without a particular need to understand physics in depth?

For someone just curious about modern physics, without any specialized knowledge or advanced mathematical skill, it might be overwhelming.

I suspect many of us would say yes. One of the things Feynman was known for was his knack for bringing ideas down to earth.

As he opens in QED, you won't be able to solve heavy physics problems analytically in a short period of time, but with a little effort, you'll certainly be able to qualitatively understand the situation. And there's quite a lot of beauty to have there, even without heavy math (but there will be math!)

Yes, it is especially useful as they are vary approachable. That said they are also as deep as any 3 semester course in physics you're likely to take so at some point you will need the math skills to keep up.

Disappointed it's explicitly not for download, but it's still excellent to be able to have access to all of these.

If you're reading it "on line" you've already downloaded it.

Yeah, but you can't put it easily on your tablet and read it offline while sitting in the park ;-) Still liking it a lot.

That's what I was wondering about. You'd be saving the lectures, not downloading them, if you did that. The license needs some clarity.

"Saving" vs. "Downloading" is not a duality we should entertain either. If it is downloaded, it is likely saved to a permanent storage, and maaaybe some process will eventually delete it. In any case this should not be the territory for law.

Why don't they want it anyway?

Hopefully some talented soul will write a script to convert these HTML files into mobie, epub and PDF.

From the landing page:

"However, we want to be clear that this edition is only free to read online, and this posting does not transfer any right to download all or any portion of The Feynman Lectures on Physics for any purpose."

They don't know what the word "download" means. This statement is nonsense.

"Download", as used in practice on the internet when referring to documents generally means copying the whole thing to your computer such that it can be used there without further internet access.

It generally does not include temporary transfer of small parts of the document for immediate reading, except when the focus of the discussion is about the underlying mechanics of the transfer.

This supposed duality is nonsense. A change of cache settings in your browser amounts to the same result. There's no such thing as a "temporary transfer", and I think we should not entertain the notion.

I don't see how it's any different from time-shifting with VHS. In this case, you're just using a longer-term "temporary" format (epub, mobi, pdf) which allows you to peruse the website later.

a) 304 not modified. Too late.

b) That's not how the internet works. One has already wgot the entire thing.

I don't know if you can actually take that right away however. I'm not aware of any precedent for this situation.

Lets hope that talented soul doesn't end up like Aaron Swartz.


This repository previously included a toolchain to build a collection of eBooks, in ePub and MOBI formats, from Caltech's online edition of the Feynman Lectures. Those scripts have since been removed, in response to the suggestion that their continued availability might lead to a permanent discontinuation of HTML access.

If anybody was wondering and looking at the forks, these scripts don't work anymore. They have converted the links to simple Javascript functions to link to chapters which stop these scripts from running now.

pdf. Not sure how kosher the copyright is

All 3 volumes: http://selfdefinition.org/science/25-greatest-science-books-...

That's a terrible quality pdf. For $14.99 you can purchase the enhanced version here: http://www.basicfeynman.com/enhanced.html It was very cool of the publishers to allow this, and they deserve our support.

Otherwise, if you must download the basic version, go to the piratebay and search for "Feynman Lectures on Physics (epub,mobi,html) - FIXED"

Please note that this is only a small subset of his lectures. They are the "Six Easy Pieces".

  SIX EASY PIECES, taken from these famous Lectures on 
  Physics, includes the most approachable material from the 

The pdf is a fairly accurate copy of the print books which I own but which are heavy things to lug about.

a Kindle format would be amazing as I can take it anywhere with my Kindle and learn on the go.

pandoc will do pretty much exactly that.


every now and then i go into the library and read a chapter out of my hardcover set of these. my kids do the "geeez dad" thing when i make them sit with me and look at them.

classics.. to be sure....

edit: i almost feel like these shouldn't be something that gets digitized.....this knowledge and its presentation belongs in a tactile medium...

The plural of anecdote is data, so FWIW I'm exactly the opposite: not just for textbooks, but even for hardcover literature books I have right there in my bookshelf, I often end up digging up some PDF or Google Books version regardless. I guess I miss the scrolling/zooming, plus all the meta-textual, cross-referencing stuff like having multiple copies of the book in different sections side by side, easy access to references and definitions, etc.

What one finds 'classical' is highly relative: remember Socrates famously despised books as a degrading and pernicious medium, for one [1].

[1] http://wondermark.com/socrates-vs-writing/

Socrates' ideas, or rather Plato's representations thereof, belong to a cultural context radically different from our own and have absolutely no relevance. Greece was undergoing a transition from orality to literacy at the time. It was also in the early stages of actual educational institutions. What the distribution of a few manuscripts in that context meant relates to nothing in our modern world.

Not to be a jerk about it, but the misuse of history is characteristic of very pernicious rhetoric.

Wow chalk one up on "completely missing the point." Gone35 was drawing a comparison between the Greek's transition from orality to literacy and our transition from literacy to a more digital communication media.

Books are clearly worse in virtually every context than one on one dialog with the author.

The advantage of contact with people separated in space or time seem less meaningful at the time. But, venerating books over one on one contact is a huge mistake.

> Books are clearly worse in virtually every context than one on one dialog with the author.

This is not the case with fiction or poetry, where what is communicated is often precisely what cannot be communicated socially or even explicitly. The experiences of both writing and reading are often in a different realm altogether than those of speaking and listening face to face -- one is not a watered down version of the other. They have different qualities.

And even in the case of scientific and mathematical exposition, where your statement is more often true, there are many exceptions. For example, I think of professors I've had who could write lucidly but were poor teachers, both in the classroom and in office hours. Either their social skills stood in the way of their communication, or their verbal skills were not as good as their written ones. They needed time and solitude to express their thoughts clearly.

People can recite books just fine, let alone poetry. Granted, it's something of a lost skill, but one on one interactions are not limited to dialogs even if they may enhance exposition.

So, you gain absolutely nothing by writing the spoken word down as a skilled orator can speak with a nuteral tone when desired but the written word can't add inflection.

Sometimes deliberate ambiguity is part of the art. (Also, on a more practical level, books are better at random access.)

> Books are clearly worse in virtually every context than one on one dialog with the author.

This is what Feynman himself wrote in the preface to the books under discussion.

To be sure, I too prefer a book. But there are plenty of times I would love the option to reference a book at an inconvenient time (like when I'm at work 50 miles away). Having a low fidelity option is preferable over none at all in these cases.

Someday we'll have an honest-to-god book with e-ink, which will reconfigure itself to whatever we want to read and get the best of both worlds. (PopSci promised me this more than a decade ago and I'm bitter it hasn't happened yet!)

Agree with this.

Also if I get into a book, I always end up buying the thing as I don't want any electronic distractions taking away from it.

>> "I don't want any electronic distractions taking away from it"

Reading on Kindle is pretty distraction free I find.

Until it goes flat, you drop it or the damn thing decides you're not allowed to read the book any more or the ebook is a poorly OCR'ed copy with mistakes in it...

Plus I can't give my books to other people to read when I'm done.

I had a Kobo and a Kindle and they were horrid.

I understand but no thanks.

These books show more than anything else why Feynman is so revered among physicists as a teacher. An introductory course in physics, simple yet demanding, and shot through with Feynman's unique approach and personality.

Feynman actually found that the lectures kind of flopped as a semesters courses. It was too intense, IIRC.

That's correct. Having said that, they're a fantastic refresher for someone who has studied all of this at the high school / university level and wants to get a crash course. Feynmann loved his technical crash courses and these lectures show that he has a mastery of distilling out all of the details and leaving none of the chaff.

this is obviously a great news for Physics lovers like myself. I have been always intrigued and fascinated by Physics and unfortunately did not able to pursue it as my career but having free access to Feynman's lectures would definitely ignite passion in me and lot of others who are interested in subject.

Just chapter 1 contains answers to many questions that I've had on the back of my mind.. Why does water ice expand when it melts? If water ice is a crystalline structure, how can it vary in temperature (e.g. -5 degrees to -10 degrees). A very good read.

Perhaps you misspoke or I'm not understanding correctly what you mean but from the book:

"Another thing we can see from Fig. 1–4 is why ice shrinks when it melts. The particular crystal pattern of ice shown here has many “holes” in it, as does the true ice structure. When the organization breaks down, these holes can be occupied by molecules. Most simple substances, with the exception of water and type metal, expand upon melting, because the atoms are closely packed in the solid crystal and upon melting need more room to jiggle around, but an open structure collapses, as in the case of water."

I misspoke, I meant shrinks.. thanks for the heads up.

Project Tuva has a great series of lectures Feynman gave around that time http://research.microsoft.com/apps/tools/tuva/

Silverlight only. Too bad MS cares more about pushing their proprietary technology than sharing important historical / educational material.

How does this compare to Susskind's "The Theoretical Minimum"?

Susskind's is much shorter and goes into very little detail. It's really intended to give you a foundation for learning physics, while Feynmann's is meant to teach you lots of physics.

The Feynman lectures certainly will teach you a lot, but I think it would be a fairly trying textbook for learning a lot of the material for the first time. Among other things, a very serious deficiency for self-education is a complete lack of problems to work (which just reflects that these really were lectures).

What would you recommend for self-education?

That's a tough question. One of the most appealing things about the Feynman lectures is the breadth and how self-contained it is. I don't think there are really good analogues for that. The closest thing I can think of is one of the monster first-year physics tomes like Halliday and Resnick. That will teach you much of the basics (large chunks of Vol. 1 and 2 of the Feynman lectures), has huge numbers of problems, but it is of course less fun. It is also probably comparably or more expensive.

Going much further than that gets tricky, because you will usually need more development in math in concert with the physics. The omnibus "engineering mathematics" type books will cover a lot of it but I don't really like them. Boas's Mathematical Methods in the Physical Sciences would be something I would look at. For more detailed looks at electromagnetism and quantum mechanics, I (and many others I know) really liked David Griffiths's textbooks. The Feynman lectures make an excellent supplement to these for the different perspective and interesting physical insights.

Does that apply to Susskind's video lectures as well?

Don't forget the audio is out there too!

Is it actually possible to learn this through audio? With equations and so forth I would imagine it being rather hard. Do you have any experience with it?

Yes I have the audio. No, it is no substitute for the book. The audio is of the lectures. The books are based on the lectures. It's just nice to have the audio to go along so you can hear his personality.

Yeah I could see how that would be beneficial. And I guess that it could work for repetition as well. Where did you get the audio?

Well, the first rule of * is you do not talk about *.

It is awesome how while the page is loading you see stuff like this:

"Now if we multiply Eq. (41.19) by [math], [math]. We want the time average of [math], so let us take the average of the whole equation, and study the three terms. Now what about [math] times the force?"

Soo... am I going to need math skills to understand this stuff?

Yes. Calculus was basically invented to solve physics problems.

Honestly, I feel that Calc should be taught way earlier, the way that physics is taught in school feels rather incomplete. I mean without calculus, is quite difficult to understand physics.

An offline version of the website is still floating around the Internet space.

Thanks for the material. Anyone working towards translating the material?

Has anyone completed all of the 3 parts? How much time did it take you ?

It's generally a three semester to a full two year sequence at most universities. You can of course go faster or slower depending on your own capacity to self-study and learn, but most bright people will probably fall somewhere in that spread to get a solid grasp of the total contents.

That said, it's always helpful at first to skim through and get a surface understanding of the whole picture before you dive in and try to understand it all. You can probably complete a surface scan like that in a few weeks or months. I studied these becomes along with my high school physics course and completed the books in about a year, but I was spending double the usual amount of time on this stuff. As a high school student, I didn't have anything better to do, but as an adult I'd expect it to take me two dedicated years.

One of the rare cases of "internet done right".

Great lecture, this very useful :) to all fresher

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