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A 9-line summary of textbook physics

motionmountain.net

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Re: A 9-line summary of textbook physics

#81

Post by dhosek »

ravi-delia wrote: post #40
sdoering wrote: post #26

Earlier quoted context omitted.

> Do not use a marker, a pen or a pencil to highlight or underline text on paper. It is a waste of time, provides false comfort and makes the text unreadable. What a load of elitist BS (pardon my French). When I was at University we were trained early on to cut the notion of a book being sacred. We should mark, note, create meaning on the pages with pens. I would not have been able to learn as much in my life if I ha…

I sort of agree with the book on highlighting and underlining. If you don't jot a note down in the margin, you'll forget your state of mind and have no idea what made some underlined section meaningful. A false comfort.

When I taught LaTeX classes, I would often see students highlighting whole pages of the class notes I passed out. I often said that I should just print them on yellow paper to save them the trouble.

Re: A 9-line summary of textbook physics

#83

Post by mhh__ »

323 wrote: post #41

I've read a few times that you can derive the Maxwell equations from knowing that U(1) exists, as this article implies, that every point in space has (among other things) the symmetry of a circle. But I've never seen this derivation. I assume it's either trivial or too complicated. Anyone has a link or thoughts on this?

Read the book "Physics from symmetry" by Jacob Schwichtenburg

Re: A 9-line summary of textbook physics

#84

Post by mhh__ »

la64710 wrote: post #35

Why do the first chapters of all physics textbook ONLY talk about Greek philosophers and scientists and NEVER talk about contribution to Science from eastern civilization like India and China ? These civilizations have a very rich heritage and astounding contribution to many underlying scientific philosophies. Yet generation after generation of writers ignore them and it is sad to see that being true even today. It i…

Because we don't care about the real history, it's just a euphemism for laying down the basics of things like reference frames.

Re: A 9-line summary of textbook physics

#85

Post by vixen99 »

sdoering wrote: post #26
Reventlov wrote: post #6

I opened a volume of the books linked in the page, and found this: « Learning allows us to discover what kind of person we can be. Learning widens knowledge, improves intelligence and provides a sense of achievement. Therefore, learning from a book, especially one about nature, should be efficient and enjoyable. Avoid bad learning methods like the plague! Do not use a marker, a pen or a pencil to highlight or underli…

> Do not use a marker, a pen or a pencil to highlight or underline text on paper. It is a waste of time, provides false comfort and makes the text unreadable. What a load of elitist BS (pardon my French). When I was at University we were trained early on to cut the notion of a book being sacred. We should mark, note, create meaning on the pages with pens. I would not have been able to learn as much in my life if I ha…

I think the author does have a point though it clearly doesn't apply to everyone. 'Elitist BS' is rather strong. You take a different view but perhaps you've never studied in a part of the world where books are in short supply and one expensive copy is shared. I underlined passages in books in the past and now regret imposing my then partial view via permanent marking. Just a thought but a cataclysmic extinction event on Earth might well either destroy most electronic media or put it beyond general access. Surviving physical books might then become generally sacred once more as they are in many people's present day collections. We're rather too ready to think that the current ease with which we can check out almost any topic will be forever a permanent fixture. There are days when I doubt it.

Re: A 9-line summary of textbook physics

#86

Post by PrettyPebble »

_Nat_ wrote: post #79
PrettyPebble wrote: post #75

Earlier quoted context omitted.

If the 9 lines are wrong, just show it... Thousands of scientists are trying the same since 50 years.

It's not that they're " wrong " so much as that they're incoherent and largely non-sense. Sorry if that seems harsh, just.. this looks like someone's having some sort of crisis. It's worrisome.

No, it is fun! The scientists who are looking for exceptions to the standard model and to general relativity since 50 years are having a crisis at present, as often told.

The 9 lines imply all equations of physics. Every Lagrangian of physics is included. The lines are also coherent: none contradicts another. They are complementary: the cover all observations and all fields of physics. No field of physics is left out. The lines are also correct: every calculation fits with observations withing measurement accuracy, since the standard model (with neutrino masses and PMNS mixing) and general relativity exist.

Re: A 9-line summary of textbook physics

#88

Post by blablabla123 »

criticaltinker wrote: post #15
PrettyPebble wrote: post #2

Fun fact: all physics experiments ever made can be described by 9 lines, without any deviation between theory and observations. The 9 lines are sufficient to describe quantum physics and gravity. It seems that the 9 lines even contain all (update: natural) sciences, not only physics. Finding an exception to the 9 lines will make you famous. So will the discovery of a 10th line. Thousands of researchers work towards t…

This is satire right? You might be getting downvotes because it’s not clear if you’re serious, and those claims seem quite ridiculous at face value.

I would take this with a huge grain of salt. But generally it's quite astonishing with how few assumptions such complex theories can be derived. Also the mathematical apparatus has really all batteries included speaking of Lagrange formalism and its Action (point 1)

Re: A 9-line summary of textbook physics

#90

Post by whimsicalism »

ravi-delia wrote: post #37
mhh__ wrote: post #23

The 9 equations aspect is pretty pointless but the chapters on the right hand side could be ok. One of the things that makes physics different to most subjects is that we can make an explicit goal of being smug and rederiving the laws of physics from the simplest possible principles. I think the book seems to do this, but just summarizing like done on this webpage is a bit daft.

I think the way these are phrased do a better job expressing the "vibe", for lack of a better word, of our current understanding. That the particles and constants are declared by fiat, with behavior constrained by simpler laws, is an understanding I didn't come to until I took a QFT course. The physicist's God is as concerned with forbidding seemingly pointless things as the biologist's God is with beetles.

It is interesting that we humans have so much difficulty breaking away from anthropomorphizing.
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