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## Quantum Physics For Everybody145

Posted by kdawson
from the this-time-without-the-math dept.
fiziko writes in with a self-described "blatant self-promotion" of a worthwhile service for those wishing to go beyond Khan Academy physics: namely Bureau 42's Summer School. "As those who subscribe to the 'Sci-Fi News' slashbox may know, Bureau 42 has launched its first Summer School. This year we're doing a nine-part series (every Monday in July and August) taking readers from high school physics to graduate level physics, with no particular mathematical background required. Follow the link for part 1."
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## Quantum Physics For Everybody

• #### No mathematical background? (Score:3, Insightful)

on Tuesday July 06, 2010 @05:18PM (#32817630) Homepage

Grade school level math. The most complicated math in the series is this: “if a times b is less than 6, and we measure a to be 2, then b must be less than 3.” If you can follow that, you’ll be fine.

Physics that uses no more math than this is not graduate-level physics.

• #### Re: (Score:2)

Well, it doesn't say "no math", it says "no math background required." Presumably this means they'll be introducing math concepts in this course as well, starting with 8th grade pre-algebra and ending up at advanced calculus. Seems rather ambitious for a 9-part series of PDFs.
• #### Re: (Score:2)

Considering that their first PDF is only 6 pages long and only text, I don't expect any serious physics thaught in that course.
• #### Re: (Score:2)

Physics that uses no more math than this is not graduate-level physics.

Agree. When you leave the math out, it's not quantum mechanics; it's philosophy.

To be fair, I suppose that they could teach the math as part of the course. (If they take the Dirac abstract-algebra approach, it may be that you have to learn it all from zero anyway.)

• #### Re: (Score:3, Insightful)

Perhaps they mean teaching the theory and not the applied physics?

I mean there was a whole lot of high school physics that didn't need any math whatsoever to understand, but the math simply helped its application.

And as a side note, All they layed out was a puzzle in Linear Algebra. Essentially, linear algebra branches off into some complex systems like encryption and game-theory, but in essence the math behind it is not any more complex than using constants to define variables.

• #### Re:No mathematical background? (Score:5, Insightful)

on Tuesday July 06, 2010 @07:27PM (#32819172)
I disagree. I didn't realize it until college, but physics without calculus is about is as satisfying as having someone describe a piece of music to you.
• #### Re: (Score:2)

That presumes that you like music..... I mean math.

A lot of us don't. Even Stephen Hawking has said he's not thrilled with math, and develops most of his ideas visually in his head (source: his book Black Holes and Baby Universes). He only uses the math as the final step, to describe what he sees in his head, not because he enjoys it.

• #### Like it or not maths is still needed (Score:2)

He only uses the math as the final step, to describe what he sees in his head, not because he enjoys it.

Exactly - in order to describe physics you have to use maths. It is certainly possible to teach the basic concepts but if you think you are learning "graduate level" physics you clearly have no idea what graduate level physics is because that requires maths in order to communicate a full understanding even though the understanding in your head will be in "pictures".

For example I can simply tell you that in nature every symmetry produces a conserved quantity. You can think about it for a while and perhap

• #### Re: (Score:2)

'Noether's theorem'

looks like she's saying things must be in a transient/flux state.

or each action must also be symmetrical and have an 'interface'

and indeed, each symmetry must also have an asymmetry and interface.

this requires latent 'constants' (I can't remember if the laws of super duper symmetry required some things to be constant absolute and some things to be relatively constant) within the system and means that the system must be in a status of continuous flux.

conservation laws (and their a/symmetri

• #### Re: (Score:2)

I'd say even more than that. My 1st year of physics I found if painfully difficult to learn what the text was trying to teach... in large part because they special cased everything to keep the required level of math down (otoh at the very same time the Feynman Lectures seemed fairly easy to follow by comparison). Then I took a course in ODE's and PDE's and just about everything I had come across in all of 1st year Physics dropped/popped out as simple examples in this one course.

My advice to anyone wanting t

• #### Re: (Score:2)

Perhaps they mean teaching the theory and not the applied physics?

It's the other way around: theoretical physics is even more concerned with math than applied physics. There's a reason why theoretical physics is also called mathematical physics. And I guess you confuse working the numbers with math.

Furthermore, you can't separate physics and mathematics because the latter is the formers language.

• #### Re: (Score:1, Troll)

I agree.
"Intelligence for dummies" by "I. schmel profit".
"Quantum Physics for bears"
citing "Introduction to Trailer Court physics" on your resume for LHC would certainly get you noticed.
• #### Re: (Score:2)

Physics use mathematical tools and most of its notation. However, this serves as a means to an end. That being said, you can also follow Leonard Susskind Stanford lectures on Quantum Physics and learn how Einstein's worked out that E=mc^2 with grade 13 math.

• #### Re:No mathematical background? (Score:5, Informative)

on Tuesday July 06, 2010 @07:45PM (#32819378) Homepage

Actually, I was working on the ATLAS detector that is in place at the LHC when I started writing for Bureau 42 almost 10 years ago. And I don't know how we profit off of something that's free...

My philosophy (which is in lesson nine, and probably should have come sooner; lesson one is more focused on why we need quantum mechanics, and the rest develops over time) is that the concepts and ideas of physics are represented by the math, but not defined by them. Math can certainly point out directions to look at and avenues to explore, and indicate connections between ideas we hadn't previously noticed, but as a student, I always found that the worst possible reason for a physics phenomenon was "because the math says so." This is about getting those ideas across for people who want to learn about the ideas. The ideas covered in the last two lessons are not typically introduced before grad school. (Lesson one starts at the high school level, which is all I wanted to assume from my audience.) Will you be a researcher when you're done? No. Will you have a better understanding of popular science articles relating to quantum physics? I certainly hope so.

• #### Re: (Score:2)

People profit on free things in the same way that Google profits from giving away free search.
I did work with NASA 40 years ago and so I guess that makes me correct also. Wikipedia already has good reference and has some people that maintain the reference well. No point in muddying the waters.
http://en.wikipedia.org/wiki/Quantum_mechanics [wikipedia.org] It is a difficult science and the relationships are modeled with math. Understanding math is not a suggested dependency it is a prerequisite in any curriculum.
As some
• #### Re: (Score:2)

The Bureau 42 authors don't use the site for profits. Most years, ad banner revenue is about the cost of renewing the domain name, and none of us get paid to post our stuff. We just have fun in our spare time. That's where this came from; when doing my M.Sc., I found I enjoyed teaching in labs far more than I enjoyed doing the actual research. That realization and a case of bilateral elbow tendonitis prompted me to switch to education. Now I teach K-12 (along with other tasks) at the private education

• #### Re: (Score:2)

My philosophy...is that the concepts and ideas of physics are represented by the math, but not defined by them.

Correct - maths is the language of physics and just like any language it is used to express ideas and concepts. As such you can certainly, albeit it crudely, explain the concepts in other languages such as English which lack the precision of maths, in much the same way that you lose a lot of the beauty and depth of Shakespeare if the bard is translated into, say, French. Similarly you are fooling yourself, and more importantly your readers, if you think you have communicated those concepts at the graduate

• #### Re: (Score:2)

Personally I've read so much "math free" stuff about Physics and especially QM and gained very little from the experience.

You're better off finding better ways of teaching people math.

• #### Re: (Score:1)

You can get basic points in physics across without using math, but in general if you want to get to the interesting bits you have to be willing to write down some equations. For instance, I can tell you that gravity pulls things together, which is the basic idea, but if you want to know why planetary orbits are elliptical or what the escape velocity from earth is, then you have to do some calculus. In quantum mechanics, the math involved gets deep rather quickly.
• #### Re:No mathematical background? (Score:5, Interesting)

on Tuesday July 06, 2010 @05:37PM (#32817916) Homepage Journal

My personal opinion is that you CAN discuss the principles without going into more details. I think it's pretty easy to explain the concept of a Hilbert space with absolutely no knowledge of calculus, because it's just geometry and common sense.
It is problematic to teach physics without math, because you can get it horribly wrong. But you can explain graduate level concepts without math, and you can certainly describe the experiments that prove a formula works, even if you don't go through the complicated math involved in connecting the theory, formula and experiment.
It took some time to get from quantum physics to the specific heat of metals in the statistical physics course. But I can tell anyone on the street "look, if we measure the way metals conduct heat, we find that they behave in a certain way. we are only able to explain that if we use quantum physics to describe part of the electrons as a gas moving around inside the metal. classical physics fails.", and that should be enough for a basic idea.

• #### Re: (Score:1, Flamebait)

Oh certainly. I do agree with you. But discussing the concepts and principles is not graduate level physics, it's conceptual physics, which is what you teach to undergraduate poets and business majors. Nothing wrong with it, and it certainly is very important and worthwhile, but it is not graduate level physics, which is intended to prepare you to do actual novel physics research on your own.
• #### Re: (Score:3, Funny)

I think it's pretty easy to explain the concept of a Hilbert space with absolutely no knowledge of calculus, because it's just geometry and common sense.

I don't know about you, but lacking a background in Physics, I found it *very* confusing to jump from integration in 3-D over a Hydrogen probability density wavefunction, to suddenly talking about the *infinite-dimensional* Hilbert function space. Besides, if the students have a problem visualising that if a < b then a+x < b+x, they may also lack th

• #### Re: (Score:2, Informative)

A Hilbert space is a complete vector space with a scalar (dot) product. The "complete" just means that any infinite sequence of items such that the distance between two successive ones goes to zero has a limit (the set of rational numbers is NOT complete). A trivial example is normal Euclidian 3D space.
You don't need to explain anything about functions in order to explain Hilbert space, because any Euclidian space is a Hilbert space. When you do know about functions, you just show that any linear differenti

• #### Re: (Score:2)

The "complete" just means that any infinite sequence of items such that the distance between two successive ones goes to zero has a limit (the set of rational numbers is NOT complete).

Wrong. You either don't know what completeness means, or you've oversimplified to the point where you're harming readers who might trust you to explain the concept correctly.

Counterexample: Pick a sequence x_1 = 1, x_2 = 3/2, ... x_{n+1} = x_n + 1/(n+1). If you think of these values as angles on the unit circle, then

• #### Re: (Score:2)

you're right, of course. I was just trying to explain what a Cauchy sequence is, and I didn't do it properly...

• #### Re: (Score:2)

How the hell is this flamebait?
• #### Re: (Score:2)

well, there is a mistake in my definition of a complete space. and fritsd was modded funny for some reason.

i'm relatively new, so I assumed this was a "welcome to slashdot" kind of thing. there's also an AC that called me an asshole for this same post. something must be wrong with it.

• #### Re: (Score:2)

Welcome to Slashdot! :-) It can be somewhat harsh sometimes.
I was not the AC who called you asshole, just to clear that up.
I don't know why my posting was marked funny, maybe I made a mistake in it (getting rusty). I understand and agree with your explanation that the "where" is 3-D space and the superposition of n different orthogonal wavefunctions Psi(x,y,z) = \sum_i^n C_i psi_i(x,y,z) is a "point coordinate" in n-D (function-)space, all I wanted to whine about in my original posting is, that for a st
• #### Re: (Score:2)

I think it's pretty easy to explain the concept of a Hilbert space with absolutely no knowledge of calculus, because it's just geometry and common sense.

I agree, but to understand why and how a Hilbert space important to QM, you need the features of Hilbert spaces that are unlike Euclidean spaces.

To see why this is relevant, take the Uncertainty Principle. It can actually be stated for systems described by finite-dimensional Hilbert spaces (for which one could have a nice geometric intuition), but it's not that interesting. The real understanding (at least for me, and I suspect for most people) only comes when you learn the position and momentum operators,

• #### Re: (Score:2)

But the fact that we can state the Uncertainty principle in a finite dimensional Hilbert space (as you point out) shows that the Uncertainty principle does rely on properties of infinity. It fact in the finite dimensional case it becomes somewhat easier to understand what is going on. Take the spin-1/2 system which is two dimensional. The eigenvectors any of the operators s_x, s_y or s_z form a basis for the state, however each operator's eigenbasis is not parallel to any other operator's eigenbasis. A vect

• #### Re: (Score:2)

In infinite dimensional cases things are more complicated because there are various subtitles that can arise. But these subtitles are not at the core of the uncertainty principle, merely a technical distraction that needs to be addressed.

I disagree that it's merely a distraction. Yes, when teaching the Uncertainty principle for the first time, it may be a good idea to show it for finite dimensional Hilbert space (in fact, I wish it was done this way, it's so much simpler, like you said!). For your example of a spin-1/2 particle:

delta(s_x)*delta(s_y) >= abs(<[s_x,s_y]>)/2

It's very nice for an introduction, and it can be derived with very simple math, but you can't honestly say it's graduate-level Physics if you can't even do it for

• #### Re: (Score:2)

I think it's pretty easy to explain the concept of a Hilbert space with absolutely no knowledge of calculus, because it's just geometry and common sense.

But it *isn't* just common sense. Hilbert space is far stranger than ordinary 2D or 3D space, and if your experience is limited to those two examples, then you'll get things wrong.

Here's an example: draw a square in the plane, and fill it randomly (uniformly) with lots of points. They cover the square roughly evenly. This is also true in 3D. But if

• #### Re: (Score:3, Insightful)

My personal opinion is that you CAN discuss the principles without going into more details

And that discussion would be as useful as discussing topics like OO-programming principles with someone who has never written a line of code. Or like discussing the issues with MySQL with someone who has never used a database or written a line of SQL.

You can make someone think they "understood" the physics, when, in fact, he haven't understood anything. Much like how you "explain" how you fixed a particular tricky bug to the upper management.

• #### Re: (Score:2)

it depends on the teaching approach.

more 'theoretical' set theory based stuff, yeh loads of maths.

but you should be able to explain things using concepts, which the audience 'can' grasp without knowing the precise math behind it.

For instance, you could explain Newtonian physics via example and a persons every day experience. You'd get the basic principles behind it accros with no need for maths.

every action has an equal and opposite reaction.
and some clips of experiments to demonstrate this such as newtons

• #### Re:No mathematical background? (Score:5, Insightful)

on Tuesday July 06, 2010 @06:02PM (#32818194)

What's with all the negative comments? Anyone look at the lecture 1 PDF? Anyone actually do physics for a living?

As I write this, I'm staring at a whiteboard drawing of three equations in my den; E=mc^2, E=hc/lambda, r=2GM/c^2. They are there show my 13 year old niece how much energy a human body is equal to, a question she asked after watching K-PAX two nights ago on Netflix. Then she asked how much energy is in a single photon, then she asked how much energy is in a black hole. All questions a little girl might ask had she been exposed to basic ideas in modern physics, aka television.

Does she fully understand quantum mechanics, probably not. Does she she understand the jist with her pre-algebra background, sort of. Did she learn something and does she feel 'smarter' now... you betchya!

She annoyed my sister for hours about how a tree could power the whole world, or a tiny little bug could drive her car for years. My explanations, her worlds, and now a scientist in the making.

My point, you don't need to be able to derive Maxwell from F=ma, as my advisor's advisor did while backpacking across the Rocky Mts., to understand nature at its most simple, what you see is what you get, level. You also don't need to be some bearded mystic holed up in a university to appreciate, understand, or even contribute to our vastly poor knowledge of nature.

• #### Re: (Score:3, Interesting)

I don't disagree with you, and I was not intending to claim that the lecture PDFs are not worthwhile. But I stand by my claim that they do not teach *graduate level* physics. They may teach the concepts that are dealt with in graduate level physics courses, but a graduate level physics education prepares one to teach or do research, which this sort of physics-without-much-math most certainly does not do.

And yes, I do physics for a living.
• #### Re: (Score:2)

And yes, I do physics for a living.

Obviously. :-)

• #### Re: (Score:2, Funny)

Well, the time-independent Schrödinger equation requires nothing more than high-school math:

Hpsi = Epsi

Just divide out psi and you're done!

* Thanks, Slashdot, for allowing Greek letters...

• #### Re:No mathematical background? (Score:5, Insightful)

on Tuesday July 06, 2010 @06:40PM (#32818578) Journal

Physics that uses no more math than this is not graduate-level physics.

I call bullshit, politely though. Not only can it be done, you've got to understand what you're doing well enough to step out of the higher level math. One of the most spectacular instances teaching I ever witnessed was at Purdue, where a class on relativity for non-science students was held, using nothing more than F = ma and a^2 + b^2 = c^2. Anyone can become an expert and talk expert to other experts and future experts. The higher the level the more jargonized and incomprehensible it becomes to everyone else. Worse, it becomes a sign of rite-of-passage, a badge of membership and a competition among its adherents, who constantly push the envelope on this. In doing so they become more and more isolated and insulated, viewing others as outsiders, people to stay away from if not look down on. They become socialized to not speaking outside their box, and pressure is applied from the group ion any member who does try to talk outside.

Anyone who can understand a field at the expert level but can explain it in non-specialized language without polysyballic words probably understands it far better than those in the specialists' club. An often misstated (but flexible enough to still work) quote from Ernest Rutherford is "An alleged scientific discovery has no merit unless it can be explained to a barmaid." There's people out there doing this thing which 'can't' be done. Go listen to them.

• #### Re: (Score:2, Insightful)

I'm not saying that it isn't physics because you aren't using math. I'm not saying it shouldn't be done. I think that explaining physics on a conceptual level to non-scientists is a really, really good plan.

But, a graduate level education (in any field) is intended to prepare you to teach and to do novel research. You cannot teach physics, and you certainly can't do novel physics research, if you don't know any more than grade school math. It is simply impossible. So, the people who are creating what
• #### Einstein (Score:3, Interesting)

I will add to this one of the greatest physicists around, Albert Einstein, did not know the necessary maths when he wrote his first theory. The maths was done for him, though he did later learn to do mathematics.

Science as we know it is not about the maths, but being able to produce a solid theory that stands up under scrutiny. Using scientific process helps add weight and often mathematics can provide a calculable way of showing numerical relationships, but if the reasoning for the theory is sound then the

• #### The ivory tower syndrome (Score:2)

The higher the level the more jargonized and incomprehensible it becomes to everyone else. Worse, it becomes a sign of rite-of-passage, a badge of membership and a competition among its adherents, who constantly push the envelope on this. In doing so they become more and more isolated and insulated, viewing others as outsiders, people to stay away from if not look down on. They become socialized to not speaking outside their box, and pressure is applied from the group ion any member who does try to talk ou

• #### Re: (Score:2)

An often misstated (but flexible enough to still work) quote from Ernest Rutherford is "An alleged scientific discovery has no merit unless it can be explained to a barmaid."

That was just Ernest trying to explain how all that time he spent talking to barmaids he was actually working.

Occasionally it pays off to be smart...

• #### Re:No mathematical background? (Score:4, Informative)

on Tuesday July 06, 2010 @07:17PM (#32819024) Homepage

It's hit the concepts dealt with at the graduate level, but I left the math out to make those concepts accessible to people who don't have the heavy mathematical background. I'm half way through writing next year's summer school (linear algebra, full mathematical glory, ending with tensors), and the 2012 curriculum will be Einstein's Relativity and have two parts to each lesson. The first part will be all conceptual, like this, and the second part will have all of the math. 2013 will be real analysis, 2014 assessment theory, and years beyond that haven't been pinned down. The "Bureau 42 teaches" link at the side has everything along these lines listed, with links if they've already been posted.

• #### Re: (Score:2)

Sorry, I did not mean to degrade your wonderful efforts. I think that a well written accounting of conceptual physics is an excellent thing to have.

However, I would caution you to take great care not to overstate what your students are receiving. There are already way too many people out there who think that you don't really need math and rigor, that they can do physics if they just think really hard about weird things, and that "the scientific establishment" only uses math in order to maintain some ima
• #### Re: (Score:3, Informative)

Okay, I can see that point. I admit the language used was imprecise; I was trying to balance between describing what I was doing and keeping it short enough to work as a Slashdot snippet. Perhaps I leaned too far one way. The source article specifies "graduate level physics concepts" instead of just "graduate level physics." This was a submission issue, rather than a source material issue.

• #### Re: (Score:2)

Conceded. Best of luck!
• #### Re: (Score:2)

Grade school level math. The most complicated math in the series is this: “if a times b is less than 6, and we measure a to be 2, then b must be less than 3.” If you can follow that, you’ll be fine.

Physics that uses no more math than this is not graduate-level physics.

Physics that uses no more math than this is not college-level physics, unless you want to count the first week or two of the not-for-majors version of the 100-level stuff. Even that requires a fairly decent grasp of algebra and trigonometry.

You can talk about quite a few concepts in college-level physics provided that you do so in relatively broad terms. But reaching graduate level physics in any honest sense requires quite a bit of advanced math. Further, it is not something you can learn in any real sense

• #### Re: (Score:2)

Griffiths' text is commonly used, but I wasn't thrilled with it. I'm of the "do the math right or not at all" mentality, and his use of the probability distribution with operators instead of the psi* operator psi proper methodology in the first few chapters forms bad habits with students. It only works because he carefully chooses examples whose operators do not involve derivatives. His electricity and magnetism textbook is fantastic, and his particle text is great, but I'm not happy with his quantum tex

• #### oblig XKCD (Score:2)

Here. [xkcd.com]
• #### Re:oblig XKCD (Score:4, Interesting)

<dales' at' `digitalfreaks.org'> on Tuesday July 06, 2010 @05:37PM (#32817910)
I loved that one.

Of course, he neglected to point out that mathematics is applied philosophy, and that philosophy is applied sociology...

• #### Re: (Score:2)

I disagree in that mathematics is applied philosophy, I think its a fundamental law of the universe.

• #### Re: (Score:3, Interesting)

I disagree in that mathematics is applied philosophy, I think its a fundamental law of the universe.

Mathematics is applied Logic, which is a subset of Philosophy.

• #### I disagree (Score:2)

Logic at his purest form is not dependent on *ANY* material. Philosophy involve more than logic is dependent on logic, the same way physic involve more than math but is dependent on math. So philosophy is applied logic to idea and existence etc... Logic is not a subset of philosophy, philosophy is USING logic. Otherwise you could declare math a subset of physic. So at the core of EVERYTHING, logic, is there present and the most purest of all material.
• #### Re: (Score:2)

I disagree in that mathematics is applied philosophy, I think its a fundamental law of the universe.

This is how we know that you're not a mathematician...

• #### Re: (Score:2)

Actually one discipline is missing in that strip. There should be a philosopher to the right of the mathematician.
• #### Biggest problem with this course (Score:2, Funny)

by Anonymous Coward

What they don't tell you is the course is a superposition of a nine-part series, and that you can't know what course you are going to get until you actually open the pdf file, which is a pretty dicey proposition these days.

• #### How do you talk about physics without mathematics? (Score:5, Insightful)

on Tuesday July 06, 2010 @05:23PM (#32817686)
Mathematics is the primary language by which physicists describe the world around us. Discussing post-16th century physics in any other terms is like discussing poetry purely by means of interpretive dance.
• #### Re:How do you talk about physics without mathemati (Score:5, Funny)

on Tuesday July 06, 2010 @05:30PM (#32817808) Homepage

discussing poetry purely by means of interpretive dance.

I don't know how you found out about their next lecture series, but I think it would be best if you kept that information to yourself until they get closer to releasing it.

Let me just say, though, that it's almost impossible to truly understand French Medieval poetry until you've seen it performed by a dude in a black unitard.

• #### Re: (Score:2)

You tell 'em, you "villain [wikipedia.org]", you!
• #### Re: (Score:2)

This. To grasp even basic quantum mechanics you need to know about linear algebra (to understand the bra/ket notation and why a*b doesn't equal b*a), improper integrals and complex functions (to understand the wave function) and preferably partial differential equations too (to derive the solutions of some simple cases). And that's just the beginning of it.

I really can't see an accurate description of quantum mechanics without quite heavy use of mathematics. This web course might very well be a good intr
• #### Re:How do you talk about physics without mathemati (Score:3, Interesting)

It's more like discussing modern dance by performing it as a sequence of ballet moves.

Or deconstructing poetry.

In the end, mathematics is a means of manipulating facts to reveal other facts in a deterministic manner (even if they're facts about non-deterministic things). If you can't subsequently describe both sets of facts in terms a non-mathematician can understand, you haven't reached a result that non-mathematicians will know about, much less be able to form

• #### Khan Academy physics? (Score:1)

How do the classes go? Something like this I imagine:
"Revenge is a dish best served cold - and it's very cold in the vacuum of space. Around 2.725 Kelvin; which is -270 deg Celcius. That is minus 27 tens, and that's terrible....ly cold."
"KAAAAAAAAAAAAAAAAHN!"

Now that's a school I could go for...

• #### So far, I'm not impressed (Score:3, Interesting)

on Tuesday July 06, 2010 @05:48PM (#32818038) Homepage

I read the first lesson, and while it's interesting, so far I'm not impressed.
It presents some of the problems with classical physics, but it seems to focus on the wrong problems. The first problem it mentions is that information can't travel faster than the speed of light-- but to address that problem you need more than just introductory quantum mechanics, you need relativistic quantum mechanics, and I just don't think you can get to Dirac's equation in a nine part series without math. Then they ask a question about nuclear physics ("what holds the nucleus together?"), for which, to even understand the question correctly, you need some information that the reader doesn't have yet (for example, what do they mean when they say that the only macroscopic force is electromagnetic? In fact, all the forces you do experience in everyday life actually are electromagnetic in nature... but you need quantum mechanics to really understand that! It sure isn't obvious that the force that keeps you from falling through the ground to the center of the Earth is electromagnetic). And this really isn't fundamental to quantum mechanics, either. Next, the nucleus mass question is, once again, a question of relativity and not quantum mechanics (although at least one that can be answered without resorting to the Dirac equation!). And the final question seems to require addressing the equation of state in ultradense matter at the beginning of the universe! Good luck with explaining that with grade school math.

• #### Re:So far, I'm not impressed (Score:5, Insightful)

on Tuesday July 06, 2010 @06:00PM (#32818180) Journal

Would you be impressed if you didn't already know the subject?

• #### Re: (Score:2)

actually, someone who knows the subject can tell when a particular line of though will lead you where there be dragons. and they're usually right.
also: "how can I be impressed if what you're saying has no obvious connection to what I understand as reality?"

• #### Re:So far, I'm not impressed (Score:4, Informative)

on Tuesday July 06, 2010 @06:03PM (#32818208) Homepage

for example, what do they mean when they say that the only macroscopic force is electromagnetic? In fact, all the forces you do experience in everyday life actually are electromagnetic in nature...

With the exception of gravity, of course

• #### Re: (Score:2, Flamebait)

And love.

• #### Wrong : love is based on EM force (Score:2)

Love is the behavior which is the result of chemical reaction in the brain and the body (neurotransmitter, hormone, neuron state etc...). Love *IS* based on chemistry , and therefore fully based on electromagnetic force, QM. All our emotion are based on chemistry. A complicated system, surely, one for which we have only superficial model definitively, but in absence of evidence to the contrary, those are definitively system where only biochemistry is at play.
• #### Re: (Score:2)

The thing that didn't impress me (with all the questions being asked and all) is that they state the mass of the nucleus is not equal to the sum of the components and in fact is usually less. Okay, good observation but my immediate question is how did they measure the mass of the components individually and then the nucleus as a whole? Then once I understood that I'd wonder how could the result of this method be affected in ways not originally intended that would could the mass of the nucleus to appear to b
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The protons have a mass that's relatively easy to measure. The charge is very well known, as is the interaction of moving charges with magnetic fields. If you fire a proton through a magnetic field, it will be accelerated into a circular motion, and the easily-measured radius of the circle (visible in a bubble chamber) will indicate what the mass is.

For neutrons, it's much harder. Early measurements at the time were imprecise compared to today's. Now that we better understand the mechanism of radioactiv

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So true, I couldn't agree more about the focus on the wrong problems.

I was expecting something like an introduction to really basic quantum stuff, like superposition, entanglement, measurement, etc. This can actually be done the right way with very little math, like this excellent series of lectures from Stanford [youtube.com], where you can learn something that is actually right, not just analogies.

Instead, based on what's in the first lesson, it looks like it will try to talk about a lot of things, explaining none of t

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Instead, based on what's in the first lesson, it looks like it will try to talk about a lot of things, explaining none of them really right.

So, which parts could I have explained better?

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So far, for an introduction, there's no bad explanation. But it seems they're promising to explain a lot more that is reasonable to expect: are they really planning to go all the way up to relativistic QM without math? If not, why bring up relativity at all?

There's a lot of QM to explain before getting into that: superposition, entanglement, Bell states (to see what's really weird with entanglement), measurement, uncertainty principle, etc. And that's just the foundation, then (based on Lesson 1) it seems t

• #### Well, its possible (Score:2)

By abstracting all the mathmatical conjecture. But then, you're left with "A brief history of the universe", and I suppose, tack an exam (of course, abstracting from the math), and you now have a "graduate-level" course.
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But then, you're left with "A brief history of the universe", and I suppose, tack an exam (of course, abstracting from the math), and you now have a "graduate-level" course.

I humbly submit Feynman 1988 [princeton.edu] as a counterexample. Therein, the author describes the basics of quantum electrodynamics using what appears to be little more than grade school mathematics.

I write "appears to be" because his presentation amounts to an extremely casual exposition of elementary ideas from rather more advanced mathematics (comp

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Incidentally, complex algebra is, in a sense, "the algebra of scaling and rotating little arrows" Feynman describes.

Yes, we know this (see here [wikipedia.org]). But the whole point of complex algebra is to go the other way, namely from geometry and scaling and little arrows to algebra as a way of simplifying calculations and improving understanding.

The status quo before the discovery of analytical geometry was Greek style synthetic calculations, which are much too cumbersome in the presence of viable alternatives.

• #### I wonder if this is really useful (Score:2)

As a CS student I have not studied much physics; but I'm a very curious guy so I could not resist to follow the link. Their requirements are: average level intelligence, basic maths and a PDF reader. Sounds like perfect for me... or too perfect? W. Blaine Dowler took his time to write in LaTeX, which automatically made me think it can be trusted - don't ask me why. But, on second thoughts, this doesn't sound right.
At back at school we were taught that physics has laws and mathematical models, which are an
• #### Remove the fallacies first (Score:2)

The paper is simply packed with logical fallacies. Yes, many of these are commonly accepted in the physics community, and are indeed the cause of the current pithy state of physics research, that continues to leap from one absurd conclusion to the next, discarding logic in the process. But is it really a good idea to pollute the minds of the next generation with them? The paper starts with a misconception right from the start:

> Nothing, not even information, can travel faster than the speed of light.

Here

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Funny, you are criticizing the lesson for the questions raised in this lesson, and then providing many of the exact answers that are coming in later lessons...

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