Science without Determinism

[cfgauss]

Originally Posted By: Student of Trinity

What is "the SR action"? There are Lorentz invariant actions for various fields other than gravity, but the metric itself has no action of its own in SR. Insofar as mere terminology matters, the normal definition is that SR means flat spacetime. What's more than just terminology, though, is the fact that to get GR you need to do more than just relax the assumption that the metric is flat. You also need to add the Einstein-Hilbert action, which isn't there at all in SR.

[...]

GR can be considered a gauge theory, but it is not like other gauge theories because the gauge field for Lorentz transformations is the Christoffel symbol, but in GR it's important that this is derived from a metric, for which no analog exists in other theories. This brings us back to the Einstein-Hilbert action: it's an action that can't be generalized to other gauge theories, because it needs the metric. It's not the only possible or even the only reasonable action, for a Lorentz group gauge theory (the Kretschmann scalar would be fine, for instance). it's just the one that correctly describes gravity.

The SR action is just the usual point-particle action in SR. What else would it be? From the algebraic point of view, the metric just is the map between tangent and dual spaces. There's nothing special about it.

But the point is that the SR point particle action is a special case of the Einstein-Hilbert action! And exactly how you get the GR action is to take the SR one and make it locally lorentz invariant. Every word I've said is in MTW if you don't believe me .

And--repeat after me--there's nothing special about the metric! It's just that the other-than-gravity-gauge-theories have an INTERNAL metric instead of the spacetime one. But that's okay because the spacetime one was really internal anyway, it's just that we have a convenient description of the things we can easily measure that puts it into a more "concrete" framework. Although working with lie algebras in one theory and manifolds in another does not make this manifest by any means!

If you'd like a more careful description of why GR is exactly the same kind of gauge theory as all the others, I invite you to check out "differential geometry, gauge theories, and gravity" by Gockeler and Schucker, or any of the other hundreds on the same topic (that's just the one that comes to me off the top of my head).

But you can't argue about this, it's actually the whole point of the modern mathematical construction of gauge theories . It's actually part of what makes symmetries like (local) SUSY not totally nuts, since naively that's some crazy internal/external symmetry.

Quote:

Classical Kaluza-Klein simply is not quantum field theory by any stretch. You can get mass quantization by compactifying the fifth dimension, but this does nothing to make the gauge fields into operators. Quantizing Kaluza-Klein has all the same trouble as quantizing GR: no-one knows how to fix the gauge without reference to some background metric, and if you try to proceed by perturbing around some given metric, the theory is manifestly non-renormalizable.

Classical KK theories give you classical yang-mills theories. There's nothing wrong with the classical versions of the theories. In fact, a lot of effort was put into looking at classical QCD in the 70s and 80s to help understand why it works like it does.

And the trouble in quantizing GR is not actually that. That's only a superficial problem (in other words, if you fixed the gauge fixing problem it would still be nonrenormalizable). The real problem runs much deeper than that and has to do with what an effective theory is (c.f., four fermi theory).

There seems to be a lot of confusion about what the problem with quantizing GR is in some of the literature (why is another story ) but the background is not it. Most of the confusion comes from the LQG people, and let me assure you, that they do not know anything about gravity or QFTs!

It's harder to find a source for a good detailed explanation of this, but Zee's field theory text talks about it in some detail. You can find some good discussions in some of the literature from about the 80s, since people were still looking into things like canonical QG then. But I do not know any sources off the top of my head.

[Lilith]

this thread rules, physicists please keep posting in it, everybody else please just keep watching in awe and try not to make it worse

[Student of Trinity]

Originally Posted By: cfgauss

The SR action is just the usual point-particle action in SR. But the point is that the SR point particle action is a special case of the Einstein-Hilbert action! And exactly how you get the GR action is to take the SR one and make it locally lorentz invariant. Every word I've said is in MTW if you don't believe me .

Oh, I believe it's in MTW, though I don't have MTW around. (My GR book is Wald.) But John Archibald Wheeler in particular is as famous for his glib hand-waving as for his brilliance, and MTW's reputation is quite consistent with containing overblown arguments that have enough substance not to be crazy, but not really enough to make them appropriate for a textbook. To me this sounds like one of those.

The point particle action is a one-dimensional integral, over the particle's proper time; it is a functional of the metric along a worldline, but not of any of the metric's derivatives. It's a scalar, so it's automatically invariant under any co-ordinate transformations, and doesn't need anything done to it to make it locally Lorentz invariant. How do you get the metric derivatives in there to make up the Ricci scalar? How do you put in Newton's constant? Or rather, how do you do these things without, surreptitiously or explicitly, simply postulating GR instead of SR?

The metric is special, because the Christoffel symbols of GR, which are the gauge fields for local Lorentz transformations, are defined in terms of the metric and its derivatives. In a Yang-Mills theory like all the gauge theories in physics other than GR, the gauge fields are primary, and not defined in terms of anything else. This means that GR is a constrained kind of gauge theory; its index-three gauge fields are determined by an index-two field and its derivatives. The SU(N) Yang-Mills gauge groups have manifolds on which you can define a metric, but this metric is fixed, and does not determine the gauge fields.

The second special thing about the metric in GR is that it allows contractions between spacetime indices and the gauge group indices, since the gauge group in GR is spacetime rotations and translations. There's no way to contract SU(3) Gell-Man indices and spacetime indices, for instance; the Gell-Man indices label directions in color-space, and there's no way to match them up with directions in spacetime. That's why there exists no object analogous to the Ricci scalar in Yang-Mills; the gravitational analog of the Yang-Mills Lagrangian is the Kretschmann scalar, which is quadratic rather than linear in the Riemann tensor.

These are hardly minor technical variations. The fact that the Einstein-Hilbert action is first order rather than second in the Riemann tensor is why the gravitational coupling constant is dimensionful, which is why gravity is non-renormalizable. On the other hand, the fact that the dynamical variable is the metric rather than the gauge field (Christoffel) means that Einstein-Hilbert still yields second-order equations of motion, despite being linear in the derivatives of the gauge field. So GR dynamics is a unique alternative form of gauge theory; viewed as a gauge theory, it has special constraints and a special action. Of course it's not really worth arguing over whether or not to call GR a gauge theory; but the substantial point is that comparing GR to other gauge theories is of very little practical help in understanding it, because solving Einstein's equations is very little like solving Yang-Mills equations.

There is probably also a large literature on why GR is not exactly the same as all other gauge theories. Or maybe not; the points I have just outlined are quite basic, and there's not so much more to be said about them. One could no doubt bog down in pointless argument about whether or not the similarities between GR and Yang-Mills are more important than the differences. It's a simple fact that GR is quite a special kind of gauge theory.

On the other points we probably do not really disagree; I was responding to what were perhaps simply careless statements in your earlier posts. I have no hatred for classical field theories; I was taking issue with your initial suggestion that Einstein's work on Kaluza-Klein models meant that he contributed to quantum field theory. You do seem to agree that gauge-fixing is an unresolved problem in GR. I do not believe that quantum gravity is obtained by somehow canonically quantizing GR; I was responding to your earlier suggestion that canonical quantization of a classical Kaluza-Klein theory was straightforward.

Actually it is by no means clear whether the gauge fixing problem is profound or superficial. The traditional hypothesis among general relativists has been that it is profound, and that deeper understanding of the dynamics of spacetime geometry will someday lead to fundamental generalizations of quantum theory. The traditional hypothesis among string theorists has been that GR gauge fixing is a superficial problem which will be resolved automatically when GR is recognized as a low-energy limit of a larger theory that is strictly orthodox in its quantum mechanical kinematics. It's important to realize that both hypotheses are just that. Neither camp has yet actually produced its hoped-for theory of everything, so neither has any right to thump the table about this.

[cfgauss]

Hah, no kidding about MTW making overblown statements. Although part of that is due to it being written in the 70s when it was still far from clear if how important those kinds of statements were! And sorry if I was being vague earlier, I was trying to keep it simple, plus I've been sick and didn't really feel like being too careful .

 

But the problem is that diffeomorphisms are more than just reparamaterizations since there's an extra pushforward involved. Or you can think about how densities have to properly transform. So there is some subtlety in correctly working with the action here. And the subtlety is exactly where you pull the GR out of of course . In the same way that H=0 is a perfectly good Hamiltonian to do GR with!

 

Anyway, I've done this exercise before so I know it is possible . IIRC, the idea was to start with an infinitesimal transform like

x^mu -> x^mu + a^mu(x)

which changes the metric (according to normal calculus),

eta^{mu nu} -> eta^{mu nu} - (a_mu,nu + a_nu,mu)

which breaks invariance, and introduces those derivatives that will cause all your problems (and obviously for global transforms the da terms are zero and you get back normal SR with global infinitesimal transforms we all know and love). [You can also build SUGRA this way too.]

 

I believe you can also look at this in terms of the lie derivative generating your symmetries if that way sounds more fun.

 

The way you fix this ends up introducing some funny combination of other derivatives that look suspiciously like covariant derivatives and curvature tensors and all that stuff!

 

I just checked in MTW and couldn't find it offhand because they're windbags. But I did find a statement in another text that "this is not well known" and a reference to an article,

Kibble, "Lorentz Invariance and the Gravitational Field" J. Math. Phys. 2, 212 (1961)

Quote:

An argument leading from the Lorentz invariance of the Lagrangian to the introduction of the gravitational field is presented. Utiyama's discussion is extended by considering the 10-parameter group of inhomogeneous Lorentz transformations, involving variation of the coordinates as well as the field variables. It is then unnecessary to introduce a priori curvilinear coordinates or a Riemannian metric, and the new field variables introduced as a consequence of the argument include the vierbein components as well as the `local affine connection'.

 

At any rate, the point was that global symmetries lead to local symmetries, which lead to covariant derivatives, which lead to new equations of motion from old equations of motion.

 

Regarding the exact forms of yang-mills theories vs. GR, you're right that they differ, I certainly don't disagree with that. But that's actually not important in terms of their gauge theory structure. The specifics (eg, depending on derivatives of the curvature tensor) are restricted be whatever they are by the larger structure of the symmetries. (It is of course important in their solution structure!)

 

In general, we've got a principle bundle P with structure group G over a manifold M. The gauge group ends up being something like a restricted automorphism group of P (so it can't mix up fibers or anything funny).

 

So a principle bundle P(M,U(1)) is a generalized E&M on a manifold M, and any action it has is restricted by being compatible with all of the structure, such as the allowed automorphisms of P. (Plus some additional structures and details that let us do physics.)

 

Then you can see pretty clearly from here that GR is going to be a little perverse with a structure group of diff(M)!

 

But it's in this sense that GR is a gauge theory like E&M or QCD. And if you really look through the "definitions" of what it means to be a yang-mills theory, this is what you're ultimately lead to.

 

Of course that's a very general construction and pretty clearly you can get lots of very different things out of it! And there are certainly lots of constraints you may want to add to make a specific theory, like E&M besides just saying it's P(M,U(1)).

 

But there are still a number of very nice fairly general statements you can make about these kinds of gauge theories in general that make this construction useful (in addition to providing a recipe for explicitly constructing them when you follow the details!).

 

For example, you can instantly see how totally awesome doing complex E&M to solve 2d problems is with this structure! It's a little more than how your intro classes point out that, "oh, this just happens to satisfy the cauchy-riemann equations!" This is why that coincidence happens!

 

This general structure is also why you can do what that paper above cited.

 

And is also why Ed Witten has put a crazy amount of time into looking at this kind of geometric structure .

 

Quote:

Actually it is by no means clear whether the gauge fixing problem is profound or superficial. The traditional hypothesis among general relativists has been that it is profound, and that deeper understanding of the dynamics of spacetime geometry will someday lead to fundamental generalizations of quantum theory.

 

True enough, but it turns out that the GR people's intuition that something funny happens with geometry on small scales is almost exactly the same as what we expect string theory to do to our picture of geometry on small scales!

 

In some ways, both of the arguments are right. The full quantum theory does require knowing short distance physics, which requires knowing about short distance geometry. So from that point of view the gauge fixing problem is "important."

 

On the other hand, in principle, that didn't have to happen. And, in fact, once someone knows the full correct theory, there's nothing stopping them from writing down an intermediate effective theory that integrates out those degrees of freedom which is renormalizable by constructing it from the beginning to have divergences be exactly canceled by knowing the answer in advance. From that point of view, it's not important.

 

Of course, neither of those things are unknown to theorists, but the impression I get in general (even from the QFT/model building people) is that the effective field theory lessons should be taken more seriously than GR's (since you can even see SR as an EFT for GR, classical E&M in matter as an EFT for E&M, etc).

 

Incidentally, you're obviously a physicist; what kind of physicist are you?

 

 

[Student of Trinity]

I'd still love to see how Lorentz invariance can introduce Newton's constant.

 

Tom Kibble's a very careful guy, though, as well as being a Grand Old Man now, so his J Math Phys paper is probably fine as far as it goes; I suspect it doesn't go as far as claiming to deduce GR entirely from localizing SR. I believe I may even be familiar with what he does, since something that sounds very similar is treated in Wald (a very good book for advanced topics, just as it is miserable for the basics). At least in Wald's discussion, a vierbein plus the Minkowski metric is so directly equivalent to a (pseudo-)Riemannian metric that it's all really just an equivalent alternative formalism, and not any logical reduction. (If I remember rightly, to get GR you have to impose relationships between the vierbein and the spin connections, and these are of course tantamount to the Riemannian formulation.) Essential for treating spinor fields in curved space, though.

 

I started off in high energy theory, while string theory was in its second death, but got more interested in non-equilibrium quantum stat mech than in trying to guess the Planck scale theory from Higgs scale data. (Once I realized that the previous 16 orders of magnitude had taken us from banging rocks to QCD, I became deeply skeptical of attempts to go as far again within the very conservative approach of string theory.)

 

So for the past dozen years are so I've worked theoretically on stuff you can do with quantum gases. Nowadays I say my theme is quantum thermodynamics. It's a nice field because there are lots of beautiful experiments, and the theory is tractable, but you can also address deep questions like the origin of irreversibility and the emergence of classicality. And, uh, Hawking radiation.

 

I'm currently a professor at a university in Germany, although my German still isn't very good yet. This semester I'm teaching electrodynamics, and shouting 'Mush! Mush! On, you huskies!' to my grad students. Well, feeling like shouting that.

[The Mystic]

Originally Posted By: Ephesos

Also, I wouldn't really even call it a site. More like a drunken rant rendered in long-winded HTML. Anyone who clicks the link should be warned, it's very odd.

Thanks for the warning; it was definitely warranted.

I wonder what they were (or, more accurately, weren't) drinking & smoking when they made that site. People have told me I'm crazy; I know I may be a little weird at times, but compared to the people behind that site, I'm perfectly sane.

[Dantius]

Originally Posted By: The Mystic

I wonder what they were (or, more accurately, weren't) drinking & smoking when they made that site

I'm sure what hapenned was that he actually discovered the secret of the univers, but it drove him insane, and he can't communicate it to anyone, but then the Internet came along.

[Kelandon]

God damn, sometimes I miss beyond-first-year physics.

[cfgauss]

Originally Posted By: Student of Trinity

I'd still love to see how Lorentz invariance can introduce Newton's constant.

My vague recollection of carefully going through this was that it's related to how you get the "gauge fields" out. Although I don't think it was literally the coupling constant, it was something like how you can rescale A^mu to eA^mu to get rid of / add in the coupling constant in QED.

Quote:

At least in Wald's discussion, a vierbein plus the Minkowski metric is so directly equivalent to a (pseudo-)Riemannian metric that it's all really just an equivalent alternative formalism, and not any logical reduction. (If I remember rightly, to get GR you have to impose relationships between the vierbein and the spin connections, and these are of course tantamount to the Riemannian formulation.) Essential for treating spinor fields in curved space, though.

Yeah, that's exactly right. And that's why technically this global->local formalism gives you something slightly more general than GR. You still make some simplifying assumptions, like getting rid of torsion to get normal GR. But those were steps you had to take anyway to get to GR.

Quote:

I started off in high energy theory, while string theory was in its second death, but got more interested in non-equilibrium quantum stat mech than in trying to guess the Planck scale theory from Higgs scale data. (Once I realized that the previous 16 orders of magnitude had taken us from banging rocks to QCD, I became deeply skeptical of attempts to go as far again within the very conservative approach of string theory.)

Well, the reason I like strings, and the reason I take it seriously (aside from the very nice phenomenological-ish arguments given in intro string texts) is that it's sort of the ultimate generalization of this general gauge structure idea. Although it's not always particularly easy to see. But it's part of the reason so many theorists think string theory is "obviously" correct, since it's the only tractable, sensible generalization of QFTs. (For certain values of "obvious," "correct," "tractable," "sensible," "generalization," and "QFTs" of course!)

Although we've got AdS/CFT now which is pretty nifty! So we can do at least one field theory .

Quote:

So for the past dozen years are so I've worked theoretically on stuff you can do with quantum gases. Nowadays I say my theme is quantum thermodynamics.

Statmech is not something that my school's focused too much on (well, recently that seems to be the case with all subjects, but that's a different story), so this is an area that I'm embarrassingly ignorant on . But what I have read about it looks pretty neat.

Quote:

I'm currently a professor at a university in Germany, although my German still isn't very good yet. This semester I'm teaching electrodynamics, and shouting 'Mush! Mush! On, you huskies!' to my grad students. Well, feeling like shouting that.

That's fun. Electrodynamics has a lot of fun stuff you can talk about. Just make sure to actually talk about it . My class was just "boundary conditions!" and "series expansions!" and god it bored me to death!

I'm still a grad student though, so I don't get to teach anything fun yet. All I've gotten to do, aside from teaching I did on my own earlier, is to babysit students while they fill out worksheets in "class." That's right, my department thinks that's an excellent use of time. Oh, and it really is babysitting because we can't like, give them answers or anything, that'd be crazy! And that they think grad students are not competent enough to actually teach. (Yay internal politics!) Although I don't have to teach now because we ran out of money!

[Lilith]

Originally Posted By: cfgauss

I'm still a grad student though, so I don't get to teach anything fun yet. All I've gotten to do, aside from teaching I did on my own earlier, is to babysit students while they fill out worksheets in "class." That's right, my department thinks that's an excellent use of time. Oh, and it really is babysitting because we can't like, give them answers or anything, that'd be crazy! And that they think grad students are not competent enough to actually teach. (Yay internal politics!) Although I don't have to teach now because we ran out of money!

duuuuude, i'm a high school teacher and even i don't have to put up with that kind of micromanagement

[The Mystic]

Originally Posted By: Kelandon

God damn, sometimes I miss beyond-first-year physics.

I don't; then again, by some fluke, I never had to take a physics class.

[Erebus the Black]

Wow, I'm going to need a time dialator in order to read this thread.

Anyone got, or knows how to build one?

[Niemand]

You don't necessarily need specific equipment, you just need to Lorentz boost yourself, relative to your computer screen. You could try running past it really fast.

[Randomizer]

Originally Posted By: cfgauss

I'm still a grad student though, so I don't get to teach anything fun yet. All I've gotten to do, aside from teaching I did on my own earlier, is to babysit students while they fill out worksheets in "class." That's right, my department thinks that's an excellent use of time. Oh, and it really is babysitting because we can't like, give them answers or anything, that'd be crazy! And that they think grad students are not competent enough to actually teach. (Yay internal politics!) Although I don't have to teach now because we ran out of money!

Most universities use grad students as cheap labor. Until I got a research assistantship, I either had to teach the laboratory section of introductory physics classes or grade papers. I could have used Student of Tritiny's whip to keep the students on course.

[A less presumptuous name.]

Originally Posted By: Thuryl

duuuuude, i'm a high school teacher and even i don't have to put up with that kind of micromanagement

A quick word of advice: Never come over the pond and try to teach in a public school. The bureaucratic crap and red tape will drive you insane.

[Slawbug]

That's an extra big pond.

 

I dunno, my experience is less one of dealing with insane bureaucracy and more that the insane bureaucracy completely shuts you out of doing things and forces you to do others. It's not a matter of getting through red tape, it's a matter of avoiding the brick walls that are everywhere.

[A less presumptuous name.]

Well put. When I was in Iowa, there were ways for good teachers to work the system so things could actually get done. There are always a few good people out there who know the secrets and will do the right thing. Sadly, such people are few and far between.

[Slawbug]

The problem is that most of those people will do far more good if they can apply their pragmatic ability somewhere with more freedom, i.e. a private school setting, and most of them act on that and make that move.

[A less presumptuous name.]

That is definitely the case here on the East Coast. My neighbor teaches AP Chemistry at one of the better private schools in the area. He's a great teacher, and I wish I had him instead of my teacher, who doesn't know what he's talking about half the time.

[VCH]

The sad thing is Canadian schools, at least in BC, are moving slowly towards the US (or is it just California) style of testing then testing then testing some more. Because we all know that data are so very important, especially when the administrators do nothing with the data, lol.

 

That being said, you can pretty much do what you want in the public schools system, as nobody really as the power to fire you or tell you how to do anything. Having seen the school system from the inside I can say you basically are your own boss, and ignoring people that have positions of "power" is quite easy. In my opinion it makes teaching an attractive job.

[A less presumptuous name.]

Even if you can do whatever you want, that just makes most teachers not do what they should. If they can do whatever they want, they will just do nothing.

 

And I really don't think that there is very much freedom if you want to keep you job for a good long time. There is a reason there are not enough good teachers, and it's not because people dislike freedom.

[cfgauss]

Originally Posted By: Thuryl

duuuuude, i'm a high school teacher and even i don't have to put up with that kind of micromanagement

That's not even the beginning of the kind of crap I get to put up with . Well, not anymore, because they don't have money to pay me to do that now. They also don't have money to pay me for research either!

Originally Posted By: Master1

Even if you can do whatever you want, that just makes most teachers not do what they should. If they can do whatever they want, they will just do nothing.

I think this is definitely not true! The reason most teachers don't do a good job is exactly because of all the micromanagement and administrative crap.

If someone came up to me and said I had to teach intro physics from this specific book to this group of 500 people who don't care at these times each day and go over these topics and conform to this way of talking about things and tie in with these in class worksheets and with these labs and have tests on these dates (that are written by someone else so every class gets identical ("fair") tests) and assign these specific homework problems.... etc, etc... I would not do a great job either!

Of course the biggest problem is having students who mostly don't care. Although it's a system with feedback. We're limited so much we can't have fun, the students see us not having fun so they don't enjoy it, we see them having no fun and don't enjoy it....

And not being able to go over your own topics can be devastating too!

I mean, there are a lot of amazing, clever, and weird things in intro mechanics that are very easy to understand, and shed light on important ideas that are not covered in any textbook that I know of! And were never covered in any class I've ever taken! (In addition, of course, to the mistakes, and technically-not-mistakes-but-will-confuse-any-reasonable-person-who-reads-them-es that the intro books are full of.)

Although I've noticed some of the physics for non-scientists classes go over some stuff a little.

In fact, I've noticed in TAing labs for intro physics and physics for humanities classes that the physics for humanities students tend to understand things substantially better!

Once, when I was grading for both classes at once, I accidentally mixed up some of the labs from the non-scientist class (which is credit/no credit only) with the scientist one (which is graded), and accidentally graded them. (The labs are identical because no one's bothered to make separate ones in this university's existence). They all (5 or so) got nearly 100% except for one student who didn't do the whole thing, which is typical quality for that class. The average grade on the for-scientists class was more like 50%, and there were only 1 or 2 nearly perfect scores, which is typical for them as well.

I've pointed this kinda stuff out to many of my peers and they don't believe me! Then I say stuff like:

Originally Posted By: me

"They never talk about why things are like they are in the for-scientist classes! They just ask them to memorize things! Did you know they don't even talk about what F=ma means, or why it's =ma and not something else? Or *why* energy or momentum are conserved!?"

Originally Posted By: them

(after blankly staring at me for a few seconds) "But F=ma just, uhh, is.... conservation comes from Nother's theorem and they can't under..."

Originally Posted By: me

"Did Newton know about Nother's theorem? No, he didn't! How do you think they figured this out then!"

Originally Posted By: them

...

Yeah. Abysmal!

To top it all off their focus on "memorize these things and calculate stuff" results in students not being able to do calculations other than the ones spelled out for them in the textbook!

But go ahead, force us to teach that way, you've been doing physics education for years and obviously know what you're doing based on these decades of students not knowing how to do physics!

Can you tell I'm annoyed at these people?

I once, as an undergrad, was annoyed that they didn't have a baby QFT for undergrads class. So I, and a friend, made our own. We made a lecture class teaching baby QFT, in our own free time.

We had like 30 undergrads and master's students show up. I had multiple people thank me and tell me I did a great job and they never understood it until I explained it to them.

To this day that terrifies me.

[A less presumptuous name.]

Originally Posted By: cfgauss

Of course the biggest problem is having students who mostly don't care. Although it's a system with feedback. We're limited so much we can't have fun, the students see us not having fun so they don't enjoy it, we see them having no fun and don't enjoy it....

I hate students who sit in high difficulty (according to the school) classes but couldn't care less. They take the AP classes for college credit, but don't care about the content. It's especially big in my school, and especially big in math. With all the required topics and smart students, we have challenging classes in topics that few people are passionate about but everyone has to take.

I really care about what I'm learning, and I try my hardest (except for in the stupid state-organized English curriculum). Why can't other people care?

Oh, and don't even get me started on cheating.

[Sudanna]

*Empathizes with cfgauss*

 

Well, sort of. Nalyd's mom is a teacher (at a high school level, and a high school for pregnant teens, so sadly not the best education around) and even she won't shut up about this kind of stuff. Though in high school, it's more the curriculum being dominated by standardized tests than active interference.

[cfgauss]

Originally Posted By: Master1

I hate students who sit in high difficulty (according to the school) classes but couldn't care less.
[...]
With all the required topics and smart students, we have challenging classes in topics that few people are passionate about but everyone has to take.

Yeah, that's all a big part of the problem. That's why here, we have something stupid like 2000 students in each quarter of intro physics per year. Probably another 2000 in the off-sequence quarters.

And who's in there? Pretty much everyone because it counts as one of the required "sciency class" credits. Because, really, you can't be a well-rounded college student if you can't solve the differential equation for a simple pendulum in the small amplitude limit! [Eh, well, actually most people coming out of the class can't since they don't expect you to be able to do any calculus in the course titled "calculus based physics for scientists"... but still]

The humanities requirements are even better! Because at my school, there were more required credits in them, but far fewer actual classes.

The end result? Well, if you go to a doctor and die in the operating room, you can feel satisfied that while he didn't get to take that extra surgery class that could've saved you, he can appreciate this nice 9th dynasty Egyptian statue in the lobby, thanks to that quarter of art history!

Then there's of course the artist who can't quite remember the difference between 8th and 9th dynasty Egyptian art because he had to take all that physics .

Talk about poor allocation of resources!

Originally Posted By: Decorated Zombie Veteran

*Empathizes with cfgauss*

Well, sort of. Nalyd's mom is a teacher (at a high school level, and a high school for pregnant teens, so sadly not the best education around) and even she won't shut up about this kind of stuff. Though in high school, it's more the curriculum being dominated by standardized tests than active interference.

When I look through math and physics history, I am occasionally a bit surprised when I learn some famous (usually c.1900s) person was a high school teacher.

Then again, I'd love to teach kids about math or science if someone would pay me a reasonable amount of money, I was actually in charge of things, and didn't have to deal with all kinds of administrative stuff constantly.

In fact, when I do get the chance to talk to young kids, I'm always amazed at how grade school kids can qualitatively understand fairly sophisticated ideas in math that they otherwise wouldn't have seen until grad school. And they usually don't even know it's math until I tell them, and even then they don't really believe me because math is boring and all about memorizing that damn multiplication table .

Someone needs to go and tell these standards people that a significant fraction of professional mathematicians don't have that memorized because they know how to figure it out!

I don't know how many advanced math or physics lectures I've taken where they'd say something like "so 6*7 is... uuh, well 6*5 is 30... so 36, 41, 42!"

Oh--and that reminds me, in high school I taught/TAd math at a community college (arithmetic through calculus). It always amazed me how it'd totally blow people away when I mentioned stuff like "well you can do this quickly in your head because 6=5+1 and you can easily add 5 and 1 without counting!"

Because this stuff is apparently not in textbooks.

Because it would be cheating.

Seriously.

Edit:
And, this just reminded me also! If you haven't, read what one of the most brilliant physicists ever thinks about the textbooks we use in schools! And the situation today is exactly as it was then, sadly.

http://www.textbookleague.org/103feyn.htm

Quote:

[...]The reason was that the books were so lousy. They were false. They were hurried. They would try to be rigorous, but they would use examples (like automobiles in the street for "sets") which were almost OK, but in which there were always some subtleties. The definitions weren't accurate. Everything was a little bit ambiguous -- they weren't smart enough to understand what was meant by "rigor." They were faking it. They were teaching something they didn't understand, and which was, in fact, useless, at that time, for the child. [...]

Now that I think of it, this is the same argument, almost word for word, I had with a physics education person around here the other day regarding the intro physics curriculum....

[Dikiyoba]

Quote:

[...]The definitions weren't accurate. Everything was a little bit ambiguous[...]

Heh. The textbook for my ecology class certainly has that issue. At least we're using a previous edition so no one is forced to pay an exorbitant amount for it.

Dikiyoba.

[Lilith]

A teacher said something very wise to me once: "a textbook is not a unit plan". It is a resource, and as a resource it is mostly good for telling you as a teacher what's going to be on the state exams, providing review questions that you can give your students, and occasionally offering pretty diagrams for the kids to look at. I can't think of the last lesson I taught where I had students read more than about half a page directly from the textbook; I'm too interested in biology to teach my students somebody else's ideas about it.

 

I had to teach some geometry to some Year 7 students this week and I didn't feel like making the class calculate the internal angles of every regular polygon up to the octagon, so I made a lesson on straightedge-and-compass constructions instead. There's nothing on it at all in the textbook and it will probably never be of practical use to any of my students, but I thought it would be fun, so I did it, and they loved it. Then this morning I taught the same class about tessellations and spent half the lesson chatting with them about crystal structures and M.C. Escher's art. They're going to cover all the "important" stuff again in Years 8 and 9 anyway, so I figure keeping them interested is more important than working through the curriculum at this stage.

 

dammit, i told people not to ruin this thread and then i went and ruined it myself by turning it from physicschat into teacherchat

[Sudanna]

You're convincing all of us impressionable youth that college is a waste of time. Bad CFG!

[Randomizer]

Originally Posted By: Decorated Zombie Veteran

You're convincing all of us impressionable youth that college is a waste of time. Bad CFG!

It depends what you are going to college to do and where you go. Some professors shouldn't be allowed to teach and some can only teach their favorite subject. After all teaching is never discussed during their hiring process.

[Student of Trinity]

Well, it sometimes is, some places.

 

I have to say that after teaching for several years now, I have more sympathy for textbook authors than I used to have. I have had very many episodes of enthusiastically deciding to clarify some basic point that none of the rotten old textbooks ever properly addressed ... only to discover that there was a darn good reason they skated past it; namely, that despite being a basic and obvious issue, it was a most ungodly can of worms. After finally being up writing lecture notes at 3 am one too many times over this kind of thing, I started to consider that discretion has its points vis à vis valor.

 

I still do think that things can be done a lot better than most books manage. But it's a heckuva lot harder to do that than I used to think, because even quite basic physics is astonishingly full of amazingly tricky points. When you learn them as a student, you are led blindfolded through the minefield, and you duly turn left and right at random spots because your text or teacher tells you so, without realizing what huge mines you are avoiding by doing that. To remove one of those mines instead of leading around it requires not one but two major intellectual efforts: first to understand the real story yourself, and then to discover a way of presenting it that will be clear to students.

[Enraged Slith]

Physics class was fun until the AP buffer I had ran out and I suddenly had to understand everything I'd been taking for granted. Also, calculus was suddenly introduced into the mix.

 

Just as a general tip to all of you youngsters about to head off to college, it's absolutely crucial that you understand your math concepts, especially when your science classes start requiring you to integrate things for yourself.

[Celtic Minstrel]

Originally Posted By: cfgauss

I don't know how many advanced math or physics lectures I've taken where they'd say something like "so 6*7 is... uuh, well 6*5 is 30... so 36, 41, 42!"

I don't usually remember 7 times 6, either. Or 8 times 9, or 7 times 9.

[cfgauss]

Originally Posted By: Student of Trinity

I still do think that things can be done a lot better than most books manage. But it's a heckuva lot harder to do that than I used to think, because even quite basic physics is astonishingly full of amazingly tricky points.

Yeah! No kidding! But the fact that most people are completely unaware of this when they take physics, and most intro professors look at students like they're morons when they notice themselves (since many professors don't know about the issues) is a problem.

It's also why only people who work in a field should write textbooks in a field (I do not in fact believe that most intro book writers are even physicists). Your intro mechanics book had better be written by one of the guys who solves mechanics problems for a living (surprisingly not only do they exist but there's a lot of interesting stuff you can do that just hasn't been done).

That's why eg, Weinberg's QFT books are so great for learning QFT (the second time). And it's also why people who don't realize what's really going on in qft think some of his notation is a bit insane, but it really highlights important subtle points that you'd miss otherwise!

But this is definitely nontrivial to do. On the other hand, one should really arrange things to have all the time they need to write a good book!

Originally Posted By: Enraged Slith

Just as a general tip to all of you youngsters about to head off to college, it's absolutely crucial that you understand your math concepts, especially when your science classes start requiring you to integrate things for yourself.

Yeah, that's important, but certainly tricky. My normal advice is to buy/check out 2 or 3 additional books on a topic that's important, but the problem is that all of the intro calc books that I am aware of are in fact identical!

Although I hear Folland has an intro calc book used for honors undergrad classes that's supposed to be very good.

There's a book "calculus made easy" or something that has some very nice descriptions of things in terms of the "infinitesimal" approach that calculus was initially developed with (but a more modern notation, but without modern rigor). It's very different than normal approaches, but if you understand carefully why it's identical to the normal limit approach for differentiation and integration, you shouldn't have any conceptual problems for a while.

Originally Posted By: Decorated Zombie Veteran

You're convincing all of us impressionable youth that college is a waste of time. Bad CFG!

I have been told by a number of people "don't do theoretical physics unless you can't see yourself doing anything else!"

Although this is more an unfortunate fact of political and administrative environments than science.

Originally Posted By: Thuryl

I had to teach some geometry to some Year 7 students this week and I didn't feel like making the class calculate the internal angles of every regular polygon up to the octagon, so I made a lesson on straightedge-and-compass constructions instead.

That's good. That kinda stuff is a lot more interesting, because it makes people actually think instead of following the recipe that they don't really understand.

Although my very favorite thing about learning geometry was learning to use formal logic to prove things. I always went out of my way to prove things by contraposition for a while after that .

[Student of Trinity]

Physics programs in North America are, quite simply and literally, elitist. The attitude prevails quite sincerely that only a few specifically talented people should take a degree in physics. My own undergrad program started with 130 students in the first-year Honours Physics lecture, and ten of us graduated four years later. And that huge attrition was pretty much the deliberate goal of the program. All the exams tended to have one problem out of four that was a real brainteaser, requiring some flash of physical insight during the exam to solve. If you couldn't do that, you were writing out of 75%. So all the grade distributions were bi-modal: a handful of A's, and a bunch of C's. There were few B's in physics. Eventually all the C's left, and the A's graduated.

 

And maybe that's how it should be. Our group of 10 included 2 who wanted to be high school physics teachers, and 8 who went on to grad school, of whom at least three ended up as professors. The world does not need all that many academic physicists, but the ones it does need have to be people who are especially good at physics.

 

But in Germany it's all a different story. Here, a Diplom in physics is apparently a well regarded qualification for all kinds of business or technical careers. Lots of people who would never get a North American BSc in physics struggle through to get their Dipl. Phys., with a mediocre final grade, and then apparently go on to have successful careers in industry or business or government or something. The difference I see is that we graduate about 50% of our incoming classes, instead of under 10%.

 

There are too many differences between German and North American education systems to make any serious analysis beyond this fact. German secondary education is streamed starting from fifth grade, and the top tier of high school ('Gymnasium') seems to be pretty rigorous. University grades in Germany depend mostly on thesis work and oral exams taken only at the end of the program, so weaker students don't get so discouraged half-way through by a transcript that's filling up with C's and D's.

 

German professors seem to have quite similar attitudes to their North American colleagues, so it's not as though we are all populists trying to make physics safe for everyone. In fact the German educational tradition is much more sink-or-swim-on-your-own than in North America; professors feel very little responsibility to ensure that enrolled students learn the material. After all, tuition fees here are negligible token payments, where they exist at all.

 

But still somehow university physics education in Germany has its own cultural momentum, and it favors a lot more people getting through.

[Randomizer]

Originally Posted By: cfgauss

It's also why only people who work in a field should write textbooks in a field (I do not in fact believe that most intro book writers are even physicists).

I've seen some that were writing in their field and shouldn't have. The worst example was a text that had on average one mathematical error per page.

One book's second edition was removed from sales and replaced with its third edition because it was easier than adding an errata.

[cfgauss]

Originally Posted By: Student of Trinity

Physics programs in North America are, quite simply and literally, elitist. The attitude prevails quite sincerely that only a few specifically talented people should take a degree in physics.

The interesting thing here is that that's only half true. I've learned more and more that while physics is "competitive" (at least at the places I've been to or heard about directly) it's not competitive in the sense that "the people who're good at doing physics do well" but more like the people who play along or are willing to solder in the basement or something will do well .

Although I've certainly met some smart people, I've also met a bunch of people who've made me gasp at their lack of any knowledge! And I've been surprised at the very anti-student culture (at least at my university) that doesn't really encourage any independent work, or let people stand out for being good at physics very well.

This is partly due to my university's personal problems though . I've heard from some friends at other places rumors about professors actually going out of their way to make sure students are not worked to hard or to easy, and actually do things they're interested in.

Although I am not 100% convinced this is true based on my cynical experiences .

[Randomizer]

It depends upon the professors. Some will make sure that their research graduate students pass as long as they are helping the professor while others won't help out at all.

 

The was one physics professor at the University of Arizona that was known for encouraging his research assistants to sign up for classes and then send then off campus to do his research during the class time.

 

Whereas another was supposed to have walked into his assistant's defense exam and said that the student was passing no matter what happened.

[cfgauss]

That's certainly true. But the university's environment has a lot to do with it too. And from most people I've talked with, small universities tend to be far better in this regard, since they lack the overwhelming bureaucracy that tries to mandate how things are done, and are responsible more to their peers.

 

For example, in the large university I'm at, there're rules that say something to the effect of every grad student who passes the qual is required to have a thesis adviser by some date, and the department is obligated to provide one. But because it's such a large department, and many professors don't even know each other, it's a diffuse responsibility. So no one cares enough to say things like "hey this guy is smart, but doesn't have anyone to work with, let's help him find someone."

 

The only people anyone knows are in their research groups, which doesn't help any students if the group doesn't want them, and the only people who feel obligated to help probably want that student anyway.

 

But at smaller schools I've heard of professors going out of their way to help students find work. But to my knowledge no one has ever done anything like that here! Other than vague advice, like "hey you should talk to some people."

 

I know one of the really smart guys here from Caltech has had a lot of trouble finding people to work with, and that's a scary state of affairs!

 

And in what's I'm sure an entirely unrelated story we've recently had like 30% budget cuts and the school's plan is to make up that money AFAIK entirely through raising tuition and increase class sizes.

 

Of course that hits the state maximum yearly % increase long before it's enough to pay that off, so who knows what their plans are to stave off death until then.

 

But, hey, practically every building and courtyard has a very expensive piece of modern art in it! So at least we planned ahead for our financial future here.

 

And I'm sure the artists who made them appreciated the mandated physics classes they had to take for their general education requirements!

[Student of Trinity]

German graduate school is also different in this respect. Effectively, the cut between grad and undergrad comes a year or two later here, after all coursework. The doctoral degree is a pure research apprenticeship, all dissertation. In one way this makes the whole graduate school experience exactly parallel to that in North America, with the same stages and durations, just administered a bit differently. But in another way it means that the entire North American graduate school stage is completely eliminated here: up to the doctoral dissertation you are really an undergrad, and then the doctorate is just a junior grade post-doc, in which you are working as a freelance scientist on a short-term contract while acquiring a further professional qualification.

 

In German, doctoral students are not considered students; they are 'Doktoranden'. They are junior scientific coworkers, and are hired and paid as such by individual professors — exactly the way post-docs are hired and paid all over the world, just at a lower scale. A Doktorand is hired to work on the advisor's research projects — that's the explicit and official deal. If after three or four years they have made original progress in this research, then on top of their modest salary, they earn the coveted title of Doktor.

 

You don't apply to a departmental graduate program; there is no such thing. You apply for an individual Doktorand position advertised by a professor, and if you get the job, your affiliation with the department and university is as a member of your advisor's research group. Your contract typically comes up for renewal annually, and if your advisor were to drop you, you would simply be gone — you are not an enrolled student of the department the way you were as an undergrad, and nobody has to find you another doctoral advisor. I've never even heard of that actually happening, but in principle it's the bottom line.

 

It has quickly become apparent to me that, at least in a discipline like physics, the German system just makes more sense than the North American one. Graduate level coursework is still coursework; the distinction between Master's-level and senior undergrad courses is so fluid, that often one single course counts as both. So, up to the dissertation, there really is no good reason to distinguish grad students from undergrads. They're only about as different from a 4th year undergrad as a 4th year is different from a 3rd year. Then at the dissertation stage, what happens in practice in good North American programs, in good groups and for good and fortunate students, is indistinguishable from the German way. It's only in cases where something is not really working right that a North American PhD student has a different experience from a German Doktorand.

 

(Although long abandoned in Germany until reintroduced in this decade, the Bachelor and Master degrees date from the Middle Ages. But the modern doctoral degree was invented by 19th century German universities, along with the modern role of universities as research institutions. Professors as researchers and the doctorate as research apprenticeship were concepts that spread quickly round the world, but not without resistance. Harvard psychology professor William James wrote a heartfelt plea against 'the Ph.D. octopus' in 1903.)

 

 

[cfgauss]

In some ways that seems a lot better to me. The first year of graduate classes here were pretty much a waste of time for a lot of people here, but they feel like they have to require it for the sake of demanding everyone pass quals on the subjects (which are really nothing more than the same finals you just took, but again). And it seems like that waste of time could at least be made into something contiguous with your previous education in that case.

 

On the other hand, I don't think showing you can pass classes is enough to show someone can be a competent scientist. I've known a lot of people who do well in classes and quals because they just memorize everything, but when I say "hey, I just read about this new thing, what to you think?" I get a blank stare, and an "I don't know."

 

I think (and it's my impression that this is how it used to be) that having a master's in between undergrad and phd work makes the most sense. It actually shows one can understand the basics of his field well enough to apply it to solve an interesting (though not necessarily fundamentally new) problem, which is exactly the kind of skill scientists need to have.

 

Not to mention it is a much better stopping point for people who want to work in industry rather than research, since a thesis illustrates technical competence more than grades do (which IMO don't show anything at all).

 

It would also be endlessly more fun to write a master's thesis than take a half dozen 6 hour tests! That's actually ridiculous enough that I find it personally offensive.

 

Although, given the amount of effort I've learned some admissions people put into reviewing applications, I doubt many would actually read any theses well enough to determine if someone was competent or not... (apparently we can't even get people to review papers for journals properly any more, so it seems this has little hope!)

[Student of Trinity]

I agree about the value of a Master's thesis. I was maybe one of the last people to do one as part of a normal North American grad school career. The idea persisted a few years longer in Canada than in the US that you took all three degrees in a row, instead of rolling from the Master's to Ph.D. program after finishing your coursework, without doing the small thesis. I was on the tail of the curve, I guess, because my wife graduated at the same school (different department) at the same time, without a Master's.

 

It was a very good preparation for the PhD to do a smaller scale thesis. I had quite a hard time with my MSc thesis, and it took me about two and half years to finish the degree, instead of the canonical two years. My advisor was a brand new professor, and as I now know is typical, his first assigned student project was much too hard. But then even though I entirely changed topic in my PhD after one year wasted on a topic I hated, I was able to finish my dissertation in the next two years, because with the MSc thesis under my belt, I knew what the end product was supposed to be like.

 

But for all the reasons cfgauss mentions, it makes sense to include a small thesis as the last part of an undergraduate education. And a lot of places do have a thesis requirement for an honors Bachelor degree. So again the German system seems more reasonable to me.

 

Of course it's also true that the amount of material one needs to master to function today as a journeyperson scientist is a lot more than it was a hundred years ago. It probably does make sense to have a three-level system now, and I hope that the new German degree structure will work this way. If you do have to have a two-level structure, I think the traditional German Diplom-Doktor system, which is/was like Master-Doctor, is a better choice than the current North American Bachelor-Doctor scheme.

 

What remains unclear is whether the middle degree of a three-level system should be paid and administered more like the first degree, or more like the third, or as something different and in between. At the moment the German Master's is being treated as a senior undergraduate stage; the outmoded North American pre-doctoral Master's was treated as a junior doctorate. As I've said, I think the first option is better than the second. I don't really know what sort of different and in-between system there could be, but it would probably be nice to evolve one.

 

Actually the post-doc stage is then a fourth level, even though there is no degree attached to it. The post-doc is by now a fixed stage in the academic career track, though its duration varies wildly, but it works the same all around the world, and it seems to work okay without any formal credentials being involved. The potential hirers interested in post-doctoral experience will know how to assess your publications and your letters of reference, or they wouldn't be interested in post-doctoral experience.

[cfgauss]

I've seen a few places who use undergrad theses. I don't get the impression they're terribly useful, though, since you don't really have quite enough background to do very much at that point. As an undergrad, you really don't get to take any serious classes in your major until your third or so year. So only the last two or so you can use to really learn physics. And often you have to take third year classes in your fourth year because of conflicts with gen ed classes.

 

Although if it were combined with a master's type program that would make a lot more sense. Although personally I think having separate degrees could end up being helpful to make it easier for people to switch schools if theirs isn't active enough in the topics they're interested in at that point.

 

I'm tempted to say a master's should be more like a doctorate, since that's what it's preparing most people for, and since that allows more free time to be able to do research rather than classes. Although there're still a lot of intermediate and advanced coursework that could be done.

 

I'm not really sure about post docs though, I don't have any experience with that yet! In principle it seems nice, since it would seem you can have that time to concentrate more on research that you would've as a student, but don't have the responsibilities of a professor. But I don't really know.

[Slawbug]

My impression, coming mainly from different graduate departments at my alma mater and from professionals in the fields I have worked in, is that in the US the master's degree has really fallen off a cliff as far as academic relevance goes, and that it is only really relevant in non-academic settings that use it specifically as professional qualifications. In effect this restricts it to fields that have professionally-oriented mid-level degrees. MA's and MS's seem to be largely useless.

[Student of Trinity]

That's true — the Master's degree is obsolete as an academic qualification in the US and Canada. At least for a while there it might qualify you to be a high school department head, but I'm not sure even this is true now; it might be that this needs an M.Ed. now, which is more of a professional qualification like an MBA. But it is too bad that the pre-doctoral Master's is dead.

 

It's true that there isn't much that even remotely looks like research that you can do by fourth year undergrad. (The American terms 'senior' 'junior', 'sophomore' aren't used in Canada or Europe.) But there are plenty of opportunities for longer independent projects on basic topics that get written up into an undergrad thesis. For instance, although this wasn't a thesis, I learned an awful lot from an advanced one-semester lab course that had me design and carry out a single simple experiment from scratch, instead of simply following directions with pre-fab apparatus for a weekly lab.

 

After the professor gently discouraged my initial proposal to repeat the Pound-Rebka experiment with gamma rays running through fiber-optic cables, by pointing out that gamma rays don't turn corners just because a little bit of glass does, I wound up measuring the normal mode spectrum of ten coupled masses on an air track. It took me the semester to get it all working, make sense of it and write it up. My frequency curve fell systematically below the simple theoretical curve at high frequencies, and it was only years later that I figured out that it was due to heating in the connecting springs. Since the simple theory didn't even include the springs, but just assumed an instantaneous force between the sliding masses, this really brought home to me how non-trivial it is to use an 'effective theory' that eliminates real degrees of freedom. And although this one lab course didn't seem decisive at the time, that has turned out to be the main theme of my research career.

 

And when the course professor saw my nice normal modes emerging from the jumbled motion of air track sliders, as I dialed the driving arm through the resonant frequencies, he clapped me on the shoulder and declared, in his beautiful Edinburgh accent, "Eh, it's grand!" That was an important scientific insight, too. It wasn't enough to turn me into an experimentalist, but it probably did help motivate me to seek a field with active experiments.

 

The post-doc is a necessary stage in a modern scientific research career. You cannot get a faculty job with a fresh Ph.D., no matter how brilliant you are; you have to do at least two years of post-doctoral work, and two such post-doc stints, in different groups, is more normal. That's how you pick up the three recommendation letters from famous researchers that are the standard requirement for a faculty application. One is normally your PhD advisor, and the group leaders of your two post-docs are the default other two. If you make a big enough splash in one post-doc you can find some other random contact to be number three, but this is less usual. If you manage to do well enough to get more post-doc jobs, but not well enough to get a faculty job, you can stretch your post-doc career further, and accumulate more letter-writers. It's still somewhat of an up-or-out career stage, though, because the longer it's been since your PhD, the fewer funding sources you're eligible for as a post-doc.

 

(I spent ten years as a post-doc, which may not be a world record, but is definitely at the extreme end of what's possible. Then I caught up by skipping straight to full professor, though — you can do that in Europe, where the North American tenure track system doesn't exist.)

 

Post-docs in physics are normally paid quite decently, and allow you to do independent research. In fact, you don't have to do anything else: no teaching, no grant proposals, no committee work. You're nobody's slave. Apart from the fact that you're under huge pressure, because your academic career will grind to a halt in a year or two if you can't generate impressive enough publications before then, it's a good life. In active fields in which a PhD has good industry opportunities, it's easy to get post-docs. In fields like string theory, it's the wall of fire.

[Dintiradan]

Every time Student of Trinity brings up the Masters/Doctorate distinction, I'm taken aback. All I can say is that Masters programs for Computing Science in Canada are alive and well.

 

It wasn't until a discussion on these boards not too long ago that I realized you could apply for a Doctorate program without first doing a Masters. Here, the option simply isn't there - you must do a Masters first. Oh, there's a little line in the handbook that says gifted students can be fast-tracked through a Masters, or skip one entirely. But a professor will quickly tell you, without rancour, the option is only there for true geniuses. A Comp. Sci. professor would be hard-pressed to think of five students who went straight from an undergraduate to work on their Ph.D.

 

At my Comp. Sci. department, there are two options for pursuing a Masters - course-based and thesis-based. The course-based approach is strongly, strongly discouraged. The thesis-based route still has courses. Some of them are joint undergrad-Masters courses. One I sat in for a couple of days was on machine learning - students had to investigate a recent advancement in the field and prepare a short lecture on it for the rest of the class. I dropped because it would have been a horrendous time sink and I was already at full course load. From what I hear, some Masters courses have the students study an open problem and attempt to solve it.

 

I was talking with a professor in Toronto a few months ago, and he confirmed what the rest of you are saying about the decline of Masters programs. He said that a Masters degree from the U.K. carried a stigma - it's a mark of someone who tried to get a Ph.D., but failed. He also said that a Canadian Masters degree carried a lot more respect than one from the States. He may have just been talking about Comp. Sci. Masters, but it seemed he was talking in general.

 

It's not uncommon for someone to take a Masters, write a thesis on software engineering or user interface design, and then join the workforce. Some places like Google virtually require their applicants to have a Masters degree.

 

--

 

RE: Undergraduate theses: That would be cool, but I don't know where some programs would find the time. My program has a number of courses which are de facto capstone courses. I like them; they're just ridiculous sinks that steal your time away from 'normal' (busywork) courses.

 

I'm not sure how capstones or internships would apply to the 'normal' sciences, though.

[Slawbug]

Google definitely does not require their applicants to have Masters. I have several friends from undergrad who all went straight to work for Google as software engineers with just a BS.

[The Mystic]

Originally Posted By: Celtic Minstrel

Originally Posted By: cfgauss

I don't know how many advanced math or physics lectures I've taken where they'd say something like "so 6*7 is... uuh, well 6*5 is 30... so 36, 41, 42!"

I don't usually remember 7 times 6, either. Or 8 times 9, or 7 times 9.

Back in the day, I spent a month of math classes doing nothing but memorizing multiplication tables up to 12 times 12. Now, a little more than 20 years later, I still have to think of the answer.

Originally Posted By: Randomizer

I've seen some that were writing in their field and shouldn't have. The worst example was a text that had on average one mathematical error per page.

The worst example I've seen was when I scanned the textbook for a Java class I was planning to take; it was written by techies, for techies, and in the language of techies, and would've needed at least a bachelor's degree to even begin to understand the introduction. Needless to say, I never took the class, and took VB instead.

[Celtic Minstrel]

Originally Posted By: The Mystic

The worst example I've seen was when I scanned the textbook for a Java class I was planning to take; it was written by techies, for techies, and in the language of techies, and would've needed at least a bachelor's degree to even begin to understand the introduction. Needless to say, I never took the class, and took VB instead.

Not taking a class due to the textbook seems a little silly, though; my university classes have yet to use a textbook extensively, even when they do require one. In fact, I probably could've gotten along fine without even purchasing a few of the textbooks (though others are useful for review and problems to solve).

[Student of Trinity]

Huh — that's very interesting to learn, that the Master's is alive and well in CS, at least in Canada. I wonder whether this reflects the fact that there are more opportunities in North American industry for CS grads than in the natural sciences, so that a step between Bachelor and doctorate has a market niche.

[The Mystic]

Originally Posted By: Celtic Minstrel

Originally Posted By: The Mystic

The worst example I've seen was when I scanned the textbook for a Java class I was planning to take; it was written by techies, for techies, and in the language of techies, and would've needed at least a bachelor's degree to even begin to understand the introduction. Needless to say, I never took the class, and took VB instead.

Not taking a class due to the textbook seems a little silly, though; my university classes have yet to use a textbook extensively, even when they do require one. In fact, I probably could've gotten along fine without even purchasing a few of the textbooks (though others are useful for review and problems to solve).

Actually, it wasn't so much the textbook that deterred me from taking the class, though it was a factor. What really turned me off was the name of the instructor listed in the class schedule; he had a reputation for assuming that you've read the textbook before the first class and had understood every word, and that you were taking the class as part of a continuing education program so you could keep your cushy desk job. He also had a serious dislike for undergrad students.