{"id":4921,"date":"2010-08-04T10:10:19","date_gmt":"2010-08-04T10:10:19","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2010\/08\/04\/reader-request-whats-the-matte\/"},"modified":"2010-08-04T10:10:19","modified_gmt":"2010-08-04T10:10:19","slug":"reader-request-whats-the-matte","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2010\/08\/04\/reader-request-whats-the-matte\/","title":{"rendered":"Reader Request: What’s the Matter with Stat Mech?"},"content":{"rendered":"

On the reader request thread, commenter Brad had several questions<\/a>; one led to yesterday’s post about superconductors<\/a>, another is a critical issue in pedagogy:<\/p>\n

\n

Finally, why did all of my stat[istical] mech[anics] courses suck? <\/p>\n<\/blockquote>\n

Statistical Mechanics is the branch of physics that deals with building up macroscopic thermal properties of materials from a microscopic model of gas atoms with particular energy states. It’s an important and powerful branch of physics dealing with things like the melting and freezing of various substances, and why entropy always increases, and things like that. It’s also a real problem area for lots of students, not just Brad.<\/p>\n

My own experience provides one really simple explanation for why my stat mech courses sucked: I took it twice (once as an undergrad, once as a grad student), and both times it met at 8:00 am. Particularly in my undergrad days, I was not fully functional at 8 am, so it’s no surprise that I didn’t retain much of the material. My undergrad stat mech class was mostly memorable for the professor, not the subject matter.<\/p>\n

<\/p>\n

(A quick story: The professor teaching the course was a really nice guy, and was well aware than none of the senior physics majors taking the class were all that enthusiastic about having class at 8am. Whenever we appeared to be flagging, he would stop class, and cheer us up with Far Side cartoons from his desk calendar. Not the cartoons themselves, mind– just descriptions of them…<\/p>\n

(“Um, ok, let’s see– oh! This is a good one. OK, there’s a cow, and she’s standing in the kitchen with a beehive hairdo– as cows do, you know- and she says… No, wait, that’s a different one. No, it was a snake, and…” It was incredibly goofy, but worked every time. Once we were awake again, he would resume the lecture.)<\/p>\n

(I’m not naming him, but anybody familiar with the department at Williams can almost certainly get it from that.)<\/p>\n

More seriously, the problem I had with stat mech was always the level of abstraction. Most of the problems in the classes consisted of either proving mathematical identities or deriving thermodynamic properties that I had no intuition for– heat capacity was a common one. It was really hard to get my head around what was going on, and why it mattered.<\/p>\n

As a result, statistical mechanics always felt like an abstract game, where we were just manipulating odd formulae governed by simple rules in order to generate new formulae that hopefully had whatever mathematical property it was that we were looking for. It never quite felt real, which made it hard to maintain focus.<\/p>\n

This is partly a function of having both classes taught by theorists’ theorists, but to some degree it’s inherent in the material– when you’re talking about systems of 1023<\/sup> particles, you’re not always going to be able to boil it down to a simple picture of the motion of individual particles. The final description will necessarily be about average properties of large groups of particles, and idealized particles at that. <\/p>\n

I’d sort of like to have a better feel for the subject– my lingering impression is basically the dismissive summary given by my famously arrogant QM professor in grad school: “There’s one idea: Z=Σ e-βE<\/sup>. All the rest is algebra.” I don’t feel my lack of knowledge in this area of physics as strongly as some others, though, so it’s not a real high priority. At some point, I suppose I’ll end up teaching it, and then I’ll know a lot more.<\/p>\n","protected":false},"excerpt":{"rendered":"

On the reader request thread, commenter Brad had several questions; one led to yesterday’s post about superconductors, another is a critical issue in pedagogy: Finally, why did all of my stat[istical] mech[anics] courses suck? Statistical Mechanics is the branch of physics that deals with building up macroscopic thermal properties of materials from a microscopic model… Continue reading Reader Request: What’s the Matter with Stat Mech?<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,13,7,138],"tags":[],"class_list":["post-4921","post","type-post","status-publish","format-standard","hentry","category-academia","category-education","category-physics","category-theory","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/4921","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=4921"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/4921\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=4921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=4921"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=4921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}