(Not) Appropriate for class

[steuard]

I'm twiddling my thumbs waiting for my flight back to LA after a job interview in Michigan, and I just took a look at the most recent xkcd comic. I'm torn: we just covered special relativity last week in my intro physics class, and I emphasized the fact that observers who move relative to one another may disagree on whether events are simultaneous or not. So this comic is remarkably timely and applicable: ideal to share with my class! (We talked about the twin paradox, too, so the mouse-over text is relevant as well.) Nevertheless, I think perhaps I'll opt against.

(If you're interested, you can take a look at the space-time diagrams handout that I wrote for the class. It's a bit terse, especially for me, but I think it covers the essentials. It's not really meant to stand on its own without lecture and class discussion, but it ought to be comprehensible at least to people who have encountered the subject before.)

Comments

[chalgaryn.livejournal.com]

Oh, so you can goof off online at the airport killing time, but you can't answer your phone or call to say "Hi!" before you get on the plane :-P

[zathrus.livejournal.com]

I had a similar train of thought: Wow, a comic that discusses a really cool physics topic! Shucks, it brings in so many other topics that could completely derail the conversation! I'll probably be talking about special relativity with my kids long before I'll want to discuss "simultaneous orgasms" with them. (Heck, I've already read them a picture book about relativity.)

I appreciate the space-time diagrams; thanks! Mind if I save them for later use?

Newt

[nemene.livejournal.com]

borderline...but...probably best to not...

Hey it would be better then the time a certail Mudd Econ Prof was showing us web-pages and then showed his history drop donw list and there was www.gangbang.com...

[ukelele.livejournal.com]

Ah! Thank you; now I get that, er, strip.

[kirin]

Yes, I am now slapping my head at missing the point on that one. The title text should've tipped me off, really.

[beth_leonard]

Certainly save the strip. You never know when it will come in handy for the right small class of grad students. Freshman... probably not so good.
--Beth

[steuard.livejournal.com]

You're more than welcome to hang on to the space-time diagram handout; in fact, I've decided to link it from my web site (so it's more or less public now). You might also want to look into whether there are books that take this approach; I think that Tom Moore of Pomona College takes a similar approach for at least some of his coverage of the topic. (I haven't read either of his textbooks that cover relativity in detail, but I know that he provides students with a computer program for printing "tilted" graph paper that automates some of the stuff I've described: that suggests that his approach must be similar.)

[steuard.livejournal.com]

That's... that's... just astounding. Don't do that.

[steuard.livejournal.com]

I see that the comic on the xkcd site has now been turned into a hyperlink to a Wikipedia article on simultaneity in relativity. I guess a lot of people must have been confused. (Heck, I might have taken longer to figure it out if I hadn't just taught the stuff.)

[nemene.livejournal.com]

I understood it the instant I read it (In my reference frame at least)

[nemene.livejournal.com]

wouldn't have been so bad, except he noticed it and then brought attention to it by trying to explain it away.