Saturday, December 01, 2007

A Plottl a Day

candleMy beloved husband and I, we've been thinking really hard what we would blog through the advent season. Since I always loved advent calendars, we finally decided to take a plot each day, and briefly explain why we have seen it so many times already that people no longer bother to say what's actually plotted on it. I hope you'll have as much fun with it as we had :-)

In this context, a quotation from a seminar I attended last month, believe it or not:

Question: "What is plotted on the y-axis?"
Speaker looks confused: "You mean the up-down one?


  1. dear bee
    why does it seem so strange and funny or tragic or the three together that the speaker forgot the y verticality or it is just mesmerized by the question and having a moment of cognitive disonance ? what did the speaker had in the slide as y units?..or the speaker was being awfully polite..

  2. For atmospheric scientists, the vertical axis is the z axis.

    One of my favorite moments in grad school occurred when one of my fellow students had to give his first talk on quantum mechanics. It seems that he had never bothered to learn the names of the Greek letters and other math symbols, so that he referred to the "del" operator as "spade" and the "psi" function as "pitchfork."

    In a slightly different vein, I recall my own first talk at a scientific conference in those pre-Powerpoint days of Vu Graphs. Having put up my slide and found it to be mirror imaged, I tried another orientation only to find it upside down and mirror imaged. After my third try found it still somehow unintellible the session chair advised me that there was only one further possibility and that I should try it!

  3. dear cip what is an atmospheric scientist? i'm dead serious, well maybe not that dead, but certainly interested in the mesanings of what is being said here

  4. el guapo,

    Atmospheric scientists study the atmospheres of Earth and other planets. My comment about z was not totally serious, but most things in the atmosphere have an interesting behavior with height, usually denoted by z. There is a certain logic to plotting the up-down coordinate on the up-down axis.

  5. Hi el,

    The above quotation is from a seminar speaker who was not a physicist. I think he was not being polite but just not sure what the question was. I find it funny because it illuminates so nicely the in-side speech we use, and we often assume everybody knows what we are talking about. The speaker btw did exactly the same from his side, and at least I only got a very vague impression of what he was talking about.



  6. What a wonderful idea! I am not sure how one goes about pursuing it, but this seems like a perfect idea for a book. I will definitely buy and read a book (in a field not my own) carefully elucidating 24 key concepts under one theme. Coupled with the holiday theme this also looks marketable to my very naive eyes. I really hope this gets picked up by someone, will provide a nice balance to the cutesy and/or gee weez genres of science books (actually, come to think of it, those genres are specific to physics, aren't they?).

  7. Hi Moshe: Glad you like it :-) I am not sure though how carefully we will manage to elucidate given that we yet have only very a vague idea what to do the rest of the month. Yeah, actually I too would probably buy a book '25 plots of contemporary physics you must have seen'. We probably won't quite achieve that (this blog has a certain particle physics/cosmology bias), but we thought we'd give it a try. It is an understandable but bad habit that people who give talks at some point no longer bother to explain what the plot shows. Best,


  8. A few suggestions of well-known plots that could be fun for this project:

    1) Hertzsprung-Russell Diagram
    2) Blackbody curve(s)
    3) Distributions (Gaussian, Poisson, Chi-Square, ...)

    Greetings from Boulder,

  9. Dear Backreaction,

    Really love your plottl a day series - have not read all of them so far but found

    1. Ising Model
    2. Pierre Auger Observatory results
    3. rotational speed of galaxy

    blogs truly fantastic. Finally a blog that does not dumb down physics/science so much that it becomes useless to the reader!! I have subscribed to your blog after reading your entries in the mixed states aggregator.

    Can you point out blogs that are similar to yours? i.e. blog that explain physics events at a level of someone who has done a Bachelors/Masters in physics and above? thanks and best of luck. I hope to be your reader for many years to come.

    P.S. its a great idea of yours to pick up a famous paper/graph and explain it to readers. Perhaps it can be a regular feature of your blog. Your summary of pierre auger was especially instructive because it taught me more that popular news accounts taught me. The journal paper of course requires some expertise to read...

  10. Hi Sidharth:

    Glad you like it. I think Tommaso does an excellent job with explaining things in an accessible way. If you haven't yet checked out his blog, you should have a look. Best,


  11. Cool Advent Calendar idea.

    Have you seen the German Embassy ones?

    [The 2006 version is at ...]

    So now each day I can click there to listen to a new German Xmas song, and then click here to check out your Advent plots. :>)

    William /wam

    ps I'd like to see a plot of our path through space, with respect to "the distant stars" ... factoring in the earth's spin and rotation around the sun, the sun's rotation around the galaxy, the galaxy's rotation with it's local cluster and the local cluster's movement toward "the Great Attractor" ... to determine how fast we are moving and the frequency and magnitude of our zigging and zagging ... or do we make closed loops along the way?

  12. Hi William,

    thanks that you like the idea - like all the other cheering words, it's a motivation to keep on going, since while we have enough plots to fill up the days until christmas easily, some texts still want to be written ;-)

    I'd like to see a plot of our path through space, with respect to "the distant stars" ...

    That's a very interesting idea! The "distant stars" are quasars nowadays, if you are interested in details, you may have a look the The International Celestial Reference Frame. As for a plot, I could imagine a 3D-representation of the different velocity vectors involved... I don't now of any at the moment...

    Best, Stefan

  13. El Guapo wrote:

    what is an atmospheric scientist?

    Atmospheric scientists are hired by rowdy bars in tough neighborhoods in the US to give these establishments a less threatening atmosphere. They will often sit at the bar doing calculations in a large notebook, sipping a glass of milk. You might wonder why a bar would pay for this, but it turns out that an overly tough clientele can drive away business and even cause a lot of damage with gun fights, while a less intimating atmosphere attracts business. It turns out that a lot of the most dangerous customers won't even enter a bar if there are a few atmospheric scientists sitting there. It's a dangerous job, of course, because you're likely to get beaten up or even shot. However, the employment prospects for fresh PhDs are so bad that more and more are looking for jobs as atmospheric scientists.

  14. *lol* I'd consider changing the field, but I can't stand milk. Also, I unfortunately have the impression women doing calculations appear somewhat intimidating outside their habitat. Or maybe it's just me. Best,


  15. It doesn't have to be milk, Bee - a Shirley Temple or some other nonalcoholic drink will do. But, I don't recommend trying to become an atmospheric scientist. The pay is bad, and establishments rarely hire women to give the place a scientific atmosphere, precisely for the reason you mention. They mainly want people who look like real stereotypical scientists out of 1950s movies: white males, preferably wearing horn-rimmed glasses.

    By the way, I forgot to explain capitalimperialistpig's joke: "For atmospheric scientists, the vertical axis is the z axis".

    While some atmospheric scientists really do serious research at bars, hoping to eventually get back into academia, others sort of go crazy serving as the visual equivalent of background music. Then they start doing wacky stuff like labelling the vertical axis the z axis - just for fun, to see if anyone notices or cares! It's sort of a standard joke.

    So, the next time you see an atmospheric scientist working at a restaurant, cafe or bar, say hi to them and check to see whether their work makes sense, or if they're doing crazy stuff like using a letter other than "y" for the vertical axis on a graph. They'll probably appreciate your interest.

    By the way, I've really been enjoying the "plot a day" feature! Great stuff!

  16. John,

    You mean some of the Atmospheric Scientists in bars are getting paid? Are their drinks comped too?

    I do know an atmospheric science post doc who worked as a bouncer - also a couple of chemists - mathematical physicists - not so many.

  17. PS -

    Just so you can tell the Atmospheric Scientists from the regular drunks.

    x is East. y is North. Oh, and dx/dt = u, dy/dt = v, and dz/dt = w

  18. Three last clues -

    Theorists look like Dustin Hoffman. Experimentalists look like Grizzly Adams. Females of either species resemble Angelina Jolie.

  19. I think you got that last one wrong. We actually all look like Sharon Stone. Just that the senior profs, traumatized because they all once were small pimply boys, find that too intimidating, so most of try to hide it. Actually, I'd know several physics departments that would do better if they'd pay more attention to the atmosphere. Best, B.

  20. CiP, they're a slow lot today. But surely you were joking, Mr Baez?


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