# Physicists: What makes sense on this gigantic blackboard, and how much holds together topically? **URL:** \ **Category:** Factual Questions\ **Created:** [July 17, 2013, 4:01pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764 "2013-07-17T16:01:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [July 17, 2013, 4:01pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/1 "2013-07-17T16:01:11Z")
In a current thread [Can those brilliant professor types really look at those long ass equations on the whiteboard?](http://boards.straightdope.com/sdmb/showthread.php?t=696770), I posted the following example, and commented on it as an aside: > [@Can those brilliant professor types really look at those long ass equations on the whiteboard?](https://boards.straightdope.com/t/can-those-brilliant-professor-types-really-look-at-those-long-ass-equations-on-the-whiteboard/663742/21): > > [A physicist’s anxiety nightmare.](http://tywkiwdbi.blogspot.com/2012/04/physics-classroom-blackboard.html) > > From a dream-sequence in Coen Bros. 2009, **A Serious Man**. The only movie where Schroedinger’s Cat is knowledgeably introduced into a meditation on a man’s Job-like moral and existential quandaries. Really. The main character is a physicist who is currently lecturing on quantum reality (in other scenes), and his entire mental and real life explicitly relates to the brilliant and funny movie. Anyway, since I brought it up in a thread about how people can read (correct or “incorrect” symbols), it seemed kind of unfair to keep people–including me–hanging about this example. How far did the set-designer/directors go in verisimilitude? Remember, also, that this is a snip from an anxiety _dream_, where logic is slippery. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 17, 2013, 4:14pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/2 "2013-07-17T16:14:37Z")
A lot of it seems to be too blurry to read in the linked pic. Clearly, even if it all actually means something, it is unrealistic as a lecture. No student could take all that in at once. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [July 17, 2013, 4:16pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/3 "2013-07-17T16:16:10Z")
Yeah, for sure. You can click on the picture to see a large view of it if you want. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 17, 2013, 4:43pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/4 "2013-07-17T16:43:02Z")
> [@njtt](#): > > A lot of it seems to be too blurry to read in the linked pic. You can blow [the JPG](http://4.bp.blogspot.com/-V1E8ODdrLg4/T3nE-eg7_PI/AAAAAAAAQN8/A9Vy3l7x-d4/s1600/blackboard.jpg) image up to full size, and then zoom in on it. Even so, I’m not getting a whole lot. In the upper right corner, I see the wavelength/momentum equation (lambda = h/p), and a visual depiction of [an electron as a wave function orbiting a nucleus.](http://ircamera.as.arizona.edu/astr_250/Lectures/Lec08_sml.htm) Halfway up the blackboard and a bit to our right of the instructor, I see an expression for total system momentum (P=sum (m1_v1 + m2_v2+…). At bottom, halfway between the instructor and our right end of the board, I see a visual depiction of [a solenoid or transformer in cross section, showing the magnetic field lines.](http://physics.stackexchange.com/questions/38067/magnetic-field-lines-can-be-entirely-confined-within-the-core-of-a-toroid-but-n) Over on our left half, there’s a visual depiction of a differential element of solid angle ([a steradian](http://www.google.com/search?safe=active&hl=en&site=imghp&tbm=isch&source=hp&biw=1078&bih=819&q=coil+field&oq=coil+field&gs_l=img.3...1453.2219.0.2297.10.6.0.0.0.0.125.125.0j1.1.0....0...1ac.1.21.img.4bk78Qf7cF8#safe=active&hl=en&site=imghp&tbm=isch&sa=1&q=steradian&oq=steradian&gs_l=img.3..0l5j0i10i24l2j0i24l3.3016.4750.1.4875.13.9.0.0.0.0.281.1123.0j2j3.5.0....0...1c.1.21.img.S7xDsN7I6Fs&bav=on.2,or.r_qf.&fp=cda15bd43fa71479&biw=1078&bih=819)), along with the integral function using it to calculate total flux of some quantity (gravity, radiation, etc.) emanating from a point source in all directions. A pic at top left shows another example of electrical current in a loop interacting with magnetic field lines passing through the loop. That’s about as much as I can make out. It seems likely that the rest of it has some basis in reality, e.g. they may have copied it all from a physics text, but not necessarily anything the Coen brothers could point to and say “this means \*.” ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [July 17, 2013, 5:00pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/5 "2013-07-17T17:00:21Z")
From a quick look, most of what I can make out seems to be straight from some introductory quantum mechanics course—there’s the old classic, the quantum harmonic oscillator both in 3d (in the form of its energy eigenvalues) and in 1d (in the form of the probability density for finding the particle at a certain position, if the system is in a certain state—the graphic with the sinusoidal line at the very top over the professor), Bohr’s atom model (top right), the quantization of spin, etc. There’s also some special relativity, and a bit of electrodynamics (I can make out at least a couple of Maxwell’s equations). Some of the things appear to hang together—there seems to be a discussion of the volume element in spherical coordinates, which might be related to the calculation of the energy levels of the three dimensional harmonic oscillator, and it seems that a discussion about magnetic dipoles was used to introduce spin, but for others, there does not seem to be any obvious connection—I’m not sure what the relativistic energy-momentum relation does there, for instance. One thing I can’t place is the quite central bit with the arrows and (what looks like) Hebrew symbols; it looks vaguely familiar, but perhaps not from a physics context? And of course, one question all those equations can’t solve: how the heck did he manage to write all the way up there? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [July 17, 2013, 5:28pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/6 "2013-07-17T17:28:59Z")
> [@Half\_Man\_Half\_Wit](#): > > And of course, one question all those equations can’t solve: how the heck did he manage to write all the way up there? Quantum teleportation. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 17, 2013, 7:50pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/7 "2013-07-17T19:50:16Z")
> [@Leo\_Bloom](#): > > Yeah, for sure. > > You can click on the picture to see a large view of it if you want. I did that before my original post, thanks very much. Much of it is still too blurry to read. I am not denying that some parts may be recognizable (or guessable at). ---
**Author:** ![Prof.Pepperwinkle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/prof.pepperwinkle/32/13627_2.png) [@Prof.Pepperwinkle](https://boards.straightdope.com/u/Prof.Pepperwinkle)\ **Post date:** [July 17, 2013, 7:57pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/8 "2013-07-17T19:57:38Z")
> [@Half\_Man\_Half\_Wit](#): > > One thing I can’t place is the quite central bit with the arrows and (what looks like) Hebrew symbols; it looks vaguely familiar, but perhaps not from a physics context? The symbols (alephs and tsades) I believe are used in infinite (or transfinite) mathematics. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 17, 2013, 8:49pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/9 "2013-07-17T20:49:47Z")
All of it seems to be legitimate physics (or possibly math, in the case of the alephs), but it’s drawn from all over the place in physics. No single course would contain all those concepts, much less any single lecture. ---
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [July 17, 2013, 9:02pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/10 "2013-07-17T21:02:00Z")
The vast majority of it looks like straightforward quantum mechanics: energy eigenvalues of the harmonic oscillator, some bits about quantum numbers, spin and magnetic moment for an electron, Schrodinger’s equation written out with vector notation, something about spherical harmonics, etc. The panel to the immediate right of the lecturer looks like electromagnetism in relativistic quantum mechanics. The drawing on the far left looks like a description of some sort of atomic process (I can’t see enough detail to be more specific), and the one on the bottom right might be a history of atomic models. I have no idea what the Hebrew letters on the panel to the left of the lecturer are supposed to represent; I’ve only seem them used in set theory (and the diagram makes no sense in that context), not in physics (but I’m a mathematician, not a physicist, and not really even a mathematical physicist). The bit about L^2 immediately above it is very standard quantum mechanics, at least. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [July 18, 2013, 2:33am UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/11 "2013-07-18T02:33:03Z")
Another physicist here to chime in that this is basically a collage of various physics concepts, without any particular unifying theme. However, it’s worth pointing out that the Hebrew letters may also have been included because the main character (the professor in the picture) is Jewish, and spends most of the movie trying to figure out what God wants from him. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [July 18, 2013, 5:20am UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/12 "2013-07-18T05:20:34Z")
> [@Prof.Pepperwinkle](#): > > The symbols (alephs and tsades) I believe are used in infinite (or transfinite) mathematics. Alephs and beths I know in that context, but what do the tsades signify? Maybe, as **MikeS** said, one should rather look at a religious context for this bit of symbology… ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 28, 2016, 3:48pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/13 "2016-03-28T15:48:30Z")
To continue: Cat and toddler thinking about gravitation? [![Imgur](https://i.imgur.com/DpIggh0.jpeg "imgur.com") ](https://imgur.com/DpIggh0) How together is the math? FTR, I revived this thread, and not the one cited in OP, or [What math is on this huge blackboard, and is the setup just a joke? - Factual Questions - Straight Dope Message Board](http://boards.straightdope.com/sdmb/showthread.php?t=757515), which are similar, if you’re into this type of thing. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 28, 2016, 4:03pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/14 "2016-03-28T16:03:53Z")
It occurs to me that the dynamics and ductus of the notation and graphing on the board are that of someone fluent and comfortable in the field. Which makes me wonder in particular about the crossed out part, if it’s jokey in addition. (Handwriting analysis glossary: [Dictionary of Handwriting Analysis Terms | Handwriting Analysis](http://atozhandwriting.com/graphology/dictionary-of-handwriting-analysis/)) ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [March 28, 2016, 4:34pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/15 "2016-03-28T16:34:28Z")
> [@Leo\_Bloom](#): > > To continue: Cat and toddler thinking about gravitation? > [Imgur: The magic of the Internet](http://imgur.com/DpIggh0) > > How together is the math? It’s all from the same field, but it’s a bit sloppy. All of the equations appear to be from the field of general relativity: [ul][li]The circled equation, partially blocked by the child’s head, is the [Einstein equation](https://en.wikipedia.org/wiki/Einstein_field_equations) that describes the interaction of spacetime with matter. [/li][li]The long multi-line equation in the upper right looks most like the [Kerr metric](https://en.wikipedia.org/wiki/Kerr_metric) to me, but it might be the [Kerr-Newman metric](https://en.wikipedia.org/wiki/Kerr%E2%80%93Newman_metric) in a form that I’m not familiar with. The former describes rotating black holes; the latter describes rotating black holes that additionally have electric charge.[/li][li]The equations in the bottom left appear to be describing the relationship between the total mass of an object (not necessarily a black hole) and the density of the matter comprising it.[/li][li]The equations in the upper left seem to be describing the two characteristic length scales for charged black holes (one related to its mass—the so-called [Schwarzchild radius](http://astronomyonline.org/science/schwarzschildradius.asp), and another related to its charge. I’m not sure whether this second one has a special name.)[/li][li]I’m not sure what the diagrams are supposed to represent, but if I saw them drawn on a chalkboard in a general relativity research group I wouldn’t bat an eye. [/li][/ul] [Here’s the original photo posted by the photographer, BTW.](http://photo.net/photodb/photo?photo_id=15426772) ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 28, 2016, 4:43pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/16 "2016-03-28T16:43:53Z")
Thanks for the proper cite. I was unhappy about not having it, but the artist’s name was visible. And the crossed-out part? ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [March 28, 2016, 5:01pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/17 "2016-03-28T17:01:15Z")
> [@Leo\_Bloom](#): > > And the crossed-out part? Looks like a partial definition of the [Einstein tensor,](https://en.wikipedia.org/wiki/Einstein_tensor) also with the cosmological constant thrown in for good measure. It’s certainly conceivable that these two would be in the same equation. As far as I can tell, the equation isn’t complete; but it’s not unheard of to start writing down an equation, realize as you’re writing it that it’s better expressed in a different way, and scratch it out and rewrite it. (I do it all the time.) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 28, 2016, 10:02pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/18 "2016-03-28T22:02:11Z")
And I would assume that the diagrams are meant to represent wormholes. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [September 2, 2016, 4:37pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/19 "2016-09-02T16:37:08Z")
OK class. Last time, we had a kid and a cat, very popular Internet topics. Today we have a another popular item, a pretty woman. [![Imgur](https://i.imgur.com/CHHXHVP.jpeg "imgur.com") ](https://imgur.com/CHHXHVP) Same query as OP. Extra credit: cite most likely source. ETA: of the math for the set designer ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [September 2, 2016, 5:34pm UTC](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764/20 "2016-09-02T17:34:10Z")
A lot of background info is [here](http://scifi.stackexchange.com/questions/72737/interstellar-movie-equations-shot). [Next page](https://boards.straightdope.com/t/physicists-what-makes-sense-on-this-gigantic-blackboard-and-how-much-holds-together-topically/663764.md?page=2)