And Now for Something Completely Different: Quantum Fields!

Do I miss assignments and exams? Definitely not, and I am now – finally, really, absolutely – determined to complete another program I had set for myself about 2-3 years ago. I had not been able to pull it off in addition to being a moonlighting student.

Since about 10 years I have been recycling my physics knowledge on a regular basis. By recycling I mean: Reading text books as a hobby – sometimes practiced at 5:00 AM, before I jumped into my company car to drive to an IT customer’s site.

I have read the occasional popular physics book, too, but I found peace and tranquility in working through long-winded mathematical derivations. I dare say, this is what kept me sane. Actually, this is the therapy I would recommend to all those burnt-out managers and consultants in the corporate world – especially to the geeky ones.

Having finished that Recapture What You Had Already Known program I was shocked that I – trained as an applied physicist – had missed some major advances in theoretical physics. I could not make head or tail of how the Higgs field is giving the particles mass.

There is some glaring irony: I was not completely ignorant of theoretical physics – I took some non-mandatory classes to understand the theory superconductivity, the field I worked in as an experimental physicist. The Higgs mechanism is very similar to phase transitions like a metal become superconducting – but obviously I was not able (anymore?) to make this mental connection.

Even worse I was ignorant of the big questions in physics. What is it exactly that we don’t know today? Where is the final frontier no theorist has boldly gone before?

Thus I set out to systematically study the language theoretical physicists speak today: Quantum Field Theory (QFT) and General Relativity (GR). I managed to work through about 50% of the books, lectures notes and videos I had selected – then I tried to take combining anything too far and finally focussed on thermodynamics, solar and wind power and the smart grid for two years. By the way, my coffee reduction program came to a grinding halt as well as you have to drink coffee as a student who has to meet deadlines and submit assignments.

I am resuming the QFT / GR program now.

Popular physics accounts of quantum mechanics often make me cringe. It’s not that Schrödinger’s equation, the double-slit experiment and Schrödinger’s cat are invalid examples – they have great explanatory power in elucidating the inherent strangeness of the quantum world (This sounds like a clichéd blurb, doesn’t it?). But real interesting stuff starts where many particles are involved and/or particles are very energetic. And this is just not covered in the simple picture (the non-relativistic Schrödinger equation).
I have already ranted about that in my post Quantum Field Theory or: It’s More Than a Marble Turned into a Wiggly Line.

We had interesting discussions about MOOCs (Massive Open Online Courses) and I had complained about gamification. You might argue that working towards a degree and submitting assignments that get graded is the old-school version of gamification, and you might be right. I try to avoid gamification now. Though I will watch educational videos as supplementary material I will not sign-up for any course now, become part of a group or participate in anything that provides me with deadlines and with feedback. The discerning reader might argue that my public announcement of a private study program is just the same way of holding myself accountable.

I try to rise to the challenge of posting some ‘pop-sci’, math-free articles about QFT although or because I want to understand it at a fundamental level. What QFT adds to the spooky weird nature of quantum mechanics are several layers and concepts of mathematical abstractions. You can explain the Higgs mechanism and symmetry breaking by referring to a potential well shaped like a mexican hat and a small marble moving in its brim. But what kind of space is this, and what exactly is the ball?

I find these concepts most fascinating – because it is these abstract ‘hyper’ spaces where classical physics start to get as interesting and spooky quantum physics. QFT builds on Classical Field Theory, and the latter is underrated in terms of geek factor.

My program will loosely follow these lectures by David Tong. I picked those because lecture notes are available, too. Above all, I enjoy Tong’s blackboard & chalk presentation style.

I have found the first lecture also on Youtube though I prefer the formats provided Perimeter Institute (previous link), with the snapshots of the blackboard displayed side-by-side with the videos.

Science geeks and life-long education junkies: Do you prefer blackboard or Powerpoint?

 

20 thoughts on “And Now for Something Completely Different: Quantum Fields!

  1. I hate powerpoint. The course I had to take over last Mondya was entirely in powerpoint, and then students complain that you sometimes only read what is there. Of course I do, some slides only contain what is there, even less. I started the process of rewriting everything. I wonder whether powerpoint will survive my attack.
    Also hate flipcharts. No space, shaky, ‘out of paper’ problems …
    I used to love blackboards, but the chalk dust these days is bad for the skin on my hands, especially in winter.
    So I now have a preference for LARGE white boards and an arsenal of eco-markers.
    🙂
    I hate tests, exams and deadlines too !!!

  2. This sounds like an exciting adventure. I hope you will take the time to distill, for the Biologists who follow you, everything you discover and express the essentials in words of few syllables that we can understand. I would be quite disappointed if all of your future posts were simply out of my reach. I look forward to hearing about everything you think is interesting. I do NOT like PowerPoint and find that the blackboard has drawbacks as well … I tend to rely quite heavily on use of a SMART Sympodium. D

    • Smart Sympodium… learned a new term, thanks. I had to google that. Now I recognize it – I have never used one, I have only taught in rooms that were equipped with flipchart, beamer, and probably a blackboard.
      It is definitely my goal to distill what I learn to something suitable for a non-specialist audience. I used to entertain my colleagues and clients in IT with quantum physics “edutainment” in coffee breaks, so that’s about the audience I have in mind: People with any science / tech-related background / or simply very interested geeks 🙂 You are for sure part of the target group!

  3. Elke, with all the great physicists and physics teachers in this world it amazes me that there does not exist online an excellent quality set of physics lectures on all interesting topics. I believe it is mainly because universities and individual are more interested in competing with one another for prestige than they are in furthering the various fields of study.

    Technically this would be fairly easy to to. For any given lecture you would need a content expert–a professor, the assistance of someone skilled in graphics and layouts to ensure that the overall presentation is of excellent quality, and a small film crew. Post production would be very straightforward as you would only need to blend in the prof and the presentation amd, possibly, to remove the odd mistake.

    Logistically this would be straightforward: no one university needs to do it all. Just spread it around. For any given language, I bet any given university would only have to do one course if they would share.

    I am not suggesting this would be a replacement for live classes, but what a way to improve on things. Students would view the lecture online and then go to class for extra examples, help with questions and such. Everyone would win.

    IN a simpler way, of course, individual faculty members could do it all by themselves if they used something like Adobe Captivate, Techsmith Camtasia or FREE Camstudio. Many might appreciate a bit of technical assistance from a student assistant but that would not be expensive at all.

    Elke I looked at both videos again, this time to see what might work. Video 1 is very appealing but, of course, is far too simplistic. It could be made into something great, though. Video 2 is more in-depth but the audio quality is not good–you have to strain to hear what’s being said. The presenter’s handwriting is not good either and he has a very annoying habit of pacing in front of the camera. Both need outside help! The first could benefit from a sibject matter expert with more knowledge and the second desperately needed technical and production assistance. A decent camera crew would have fixed the audio and a decent producer would have coached the presenter to stop pacing and to write more legibly.

    As you can tell I really do not like chaulk: It is messy, unhealthy, hard to read because of poor contrast, looks like you’re ‘winging it’ and generally difficult to work with. I also don’t much like too many powerpoints as most are very crudely done: badly chosen colours, inconsistent formatting and layouts, too small fonts, too much information on the screen and, worst of all, they are generally a crutch for a badly prepared presenter. In good hands, though, they can be pretty good.

    Some day I would like to see a physics instruction system that plays out like “mass effect” or something like that. You get to choose which topic you want to explore, choose how to approach it and, best of all, get to interact with simulations. We are a long way from there though, sadly.

    • Thanks for your detailed expert comment, Maurice 🙂
      In defense of video 1 – MinutePhysics is created for a lay audience. I could just not resist adding it because I like the cartoons so much 🙂
      I would not rely on videos as a primary source of information – not in theoretical physics (especially when it is not “computational physics”). You need to walk through the text book and bang your head against the wall then trying to follow each step or on solving problems. Videos in this context are great for concepts in my opinion (‘Feynman-style’).

      I feel that the videos available – imperfect as they may be – give students the false impression that it is possible and easy to learn something heavily math-based from “watching only”. I have often read statements like this in discussion groups: “I am a high school student / freshman / I self-study physics… and want to specialize in string theory. I think I know everything about the concepts and the math (sic!) already because I watched all related videos on MIT Open Courseware / Khan Academy / … ”

      In case of video 2 (and the related lecture) I found it useful to understand some concepts (this first lecture is a good example), but it is getting less and less useful the more detailed the derivations become. You watch somebody writing large integrals on the blackboard that can be followed more easily when you see the whole thing in a PDF document in front of you.
      To be fair, this video was not intended to provide an “online course”. It seems that they tried to record a lecture that was primarily intended to be a traditional classroom lecture. We are also missing the problems mentioned in the lecture. I assume these lectures are provided as part of an “outreach program” to “the public” – without having a target audience defined. I think you familiarize yourself with related material before you watch a video. There should be disclaimer somewhere saying: “Please don’t confuse this video – provided “as is without warranty” with a carefully designed curriculum.”

      Having said that, I have read about MOOCs that really seem to “work” better – by providing real assignments for example (working online with an equation editor). But this is exactly what I want to avoid – no deadlines, no assignments set by somebody else than me. So I deliberately picked the less perfect “course” consisting of different books, lecture notes and videos. I feel you learn a lot from “switching professors”, in particular if there are very different ways to present the material and such “philosophical differences” (path integrals versus canonical quantization)…

      • You are still absolutely right on the two most important points:
        1–we do wrong when we try to make it all easy because it most definately is not! Even the fundameltals, say, Newton’s laws. How I cringe when I hear a young physics teacher arrogantly say they are really ‘easy.’ They most certainly are not!!!! Anyone who says that clearly does not understand them at all–or is simply lying.
        2–you cannot learn from simply watching someone. That’s a good way to get started or to get help if you are stuck. You only learn when you work through it yourself.

        • Thanks again, Maurice! I fully agree – so-called fundamentals are deceptively simple. But that’s the reason why science shows on TV are so successful – baffling the audience by demonstrating very often “simple” laws in mechanics or hydrodynamics. My favorite is “Helium balloons in an accelerated car” 🙂

          • One of my profs took a group of fellow teachers (sadly I could not go) down to the Kennedy Space Centre to watch one of the shuttle liftoffs. On the way back the guys–all physics teachers–were arguing about what the balloon would do as the jet accelerated for takeoff. Harvey convinced the airline to let him take a helium balloon on board the plane on the way home… 🙂

    • “things nobody needs to remember later” …. I like this 🙂
      Structure – true! I am usually tempted to stray from my own agenda when I only use flipcharts or the blackboard.

  4. I’m so old that the only correct answer has to be black board. (I feel so wicked admitting to that.)
    Also, today is a busy one, so I will return and mull over the physics when I can enjoy the learning process at my own pace. Thanks for a geeky science post! I always feel I’m on the verge of brilliance when you post these. 🙂

    • Thanks, Michelle – but I did not really include much substantial physics yet in this post. This is the trailer for my upcoming QFT episodes! 😉

      Re blackboard versus PP I tend to pick PP as a presenter avoiding the chalk dust everywhere – but I love watching presentations on blackboard. My favorite as a presenter is probably the flipchart (should have added “other” as an option).

      • Argh, I deleted my reply. I was trying to say that I hadn’t watched the videos yet… you’re very clever to give us a primer before hitting us with the hard physics. 🙂

  5. Powerpoint is like Schrödinger’s Cat; equally alive and dead. A PP is the only thing which is seen and forgotten at the same time.

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