I have been blogging 'seriously' about physics since 2012. My motivation has been a blend of jotting down notes on interesting things I've just found, conveying my decades-old fascination with some phenomena, trying my hands at popular science writing, and reporting on my own research.
Today I am asking myself - did I learn anything from that on a meta level? To read myself, I am re-arranging the list of my physics posts and sort them by topic and sub-topic. The list says it all, I think.
I wanted to write about quantum mechanics, but it seems I was always most intrigued by classical mechanics, statistical mechanics, and thermodynamics. The latter has become my true home in physics - which has come as a surprise to myself. Yes, thermodynamics is my specialization, but years ago I rather figured that this is my job, and I rather want to follow the latest news on quantum information and particle theory in my spare time. It turned out that I am more interested in history of physics and in the evolution of concepts that are now 'well known'.
My recurring meta-topic is that classical mechanics / thermo can be as interesting, 'geeky' if you wish, mathematically 'weird', and surprising as fields that seem to be more popular.
This list may remain a static snapshot. I am editing the chronological list of my physics posts here on the blog. This list might lseem to lack some of my more applied / engineering postings, re our heat pump system and data. These are here.
Thermodynamics and Statistical Mechanics
Concepts and foundations
Random Thoughts on Temperature and Intuition in Thermodynamics
Time evolution of systems in phase space: On the Relation of Jurassic Park and Alien Jelly Flowing through Hyperspace.
Phase-space in depth: Hyper-Jelly – Again. Why We Need Hyperspace – Even in Politics.
Carnot’s efficiency, irreversibility, proof by contradiction, paradoxes: Re-Visiting Carnot’s Theorem.
Mathematics used in statistical mechanics: Spheres in a Space with Trillions of Dimensions.
Heat pump basics
Brief explanation, absolute temperature:
Why Do Heat Pumps Pump Energy so Easily?
Coefficient of Performance of a heat pump: An Efficiency Greater Than 1?
Cross-check of numbers for a large heat pump system: Pumped Heat from the Tunnel
COP versus Performance Factor: How to Evaluate a Heat Pump’s Performance?
Energy accounting, economics: Heat Pump System Data: Three Seasons 2012 – 2015.
Heat conduction, diffusivity, latent heat:
Storage Challenge: High Score!
Heat conduction, heat equation: Temperature Waves and Geothermal Energy.
Heat diffusion length: Rowboats, Laser Pulses, and Heat Energy (Boring Title: Dimensional Analysis).
Simple version, daily energy balances:
More Ice? Exploring Spacetime of Climate and Weather.
Heat transport, energy balances. Simulations versus simple energy accounting: Ice Storage Hierarchy of Needs.
Detailed version: Heat exchangers, heat equation, 1-minute time slots: Simulating Peak Ice.
Thermodynamics and energy basics, dimensional analysis
kW and kWh.
No, You Cannot ‘Power Your Home’ by One Hour of Cycling Daily.
Phase transitions, ideal gas law (pressure sensor) Mr. Bubble Was Confused. A Cliffhanger.
kWp, power, energy, energy flow: On Photovoltaic Generators and Scattering Cross Sections.
History and inventions
Einstein’s Refrigerator and other inventions:
Einstein and His Patents
Centennial light bulb, sustainability: 111 Years: A Shining Example of Sustainable Product Development?
Checking 19th century papers: Peter von Rittinger’s Steam Pump (AKA: The First Heat Pump).
Phase transitions of water, Mpemba effect: A Sublime Transition.
By an Austrian start-up – pressure gradient created by centrifugal forces: And Now for Something Completely Different: Rotation Heat Pump!
(I realize that some of my articles in the 'engineering' category would also qualify for this sub-category History. For example: I wrote a - less detailed - post on Rittinger's steam pump before. But part of the fun with these list is that you have to take those hard decisions of tagging ...)
Classical Mechanics and Fluid Dynamics
Equations of motion and Lagrangian formalism
Principle of Least Action.
Sniffing the Path (On the Fascination of Classical Mechanics)
Equation of motion, intuition in physics: Are We All Newtonians?
Motion of a falling slinky spring: The Falling Slinky and Einstein’s Elevator.
Principle of Least Action, again – extended version: Space Balls, Baywatch and the Geekiness of Classical Mechanics.
From Newton’s Law to Navier-Stokes Equations: Non-Linear Art. (Should Actually Be: Random Thoughts on Fluid Dynamics).
Estimates related to the physics of scything:
Grim Reaper Does a Back-of-the-Envelope Calculation.
Back-of-the-envelope cross-checks, hydro power: All Kinds of Turbines.
Torque, forces, precession, nutation.
The Spinning Gyroscope and Intuition in Physics.
Another way to explain how the gyroscope works: Intuition and the Magic of the Gyroscope
Coriolis force (1): The Twisted Garden Hose and the Myth of the Toilet Flush:
Coriolis force (2). Lest We Forget the Pioneer: Ottokar Tumlirz and His Early Demo of the Coriolis Effect.
Physics and geometry
My first (later corrected) proposal of a solution:
Physics / Math Puzzle: Where Is the Center of Mass?
Correcting my earlier proposal: Revisiting the Enigma of the Intersecting Lines and That Pesky Triangle.
Newton’s geometrical proof of Kepler’s laws: Mastering Geometry is a Lost Art.
Quantum Mechanics and Quantum Field Theory
Interpretations of quantum mechanics:
Is It Determinism if We Can Calculate Probabilities Exactly?
Quantum Mechanics versus QFT: Quantum Field Theory or: It’s More Than a Marble Turned into a Wiggly Line.
Started a series: And Now for Something Completely Different: Quantum Fields!
Summary on QM: May the Force Field Be with You: Primer on Quantum Mechanics and Why We Need Quantum Field Theory
Quantization – starting from statistical mechanics: On the Relation of Jurassic Park and Alien Jelly Flowing through Hyperspace.
Path integrals and symmetries: Learning Physics, Metaphors, and Quantum Fields.
Book review: Student Friendly Quantum Field Theory.
Electromagnetism and special relativity
Unification of Two Phenomena Well Known.
Charged particles lose energy when accelerating: Why Fat Particles Radiate Less.
An alternative way of understanding SR: How to Introduce Special Relativity (Historical Detour).
List of resources: Learning General Relativity.
Using physics-like methods in economics and sociology
Networking theory, instabilities:
Theory and Practice of Trying to Combine Physics with Anything
E-Mails and communications: Using Social Media in Bursts. Is. Just. Normal.
‘Philosophical’: Learning physics, culture
On trying to explain physics without math:
Real Physicists Do Not Read Popular Science Books
Re The Trouble with Physics by Lee Smoli:. I neither Met Newton nor Einstein
On learning physics. Stupid Questions and So-Called Intuition.
Re Margaret Wertheim’s Physics on the Fringe Physics Paradoxers and Outsiders.
Physics as Therapy (1) In Praise of Textbooks with Tons of Formulas (or: The Joy of Firefighting).
Physics as Therapy (2) Ploughing Through Theoretical Physics Textbooks Is Therapeutic.
This website shall finally reconnect with its roots – radices.
With the dawn of the new millennium a self-proclaimed Subversive Element has registered a bunch of domains. It was especially fond of radices.net and subversiv.at. Today, all these sites have been re-united and redirected to elkement.subversiv.at. But the site does not deliver on its promising name – I feel it became way too 'professional' recently. Historical content has been filed mostly under Physics (radices) and Art (subversiv). The category life displays some of the matter-antimatter collisions of these two worlds. Which also explains the category of the current article.
The Subversive Site was a Red Padded Cell, with Font Color = White, a so-called creative playground. The Element was aware that 'everybody' could read this but it did not care. The Merger of the sites was inevitable in the end, after a final detour of professionalization – when radices.net suddenly also hosted pages with IT Security links.
I have been a blogger, and I observed the evolution of other blogs: My anecdotal evidence shows that blogs live for about 1-2 years. If they are bound to survive they have to escape the matrix and to overturn their creators. A personal blog or website needs a 'Big' Idea. OK, not really big, but at least a-all-encompassing and abstract enough so that all the authors different threads and lines of thoughts can be silently tied together using this idea's magic glue.
My elkement.blog is relentlessly edited. It was a more philosophical site once, but I aim at following our punktwissen principles now. Articles should be concise, provide value, and perhaps also entertainment. There should be s logical connection between posts and my curated lists should help readers to find something 'useful'.
On the contrary, this site has more or less the same article over and over again – perhaps in disguise and interlaced with technical notes. It is all about my personal keeping the essence of Physics alive and useful for me. Since radices was originally a German-only science and philosophy site, the English version might not reflect this – but in the early articles on elkemental Force (at that time: Theory and Practice of Trying to Combine Just Anything) I recaptured these ideas.
So I do finally accept this – let elkement.subversiv.at have its way. This is elkement's personal site, and its primary topic is How To Learn About Physics And Why This Might Be Useful Or Even Edifying In Very Different Ways.
- Learning physics means to start somewhere in the middle. That's why a first Introductions to Physics lecture is always hard (if the lecturer has some modest mathematical aspirations). You need to look at the same phenomena from different angles, and only after a while – and some work – everything will fall into place. This process and journey of learning is rewarding in itself.
- The more related to mathematical foundations (of physics) a question is, the less googleable the answer is. You can find anecdotes, and examples, science sound-bites for entertainment. Of course you find awesome lecture notes to learn the fundamentals from Feynman Lectures to Landau-Lifshitz – but you need to 'learn' them. In contrary to the mantra of You Just Need to Know Where to Find Something (like: Google for error messages) I believe that really knowing about fundamentals without googling helps a lot with problem solving: You can walk through how a system should work, just using the resources in your head.
- Mathematics purges the brain, and this does not only help with mathematical problem solving. So I believe that the hackneyed problem-solving skills of science graduates are real (albeit it is difficult to assess the self-selecting nature of STEM degrees for people with natural 'analytical' skills). But the caveat it: Years of corporate work, powerpoint slides, office politics, distractions, pressure to deliver ad hoc can erode these skills. I have long-term tested different methods to keep physics knowledge alive and usable - and learned now that science might even provide some evidence, in a sense.
- I have been in 'cyber security' for a while and I have written lots of gloomy articles about our new smart world of automation and where everything (including heating systems) is turned into cloud-based services. Thoughts on all of this is still work in progress, I am working on internal consistency and unambiguity. I came into the world of IT as an experimental physicist, I was applying my training of troubleshooting complex 'analog systems' to digital systems. Despite the myth of crystal-clear 0s and 1s it was often better to treat them as blackboxes. I lacked the typical computer nerd's / enthusiast's background and started late – playing with Microsoft systems and Office VBA and the like. In spite of this Treat-as-a-Blackbox approach I like to understand as much as possible about a system. Yes, I know you cannot understand, yet build, a power plant, from knowing how to solve Maxwell's Equations (yet understand or solve issues in cyber security related to such power plants). Nevertheless, if I have the choice to understand something at all, I'd pick Maxwell's Equations.
Since years I am using an (angry) dinosaur as my web and blog logo. The dinosaur is from another era, and sometimes it cannot deal with 'modern' concepts of our 'smart', 'networked' world. But perhaps, it was part of this world for a while in order to overcompensate.
Now the dinosaur is getting more and more confident that its typical dinosaur activities might be more productive and positive than it thought before.
I have written about all things physics for a long time - mainly on my blog, since 2012 – but I have never been quite satisfied with the result: Too boring for experts, not exciting and popular science-y enough for the 'educated public'. I think the reason was my hidden agenda, an agenda not even obvious to myself.
I wrote about phenomena and subfields I had just immersed myself and (re-)learned about, either because this was very remote from what kind of physics I use on a daily basis, or just because I was concerned with some aspect of it but wanted to complement that with 'more theory' for the fun of it.
In spite of that, I tried to keep a style that somewhat resembles your typical 'science communications', but that was most likely to no avail. Re-reading my old blog posting I don't read so much about 'the physics' as about my own learning process. Or I remember what I actually wanted to write about, but did not – in order to violate the pop-sci agenda - so the result was something in between a learner's notes and sketches of ideas for popular presentations. For example, I (re-)learned Quantum Field Theory after all the news about the Higgs particle and LHC. Both my experimental and theoretical background was in condensed matter physics, so it really took me a while to map what I learned about so-called Second Quantization and many body systems (described in a non-relativistic way) onto your typical QFT introduction that started with Noether's Theorem and Lorentz transformations. Now in order to drive that point home (in a blog posting), to explain what was so interesting for me, I would have had to introduce all those concepts to a lay audience which I considered futile. Or I was just too lazy to learn more LaTex or too hesitant to use equations at all. I noticed, I got on all sorts of tangents when I tried to run a series on QFT – I did exactly what I did not like myself about popular texts on theoretical physics: Pontificate on more or less palpable metaphors about fields and waves, but not being able to really explain anything above a certain threshold of abstractness.
I gave up on my series before I could 'explain' what interested me most: How forces translate into the exchange of virtual particles and how I actually knew about the 'Higgs field giving particles mass' without knowing any more: I had learned about Andersen's mechanism in solid state physics, and Ginzburg-Landau theory of superconductivity. Perhaps that would have been a great example of symmetry breaking and that infamous sombrero hat potential typically used in pop-sci articles about the Higgs field?
I absolutely know that this may sound totally opaque – which is the reason why I only write about it here, on my website in that forgotten corner of the web, rather than trying to turn this into a blog post. Here, I follow my stream of consciousness and don't bother anybody on social media with it. There, I try to be somewhat entertaining and useful.
But even here, I try to write about something that somebody somewhere might be able to relate to, and here 'the internet' comes to rescue: For better or for worse, no matter how seemingly unique, special, and eclectic your hobbies and professional specializations, are – there is somebody somewhere on the net who indulges in the same combination of stuff. So, yes: It seems there is a growing community of hobbyist physics enthusiasts who feel the same and who 'practice' physics in the same way: Professionals with a STEM background who seriously learn about physics in their spare time, like R;&D managers writing textbooks about undergraduate physics or introductions about Quantum Field Theory. Like the IT server admin or the management consulting who write blog posts about what they have (re-)learned in their sparse spare time. Like the retired IT specialists who returns to what they originally studied – physics. Like me, who has an education mainly in applied condensed matter physics and who works as a consulting engineer and IT consultant.
From a down-to-earth perspective, this hobby can be worthwhile and useful: I noticed that it sharpens the mind, even if I don't use that physics and math directly on a daily basis. It's this effect that is makes the hackneyed saying about the 'analytical skills' of physics majors true. However, there is a caveat: Yes, physicists may be good at any corporate job, but I think not to lose you 'analytical edge' you need to practice the skills that originally shaped your mind. I don't know about research in psychology, so this is just my personal anecdotal experience. Living the corporate, inbox- and interrupt-driven work-style and having your mind scattered and distracted my social media does not help. There was a time in my life when I got up at 4:00 AM every day to re-learn physics, starting with Feynman's Physics Lectures. Surprisingly, that investment was well spent. I felt, my IT security concepts become crisper, more concise, and better – and it took me less time to compile them; So the ROI was great.
What triggered this article is my prime example of useful mathematical: While I had some background in QFT there was one subfield in physics I had missed completely: the theory called 'most beautiful', even by sober authors Landau and Lifshitz – the theory of General Relativity (GR). I had specialized in solid state physics, lasers, optics, and high-temperature superconductors, and GR was not a mandatory subject.
But I wanted at least to understand a bit about current research and those issues with not being able to unify quantum (field) theory and relativity. And I can relate to poor consumers of my feeble attempts at pop-sci physics: When I read popular physics books, I enjoy them as long as I have some math background - although I feel sometimes flowery metaphors make it more difficult to recognize something you actually know in terms of math. But when you would have to use new mathematical concepts you cannot understand the metaphors at all. Digression: So it baffles me when people like articles about Black Hole, the universe, and curved spaces but complain about not perfectly comprehensible explanations of more mundane physics and engineering. I believe the reason is that you 'need not' understand worm-holes etc.; so can just relax and scroll through the story, much like watching an illogical science-fiction movie. But mechanical engineering and simple thermodynamics feels like you 'should know it' and 'try a bit harder to understand it', and so it brings back memories of school and tests.
But as I said, there might be small community of people who genuinely want to learn, despite – or because of!! – the so-called hard aspects: Going through mathematical derivations again and again, and banging your head against the wall, until suddenly you understand. Which is a reward in itself, a feeling that's hard to share, and could and should not be shared anyway – in an act of subversive protest against our culture of craving for attention and 'likes'.
So for this community I'd like to share the resources I have picked for learning General Relativity: A set of free resources, each one complete and much more than just 'lecture notes'. Each of them also represents a different philosophy and pedagogical style, and I believe physics is learned best by using such a diverse set of resources.
One can debate endlessly, if and how to introduce the mathematical foundations used in some subfield in theoretical physics. As a physics major, you learn analysis and linear algebra before tackling its applications in physics and/or some mathematical tools are introduced as you go (Hello, Delta function!). I think it does not make such a difference in relation to the first courses in theoretical physics, e.g. learning about vector analysis before or in parallel to solving Maxwell's equations.
I feel it is more difficult the more advanced the math and the physics get, as you have to keep a lot of seemingly abstract concepts in mind, before you finally are presented with what 'you actually use that'. But maybe it is just me: Different presentations of GR seem 'more different to me' than different presentations of special relativity and electromagnetism.
In GR you can insist on presenting a purely mathematical and rigorous introduction of mathematical foundations first – your goal being to erase all false allusions and misguided 'intuitive' mental connections. Thinking about vectors in a 3D 'engineering math' way might harm your learning about GR just as too creative science writing might put false metaphors in your mind.
On the other hand, you could start from our flat space (our flat spacetime) and try to add new concepts bit by bit, for example trying to point out what curvature in 4D spacetime means for curvature in the associated 3D space, and what we might be able to measure.
Some authors use a mixed approach: They starting with a motivational chapter on experiments, photons in an elevator, and co-ordinate transformations in special relativity … and then they leave all that for a while to introduce differential geometry axiomatically … until they are back to apply this something tangible … until more mathematical concepts are again needed.
Sean Carroll does the latter in his Lecture Notes on General Relativity, that are actually much more than notes. He also published a brief No-Nonsense Introduction to GR that serves as a high-level overview, and he manages to keep to his signature conversational tone that makes his writings to enjoyable. Perhaps – if this was the only literature used – the mixed presentation plus digressions into special topics and current questions in physics would be a bit confusing.
But I was still searching for video lectures to complement any written text. A few years ago, I have not found any comprehensive self-contained course, but in 2015 this series of lectures was published, recordings from an event called the Heraeus Winter School on Gravity and Light 2015 – marking the 100th anniversary of Einstein's publication of GR. A nostalgic factoid I found most intriguing: The central lecture of the course by Frederic P. Schuller was given in the very lecture hall at my Alma Mater (Johannes Kepler University of Linz in Austria – JKU) that I received my education in Theoretical Physics, by Heisenberg's last graduate student Wilhelm Macke. Tutorial sheets and video recordings of tutorial sessions can be found on the conference website.
Schuller focuses on the math first, and this was really enlightening and helpful after I used other resources based on mixed intuitive physics and math. The Youtube channel of the event also has recordings of Tutorial sessions, and I found some versions of brief lecture notes. I think this is a must – and unfortunately often overlooked or downplayed in the world of free 'MOOCs'- In order to learn math really, you need to do problems and you absolutely have to walk through every single step of every derivation. It is tempting to just skip the boring proof in a text (that you thought you understood), and it is even more deceptive to watch science videos and believe you understood something. So thanks a lot to my former university to make this course available to the public.
But I was still curious if you can do without manifolds and stuff – without cheating – and I think I found the master of the genre. And again it is a signal from the past (my past): I had looked things up in Landau/Lifshitz Course of Theoretical Physics when I worked at the university. But as the 10 volumes were quite expensive I never bothered to purchase them later. Recently I jumped with glee: Due to whatever quirk in copyright law, the Internet Archive made 9 of 10 volumes available, and I downloaded them all. Browsing through table of contents I noticed that GR was actually explained in volume 2, The Classical Theory of Fields. I am totally smitten by their style, too: Elegant, terse, detached. Much like Dirac's Principles of Quantum Mechanics. And I don't agree with those who say that the explanations are too terse: Landau and Lifshitz try to stay to tangible physics, and they use math in an ingenious way, mathematicians might call it sloppy (like: 'dividing' by differentials to yield a derivative). For that reason, one should consult other resources as well, but I think LL's GR is self-contained.
These books and videos will keep with busy for a while. I also try to interlace it with a bit of QFT again, e.g. by reading Dirac's version of it. My goal for next year is to complete first courses on GR, recapitulate what bit of QFT I learned in 2013/14, and then tackle an actual former specialty again: Re-learning about theories of superconductivity, with an emphasis about how these methods are also used in particle physics.
It might be dangerous thing to announce such grand plans on the web. But next year might be a busy one business-wise, and need to braze myself accordingly.
I renamed my blog elkement.wordpress.com last November:
Theory and Practice of Trying to Combine Just Anything
The original tagline was
Physics versus engineering
off-the-wall geek humor versus existential questions
IT versus the real thing
corporate world's strangeness versus small business entrepreneur's microcosmos, knowledge worker's connectedness
versus striving for independence.
until it became
I mean it
and finally turned into
Research Notes on Energy, Software, Life, the Universe, and Everything
This means that my blog elkement.wordpress.com has found its purpose, and I am able to distinguish blogging better from publishing to this website elkement.subversiv.at. My actual research and 'science writing' is featured on my blog. Over there I am using wordpress.com features I have no desire for developing them myself for - and this website will remain my 100% home-grown self-developed pseudo-blog with a very limited feature set and no interactivity. The blog has LaTex support and allows me to present galleries of technical figures and diagrams.
These recent blog articles showcase what elkemental Force has been and is covering now (the end of a journey that started already two years ago - when heat pumps and thermodynamics replaced quantum physics):
My personal website, on the other hand, should be just this: A more self-indulgent site that provides status updates, meta-information and About-Me-style summaries. Because of that I will keep not sharing articles here to any social network.
And so yes: The hands-on engineering, physics, math and data analysis will be done over there on the blog. But there really are personal meta-thoughts on physics - so I don't have to change categories here.
(Theoretical) Physics and Me
Over the Christmas holidays I have been nearly offline from social media. I used the internet as I believe it was intended for me: To learn about something in depth and not necessarily sharing my insights or my 'progress'. I indulged in theoretical physics lectures just for the joys of it. I can rationalize: Yes, a bit of mathy gymnastics also serves me well when I deal with more mundane physics as a professional - such as toying with the heat transport equation.
But the real reason is unrelated to work: Theoretical physics and mathematical modelling of a small part of a complex world gives me the pleasure - and/or the illusion - of being able to understand and solve, well, something. Whenever I had been very stressed out in the past, close to burn-out, I got up even earlier - as 4:00 AM sometimes - to plow through Feynman's Physics Lectures or my favorite German volumes of theoretical physics by my late professor, W. Macke.
Not only did it help me to focus onto abstract details of a logical clear universe and to enter a more detached state of mind, but amazingly it also made me work more efficiently and focused later - on whatever technical challenge I had to solve. In those days, I was mainly concerned with Public Key Infrastructure, networking security, and applied cryptography.
With hindsight - and hopefully not too much hindsight bias - I feel that a rigorous training in a mathy subject boosts your results in any endeavor that needs an analytical approach. Perhaps only your physics training makes your realize that you need a more analytical approach at all, in addition to soft skills, practice, and familiarity with culture in certain industry sectors. I am thinking about project management, for example.
I believe that in any 'STEM' job, e.g. in IT, it is soothing to re-learn fundamentals often. One should know more than seems necessary about 'theory', before or in addition to knowing how to google, where to look up things, or whom of your tech buddies to call. Success in technical troubleshooting always gave me most contentment when I was doing it in my head mainly - like walking through a networking protocol the way it was designed, comparing that to messing reality, and uttering an educated guess about the root cause of an issue which was finally correct.
Whenever I had been blogging about a field of physics not related to my work - like quantum field theory - it was these mental connections I had in mind. I was trying to convey the joys of physics, but my main focus was different from most science writers' ones, so I think my writing was not engaging enough for the interested lay audience and sometimes oblique owing to too much references to math (whereas it was very basic for experts, of course).
My science writing is often a covert and feeble attempt to encourage others to tackle the real thing, that is the fundamentals and the math, and then to feel the same effects. I have seen that more books seem to have been released recently that try to bridge this gap between classical science writing (following the mantra of: Every formula will half readers) and text books.
I want to be part of that movement.
Today I am writing articles on physics mainly on my English (elkement's) blog and our German (punktwissen) blog. This site (and its precursor, radices.net) help me with curating the links to my English physics postings.
All English postings written to date are displayed below, in decending order, from the Physics category's feed on my blog.
While I gravitated against quantum theory and the connection between physics and philosophy in 2012 and 2013, I finally switched to more hands-on applied physics in 2014. Before I have done 10-15 years of soul searching; some of these posts from 2012-2013 give prove of that.
I am running a small engineering consultancy together with my husband. Following Star Trek terminology, he is Chief Engineer, and I am Science Officer.
In overly correct legalese, my job titles according to our business licences are 1) Consulting Engineer in Applied Physics and 2) IT Consultant.
We specialize in planning of heat pump systems with unconventional heat sources, that is a combination of an underground water tank and an unglazed solar collector. 'IT' means: playing with control units and data monitorin.
As we run a German blog focused on this system and I also devote a 'sub-division' of my English blog to it, I use this site (radices.net) mainly for consolidating resources and links - in the same way as I curate security / PKI related links. Perhaps these link dumps will not be very useful for anybody but myself.
I once was a laser physicist and a materials scientists - my specialties having been high-temperature superconductors, laser-materials processing with Excimer lasers, and the microstructure of stainless steel. Then I turned to IT security, IT infrastructure and IT management for more than 10 years.
In 2012 I felt the urge to reconnect with my roots as a scientist and engineer, and we started working on our own heat pump research project in stealth mode. It turned to a second 'branch' of our two-person business. There are connections between my different fields of expertise - IT security and heat pumps - like: the security of the smart grid, 'hacking critical infrastructure', monitoring and control systems. Even the data we gather with our pilot setup have turned into 'big data' that require analysis and management.
So I am actually more of an engineer than a physicist. But I am still very interested in theoretical physics as sort of a mental exercise, and I indulge in reading textbooks as hobby. In 2013 I had focussed on (re-) learning quantum field theory.
Since 2014 I am mainly blogging on down-to-earth classical mechanics or thermodynamics, and I enjoy doing cross-checks and back-of-the-envelope calculations on my blog.
Heat pump usage in different countries and history of heat pumps
- Swedish Ground Source Heat Pump Case Study (2010), by GNS Science (New Zealand based consultancy)
- History of heat pumps - Swiss contributions and interntional milestones, by Martin Zogg, Process and Energy Engineering
Unusual heat sources
- Aquifer at Oslo Airport
- (Former) Cisterns - a paper documenting research done in Iowa in 1993. I have also summarized the paper in this blog post.
Sizing heat pumps - I am trying to learn the terminology of standards commonly applied in English-speaking countries:
Power grid and availability
- March 20 (2015) Solar Eclipse - a challenge for European Transmission System Operators: Announcement by ENTSO-E, Analysis by US-based company, success story. Electricity production in Germany (select week 12 of 2015) - the dip in March 20 is visible.
- Squirrels a major issue for the power infrastructure of the US: Squirrel Power!
- #DarkNL - outage in Newfoundland and Labrador, Canada in January 2014.
Hydro power plants
In Sweden the world's largest pumped hydro storage plant might be built:
- See bottom of page 30 of
this research paper:
Besides the official estimations there are some discussions [28b] about building pumping capacity between the lakes Vänern and Vättern in Southern Sweden. The difference in altitude is 44 meters between these lakes.?
- ... and the
last page of this presentation:
Possible future? Mariestads Kraftverks AB & others 50 km tunnel between the lakes Vänern & Vättern Cost: 250 billion SEK. Installed capacity: 50000 MW .
Free long-term weather data
Inputdaten für eigene Simulationen.
Germany and Austria.
- FTP server of the German weather service. Extensive and detailed datan, e.g. ambient air temperatures, for some locations since 1950!
- Annals by ZAMG - Austrian national weather service. Daily averages since 1994 as CSV files (only if you pick the link for German readers. The EN version still links to data in the older HTML format that requires you to run a browser in compatibility mode.
- Climate data for the last decades. The navigation is something you need to get used to (Pick: Cities, Climate, Climate Robot...). Therefore I start with Ice Days for Vienna. It is a bit weird that available data seem to depend on the choice of the language (less data for Vienna in English).
The winter 1962/63 was the coldest since 250 years in Europe (German article:
Winter 1962/63 in Europa. Englisch article:
Winter of 1962–63 in the United Kingdom).
More data from a talk / slides avaiable at the website of the Royal Meteorological Society: The bitter winter of 1962/63 - this winter was unusually mild in Canada and Greenland (p.17)
Could such a winter ever happen again? "The 1963 winter is well within the population of other cold winters that have been experienced in this country ... It is not necessary therefore to seek some very special cause in order to explain it." – H.C. Shellard , Meteorological Magazine , 1968 (p.21 of PDF)
Different heating systems
Statistics for Austria: Heating 2003 to 2012 by fuels used and heating system (in Austria). Less than 15% of (primary) heating systems are stoves, and they have been on a decline in the last decade.
Units, heat values, energy costs
Tools for converting units
- Heizwerte von festen, flüssigen und gasförmigen Brennstoffen auf Wikipedia.
- Heat values of different varieties of wood, per cord.
- Energy Content in Common Energy Sources (engineeringtoolbox.com)
Properties of water (for comparing the energy stored in a water / ice tank)
- Interesting properties of water as per Wikipedia: Specific heat, density.
- Thermal properties of water (engineeringtoolbox.com)
Costs of energy - international
- Photovoltaic systems are more expensive in the US than in Germany (2014), despite prices have dropped.
- Comparion of costs of kWh electrical energy worldwide. Costs seem to be much lower in the US and in Canada than in German. This article about the details of a typical US electrical bill implies that there are delivery fees on top of energy fees. On the other hand, the value for Germany seems to include anything.
Monitoring, Control, IT
Metering and monitoring electrical power consumption
- Smart meters with data loggers and/or various interface for attaching
loggers - to be installed behind the official smart meter:
- EMU Professional, different types available with different interfaces such as M-Bus, Modbus TCP and RTU, HTTP, included logger.
- Specification of the EMU meter's Modbus RTU interface.
- EM Series by B-Control / TQ-Systems (The SMA Smart Meter is an OEM meter of that type): EM210 has a web server for online monitoring and stores log files, EM300 supports real-time logging via Modbus RTU, Modbus TCP and a simple HTTP interface (but does not store log files, and uses the web server for configuration only).
- Parsing an online monitoring website is perhaps the most universal 'real-time protocol' in case not other interfaces are available. E.g. by using Powershell, I tested with the local website of a Fronius Symo inverter and their web portal www.solarweb.com. One option: Start an InternetExplorer.Application comobject and identify the html containing the interesting value per its ID (getElementById).
Manuals of data loggers by Technische Alternative Gmbh (for control units UVR1611, UVR16x2)
- C.M.I - Control and Monitoring Interface
- BL-NET Bootloader
- Logging with CMI and BL-NET on the same CAN bus in parallel is not supported.
- Bus topology. Note that UVR1611 is automatically terminated by default.
Heating with computers
Computers installed in private homes provide their computing power to cloud services - while heating those homes.
- Paper presented at the conference Hotcloud 2011: The Data Furnace: Heating Up with Cloud Computing.
- A prototype based on a similar idea, in need of crowdfunding, 2015: Project Exergy wants to build a home computer that also heats your house.
Basics (Physics) - Mechanics, Electrodynamics
The Feynman Lectures of Physics
Explaining science and technology is my passion and my mission - as a physicist, engineer and IT expert.
All children are curious scientists: We want to know 'how stuff really works'. However, in science education answers are finally given in the language of mathematics - which might kill curiosity.
I admit that I can indulge in math at times, just for the sake of it. Theoretical Physics was my personal therapy in fighting the detrimental impacts of having been sucked into Dilbert's (corporate) world once.
Nevertheless, I understand your discomfort - math haters / deniers. Fundamental theories in physics, such as string theory, seem to have developed a purely mathematical life of their own. Algorithms loom large: Corporations dig Big Data to predict our behaviors as consumers, and of course there is the NSA. And Facebook ads.
Thus I am determined to dissect and expound scientific underpinnings of, well of basically anything interesting I come across in physics, engineering or IT. As an IT consultant I sometimes gave stand-up quantum physics edutainment sessions in coffee breaks. So you are my target group: Experts in any science-y, geeky, technical or other quantitative field.
I am indecisive: shilly-shallying between excitement about curved space-time and multiverses on the one hand, and focusing on hands-on research and development from whose impacts we - taxpayers, John and Jane Does - will benefit in our lifetimes.
Currently my (science) writing is focused on
- Quantum Field Theory. When the Higgs boson was discovered in 2012 I realized that I cannot make head or tail of how the Higgs field gives the other particles mass. Based on the theory of superconductivity and phase transitions I had once been exposed too - I actually should have. Thus I am set to (re-)learn QFT.
- Thermodynamics - this is were fundamentals (entropy and the arrow of time) meet hands-on engineering (heat pumps).
And I am pondering on:
- classical physiscs and its underrated geek factor Why does a spinning top not fall over? Is it true that the sense of rotation of vortices in water flowing down the sink of your bathtub or toilet flips at the equator?
- the philosophical implications of different, but yet mathematically equivalent theories: This holds for quantum mechanics and determinism, but also for classical dynamics. The principle of least action adds a touch of multiple universes to Newtonian mechanics.
- how physics tools are used to model complex systems, such as the economy and stock exchange prices or how revolutionary ideas percolate society.
- the illusion of intuition in physics and related philosophical ideas: The Spinning Gyroscope and Intuition in Physics, Are We All Newtonians?
- Power engineering and the implications of 'internet-icizing' the smart power grid: Greatest Innovation Ever, Controlling the Four Elements. Or: Why Heat Pumps Are Cool.
- History of science, old patents and inventions in particular: Einstein and His Patents.
- Information technology and IT security. Cyber Security Satire?, My Google Searches Might Heat Your Home.
- how orthodox science relates to outsider physics: Physics Paradoxers and Outsiders.
Here I maintain a list of physics books, documents, blogs, and lectures I read / watch or that I have put on the (virtual) bedside table.
The collection is not some carefully crafted, balanced list - I am not searching for resources to add them here but I add what is interesting to me as a professional or a dilettante science blogger. I apologize for the mixture of German and English resources, and the structure is always work in progress.
This list had been formerly curated on my blog, on a page called Physics Books on the Bedside Table. I decided to migrate these links over here as in 2014 I had started to curate all my tech / science links on radices.net.
Popular Science Books 'enthusiastic'
- The Particle at the End of the Universe by Sean Carroll
- Knocking On Heaven's Door: How Physics and Scientific Thinking Illuminate our Universe by Lisa Randall
- Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions by Lisa Randall
- The Universe in a Nutshell by Stephen Hawking
Popular Science Books 'critical' (Note: This is not 'Alternative science')
- The Trouble with Physics by Lee Smolin.
- Farewell to Reality: How Fairytale Physics Betrays the Search for Scientific Truth by Jim Baggott. See a review on wavewatching.net here.
History of Science and Biographies of Physicists
- The Strangest Man, a biography of Paul Dirac by Graham Farmelo. See also the review by Peter Coles.
- carnotcycle – the classical blog on thermodynamics, by Peter Mander.
- Physics on the Fringe by Margaret Wertheim. I blogged about his book here.
- Genius: The Life and Science of Richard Feynman by James Gleick.
- Isaac Newton by James Gleick
- Einstein: A Biography by Jürgen Neffe
- Inside The Centre: The Life of J. Robert Oppenheimer by Ray Monk
Quantum Physics, Quantum (Field) Theory
Oersted Medal Lecture 2002: Reforming the Mathematical Language of Physics, as recommended here. Actually, this is about all of physics and how more powerful, concise, and elegant Geometrical Algebra would do away with concepts that just appear tacked on – as there is an underlying hidden structure. It is useful in classical physics but especially to understand the seemingly weird world of the complex wave function.
- Lectures on Quantum Field Theory by David Tong. Videos of his lectures delivered at Perimeter Institute can be found here (different formats available). These lectures were my starting point for (re-)learning QFT having been exposed to mainly condensed-matter-related and non-relativistic quantum statistics and 'second quantization' 20 years ago.
- Quantum Field Theory in a Nutshell, a concise textbook by Anthony Zee. David Tong highly recommends this book, saying tongue-in-cheek: He lies to you all the time, but in a good way. It is not an easy read because the presentation of the material is quite condensed. You have to fill a lot of intermediate steps in derivations. On the other hand this makes it a great book for serious self-study. It shows that Zee is a gifted writer of popular science books as well as his conceptual overviews are spot-on and very helpful for tackling the hard stuff.
- I trust Graham Farmelo on this and put Stephen Weinberg's book on my To-read-list.
- Student Friendly Quantum Fielf Theory by Robert D. Klauber. Klauber describes and writes out details in derivations, avoids all references to so-called trivial, obvious and easy steps, and he refers to his own learning QFT often. The book seems to have been written from the learner's perspective – he often anticipates those typical baffled student's questions and answers them before you dared to ask it. More praise in this post of mine.
- A lecture on Quantum Field Theory in German, by Gerhard Soff. I like these lecture notes because topics are reviewed from different angles (such as: canonical quantization versus path integrals) and the derivations are done in detail for all the different options.
- The Fun is Real. Blog author Warren Huelsnitz definitely meets his goal: to sort through the myths and misconceptions, and the excessive and misleading hype, associated with quantum physics.
- An Island In Theoryspace – an awesome blog by Jaques Pienaar on physics (mainly of the quantum variety) and sometimes also on its interface with philosophy.
Quantum Computing and Quantum Cryptography
The first field that rekindled by excitement for physics in about 2003, having worked in IT already for some years.
- wavewatching.net. A blog written by a physicist and IT consultant who tries to separate fact from VC fiction and to predict what impact quantum computing will have on corporate IT.
- Lecture notes on General Relativity by Sean Carroll plus his No-nonsense summary on GRT.
- Special and General Relativity – a German textbook by N. Dragon that covers it all. Amazing what kind of material is available for free! Using an unsual way to present Special Relativity (German) – I learned from physicspages.com that this is called k calculus.
Thermodynamics and statistical mechanics
Fascinating water, water vapor, and ice
- Mpemba effect from a viewpoint of an experimental physical chemist, the winning paper in this contest.
- Lecture on the 2nd law and thermodynamics – a summary of what has happened since Boltzmann.
- A lecture on Thermodynamics and Statistical Mechanics in German, by Michael Potthoff. I searched for lecture slides rather than notes in order to use them as quick “refresher” on the subject. These slides are excellent because very concise but still complete.
Classics: Basics and fundamentals – books and blogs that cover all of physics
- The Feynman Lectures on Physics. Vol. 1 is available online since September 2013!
- The 6 volumes my former professor in Theoretical Physics has written: Wilhelm Macke, who was Heisenberg's PhD student: Ein Lehrbuch der Theoretischen Physik: Teilchen – Felder – Wellen – Quanten – Thermodynamik und statistische Mechanik – Quanten und Relativität (Basically: Mechanics – electrodynamics – fields – thermodynamics and QFT). I was more than happy to discover that so many second book shops are now selling used books over the internet – and that Prof. Macke's books are still available as they have been out of stock when I was a student.
- The German physics text books I used in high school (last 4 years) by Josef Schreiner. I am still in awe of the way Schreiner was capable of tailoring all of classical and modern physics to high school students – incl. quantum mechanics and relativity at a rather advanced, but still accessible level.
It is very interesting to compare Feynman's and Macke's books – they have been published at about the same time and might serve as good examples for both excellent, but different ways to describe physics from scratch – 'American' versus 'German'.
- A very detailed blog – physicspages.com – Physics Tutorials with lots of examples, introductions and the author's solutions to text book problems.
- Scientific Finger Food: Sebastian Templ achieves his goal – quote from his About page: “I give my best to break it down into simple language. In doing so, I hope that I can serve you some pieces of physics, which I like to think of as being clear to me, in 'delicious and manageable bites' “.
- motionmountain.net: Six volumes on physics, written by a physicist who works as an innovation manager. Probably the most professional hobby / moonlighting physics project I have come across.
Classical (point particle) mechanics
- The physics of rotation by Cleon Teunissen. Classical mechanics at its best, see for example: Gyroscope Physics.
I have always wondered why my English articles about science, career (and the universe and everything) have different tone than my German ones.
The English version dated 2008 differed from the German version. After reading Bertrand Russell I dare to say that my English way of thinking about science was more Russell-like whereas my German version was a little bit too fluffy and written in 'longing for consensus mode'. Probably the statement on 'popular science books' was a bit too harsh.
Today I consider the following the most important aspect of science - both in retrospect as well as with respect to my current relation to science:
I am still most interested in the fundamentals of physics and in theoretical physics. Such as: Explaining why the sky is blue or how a heat pump works - both in words and pictures but also drilling down to the mathematical proofs. I admit that this is not primarily driven by the necessity to build technical solutions (although I do not object to apply that knowledge to real-life problems, of course). I believe that this way of scientific thinking has a value that stands on its own. It is not just 'technology' and 'formulas', it is rather part of our culture.
I re-discovered some really old books on physics last year. In contrast to the saying of the exponential growth of knowledge the very core of physics is unchanged. Strong foundations are even more valuable today in order to judge the overflow by so-called new stuff. I feel that immersing in these details and the full broad picture of nature as seen through the eyes of science allows to thrive (survive?) in modern project busywork more easily.