Using stereographic projection, you create a distorted image of the surface of a sphere, stretched out to cover an infinite plane. Each point on the sphere is mapped to a point in the equatorial plane by a projection ray starting at a pole of the sphere. Draw a circle on the sphere, e.g. by intersecting…
Tag: Learning
Peter M. Schuster on History of Science
The late Dr. Peter M. Schuster was a physicist and historian of science. After a career in industry, he founded a laser technology startup. Recovering from severe illness, he sold his company and became an author, science writer, and historian. He founded echophysics – the European Center for the History of Physics – in Pöllau…
Hacking
I am joining the ranks of self-proclaimed productivity experts: Do you feel distracted by social media? Do you feel that too much scrolling feeds transforms your mind – in a bad way? Solution: Go find an online platform that will put your mind in a different state. Go hacking on hackthebox.eu. I have been hacking…
Infinite Loop: Theory and Practice Revisited.
I’ve unlocked a new achievement as a blogger, or a new milestone as a life-form. As a dinosaur telling the same old stories over and over again. I started drafting a blog post, as I always do since a while: I do it in my mind only, twist and turn in for days or weeks…
Consequences of the Second Law of Thermodynamics
Why a Carnot process using a Van der Waals gas – or other fluid with uncommon equation of state – also runs at Carnot’s efficiency. Textbooks often refer to an ideal gas when introducing Carnot’s cycle – it’s easy to calculate heat energies and work in this case. Perhaps this might imply that not only must the…
Computers, Science, and History Thereof
I am reading three online resources in parallel – on the history and the basics of computing, computer science, software engineering, and the related culture and ‘philosophy’. An accidental combination I find most enjoyable. Joel on Software: Joel Spolsky’s blog – a collection of classic essays. What every developer needs to know about Unicode. New terms…
Ploughing Through Theoretical Physics Textbooks Is Therapeutic
And finally science confirms it, in a sense. Again and again, I’ve harping on this pet theory of mine: At the peak of my immersion in the so-called corporate world, as a super-busy bonus miles-collecting consultant, I turned to the only solace: Getting up (even) earlier, and starting to re-read all my old mathematics and…
Learning General Relativity
Math blogger Joseph Nebus does another A – Z series of posts, explaining technical terms in mathematics. He asked readers for their favorite pick of things to be covered in this series, and I came up with General Covariance. Which he laid out in this post – in his signature style, using neither equations nor…
Random Things I Have Learned from My Web Development Project
It’s nearly done (previous episode here). I have copied all the content from my personal websites, painstakingly disentangling snippets of different ‘posts’ that were physically contained in the same ‘web page’, re-assigning existing images to them, adding tags, consolidating information that was stored in different places. Raking the Virtual Zen Garden – again. (Voice from…
My Flat-File Database
A brief update on my web programming project. I have preferred to create online text by editing simple text files; so I only need a text editor and an FTP client as management tool. My ‘old’ personal and business web pages are currently created dynamically in the following way: [Code for including a script (including…
On Learning
Some years ago I was busy with projects that required a lot of travelling but I also needed to stay up-to-date with latest product features and technologies. When a new operating system was released a colleague asked how I could do that – without having time for attending trainings. Without giving that too much thought, and having my…
How to Introduce Special Relativity (Historical Detour)
I am just reading the volume titled Waves in my favorite series of ancient textbooks on Theoretical Physics by German physics professor Wilhelm Macke. I tried to resist the urge to write about seemingly random fields of physics, and probably weird ways of presenting them – but I can’t resist any longer. There are different…
Non-Linear Art. (Should Actually Be: Random Thoughts on Fluid Dynamics)
In my favorite ancient classical mechanics textbook I found an unexpected statement. I think 1960s textbooks weren’t expected to be garnished with geek humor or philosophical references as much as seems to be the default today – therefore Feynman’s books were so refreshing. Natural phenomena featured by visual artists are typically those described by non-linear…
In Praise of Textbooks with Tons of Formulas (or: The Joy of Firefighting)
I know. I am repeating myself. Maurice Barry has not only recommended Kahneman’s Thinking, Fast and Slow to me, but he also runs an interesting series of posts on his eLearning blog. These got mixed and entangled in my mind, and I cannot help but returning to that pet topic of mine. First, some statistically…
“Student Friendly Quantum Field Theory”
As other authors of science blogs have pointed out: Most popular search terms are submitted by students. So I guess it is not the general public who is interested in: the theory of gyroscopes, (theory of) microwaves, (theory of) heat pumps, (theory of) falling slinkies, or the Coriolis force. I believe that these search terms…
Learning Physics, Metaphors, and Quantum Fields
In my series on Quantum Field Theory I wanted to document my own learning endeavors but it has turned into a meta-contemplation on the ‘explain-ability’ of theoretical physics. Initially I had been motivated by a comment David Tong made in his introductory lecture: Comparing different QFT books he states that Steven Weinberg‘s books are hard reads because at…
Space Balls, Baywatch and the Geekiness of Classical Mechanics
This is the first post in my series about Quantum Field Theory. What a let-down: I will just discuss classical mechanics. There is a quantum mechanics, and in contrast there is good old classical, Newtonian mechanics. The latter is a limiting case of the former. So there is some correspondence between the two, and there are rules…
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…
Stargate: Succumb to the Power of the Ritual
Thanks for your prayers, voodoo magic, encouraging tweets or other tweaking the fabric of our multiverse: Yesterday I have passed my final exams and defence – I did very well, and I am a Master of Science in Sustainable Energy Systems now. As the sensationalist title indicates I tried to play it cool but finally…
Do I Have an Opinion on Education at Large and on MOOCs in Particular?
Something education-related seems to have hit the blogosphere – many blogs I follow cover online-courses, teaching and education yesterday. My feelings are mixed. Important note: Though this was intended as a balanced review. But it ended up as one of my usual posts attributed to this genre I have no name for. I could invalidate…
The Twisted Garden Hose and the Myth of the Toilet Flush
If you have wrapped your head around why and how the U-shaped tube in the flow meter (described in my previous post) is twisted by the Coriolis force – here is a video of a simple experiment brought to my attention by the author of the quoted article on gyroscope physics: You could also test it…
Random Thoughts on Temperature and Intuition in Thermodynamics
Recent we felt a disturbance of the force: It has been demonstrated that the absolute temperature of a real system can be pushed to negative values. The interesting underlying question is: What is temperature really? Temperature seems to be an intuitive everyday concept, yet the explanations of ‘negative temperatures’ prove that it is not. Actually, atoms have…
Quantum Field Theory or: It’s More Than a Marble Turned into a Wiggly Line
I had been trained as an experimental physicist which meant I was good at locating vacuum leaks, adjusting lasers and lenses, telling reasonable data from artefacts, and being the only person that ever replenished the paper feed of the X-ray diffractometer (Yes, at that time we used paper records). Exactly because of that I took pride in the…
Are We All Newtonians?
In my most recent posts I showed off: 1) Sandra Bullock killing a computer virus and ordering pizza online, 2) a cartoon making fun of all academic disciplines I refer to this blog, 3) images of cute furry animals – dead and alive. I will not be able to top that. Thus I feel free to bore you…
The Spinning Gyroscope and Intuition in Physics
If we would set this spinning top into motion, it would not fall, even if its axis would not be oriented perpendicular to the floor. Instead, its axis would change its orientation slowly. The spinning motion seems to stabilize the gyroscope, just as the moving bicycle is sort of stabilized by its turning wheels. This sounds…
Stupid Questions and So-Called Intuition
At the beginning of my career, I organized a meeting of a research project team. I was still an undergraduate student. The project was concerned with the development of thin superconducting films for microwave circuits, and my task in the project was the optimization of those films. But I was not an expert in waveguides…
Real Physicists Do Not Read Popular Science Books
At least this is what I believed for quite a while. Now I think I was wrong – not only for the reason that also real scientists might enjoy light entertainment or stay informed about their colleagues’ science outreach activities. First of all, I am not even sure if I still qualify as a real…
elkemental Force 