Posts

The limitations of technology

In this age of technology, this era of digital revolutions, the question becomes more and more relevant how far technology can get us and what its limitations are. Surprisingly enough, already one century ago, even before the first computers existed, these limits have been settled. These had been found by Kurt Gödel and Alan Turing. They proved that so-called “self-reference” was always inevitably leading to logical paradoxes destroying the rigorous foundations of both mathematics and computer science. Self-reference is the ability to completely describe yourself - stepping back and reflect on yourself. Their proofs are ingenious, both simple on the high level as complicated on the detailed level. But let’s take some time to step back and reflect ourselves; bear with me and try the following thought-experiment to better understand what Gödel and Turing were saying. Suppose I would offer you the perfect VR device, that is one where you cannot not tell the difference between the "...

QED: The Strange Theory of Light and Matter

This book is about quantum electrodynamics, the theory which describes how light and matter interact on the smallest scales. As can be expected from any book by Richard Feynman, this book is a joy to read. Feynman manages to explain in clear layman's terms why it seems that light travels by straight lines, how light reflects from surfaces, why it behaves wave-like and how light-particles interact with electrons. In the final part of the book he concludes with an appetizer on the so-called quantum chromodynamics (QCD), which is the theory of the (strong) interaction between even more exotic particles. Feynman takes the reader by the hand starting with simple examples and step-by-step advance on those examples pointing out the strangeness of the theory when scales or distances get very, very small. It would not make sense to summarise here what is so perfectly described in his book, best is to read it yourself. However I want to mention the main take-out for me, which is that the ...

Let inspiration be your compass...!

Were you ever, when taking a bath, suddenly struck by the insight that the upward force on your body by the surrounding water is equal to the weight of the water displaced by your body? It’s a matter of balance between the displaced weight and the induced upward force. It inspired Archimedes to his law of up-thrust. Were you ever, when taking a nap, suddenly awaken by the fall of an apple on your head, and came to realize that you were hit by the force of gravity? The same gravity holds the moon into orbit, and, less distant, our airplanes. This was also a matter of balance, which inspired Newton to his famous laws of gravity. And did you ever look at a pocket compass and wondered what it was in the surrounding empty space that was moving the needle? Where do you go to when there is nothing surrounding you? This wonder inspired Einstein to his theories of relativity and gravitation.All these great men were inspired by Mother Nature to represent the real world by simple models. Their i...