I don't know why I needed this, but it was interesting. I was studying the possibility of increasing the controllability of the descent vehicle and gradually moving on to the topic of flapping flight, or rather simplifying it to asymmetric vibration, accidentally discovered a contradiction in some areas of physics. I was surprised that no one paid attention to this before, and many people told me that it violates fundamental laws. But I went on principle and eventually was able to publish an article, albeit in a second-rate, but still peer-reviewed journal. Unfortunately, this is a Russian journal and the entrance is now only through VPN, but I have a translation elsewhere. This is an article about a flying saucer, the shape of which really depends on the principle. This is very far from something real, but still something to think about.