This story happened many years ago. In order to remain anonymous, I completely changed its scientific part (so please don’t judge strictly, I’m doing other things, and Irka too) and the names of the two heroines.

A long time ago, three young women colleagues went to a conference in the UK. Two of them were under thirty, but they looked twenty. Irka - a tall light-haired beauty with a child's face and voice, touching blue eyes of the colour of the Volgograd sky and a good look, I - a medium-sized chatenka with long hair and eyelids, glowing eyes and round red cheeks, a positive appearance note excel. Marina was slightly older, thin, rapid, with an amygdala-like cut of serious eyes and a dull smile. We were very pleased with the trip - the conference promised to be interesting, the place was beautiful, and I wanted to see friends and colleagues.

The plane landed, the line for border control we stood, and we were going to go further. We always crossed the border quietly: the French joked when they saw our serious science in the "profession" item, and, having thrown a couple of mysterious looks and smiles, placed a stamp, the Dutch missed quickly, the Spaniards laughed and wished good. But this border guard was not a shirt. When he heard that we were going together, he called all three together. He made the expression of the receptionist of the Soviet laundry and began to ask various questions in a prosecutor’s tone:

Where are you born?
In Leningrad.
This city is called St. Petersburg. He told the accuser.
Yes, but then it was called Leningrad, so it is recorded in the documents.
In which country?
I currently live in Russia.
The date of birth?
Such a number, month and year.
Are you sure?
I had the feeling that this was not a border control, but a yellow house. I say, I am sure.
Well well well. Where are you born? He turned to Irka, who looked at him with wide open blue eyes. Irka informed and spotted something about the conference to which we are heading.
Do you work where? What kind of institution is this? Suspiciously he asked, holding in his hands our work certificates.
Even after a couple of rounds, during which he asked some questions twice, he decided to learn more about the purpose of our trip. He studied invitations from the organizers, documents on financial support, hotel reservations, theses of reports. We talked about the conference. He struck us for twenty minutes. The sense of stupidity of what was happening increased. Having taken my theses into his hands, he decided to ask me about the subject of my work.

At that moment, I was already full of talking in my throat. I love my work and am willing to talk about it in detail. I asked – now listen.

You know, of course, that your great compatriots Thomson and Tate formulated at one time the theorem of the stability of systems with gyroscopic forces. Later this theme was developed by Raus and Lyapunov. Raus’s theorem with the addition of Lyapunov, I believe, is of a philosophical nature. It states that if there are "hidden" movements of cyclic coordinates in the system, such as rotations of axisymmetric bodies, which do not affect the potential energy of the system, but give an addition to the kinetic, then this addition serves as an additional effective potential energy of the reduced system, in which "hidden" movements are absent. This means that the rapid rotation of axisymmetric bodies can serve as a sprinkle that gives additional stability to the system.

The border guard had a difficult expression on his face, he wanted to say something, but I, not allowing him to insert words, not translating the breath, joyfully continued:

I had the idea that by controlling the speed of these hidden movements, we could get various interesting effects. Especially if you connect the appropriate feedback to the object, say, if it begins to lose stability, then increase the speed of rotation, when going into the desired mode, reduce it, so as not to lose energy. In addition, the question arises, what will happen if these coordinates are not truly cyclical, but are them in some mediated sense. What then happens to the sustainability of the average movement? Can a multi-scale method be applied to its analysis?

“Thank you...” said the border guard.

No, I think you got, a fascist, a grenade! I won’t take you for the button, of course.

“Sorry, I haven’t explained it to the end,” I said decisively and went closer to the window with enthusiasm. “We are considering a specific task for the system of bodies with wolves, and one of the questions that we are solving is about choosing the representation of the tensors of the corresponding bodies. It is dictated, it turns out, not only by the geometry of the task, but also by its initial conditions!

Irka and Marinka stood with impenetrable attentive faces, showing sincere interest in my speech and readiness to dialogue, and looked with their big eyes to me, then to the border guard.

I understood! The border guard said. Enough is enough, thank you!

Are you sure? - I wanted to tell me, but I decided that the alaverda here will not serve anyone for the benefit.

He asked the names of the reports of the girls, and, only Irka was going to devote him to the secrets of paradoxes to Penlev, said darkly:
No need to explain the content. And when we shrugged our teeth, the clouds missed us.

We walked away a little, and the girls began to sneak. I was still angry.
What kind of donkey was he, what did he want from us? I asked them.

They looked at me with pity and said something I just couldn’t think of:
– Lenka, he thought we were going to do prostitution. He couldn’t believe that three young girls were going to present at a famous math conference.