To Jarek Strzałko - In Memoriam

Jarek Strzałko was born on 21.09.1945 in Łódź and died on 21.01.2017 in Marianów Sierakowski. He was associated with the Department of Machine Dynamics for the last ten years (2007–2017). He had over 50 years of experience at the Łódź University of Technology and the Faculty of Mechanical Engineering, including studies that he began in 1963. Fascinated by mechanics, he worked scientifically even during a serious illness: he supplemented the book with new examples of tasks and had fun solving them - the effects are visible in the Fundamentals of Analytical Mechanics textbook, he was interested in the classes and progress of younger colleagues from the Department - he browsed their latest publications on the Internet. Before joining the Department of Machine Dynamics, he was at the Department of General Mechanics, where he started working as an assistant (1969) and continued after completing his doctorate (1975) as an assistant professor, until his habilitation (2000). This was a time when he intensively deepened his knowledge, collected and studied monographs on mechanics (he left a rich collection of literature published in the second half of the 20th century). He spent many hours at work, sometimes, to relax, he played chess or ping-pong with his colleagues (there used to be a table in the basement of the A22 building). His partners knew that he did not like to lose.

He acquired the skills in solving mechanics problems while working on a collection of problems, published before World War II, by Z. Straszewicz, about which Prof. Jerzy Leyko said: "they are not easy". This is how the unique script Tasks from selected issues in mechanics was created. Since around 1980, he became interested in programming. This was the time of the first microcomputers: 8-bit Meritum, Sinclair Spectrum ZX, then the first PC with a 10 MB hard drive. There was a possibility of using such equipment for calculations, using it in the laboratory (and also for playing snake, and later chess). There was a growing interest in computer methods in mechanics, e.g. the finite element method - his first publication on this subject is from 1983.

The 1990s brought a series of works on the analysis of the motion and stability of mobile cranes. They were created using the Mathematica system, which became his new hobby. The issue of assessing the correctness of solutions, numerical equations of dynamics, for various types of models of mechanical systems was the subject of Jarek's habilitation thesis. He prepared it in the late 1990s, but illness forced him to postpone the habilitation colloquium for almost two years.

In the years 2003-2007 he worked at the Department of Production Systems, where the Department of Analytical Mechanics was established and he headed it. This was the time of creating a new mechanics laboratory and preparing scripts: Laboratory exercises in mechanics - for the master's course, Materials for exercises in mechanics, Lectures in general mechanics. It is worth mentioning that while developing them he made extensive use of his talent for programming - the tasks included in these materials were generated, as well as drawn and solved automatically in the Mathematica system.

Work at the Department of Machine Dynamics was the last period of his work at the Lodz University of Technology, a fruitful period for an already outstanding specialist in the field of classical mechanics, using modern computational tools. The effect of cooperation with the team of prof. T. Kapitaniak's important publications on coin tossing and dice (e.g. Dynamics of coin tossing is predictable, Understanding Coin Tossing, Can the dice be fair by dynamics?, Les dés sont pipés) and a monograph (Dynamics of Gambling: Origins of Randomness in Mechanical Systems), which analyzed, among other things, the dynamics of roulette.

Jarek took teaching very seriously and prepared thoroughly for classes. He fulfilled all obligations and agreements in the same way. Competent, demanding, sometimes principled, he sometimes softened - for example, when assessing an exam paper, he said "very, very, very poorly" and gave a grade of C.

One of his former students - prof. K. Czołczyński - said about him nicely and warmly:

He was a Great Teacher.

I addressed him as MASTER.

He mistakenly thought it was a joke...

For me he was also a Master, and also a long-time Collaborator and Friend.

Julek Grabski