Girl with a knot
Based onSt. Wyspianski  Dziewczynka z wazonem See: Galeria malarstwa polskiego

For more pictures see:

Knots in art  :-)

Piotr Pieranski
Poznan University of Technology
Laboratory of Computational Physics and Semiconductors
Nieszawska 13A, 60 965 Poznan, Poland

office: +48 61 665 31 63

home: +48 61 862 58 53

cellular:  +48 606 81 40 46




How much money you need to make an experiment, the results of which can be published in a top quality physical journal?

I have been asking myself the question since I started my carrier in science.
Today, I know the answer:

There is no lower limit.

You may spend 1 000 000 $ to produce a paper which will be accepted by the referees. But, if you are clever enough, 10 $ is more than sufficient.

The research in physics, as any other kind of the human activity, displays an enormously wide range of diversity.
It can be:

Physics can be fun. The flying frog experiment is the best example. Its authors, Geim and Berry, enjoy science. I am convinced, this particular piece of physics attracted to the wonderful playground of science more brilliant children than any of the billion dollars experiments.

Looking into my own work I find it it certainly located within the last two categories. Cheap and serious is what I think I managed to achieve in most cases, but the most precious cheap and funny level I reached no more than twice.

It is my aim to show you a few examples from my own and others work. Have a look and think. And remember: cheap cannot mean shabby, funny cannot mean ridiculous. It can be cheap and funny but it must be science.


Bouncing ball
Magnetic holes

Wonderful threepenny experiments in the nonlinear dynamics can be found in Elisha's Moses home pages. The falling paper experiment is a good example.

Peas on the drum
Gravity's rainbow

Some of the experiments performed on the granular materials belong also to threepenny physics class. Experiments made by Stephane Duoady, Éric Falcon, Stéphan Fauve and others (Laboratoire de Physique Statistique, de l'Ecole Normale Supérieure)  are certainly of the kind.


Physical knots - an introduction

Spaghetti knots
Gordian Unknots 
Open knots tightened on the perfect rope
Closely packed helices

Introduction into the problem of ideal knots

Symmetry of ideal knots
Symmetry breaking in large torus knots
The ideal trefoil knot
Quasi-quantization of writhe
Problem of the ideal twisted pair
Figures of ideal knots with up to 8 crossings
Parameters of ideal knots with up to 9 crossings
Tendril perversion
Hamiltonian knots

AMS Meetings

"Physical Knotting and Unknotting", Las Vegas 2001
"Calculations and Simulations in Knot Theory and Its Applications", San Francisco 2003
San Francisco 2003, individual photos


It's really nice to have a twin.
If you happen not to have one, think about it next time  ;-) 

Graphics and photography


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Last revision: August 16, 2004