Schlieren Imaging

A way to visualize the density of air using a parabolic mirror, a point source of light and a sharp edge.

A large educational course for high schools and elementary schools about astronomy, for the RedMonster company of Unicorn Publishing.

400+ quiz questions
38 lessons on 9 different topics

Five-part lecture series at Prague Observatory with Adam Šimek. HαF.

Historical-Astronomical-Philosophical seminar (HαF), during 2020. Reading original texts from Copernicus, Galiei, Kepler, Bernard de Fontenelle, Cardinal Cusanus, but also other authors such as Giordano Bruno and even Dante Alighieri.

Introduction.
Our Position in the Cosmos.
- Lucretius: De Rerum Natura. Where is Earth? Is space bounded? Does it have a center? Is the Sun above us? Basil of Cesarea: Hexaemeron. How can the Earth not fall down? Dante Alighieri: axiological ordering of the universe.
De Revolutionibus.
- Reading from Copernicus. Precedessors: Aristarchus, Philolaus (from doxography only). Cusanus. Prefaces to the 1st book of De Revolutionibus. The roundness of the world and the Earth. The motion of heavenly bodies is circular. Why the motion of the Earth is circular. Copernicus' explanation of (the non-observation of) paralax. His axiological arguments. The order of the heavenly spheres. The other books of De Revolutionibus.
Heresy of G. Bruno.
- The Ash Wedenesday Supper. D. Špelda's reading. The trial with Bruno and Galileo. Why was Copernicus "left alone"? Was Bruno a "martyr of science"?

Arago / Poisson / Fresnel spots

In principle, Arago spots can be used to construct a telescope without any lenses.

Arago spot of 3mm ball

Arago spot of 3mm ball: detail

Arago spot of 27mm (50 CZK) coin

Barometric expedition to Sněžka mountain (1603 meters above sea level), 2021

Raspberry Pi barometer

Used a digital barometer, several thermometers, a hygrometer, and an LCD screen for on-site viewing. Compared with GPS data.

Aneroid barometers

Of a large size, carried to the summit throug snow.

All the used devices.

Made as t-shirts.

Fractals from Kepler's equation.

By solving Kepler's equation (E = M + e sin E) iteratively, we get a construction similar to the construction of the Mandelbrot set.

Fractal generated by iterating Kepler's equation for real values of eccentricity.

Fractal generated by iterating Kepler's equation for imaginary values of eccentricity.

Civil twilight

Wikipedia states that civil twilight is a period of time, when the Sun is below the horizon, and yet there is enought light to read and play ball games. We decided to test this hypothesis.

Arago / Poisson spot

Hyperbolic walk in the shade of the moon around Liblice transmitters

Singular Value Decomposition

Finding the best apple

A committee of 5 tasters has gathered on Zizkov hill, one of the most prominent Prague landmarks, to find the best apple. We tested 25 varieties split into 200 samples.

Optimal popcorn preparation

Wait for the interval between pops to diminish to 1 pop per 2 seconds. At that point, 98% of the poppable kernels have exploded and you prevent burning.