Random walk

Prague and its population have a strong link to astronomy and science.

It is impossible to miss the thousands of tourists coming each day to the main square of Prague (Staroměstské náměstí) to observe the mysterious and beautiful astronomical clock, exhibiting amazing ornaments linked with astrological symbols, in addition to the gothic and mystic style of the city.

For example, at the Technical Museum of Prague, we can find amazing automates aimed to reproduce the movement of solar system planets, and many astronomical instruments (different types of telescopes, machines to reproduce movements of solar system planets, ...).

But how are produced these objects?

Such automates are aiming to reproduce the behavior of the solar system as a function of time, which actually means to express the laws of nature into equations. The action summarizing this process is modeling, and is actually the work of natural scientists (physicist, biologist, astrophysicist, and mathematicians).

Defining the time basics for human beings

Such machines brings to my mind how our scheduling system that we all use is related to astronomy. How much was based on astronomy, and how much on cultural and religious reasons ? One can make a small analysis:

• One rotation of the Earth around itself defines (approximately!) the duration for one day.
• One rotation of the Earth around the Sun defines (approximately) the duration of one year.

Hence, we identify several puzzling questions.

• What defined the number of 24 hours in a day ?
• Why do we use 12 months to define a year? Maybe connected more or less to the period of moon ?

Which process actually defines the duration of a second ? If we have a look to the physics, the last definition of the second is the "time for which light is propagating on 299,792,458 meters", despite this definition has no link with human reasons which have lead to take this convention as a definition to rythm daily life of population.

More info there: http://en.wikipedia.org/wiki/Second#History

Edit: It appears actually that the given definition is valuable for velocity of light. Not for the second. But still, how did we arrive to define the second with its current duration ?

Other amazing devices from Bohemia

Another great device I found in this wonderful region of Europe is the "Light Mill" or the Crookes Radiometer (http://en.wikipedia.org/wiki/Crookes_radiometer).

This amazing device has been invented during the XIXth century and does not need any battery to spin during days...

However, Crookes orginates from UK, but Bohemia is producing a lot of them thanks to their well-know quality of their crystal.

Why Bohemia focused so much on astronomy and optics so far ?

One of the reasons came to my mind by visiting the Technical Museum of Prague. By going to the basement of the museum, you can realize how much Bohemia is rich from her soil and ground, especially for richness of its mines full of different minerals, crystals among centuries. It explains why glass is so present in the culture of inhabitants of this marvelous city. It can also explain why bohemians were linked to astrology and numerology in the books I was given to read at school during childhood in France.

Bohemia and myths

And just for supersticious, pataphysicist, and witchcraft fans, I would add few questions which let some free space for any mysticist reading this. Are woman menstrual phases related to moon phases ? But the answer has been demonstrated to be : "no", say several scientific studies.

And is there a link between these phases and the treatment applied over women in religion linked to the cult of the Moon ? This time, I would say definitely yes...

See details on these questions here (in French).

• http://fr.wikipedia.org/wiki/Effet_de_la_Lune_sur_les_naissances
• http://www.le-sidh.org/site/article_242.html

Maybe some mystics present in Prague could open some ways to give more hints on this kind of popular believes.