There is an opinion that the glass is actually not a firm body, but the so -called hypothermia, so the glass in medieval structures is thicker at the lower edge. We decided to check whether the glass is really - this is a liquid flowing down over time.

The opinion that the glass is actually a liquid can be found in posts in various social networks and on forums. Various specialized resources also write about this, for example website glass factory in the hose-chrostalny. Questions about the aggregate state of glass are asked by resource users with questions and answers "Mail.ru answers" And "Yandex.ku". Basic argument in favor of the fact that glass is still a liquid, Consistent The fact that in the medieval stained glass windows of the glass is thicker at the lower edge, that is, over time they are glass. The allegations that glass is fluid is found even in authoritative scientific publications. For example, in Russian an article substantiating this was Published In the journal "Science and Life" in 1983.

The idea that the glass may flow down eventually was appeared at the beginning of the 20th century. Detailed experiments on glass fluidity Described Russian chemist, candidate of chemical sciences and popularizer of science Ilya Abramovich Leenson in his article “Whether Window Styles flow”. The first to conduct such experience was physicist Robert Ralie when he noticed that his colleagues were trying not to store glass tubes for experiments in an upright position. They were guided by the Council from the book of Nobel Laureate In the chemistry of Wilhelm Oustild, “Physico-Chemical Research”. It noted that such tubes should be stored in a horizontal position on the support, otherwise they are deformed under the weight of their own weight. Raley decided to experimentally check if it was. He took a glass rod about 1 m long and with a diameter of 5 mm, placed it with the ends on two pins driven into the wall, and a load weighed a load weighing 300 g. Under the weight of the cargo, the rod immediately bend at 28 mm. In this state, Raley left the structure for seven years.

In parallel with Raley, the experiment, a similar design, was launched by the laboratory assistant of the American company General Electric K. Spencer. However, the load placed on the glass tube was almost three times heavier. In 1930, Ralie completed the experiment, the glass tube was bent by only 1 mm. Spencer had more visual results - the deformation was 9 mm. However, in both experiments, the load was used many times higher than the weight of the tube itself. It turns out that only under the influence of its weight deformation, even insignificant, should not occur. Spencer proposed a reasonable explanation for why some of the glass tubes for chemical experiments had a curvature visible to the naked eye. Choosing a pipe from the rack, scientists tried to initially choose the most even, the same that remained unused, were already made slightly crooked. Moreover, while chemists chose a more even pipe, they shifted the rest in such a way that their deflection was shifted on one side, and visually this could be taken as the result of the glass.

In a similar way Explained And why in the old buildings of the glass below there are thicker than at the top. In the era of manual manufacturing of glass, it was impossible to achieve the same thickness of the entire layer of glass, so the masters placed glass in the frame with a thicker end down for ordinary stability. At the same time, restorers note, such a placement was not a strict rule, and you can find buildings, during the construction of which they did not do this - in them the thicker edge of the glass is not necessarily below.

Chemist Paddy Royal from Bristol University calls The idea of glass fluidity by a city legend: “Glass, usually made of silicon dioxide, does not change its shape for segments of time comparable to human life. If it changes the form, billions of years will take. ” Professor of Materials Science, Science and Engineering, Director of the Faculty of Laboratory of Glass at the Massachusetts Institute of Technology Michael Chima expressed It is also unequivocal: "If you leave the glass at room temperature, it does not matter for what time, it will not change in any way." Doctor of Physical Chemistry, Robert Brill, heading the Cornings Museum of Glass (New York, USA), Curses A good example: in ancient temples, stained -glass windows are held by lead bindings, while the viscosity of lead is about a billion times less than the viscosity of the glass. If the glass flowed over time, forming a thickening below, then a lead binding during the same time was supposed to turn literally into a liquid state.

Brazilian scientists using a mathematical model Counted, how much time it would take glass from the medieval cathedral in order to still flow over time, taking into account its viscosity at room temperature. According to their calculations, this period is 10³² years, despite the fact that the age of our universe is only 10¹⁰ years! Similar results Received Ozgur Gulbiten and John Mauro from the University of Pennsylvania. They studied not abstract glasses, but stained -glass windows of Westminster Abbey in London. Their measurements showed that the old glass is deformed by only 1 nanometer, that is, one billion meter, for one billion years.

Modern science Found And the explanation of that slight deformation of the glass over time under the weight of the load observed at the beginning of the 20th century by Raley and Spencer. The glass really did not flow, the cause of the changes was in slow diffusion of positively charged sodium ions. Moreover, if the load is removed, then the ions will return to the original position over time and the shape of the glass tube will be restored.

And although glass is definitely not a liquid, science I did not come To the one opinion, is it possible to count the glass with a solid body. The Conversation magazine Describes This is: "There are more theories than the theorists that put forward them."