Charles University Physicist Čížek Proves the Connection Between Formation of Molecules ****************************************************************************************** * Charles University Physicist Čížek Proves the Connection Between Formation of Molecules ****************************************************************************************** “Research cannot be fully planned and you never know what you will discover”, says the Cre recipient, assistant professor Martin Čížek from the Charles University Faculty of Mathema the co-author of a paper published in the prestigious journal Science. The theoretical phy calculations influenced the models of the formation of first nebulas and starts after the fan of the Big Bang Theory TV show. When did you start to focus on collisions of electrons? During the research for my dissertation, I collaborated with Professor Jiří Horáček, who w with a new theory to describe collisions of electrons and molecules. The electron is a ver and when it crashes into a molecule, it would seem that it can do nothing to it. Professor say that it’s like a ping pong ball hitting a tank: the ball bounces back and the tank rem But this description is not completely accurate. The molecule is only held together by oth so given that the electron lingers for some time in the vicinity of the molecule, it can v molecule’s force field and cause it to vibrate or even destroy it. Doc. Martin Čížek How did you find out that the formation of molecules and that of giant stars are interconn At the beginning, the space was very hot and the atoms did not hold together, but when it electron could get caught by a proton. At that point, there wasn’t much more than hydrogen traces of lithium. Only when the molecules were allowed to form, the gas would condensate and form stars. We have shown that these two processes, although different in size, are in would not expect that the formation of molecules and giant stars have so much in common. Astronomers have been interested in the reaction due to the fact that the most frequent el about in the space is hydrogen. We published our paper in 1998, but astronomers kept using About five years ago, Daniel Savin visited us from New York and said that the variance amo is high and that our value was the highest, only to be followed by experimental and theore During his visit, I was trying to convince him that my calculations were sound. Descriptio like this tend to have many variable parameters, but our calculation is based on first pri only variable parts are approximations. And those are needed even if you don’t include any calculation and only use the laws of nature. I tried to convince Professor Savin that the are including do not affect the basic quantity he is interested in. He eventually decided experiment that would test the reaction. Previous experiments had been conducted in room t he decided to measure the reaction for different values of the energy of the collision, be astronomers need when modelling star and galaxy formation in the early space. He designed measured the data again and the curve turned out to match our calculations. That was a hug It the early stages of the history of space, the first particles to emerge were atoms. The calculated by us and tested by Professor Savin led to the formation of molecules. The fact are three times bigger than people had thought changed the way we create the models of for stars. This is why we got into Science. It was a result of three teams working together – team that provided some data calculations and a team of astrophysicists did some more calc this affects the formation of early stars. The whole operation was much faster that we had What line of research are you focusing on now? These days, I work in two main areas, the first of them still being molecules. It is very calculate diatomic molecules, but there some interesting effects going on in bigger molecu like to extend our calculations to them, too. For example, collisions of slow electrons in the main source of damage to biomolecules during the exposure of tissue to ionizing radiat area, which I started to get into during my research stay in Munich, is molecular electron It’s been over ten years since we first plugged a molecule into an electric circuit. You c molecule and run current through it and observe the changes in the current depending on th voltage. The resulting curves are very complex and we can try to explain them. To me, it’s because it’s related to my previous work – the flow of current through the molecule is sim scattering of electrons on a molecule. The molecule is attractive as an electronic component, because it’s much more flexible tha metal. In addition to that, it can have various appendages that can move or be controlled outside. Building components on the molecular level is probably still a matter of a far future, but that, the new appliances would appear magical to us – just like today’s laptop computers w somebody from the early 20th century. Another way of using these is to create smart materi to different conditions or printed electronics – pictures on the paper could come alive li Potter books. Going back to the theory of collisions, how complex are these? Electron either bounces away and the molecule stays together, or the electron remains atta the molecule has to break down. For example, if a molecule had two atoms at the beginning, having a neutral atom and a negative ion. When I joined Professor Horáček’s team, he decid the process in reverse. This approach is more complicated, because it is more difficult to particles and we had to change, improve and add a lot of code into the programs. The simpl such a process is to take a negative ion of hydrogen. After a collision, an electron can b a molecule of hydrogen is formed. This is exactly the opposite of breaking a molecule of h electron. I was working on these calculations and found out that the probability of this r times higher than the one from the previous calculations. P.K. Columbia University's Daniel Wolf Savin describes the chemistry underlying early star form "http://www.nsf.gov/news/news_videos.jsp?cntn_id=117262&media_id=67022&org=NSF"] A Star Is Born ... But How? [ URL "http://www.nsf.gov/news/news_summ.jsp?cntn_id=117262"]