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122. LIGO a objev gravitačních vln I.: Přednáška u příležitosti udělení Nobelovy ceny za fyziku za rok 2017. 1

Creator:
Weiss, Rainer and Gregora, Ivan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
gravitační vlny, gravity waves, 6, and 53
Language:
Czech and English
Description:
This article presents translations from the Nobel lectures for physics in 2017 given by all three laureates, who decided to use the same title, but each one focused on different aspects of the discovery. Weiss discussed the early history of gravitational waves and presented the concepts needed to understand the detectors as well as the challenges faced in measuring strains as small as 10-21. Barish describes how the LIGO project was organized to make steady improvements and ultimately carried out a successful scientific program. He describes signal detections as well as ideas of how to improve the detectors. Thorne presented the broader aspects of the new field of gravitational wave astronomy. He described the critical role of numerical relativity simulations and understanding quantum mechanics of precision measurements. He also gave a vision of the science that could come from an investigation of the gravitational wave sky from periods of fractions of milliseconds to tens of billions of years., Rainer Weiss., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

123. LIGO a objev gravitačních vln II.: Přednáška u příležitosti udělení Nobelovy ceny za fyziku za rok 2017. 2

Creator:
Barish, B. C. (Barry Clark) and Gregora, Ivan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
gravitační vlny, gravity waves, 6, and 53
Language:
Czech and English
Description:
This article presents translations from the Nobel lectures for physics in 2017 given by all three laureates, who decided to use the same title, but each one focused on different aspects of the discovery. Weiss discussed the early history of gravitational waves and presented the concepts needed to understand the detectors as well as the challenges faced in measuring strains as small as 10-21. Barish describes how the LIGO project was organized to make steady improvements and ultimately carried out a successful scientific program. He describes signal detections as well as ideas of how to improve the detectors. Thorne presented the broader aspects of the new field of gravitational wave astronomy. He described the critical role of numerical relativity simulations and understanding quantum mechanics of precision measurements. He also gave a vision of the science that could come from an investigation of the gravitational wave sky from periods of fractions of milliseconds to tens of billions of years., Barry C. Barish., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

124. LIGO a objev gravitačních vln III.: Přednáška u příležitosti udělení Nobelovy ceny za fyziku za rok 2017. 3

Creator:
Thorne, Kip S. (Kip Stephen) and Gregora, Ivan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
gravitační vlny, gravity waves, 6, and 53
Language:
Czech and English
Description:
This article presents translations from the Nobel lectures for physics in 2017 given by all three laureates, who decided to use the same title, but each one focused on different aspects of the discovery. Weiss discussed the early history of gravitational waves and presented the concepts needed to understand the detectors as well as the challenges faced in measuring strains as small as 10-21. Barish describes how the LIGO project was organized to make steady improvements and ultimately carried out a successful scientific program. He describes signal detections as well as ideas of how to improve the detectors. Thorne presented the broader aspects of the new field of gravitational wave astronomy. He described the critical role of numerical relativity simulations and understanding quantum mechanics of precision measurements. He also gave a vision of the science that could come from an investigation of the gravitational wave sky from periods of fractions of milliseconds to tens of billions of years., Kip S. Thorne., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

125. Linearita a relativita

Creator:
Musilová, Jana and Tyc, Tomáš
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fyzika, physics, 6, and 53
Language:
Czech and English
Description:
Na příkladu z oblasti speciální teorie relativity ukazuje příspěvek přirozený vztah aparátu lineární algebry k fyzikálním teoriím. Předkládá elementární postup při odvození tzv. speciální Lorentzovy transformace na úrovni vstupního kursu obecné fyziky v univerzitním studiu fyzikálních, resp. technických oborů a ukazuje, že k tomu zcela stačí pochopení pojmu lineárního zobrazení a zvládnutí rutinních maticových operací. Na problémech souvisejících s pojmy současnosti a soumístnosti, tzv. kontrakce délek a dilatace času ukazuje efektivnost přímé aplikace Lorentzovy transformace oproti obvyklým, takzvaně "názorným" úvahám, které je nevyužívají., This paper shows a natural connection of linear algebra to physics theories on an example of the special theory of relativity. An elementary derivation of the special Lorentz transformation is presented, at the level of a first year university course on general physics, and it is shown that, for such a derivation, understanding of the concept of linear mapping and elementary matrix operations is fully sufficient. The paper also shows an advantage of the application of Lorentz transformation to the problems of length contraction and time dilation, compared to the more usual, supposedly "illustrative" explanations., Jana Musilová,., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

126. Lipoplexy - nevírusové prenosové vektory nukleových kyselín

Creator:
Uhríková, Daniela
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fyzika, lipoplexy, fyzikální experimentální metody, physics, lipoplexes, 6, and 53
Language:
Czech and English
Description:
Lipoplexy sú nevírusové prenosové vektory vytvorené interakciou katiónových lipozómov s polyaniónom nuklovej kyseliny. Umožňujú prenos genetického materiálu do bunky. Je možné vytvoriť ideálny prenosový vektor? Článok v krátkosti naznačuje nevyhnutnosť vzájomného prepojenia fyzikálnych experimentálnych metód s biologickými postupmi pri hľadaní odpovede na túto otázku., Lipoplexes are nonviral delivery vectors formed due to the interaction of cationic liposomes with nucleic acid polyanions. They serve as carriers of genetic material to a cell. Is it possible to create an ideal delivery vector? This text introduces the combination of knowledge form two different approaches, namely experimental methods of physics and techniques in biology, in search of this answer., Daniela Uhríková., and Obsahuje použitou literaturu
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

127. Logický model hry Sudoku

Creator:
Kvasnička, Vladimír and Cádrik, Michal
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
hry, sudoku, strategie her, games, game strategy, 6, and 53
Language:
Czech and English
Description:
This paper discusses a simple logical approach to solving Sudoku puzzles, which may be interpreted as a mental model of the puzzle. The model employs an auxiliary matrix 9x9, which is formed from the matrix specifying initial given values of the puzzle in such a way that its empty squares are filled by lists of candidate values. These lists are determined by initial values together with the puzzle constraints: each column/row/subarea 3x3 is occupied by integers 1, 2, ..., 9 appearing only once. Applying the simple logical rules such as if..., then..., this auxiliary matrix is subsequently simplified in such a way that we reduce the set of alternative possibilities, where in a final stage each position of auxiliary matrix is occupied just by one integer from {1,2,...,9} and the resulting matrix satisfies the above mentioned constraints. The logical rules used may be hierarchically arranged in a sequence of increasing complexity of their preceding parts. Therefore, Sudoku puzzles may be classified according to the complexity of their solution; from the simplest puzzles to the most complex by using the rules and a back-track search., V práci je diskutovaný jednoduchý logický prístup k riešeniu hry Sudoku, ktorý môže byť taktiež interpretovaný ako mentálny model tejto hry. Použitý model využíva pracovnú maticu 9x9, ktorá je vytvorená z matice špecifikujúcej počiatočnú pozíciu hry tak, že prázdne pozície sú zaplnené alternatívnymi možnosťami určenými z počiatočnej pozície pomocou podmienok tak, aby každý riadok/stĺpec/oblasť 3x3 obsahoval čísla 1, 2, ..., 9 prave raz. Použitím jednoduchých logických pravidiel typu if..., then... túto pracovnú maticu postupne zjednodušíme tak, že redukujeme výskyt alternatívnych možností, až v konečnej fáze úpravy matice v každej pozícii máme práve jedno číslo, pričom táto výsledná matica vyhovuje vyššie uvedeným podmienkam. Použité logické pravidlá pre zjednodušenie Sudoku môžu byť hierarchicky usporiadané podl'a rastúcej zložitosti ich podmienky (antecedentu). Potom hry Sudoku môžu byť klasifikované podl'a zložitosti ich riešenia; od jednoduchých hier až po vel'mi zložité (diabolské), kde je potrebné použiť pravidlá, ktoré vo svojich podmienkach obsahujú spätné prehl'adávanie pracovnej matice., Vladimír Kvasnička, Michal Cádrik., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

128. Loschmidtovy představy o struktuře organických sloučenin, zejména benzenu

Creator:
Novák, Miroslav
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fyzika, organická strukturní chemie, physics, organic chemistry, 6, and 53
Language:
Czech and English
Description:
Před více než 150 lety Josef Loschmidt, později uznávaný fyzik, publikoval práci, v níž velice jasným a správným způsobem znázornil strukturu téměř čtyř stovek převážně organických chemických sloučenin a zejména jako první objasnil cyklickou strukturu benzenu. Bohužel tato jeho práce byla přehlížena a postupně zapomenuta, v evidentní neprospěch dalšího vývoje organické strukturní chemie., More than 150 years ago Josef Loschmidt, later a distinguished physicist, published a booklet in which he clearly and correctly depicted the structure of almost four hundred mainly organic chemical compounds, and above all deduced the cyclic structure of benzene. Unfortunately, this work was disregarded and gradually forgotten, which had a negative impact on the later development of organic chemistry., Miroslav Novák., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

129. Mach, relativita a kosmologie

Creator:
Bičák, Jiří
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
Mach, Ernst, 1838-1916, 19.-20. století, fyzici, teorie relativity, kosmologie, physicists, relativity theory, cosmology, Česko, Czechia, 6, and 53
Language:
Czech and English
Description:
We first recall the main features of Mach's radical attitude to the "philosophy of science", illustrated best by his criticism of absolute space and time, and discuss the impact of Mach's ideas on the birth of special and general relativity. The experiment to demonstrate "Machian effects" of dragging of inertial frames by a rotating body (carried out by four gyroscopes placed in an orbit around the Earth) was conceived in 1959 but only in 2014 was the satellite launched. The last results from the experiment were finally summarised at the end of 2015: they confirm the dragging as predicted by general relativity with an accuracy of 19 %. We show that a rotating black hole can even drag magnetic field lines and indicate possible astrophysical meaning of processes of this type. in the concluding parts, our investigation of dragging effects by gravitational waves and the study of Mach's principle in the context of cosmology, obtained in collaboration with Donald Lynden-Bell (Cambridge) and Joseph Katz (Jerusalem), are briefly reviewed., Jiří Bičák., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

130. Magion: první československá umělá družice

Creator:
Santolík, Ondřej
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
umělé družice, Magion (družice), artificial satellites, Magion (satellite), Československo, Czechoslovakia, 6, and 53
Language:
Czech and English
Description:
Nedávno uplynulo čtyřicet let od chvíle, kdy na oběžné dráze začal pracovat Magion, první československá umělá družice Země. Následovaly čtyři další stejnojmenní robotičtí průzkumníci blízkého vesmíru. Započali cestu, která v současné době míří k novým vědeckým přístrojům pro mezinárodní projekty družicového výzkumu okolí Země a pro meziplanetární sondy ke Slunci, k Marsu a k Jupiteru., The first Czechoslovak spacecraft, Magion, started measurements in a low-Earth orbit forty years ago. It was followed by another four robotic explorers of outer space bearing the same name. Magion started a journey, which today leads us to new scientific instruments on board Earth orbiting satellites and also interplatetary probes to the Sun, Mars and Jupiter., Ondřej Santolík., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public