Mechanics in XXI century

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Здесь приводятся наиболее яркие достижения в области механики за годы, прошедшие с начала третьего тысячелетия.

Achievements on planet Earth

• On August 1st, 2012 the Russky Bridge was opened in Vladivostok. The main bay of the bridge reaches 1104 meters in length which makes the bridge to be the longest among cable-stayed bridges in the world. Before the bridge was built Sutong Yangtze River Bridge (China) was the longest. Construction of the bridges from early ages defined technology level of countries where the bridges were built. It required deep knowledge of mechanics in order to construct them. It is easy to recall several catastrophes due to incorrect analysis of the bridge structures. The examples are The Tay Bridge disaster in 1879 (UK) Tacoma Narrows Bridge disaster in 1940 (USA). In both cases the catastrophe occurred due to incorrect dynamic analysis of the bridge subjected to wind loading.

• On January 4th, 2010 The Burj Khalifa was opened in Dubai, UAE. Its height equals 828 meters which makes it the tallest structure in the world. Before the skyscraper was built the tallest structure was Warsaw radio mast which collapsed in 1991. The significant height of the structure required solving a number of complex mechanical problems among which were the structure’s stability analysis, resistance to the wind loading, construction of high altitude elevators and water supply systems.

• On January 5th, 2005 a group of American astronauts discovered Eris which is a dwarf planet situated farther than the orbit of Pluto. Eris’ weight and size exceed the weight and size of Pluto. This discovery together with the discoveries of a number of smaller objects of the size compared to Pluto’s size that took place in 2000-2005 lead to rethinking of what a planet is and how the Solar System is organized. As a result, Pluto lost its status of a planet and together with the similar objects was classified as a dwarf planet. The number of planets in Solar System have decreased to 8. It is worth noting that the way the planets orbit the sun is entirely a mechanical problem, which solution actually helped to discover the 8th planet, Neptune.

• On October 22th, 2014 an article (Novoselov et al. 2004) was published by British and Russian scientists in the Science journal. It reported a purely mechanical synthesis of graphene, a two-dimensional material comprising of a single layer of the carbon atoms. In 2010 the two authors, Geim A.K. and Novoselov K.S. were awarded the Nobel Prize in Physics for "groundbreaking experiments with two-dimensional material graphene." The existence of two-dimensional materials was previously considered impossible. Graphene has unique mechanical properties, its rigidity and strength superior to all the known materials. In addition, being essentially a two-dimensional material, it allows one to take a fresh look at the theory of plates and shells, which was previously treated primarily as an approximate theory to describe three-dimensional objects.

• On December 3th, 2001 American inventor Dean Kamen introduced The Segway, a compact electric driven vehicle allowing a person to ride it in a standing position. The device has two wheels on the each side of the driver, the vertical position stabilization of a human is performed by a system that regulates the rotation speed of the wheels. Segway is similar to Kapitza's pendulum, a pendulum that is stabilized in the vertical position by vibration. It was investigated by Academician Kapitsa P.L. in his pioneering work (Kapitsa, 1951). Segway takes a little more space on the road than an ordinary pedestrian, but it can move at a speed up to 20 km/h over rough terrain, the battery provides a mileage of about 40 km. Over the past decade Segway has gained popularity in the tourism sector, Segways are used by the police in some countries. The further spreading of Segways is hindered by their relative high cost, however, it is clear that the development of technology will solve this problem.

Achievements in space

• On August 6th, 2012 The Mars rover Curiosity (USA) is safely delivered to the surface of Mars, that has served as the beginning of a new research mission on Mars. Curiosity can call full-fledged laboratory on wheels (weight of 900 kg), the robot of the similar size and complexity never studied other planets before. The equipment that was produced in Russia is installed on its board too.
• On October 9th, 2009 As a result of an impact experiment the LCROSS has found water ice in the polar region of the Moon. The presence of water on the Moon surface makes possible its future colonization.
• On May 25th, 2008 The Phoenix spacecraft (USA) has landed in the polar region of Mars. The conducted researches have allowed to find the water ice under a layer of soil. Availability of water testifies a possibility of existence of the living organisms on Mars in the past, and, perhaps, at the present.
• On January 14th, 2005 spacecraft Huygens has made landing on the surface of Titan, the largest satellite of Saturn. It has been found that under a thick layer of the atmosphere at the surface of Titanium there are rivers and lakes of liquid methane. It has served promotion of a hypothesis of a possibility of existence of life on the Titan on the basis of methane (instead of water) and hydrogen (instead of oxygen).
• On January 4th and 25th, 2004 Mars rovers, Spiritand and Opportunity (USA) are delivered to the opposite sides of Mars. During the movement on the red planet, mars rovers researched its surface and composition of the atmosphere, transferring data and high-quality photos to the earth. Results of researches, in particular, have confirmed existence in the past of liquid water on Mars.

Антидостижения XXI века

• 8 июля 2011 года состоялся последний старт по программе «Спейс Шаттл». В настоящее время Россия остается единственной страной, выполняющей пилотируемые полеты на Международную космическую станцию. Программа полетов шаттлов была сильно подорвана гибелью шаттла Колумбия 1 февраля 2003 года, разрушившегося при входе в атмосферу. Причиной катастрофы послужило нарушение теплозащитной поверхности челнока, вызванное падением на него куска теплоизоляции кислородного бака при старте корабля.

• 26 ноября 2003 года состоялся последний полет «Конкорда», чем была завершена эра гражданской сверхзвуковой авиации. Катастрофа, приведшая к гибели «Конкорда» 25 июля 2000 года при вылете из парижского аэропорта «Шарль де Голль» стала одной из основных причин прекращения эксплуатации «Конкордов». Катастрофа произошла в результате наезда колеса шасси на металлический обломок, случайно оказавшийся на взлетной полосе, что привело к повреждению обшивки, утечке топлива и возгоранию.

• 11 сентября 2001 года в результате беспрецедентного теракта был разрушен Всемирный торговый центр (ВТЦ) в Нью-Йорке. В высочайшие небоскребы Нью-Йорка, башни-близнецы ВТЦ на полной скорости врезались управляемые террористами гражданские самолеты Боинг 767. Башни выдержали удар самолетов, однако возникший в них пожар привел к обрушению зданий менее чем через два часа после столкновения. Причиной разрушения явилось то, что несущие стальные колонны начали изгибаться под действием высокой температуры и перераспределившейся нагрузки, из-за чего был превышен предел прочности материала колонн. В результате началось обрушение верхних этажей, породивших цепную реакцию — здания сложились по принципу карточного домика. Только спустя 5 лет началось строительство новых зданий на территории ВТЦ.

См. также

• Новости науки и техники
• Механика на стыке с другими областями знаний
• Механика

Ссылки

• Список новых перспективных технологий
• Популярная механика (интернет-портал и сайт журнала).
• Timeline of scientific discoveries
• Ten science stories that changed our decade
• The 7 Greatest Scientific Achievements Of The Last 50 Years