HISTORY OF AVIATION

 

 

The history of aviation has extended over more then two thousand years from the earlist kites and attempts at tower jumping to supersonic and hypersonic flight by powered heavier - than - air jets. Leonardo da Vinci 15th - century dream of flight found expression in several raticnal but unscientific designs, though he did not attempt to construct any of them. efforts to analyze the atmosphere from the 17th to 19th centuries led to the discovery of gases such as hydragen, which in turn led to the inovetion of hydrogen balloons. Varous theories in mechanics by physicests during the same period of time, notably fluid dynomics and Newttons laws of motion, led to the foundation of modern aerodynamics.

 

the Wright Military Tlyer aboard a wagon in 1908

SUNDIAL

 

   

   Sundial time with the help of the virtual position of the Sun in the day sky. Usually via the shadow on a flat or guilty of throwing stick, urinary positioned under different angles. If it is properly made shows exactly throughout the year. 

   For the oldest Sundial is the tomb of Knowth in the Neolithic transition time in the Valley ofte river Boyne in Ireland (5000BC). Other ancient sundials and shadow clocks were obelisks (3500BC) of ancient Egypt and Babylon (1500BC). The first written note sundials can be traced in the year 742BC. The oldtestament for about a year 700BC describes the sundial-the time from Ahaze. Probably this i the earliest record of the sunny hours, witch cannot be faund. Solar watces are know also China, but little is know about them. the ancient Greeks developed several of the principlesand forms of the sunny hours. They also perfected tge geometry and the taper into the. The Romans adopted the Greek sundials.

         World's oldest sundial, from Egypt's Valley of the Kings (1500 BC)

                            PHOTOGRAPHY

Photography is the technique of permanent recording images in different ways. The word photography was first used in year 1839, created by John Frederick William Herschel. Photography was created in year 1519, when they invented camera obscura. First photography was monochrome or black-and-white. Monochromatich photographys are not necessarily composed of pure black,white and intermediate shades of gray, but can involve shades of one color depending on the process. For example, the cyanotype process produces photography composed of blue tones. Color photography was explored in the middle of the 19th century.The first permanent color photography was made in 1861.