The 2-Minute Rule for Inventions
A sphere has two/3 the volume and surface space of its circumscribing cylinder which includes its bases. A sphere and cylinder have been put on the tomb of Archimedes at his request. (see also: Equiareal map)
The last phrases attributed to Archimedes are "Never disturb my circles", a reference on the circles inside the mathematical drawing that he was supposedly researching when disturbed via the Roman soldier. This quotation is usually offered in Latin as "Noli turbare circulos meos," but there's no reputable proof that Archimedes uttered these words and they don't surface during the account supplied by Plutarch.
"He who knows almost nothing is nearer to the truth than he whose mind is stuffed with falsehoods and mistakes."
Stem cell educator therapy: Chinese and US scientists have produced outstanding outcomes for this new procedure of getting stem cells from human wire blood to "re-teach" misbehaving immune cells.
The 1st compact cassette tapes had been released in 1962 by Philips, quickly followed by the main dictation machine in 1963. Philips was unprepared for the popularity of their blank cassette tapes because they promptly turned used internationally for use in the Business, the house and from the bedroom For numerous wannabe singers.
Initially considerably less prevalent as being a armed service weapon than the jian – the straight, double-edged blade of China – the dao grew to become well-known with cavalry during the Han dynasty due to its sturdiness, superiority being a chopping weapon, and relative ease of use – it absolutely was usually said that it's going to take every week to attain competence that has a dao/saber, per month to achieve competence having a qiang/spear, along with a calendar year to achieve competence which has a jian/straight sword. Soon immediately after dao began to be issued to infantry, starting the alternative in the jian as an ordinary-concern weapon. Late Han dynasty dao had round grips and ring-shaped pommels, and ranged concerning eighty five and 114 centimeters in length. These weapons ended up used along with rectangular shields.
Keel: The adjustable centerboard keel traces its roots for the medieval Chinese Music dynasty. Numerous Music Chinese junk ships had a ballasted and bilge keel that consisted of wood beams sure together with iron hoops.
Kite: As published in the Mozi, the Zhou Dynasty philosopher, carpenter, and structural engineer Lu Ban (fl. 5th century BC) from the State of Lu designed a wood chicken that remained traveling during the air for three times, fundamentally a kite; There exists penned proof that kites ended up applied as rescue signals when town of Nanjing was besieged by Hou Jing (died 552) during the reign of Emperor Wu of Liang (r.
Cicero describes viewing the tomb of Archimedes, which was surmounted by a sphere along with click here a cylinder, which Archimedes had asked for be put on his tomb to signify his mathematical discoveries.
In the 2nd element, he calculates the equilibrium positions of sections of paraboloids. This was probably an idealization of your styles of ships' hulls.
 In between 1064 and 1067, the Puchin Bridge in the vicinity of Puchow, a floating bridge constructed some 350 many years earlier throughout the Yellow River, was destroyed inside of a flood. This bridge was made from boats secured by iron chains which ended up attached to 8 distinct cast iron statues Positioned on Each individual river bank, Forged in the shape of recumbent oxen. The flood pulled the get more info oxen through the sandy financial institutions to the river, exactly where they sunk to The underside; following this loss, the regional officials issued a proclamation for submission of Strategies regarding how to Recuperate the statues. The approach of your Buddhist monk Huaibing was accepted, which can be explained in the textual content Liang Chi Gentleman Chih of 1192, "he used two large boats full of earth, cables from them staying manufactured rapid to the oxen inside the river bed (with the drivers). Hooks and a huge counterweight lever were also used. Then the earth during the boats was slowly taken absent so which the boats floated Considerably bigger plus the oxen ended up lifted from the river base."
Bomb, Solid iron: The initial accounts of bombs manufactured from cast iron shells packed with explosive gunpowder—instead of previously forms of casings—had been published within the 13th century in China. The phrase was coined for this bomb (i.e. "thunder-crash bomb") in the course of a Jin Dynasty (1115–1234) naval struggle of 1231 in opposition to the Mongols. The Heritage of Jin (compiled by 1345) states that in 1232, because the Mongol typical Subutai (1176–1248) descended about the Jin stronghold of Kaifeng, the defenders experienced a "thunder-crash bomb" which "consisted of gunpowder put into an iron container ... then in the event the fuse was lit (and the projectile shot off) there was an awesome explosion the sounds whereof was like thunder, audible for in excess of a hundred li, as well as the vegetation was scorched and blasted by the heat more than an area of over half a mou.
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Rocket launcher: The earliest rocket launchers documented in imperial China released hearth arrows with launchers constructed of wood, basketry, and bamboo tubes. The rocket launchers divided the hearth arrows with frames meant to keep the arrows divided, and were able to firing various arrow rockets at the same time. Textual proof and illustrations of various early rocket launchers are present in the eleventh-century Northern Tune Dynasty textual content Wujing Zongyao.