# Tag Info

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The easiest way to check if something is "straight" is to just look. Humans can pretty much tell if something is not straight, to a certain point. Another easy way is to use a piece of string. If you pull their ends apart, it will provide you a "straight" reference which you can use to compare to other things. That way you can, for ...

31

Indeed, it is much easier to manufacture an arc of circle than a straight ruler. When you rub two rulers against each other you obtain an arc of a circle (or a straight line) as their common edge. This is because the only curves of constant curvature are straight lines and circles. So nothing else will slide smoothly, without gaps. But there is a simple way ...

11

To construct a right angle, you take three cords, one of which is three of whatever unit you use, the second four of it, and the third five. Put them together in a triangle and the angle between the three and the four ones will be a right angle. This was used for a long time in ancient Egypt and Babylon. (Alternatively, you can use some other of the ...

11

The interaction of physics and artillery begins with Galileo (there was no physics to talk about before that time except the statics). There are pictures in the books before Galileo which show completely unrealistic trajectories of projectiles. Galileo developed a computational device which he called the Geometric and Military Compass, which he produced and ...

10

From Quine's Quiddities, s.v. "Lines": My own heart leaps up a little when I behold what radically dissimilar criteria all attest to one and the same trite trait, the straightness of a line. I think of four. One way of testing straightness is by use of a taut string. This test recalls indeed the origin of our word line, Latin linea; it is related ...

8

Here is a partial translation of a Russian article about the history of semiconductors (part that addresses Soviet contributions): 1948-1950. Not only in the United States, but also in other countries there have been scientific research in the field of semiconductors. For instance, a Soviet physicist V.E. Loshkarev as early as in 1946 discovered the bipolar ...

6

There are quite a few methods. If you take three almost straight objects and grind pairs against each other, they will approach a straight edge. That is, given objects A, B, and C, you grind A and B against each other, then B and C, then C and A, etc. You need a material that is soft enough that it grinds away reasonably quickly, but is strong enough that it ...

5

lmgtfy google cache of mimivanderhave.com 1945 The first double-pane, insulated window was introduced That's without attribution; door and window claims From single to double pane windows… The true evolution of double pane windows originated in 1913 when the Andersen Lumber Co. became the first to manufacture wood window frames. In 1932 they ...

4

Historians believe that the extant version of Problemata was not penned by Aristotle personally, but “while the Problemata is not the genuine Aristotelian work, it nevertheless contains an element derived from such a work”. Problemata XXXII.5 discusses breathing under water, including the oft quoted passage interpreted as referring to a diving bell:”Why do ...

4

I think the resources listed above are good background references but if you want to know how logic was introduced to actual electronic equipment then consider Claude Shannon. At the age of 21, writing his MIT Master's degree thesis, he laid out the methods of how electrical applications of Boolean logic can carry out any logical or numerical process. This ...

4

Leonardo thought it was Archimedes (287-212 BC) who invented the cogwheel gears. This would make a neat story, but history is rarely neat. In a similar matter we know that Archimedes did not exactly invent the “Archimedes’s screw”, but rather perfected it, which led to its wide use in the Hellenistic period. One can speculate that something similar happened ...

3

There are good answers here. I would like to add that a great deal of pre-industrial construction is not straight at all. Cathedrals often have walls that bend or kink from one end to the other or became kinked or curved from top to bottom. I once looked at an apartment in a building built shortly before 1500 (in England). The ceiling of the bedroom can only ...

3

Drones fly on the same principles as the ordinary airplanes or helicopters. So the main difficulty in developing of drones was the problem how to control them, not how to make them fly. And this problem of control has nothing to do with birds or insects. Actually airplanes have also little to do with birds and insects because they use different aerodynamic ...

3

The best answer to that question is the following book: The steam engine of Thomas Newcomen by L. T. C. Rolt, J. S. Allen 1977 Moorland Pub. Co. ; New York : Science History Publications, To summarize what I learned from this book. The boilers did not generate enough steam pressure to move pistons. You needed to use the weight of the atmosphere for the ...

3

For Aristotle : Problemata Book XXXII, 960b,30-31 : “divers to respire equally well by letting down a cauldron”. Parts of Animals, Book II, 659a,5 : “Some divers, when they go down into the sea, provide themselves with a breathing-machine, by means of which they can inhale the air from above the surface while they remain for a long time in the water.” For ...

3

In physics, the four most important developments had nothing to with war or the preparation of war: Newtons calculus and his theory of gravitation, Maxwells equations, Einsteins theory of special and general relativity, Heisenbergs Matrix Mechanics in QM.

3

Not only war but preparations to war, military-related research had very large influence on the development of science and technology. Of the recent examples I mention GPS, Internet, space exploration, not even speaking of nuclear energy. GPS and satellite navigation in general were originally developed for military purposes, and most importantly the ...

3

The technology is that of the "Voder" and "Vocoder" exhibited at the 1939 World's Fair in New York City. See the Wikipedia articles on the vocoder and the voder for some explanations and references to Sci Fi movies using it, and to this 1939 film clip. There is a recent pop technology history book How to Wreck a Nice Beach on the subject. The first non ...

2

Plato already distinguished between different professions and also different intellectual capacities in his Republic. His master discipline was the statesman who placed all professions in the right place in the city - read republic - so that they can best flourish. This is his conception of the philosopher-king, he who marries well both thought and action. ...

2

There's a stop, or set of stops, on many cathedral organs called "vox humana." Granted these can only produce human-like vowel sounds, but that's the first "synth" I know of. Now, prior to modern "text to speech" digital software, there was a period in the 1970s and early 80s when a limited, hardwired, voice synth was available. See for example "Firepower"...

2

In 2006 a fragment of a cogwheel was discovered in Olbia (Italy); the layer where the fragment was found has been dated to the second quarter of the 2nd century BCE (https://www.academia.edu/35795869/Un_frammento_del_Planetario_di_Archimede_da_Olbia, p. 1788). The striking characteristic of this cogwheel, however, is that its teeth are not triangular but ...

2

Just to add to the posts that talk of the need to define tolerance, two examples that I am fond of: The British surveys of northern India during the 19th century, when Mt. Everest was discovered, it was also discovered that a plumb bob in that region measurably misses the center of the earth due to the gravitational attraction of the Himalayas. See a brief ...

2

Copernicus theory was crucial for the development of all sciences. It made possible Kepler's discovery of the true planet orbits, and this lead to the discovery of the Law of the Universal gravitation. The Law of universal gravitation was a real scientific revolution. Among its immediate practical consequences were establishing of the true shape of the Earth,...

1

Since the beginning of time, people discovered that if you rub two stones together with some abrasives in between they form a flat surface. They also discovered that if you rub 2 stones together the surface may come concave, i.e we identical curvature on both stones. The solution is to use 3 stones. This method is still valid now and still in use for ...

1

I'm surprised no one mentioned the Whitworth Three Plates Method, a process that were used to make surfaces very flat using gravity, which you can read about in great detail here: https://ericweinhoffer.com/blog/2017/7/30/the-whitworth-three-plates-method

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Mostly, gravity. To get things perfectly flat people would use water. a tube with 2 graduated cylinders on either end. Raise/lower one end until the water is at the same level in both cylinders and you have your level. In terms of getting things perfectly vertical, they would use (and we still use this today), a piece of string with a weight on the end. Once ...

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