Questions tagged [measurement]

37 questions
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First attempt to measure speeds using distance divided by time?

Did the ancient Greeks, for example, speak of number of paces per heartbeat? I could see them only saying, something moved with the speed of an arrow or a running horse or a running man but that they lacked a unifying concept of speed being distance…
releseabe
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Wavelength definition of the metre

Between 1960 and 1983 the metre was defined as being equal to 1 650 763.73 wavelengths of an orange emission line of krypton-86. How did they actually use that definition? Was it possible to move the mirror of an interferometer slowly over a…
jkien
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When was the speed of a bullet or cannon ball first measured?

I would assume that the early estimates were wildly off and wonder how this measurement was done.
releseabe
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In the world before thermometers did people use freezing points as a sort of proto-thermometer?

Last night I left a bottle of cleanser in my car, and during the 5-degree night the cleanser turned to a sludge. This started me thinking. Lots of people living before the development of the thermometer probably noticed that on cold nights some…
Chaim
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discrepancy between Rømer and Fahrenheit scale

Wikipedia states that Rømer temperature scale initially set 0 °Rø for freezing brine and 60 °Rø for boiling water. (He then slightly changed the scale, but the difference is irrelevant for my purposes). It also states that Fahrenheit started with…
mau
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partly a LANGUAGE question - uncia (Latin one-twelfth) is the source of both Inch and Ounce. Does anyone know the Greek or pre-Roman equivalent?

Much as per question - Uncia is the Latin for one-twelfth and thence is used for coin (As),length (Pes),weight (Libra), area (Jugerum) etc from whence derives inch and ounce. I can find nothing much about Greek fractions not even the name for…
J King
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What is the official logo of the BIPM?

The logo on the BIPM's (International Bureau of Weights and Measures) site is this: However, when I visit the English (and, most importantly, French) Wikipedia articles on BIPM, and also when I google "BIPM logo", I mostly get the following…
Alex
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Where is the Troughton scale kept?

The Troughton scale served as the first (de facto) standard of length in the United States, from 1832 until 1856. It is a measurement scale of 82 inches, subdivided to tenths of inches, on a silver inlay in a brass bar about 86 inches long (see…
linguisticturn
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When was sealevel discovered?

Or more broadly when did people start marking everything against a common level? Or say when was it known how many feet Rome was above the sea, or if New Delhi or Chengdu was higher?
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On the choice of Earth circumference vs diameter to define the meter

I think this is the appropriate SE to ask about the following, but feel free to tell me otherwise. As I remember it, the meter is a "human" or "natural" length, because it was choosen to be exactly 1/40000th of Earth's circumference. A few minutes…
Winston
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