Questions tagged [measurement]

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6
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1answer
220 views

How were negative numbers first used in physics?

The use of negative numbers in most of today's calculations is natural. But how did the use of negative numbers began in physics? What physical quantity required the introduction of negative numbers ...
6
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1answer
134 views

When and how did usage of the term Centigrade give way to Celsius? Are/were they in fact numerically identical?

Discussion below the question Does the US National Weather Service use Celsius or Fahrenheit? and correction of my original use of "Centigrade" to the modern Celsius lead me here. For example, in the ...
2
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1answer
50 views

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 ...
2
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1answer
97 views

Why does the US keep survey miles and feet?

The United States adopted the international mile and foot in 1959, but for some reason they decided to keep alongside the older units as survey mile and survey foot. These units are almost equal to ...
2
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1answer
114 views

Was the value of the mole invented or discovered in chemistry?

For example, $\pi$ is not an invention, it is a discovery which was natural, that is ratio of the circumference of a circle to its diameter. But when we define a meter it is not a natural value it is ...
0
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1answer
82 views

How was the historical definition of the meter used in practice?

The meter was initially defined as $10^{-7}$ times the distance of the north pole to the equator. How exactly was this definition used to fabricate the actual meter sticks from which the standard ...
1
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1answer
248 views

How did people measure electric charge at the time of Coulomb?

Around the time that Coulomb gave Coulomb's law, how did people measure electric charge?
0
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1answer
70 views

Metre definition using a seconds pendulum

I have always heard that the first and most prominent definition of the metre was to use the length of the seconds pendulum - pendulum with the period of exactly 2 seconds. However, in the end it was ...
-2
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2answers
176 views

How did the integer degrees angles counting being first adopted in geometry and mathematics? [duplicate]

The purpose of this question is trying to know originally how did counting in integer degrees angles from (one degree to $360$ degrees) being adopted basically in geometry, despite the impossibility ...
5
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1answer
103 views

Do astronomers still use decimal time?

Wikipedia states that decimal time - where the time of the day is expressed as a decimal part of the day - "have been used by astronomers ever since [Laplace introduced them]". An example by Herschel ...
2
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0answers
61 views

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)...
3
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2answers
98 views

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 ...
0
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2answers
88 views

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?
2
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1answer
199 views

Is it known where Eratosthenes first heard of the “well of Syene”?

The American Physical Society's This Month in Physics History; June, ca. 240 B.C. Eratosthenes Measures the Earth says: Eratosthenes had heard from travelers about a well in Syene (now Aswan, Egypt)...
2
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1answer
202 views

Who is the Westphal behind the Mohr-Westphal specific gravity balance? And how exactly did he improve on Mohr?

I'm a Spanish Physics undergrad, and I was writing a report on an experiment we did on the lab, in which we had to measure a solid's density using the so-called Westphal balance (aka Mohr balance, and ...
4
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2answers
295 views

What did the ratio of two magnitudes mean to ancient Greek mathematicians?

My understanding is that magnitudes to ancient Greeks meant the actual line segments and plane regions (not the size of the line segment or the area of the plane region), the concept of ratio was then ...
2
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2answers
1k views

How did people count seconds before clocks were invented?

How did people count seconds? How did people count minutes? How come that every second of a clock takes exactly as much time as needed to be 86400 to fulfill 24 hours and 31536000 to fulfill a year? ...
0
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2answers
56 views

History of the word “scales” in graphing

I am curious to know who first used the term "scale" in graphing, and what exactly did they mean. Depending on which dictionary you use, a scale can mean "a coating" or a scale can mean a device for ...
3
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1answer
78 views

Lise Meitner's contribution to this experimental apparatus and research effort?

I am reading a NYTimes obituary of Otto Hahn and the discovery of fission, and I've asked in physics SE about the function of the apparatus shown in that article. The system shown demonstrated the ...
4
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1answer
95 views

History of cubit - Galilei, Kopernik, Newton

Can cubit from Galileo Galilei books " Dialogue Concerning the Two Chief World Systems", "Two New Sciences", Newtons "Philosophiae Naturalis Principia Mathematica" or Mikołaj Kopernik books convert to ...
5
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2answers
942 views

When was the measurement problem solved?

I have been looking into the measurement problem that arises when considering different interpretations of quantum mechanics. Nowadays it seems to be considered a solved problem (in fact some people ...
18
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3answers
7k views

Who first measured the distance to the Moon? How was it done?

Who first measured the distance to the Moon? How was it done? I think it had to happen after Newton, but I am not sure.
11
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2answers
312 views

Why does the statute mile have the length that it has?

Why was our (statute) mile established as it was? This happened in 1593, by the order of Elizabeth I which said: "A Mile ſhall contain eight Furlongs, every Furlong forty Poles, and every Pole ...