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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 and why?
Big Brother
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Why is the meaning of "linear" different in school and college use?
Is the map $y=2x+3$ linear?
"Of course it is." -- a high school teacher will answer.
"Nope; it's affine, but not linear." -- a college student will contradict.
This difference terminology that basic ought to have historical roots. Could you point…
Michael
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I am searching for a book of this form and content, is there any?
I would like to know is there a book that is both a history of mathematics and a collection of open problems?
I know that there exist many books that cover either larger or smaller periods of the history of mathematics and also a number of books…
user10044
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Notable theories on the far side of the moon pre 1959
On October 7th 1959, the soviet Luna 3 probe took the first picture of the far side of the moon.
It has been known since ancient times that the moon was a sphere. It would have doubtless been observed that the moon always seemed to present the same…
Ingolifs
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Euler's Derivation of Euler's Method for ODEs
I am looking for an English translation of Euler's derivation of Euler's method for ODEs, namely the update
$$
y_{n+1} = y_n + h f(y_n, t_n)
$$
What motivated Euler to consider this problem, and how does he develop the idea?
user14717
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Usage of reverse side of circular slide rule
I have a circular slide rule, but I can't figure out what the markings on the back are used for.
The front face has two logarithmic scales, the outer one runs from $1$ to $100$ (exclusive), and the inner scale runs from $1$ to $10$, so it's easy to…
Greg Nisbet
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Why would Margaret Hamilton and her team at NASA print the code on paper?
This famous photo depicts Margaret Hamilton, leader of the software engineering team for the Apollo Project, next a print out of the code she and her team wrote for the mission.
This information is correct according to this Skeptics SE post and…
user2723984
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Refraction in Newton's Corpuscular Theory of Light
Newton's theory of light stated that a light travelled in a straight line as small particles. When these particles travelled in a medium, they experienced an attractive force with the particles of the surrounding medium. This attractive force was…
Mrinaank Sinha
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How was it discovered in the 19th century that electric or magnetic forces were not instantaneous?
Marc Lange writes (page 29)
It was known by about the 19th century that any action at a distance involving electric or magnetic forces would be retarded and so undermine not only spatial locality, but also temporal locality.
How was it discovered…
Frank Hubeny
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Equivalence principle before Einstein
In a German interview some physicists were asked, what they would ask Einstein, if he were alive today. One of them wanted to know how Einstein came up with the idea of the equivalence principle, that inertial mass is the same as gravitational mass.…
Maxim
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Meaning of a cryptic sentence by Gauss on "the mobility of figures in the hyperbolic plane"
G. Waldo Dunnington writes in pages 189-190 of his biography of Gauss:
Among the axioms of geometry which do not depend on the parallel postulate are those which secure the free mobility of a figure in space. This means that space is the same in…
user2554
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Can we fairly assess Ada Lovelace's talent for mathematics?
Dorothy Stein, a biographer of Ada Lovelace, was pretty blunt in her assessment: Lovelace was a mediocre mathematician, for example see here.
I wonder if she's fair to her. The fact that Lovelace translated a printer's error "cos" (like cosine)…
viuser
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Did old Crookes Radiometers ever have a pair of terminals?
This is a question about old physics lab equipment.
This and this question led to the question in SciFi SE Crookes Radiometer at the end of a telescope in old movie scene, something about a comet? which led to the image below.
Of course one does not…
uhoh
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Looking for references to an experiment on the evaporation rate of water in sunlight
I remember reading a long time ago about some experiments measuring evaporation rate of water in large open containers (tubs) sitting on open ground. It was a simple experiment, each day the water level would be checked and recorded. From what I…
uhoh
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High voltage / current sources in 19th century cathode ray experiments
In modern chemistry textbooks, a DC source (battery symbol) is usually shown for cathode ray tube experiments by Thomson and others. Certainly, no battery can provide very high voltages needed for gas discharge experiments. Similarly, Roentgen…
AChem
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