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53 votes
Accepted

Why do we call Tycho Brahe by his first name?

The short answer is that this is how he referred to himself. He was born Tyge Otteson Brahe but at the age of 15 (1561) changed 'Tyge' to Latinized 'Tycho', see Redd's biography of Tycho and Thoren's ...
Conifold's user avatar
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26 votes

Did Galileo Galilei believe in astrology?

Galileo not only believed but taught and actively practiced astrology, like Ptolemy and Kepler before him. His primary source might have been Porphyry’s commentary on Ptolemy's Tetrabiblos. In ...
Conifold's user avatar
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25 votes

When was it realized that the giant planets do not have solid surfaces?

Prehistory goes back to the second half of 19th century after Fraunhofer introduced astronomical spectroscopy, and then Kirchhoff identified some spectral lines in the Sun's spectrum in 1860s. ...
Conifold's user avatar
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22 votes
Accepted

How did Ptolemy know that days were unequal lengths?

You are right: at the time of Ptolemy they could not measure the length of a day directly. Actually Ptolemy never discusses any clocks in his book, he probably used some crude devices record the ...
Alexandre Eremenko's user avatar
16 votes

Has science fiction ever caused scientists to do real research?

Science fiction author Arthur C. Clarke is often credited with the idea of communication satellites. link That was in 1945, long before any artificial satellite had been launched in reality.
Gerald Edgar's user avatar
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15 votes

First to realize that seasons were reversed above and below the equator?

In the Purgatorio (c.1310) Dante places Mount Purgatory at the antipodes of Jerusalem and follows the rules of hard SF by thinking out all the consequences. Longitude and time zones - this may be the ...
Martin Kochanski's user avatar
14 votes

How did Eratosthenes determine that Alexandria and Syene were on the same meridian?

We do not know. First, Syene and Alexandria are not on the same meridian, Alexandria is about 3° to the West, and second, Syene is not on the tropic (where the Sun is straight up on the summer ...
Conifold's user avatar
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14 votes
Accepted

Did Bacon analogize planets to holes in the head to explain why their number was (believed to be) seven?

This probably refers to the "argument" of the Florentine astronomer Francesco Sizzi against the validity of Galileo's discovery of the moons of Jupiter. His "argument" was ...
Conifold's user avatar
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12 votes

Did the ancient Chinese know the earth is a sphere?

There appear to be conflicting accounts of when the Chinese came to view the earth as spherical. Chinese sources might suggest the 11th century, while western sources suggest the 17th century. ...
nwr's user avatar
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12 votes
Accepted

Did Caroline Herschel know about the discovery of Neptune?

The answer is yes, she did know. Remarkably she was informed of the news mere days after the discovery in a letter from Alexander von Humboldt dated September 25 1846 which accompanied the Gold Medal ...
Krishna's user avatar
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11 votes
Accepted

Is Koestler's ‘The Sleepwalkers’ still well regarded? Is there a more recent similar source?

As the question says, Arthur Koestler in 'The Sleepwalkers' "isn't shy of taking a point of view of the events he's describing". Koestler's book offered a gripping collective account of ...
terry-s's user avatar
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11 votes
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Could ancient astronomers have proven heliocentrism?

You can't ever "prove" heliocentrism! (We can't even today. Thinking that science "proves" things is not at all helpful in doing science.) What we can do is show that a ...
Mark Olson's user avatar
10 votes

Hidden agenda of the Galileo trial?

The Assayer & Redondi's "G3" Michele Camerota's 2008 Complete Dictionary of Scientific Biography entry on Galileo describes this theory in a section entitled "Atomism and the ...
Geremia's user avatar
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10 votes
Accepted

Why was China slow to recognise the sphericity of Earth?

It is hard to say why history happened one way rather than another. But we can point at some differences between ancient Greece, Hellenistic Mediterranean or Renaissance Europe and ancient and ...
Conifold's user avatar
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10 votes
Accepted

What did the ancient Greeks know about the solar system, and how?

No they did not know this. The motion of the Sun, Moon and planets (as seen from the Earth) was known, in the sense that it could be predicted with reasonable accuracy. To do this, they used an ...
Alexandre Eremenko's user avatar
10 votes

First to realize that seasons were reversed above and below the equator?

One does not need heliocentrism for this. The path of the Sun in the sky (as seen from the Earth) was well understood in Hellenistic times, and probably long before that. It was also understood how ...
Alexandre Eremenko's user avatar
9 votes

Did Indian astronomers realize the sphericity of the earth independently of the Greeks?

(I started writing this answer from memory, but on a second look at some sources it turns out to answer the question for the statement of a rotating earth rather than that of a spherical earth... but ...
ShreevatsaR's user avatar
9 votes

Has science fiction ever caused scientists to do real research?

One such case comes to my mind: Jules Verne's novel Green ray (1882). Jules Verne popularized this rare phenomenon, and it seems that it has not been scientifically studied before. After Jules Verne ...
Alexandre Eremenko's user avatar
9 votes

Did Galileo Galilei believe in astrology?

The Galileo's astrology activities are well summarized in Conifold's answer. But, in relevance to the question at hand (did he believe it worked) I'd like to make a couple of points: The fact that ...
Tziolkovski's user avatar
8 votes
Accepted

Did Kepler arrive at his planetary laws based on Mars's orbit alone?

This is a natural question given Kepler's own account of his discoveries in his most famous astronomical work, Astronomia Nova. It is a fascinating story of of how he arrived at the idea of the first ...
Conifold's user avatar
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8 votes
Accepted

Did Galileo really see Galilean Moons?

There can be no doubt that he has seen them, for the simple reason that he determined their periods and configuration correctly, and published them. Therefore the other things (magnification of his ...
Alexandre Eremenko's user avatar
8 votes
Accepted

How scientifically valid were Galileo's heliocentric arguments?

I assume the doubts refer to the commentary on Dialogue Concerning the Two Chief World Systems in The Galileo affair: who was on the side of rationality? on Less Wrong. I do not believe that Galileo's ...
Conifold's user avatar
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8 votes

Has science fiction ever caused scientists to do real research?

While it may not be research exactly, the fictional cases of Sherlock Holmes did actually influence the way real world police agencies and detectives approached forensic science. Sir Arthur Conan ...
citrus128's user avatar
  • 181
8 votes

Has science fiction ever caused scientists to do real research?

Paul Krugman's research was caused by Isaac Azimov's Foundation novels. (For this answer, you have to accept economics as a science and you have to accept "caused scientists to do real research" in ...
user10089's user avatar
8 votes
Accepted

Was Captain Cook’s voyage to observe the transit of Venus going to enable better ship navigation at the time?

Cook's voyage had multiple purposes. One of them was observing the transit of Venus. Transit of Venus is a rare event, important for astronomy, but it has no direct bearing on navigation. Study of ...
Alexandre Eremenko's user avatar
8 votes

How did Eratosthenes determine that Alexandria and Syene were on the same meridian?

He may simply not have cared. A reasonably small distance along the east-west axis will only lead to a very small error in the distance along the north-south axis. E.g. an azimuth of 190° instead of ...
Jan's user avatar
  • 181
8 votes

Where did Ptolemy compare the Earth to the distance of fixed stars?

Ptolemy's argument can be simply explained in plain English. If the distance to stars was comparable to the size of the Earth, the stars would experience a diurnal parallax, that is the visible ...
Alexandre Eremenko's user avatar
8 votes

What was the "libration of Pallas" that Gauss studied, when Pallas is not a moon of Jupiter?

"Libration" loosely refers to longitudinal oscillations due to orbital resonances. The tidal lock and the trojans, the only situations that Wikipedia mentions, are just special cases. The existence of ...
Conifold's user avatar
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