Questions tagged [history]

Questions regarding the history of astronomy, including discoveries and scientists.

Filter by
Sorted by
Tagged with
1
vote
0answers
54 views

When we say a variable star is “fainting” does it mean something more or different than “dimming” or “fading”?

A comment below the question Does the current “fainting” of Betelgeuse show any spectral trends that differ from it's normal variability? suggests that "dimming" would be a better term, but I have a ...
5
votes
2answers
120 views

What exactly is interplanetary scintillation; what was the Interplanetary Scintillation Array looking for? Did it successfully observe any?

The Interplanetary Scintillation Array is the radioastronomy observatory (i.e. big antenna) where the first pulsar was discovered by then graduate student Jocelyn Bell Burnell through careful and ...
16
votes
8answers
3k views

Has great eyesight been necessary for astronomers?

In a different (but somewhat related) field, some baseball stars have been known to have "baseball eyes." That is, an exceptional ability to visually follow the trajectory of a 90+ mph baseball to a ...
7
votes
3answers
213 views

When did people discover that the Earth is not an ideal sphere, but a little flattened?

When did people discover that the Earth is not an ideal sphere, but a little flattened? And if you know, who was the first person to discover it?
2
votes
0answers
35 views

Syncing time for measuring the parallax of Mars

I read somewhere (I can't remember the website) that when Cassini and Jean Richer measured the parallax of Mars, they used Jupiter's (or maybe Saturn's) moons to sync their time. How was this done?
5
votes
2answers
303 views

“Table of Astronomy's” depiction of the solar system models

This is going to be a follow up question to my question about the "Table of Astronomy" from yesterday, What is this “Table of astronomy” about?. I wanted to take a close look at the three depiction ...
1
vote
2answers
79 views

The size of Copernicus’ and Ptolemy’s corrections

I understand that both Copernicus and Ptolemy needed epicycles, but one might assume that a heliocentric system would need much smaller corrections to account for the non-circular motion of the ...
2
votes
1answer
66 views

What's the origin of Clyde Tombaugh's 9-inch Newtonian telescope?

Astronomer Clyde Tombaugh is shown in a now-famous photograph at the age of 24 with his "homemade" 9-inch Newtonian telescope in this image also shown in Elva R. O'Hara's Clyde W. Tombaugh: Farm Boy ...
4
votes
0answers
61 views

When was it realised that most major moons orbit in the equatorial plane of their parent planets?

Inspired by the discussion of the moons of Uranus providing a clue to the planet's axis of rotation in this question, I'm wondering when it was realised that the major satellites are typically located ...
3
votes
1answer
116 views

Uranus' axis of rotation-when discovered?

Who discovered it, and how was that accomplished. I had assumed it was known before Voyager 2 arrived at the planet since it isn't mentioned in JPL voyager 2 Uranus Approach
3
votes
1answer
110 views

Tycho Brahe's model

Tycho Brahe made a model of universe where earth is at the centre and motionless whereas all other planet orbited around the sun. I am interested to know how he came to this model? If it is because ...
2
votes
3answers
141 views

Nicolas Copernicus discovery

As I was reading about the heliocentric model, a question came up: How was Nicolaus Copernicus able to figure out that the sun is at the center of the solar system, and that all planets orbit around ...
1
vote
2answers
57 views

Did Edmund Scientific 4¼ inch Newtonians have 90° prisms as secondary mirrors in the 1970's?

I mentioned my old telescope's secondary mirror in this answer (stiffness) but I'm not certain I am remembering correctly. My first telescope was a Edmund Scientific 4¼ inch Newtonian reflector. This ...
6
votes
1answer
147 views

When did the first annular eclipse happen?

A few hundreds of millions of years ago, the moon was closer to the Earth than it is today and hence was of a bigger apparent size. This made every solar eclipse either total or partial. Over the ...
3
votes
1answer
164 views

Sorting out Julian Day, Julian Date, Julian Day number, Julian Day Calendar, and Julian Day Table

In this answer I mention day number which is 1 on the first day of each calendar year (January 1) and increments to 365 or 366 on December 31 of that year. There was an edit proposed, which included ...
2
votes
0answers
94 views

How was the astrometry of the famous 1919 solar eclipse confirmation of General Relativity calibrated and verified?

The new New York Times article The Eclipse That Made Einstein Famous describes several events and discussions on the hundred year anniversary of the the 1919 solar eclipse and verification of the ...
3
votes
1answer
59 views

Reference: First spectrographic observations by Fraunhofer

In several books I find reported that the first scientist to perform spectrographic observations of celestial objects was Fraunhofer with the spectrographs he himself produced. I do not find though a ...
2
votes
1answer
150 views

What is the origin of the term “plane of the spirit level”?

I have heard the term "plane of the spirit level" e.g. the sun's shadows is X degrees to the plane of the spirit level to signify the surface of the earth and I see it is a common term used in ...
0
votes
1answer
58 views

Tycho Brahe Danish Astronomer Religious?

Does anyone know if Tycho Brahe was religious?
4
votes
1answer
83 views

Are there recommendations to use “Hubble-Lemaître constant” instead of “Hubble constant”?

The IAU recommends renaming the Hubble law as the Hubble-Lemaître law, as discussed at its General Assembly in 2018 (see this press release and the links therein). I have now stumbled upon an ...
11
votes
2answers
220 views

What was the first astronomical measurement which demonstrated that “the Earth is surrounded by vacuum”?

The question Who was the first to realize that the Earth is surrounded by vacuum? was closed because some users felt it was answered by answers to a different question in an different SE site: Who was ...
2
votes
2answers
101 views

Has stellar evolution ever been modeled analytically?

I'll still remember the handout my astronomy professor gave us more than several decades ago; Our Friends the Polytropes. We spent a lot of time learning how polytropes, simple analytical power-law ...
7
votes
1answer
181 views

First observation that the Sun and Jupiter (and friends) move around a common barycenter?

Answers to the question How did Kepler determine the orbital period of Mars? describing careful observations centuries ago got me thinking. What was the first analysis of observations that directly ...
2
votes
1answer
126 views

First observation that the movement of a planet or asteroid in its orbit was affected by another planet?

Answers to the question How did Kepler determine the orbital period of Mars? describing careful observations centuries ago got me thinking. Question: What was the first analysis of observations that ...
22
votes
1answer
3k views

What's the reason that we have a different number of days each month?

It always was interesting for me to understand the answer for the question: What's the reason that we have a different number of days each month? If the month is fixed on the time that the moon ...
2
votes
1answer
434 views

How does making a refracting telescope very long reduce the chromatic aberration of an uncorrected lens?

Below are two cropped views of "Johannes Hevelius's 8 inch telescope with an open work wood and wire "tube" that had a focal length of 150 feet to limit chromatic aberration." from Harvard University, ...
4
votes
2answers
116 views

Scientifically important discoveries with the help of amateurs

I am looking for examples where amateur astronomers in these days contributed sigificantly to important scientifically discoveries. I am aware of one example: Victor Buso from Argentina was lucky ...
2
votes
3answers
193 views

How did Johannes Hevelius' long telescope work? Why all the round holes?

The drawing below, found in Wikimedia and at lib.harvard.edu is of a very long tubed aerial telescope. I believe it is taken from his 1673 work Machinae coelestis. I've always wondered about the ...
2
votes
1answer
55 views

From CMB anisotropy data observed in 1992, did astronomers figure out that the universe should be accelerating before its discovery in 1998?

CMB anisotropy was measured in 1992. I assume that astronomers, then, like now, would have been able to deduce the cosmological constant and things like that from the CMB anisotropy data. Then, from ...
8
votes
0answers
212 views

What are Kepler's laws (as he wrote them)?

There are of course many, many sources that quote Kepler's laws of planetary motion. This is preventing me from finding out what I really want to know: which is - what are Kepler's laws as he wrote ...
0
votes
1answer
55 views

How was calculating the celestial latitude using an astrolable of any help to sailors?

I'm sorry if this sounds like a silly question but I don't understand how measuring the location of a star would help in sea navigation.
7
votes
4answers
245 views

Do astronomers have an established, systematic way for saying what does or doesn't orbit what? (e.g. “Mars orbits Earth”)

A recent comment An object far enough away can certainly orbit the Moon and the Earth (and the Sun) -- Mars, for instance does this. An object in the Earth-Moon L2 is also orbiting both the Earth ...
11
votes
3answers
673 views

Has anyone ever tried to make a simple telescope using ice?

I grew up with long cold winters, and saw a lot of remarkably transparent ice formed by refreezing meltwater, both in puddles and ponds, and in large icicles. I'd always thought about making optical ...
3
votes
2answers
201 views

What are the RAs of the boundaries between traditional zodiacal signs?

I'm trying to figure out at what right ascension (RA) — not celestial longitude — the sun enters the various traditional (Western) astrological signs of the Zodiac; but I can't figure out how to ...
8
votes
2answers
657 views

Which telescope's model is being shown to Albert Einstein in this file footage? What event might this be?

In the Economist video Why does time pass? there is some file footage of Albert Einstein attending some event where a model of a large telescope is on display, and being described to Prof. Einstein. ...
3
votes
1answer
42 views

The systematic review of past observations in the hope of finding things that may have been missed

I seem to remember a TV science programme which re-examined the slides that led to the discovery of Pluto and then took a fresh look at earlier slides taken of the space which Pluto was passing ...
2
votes
1answer
101 views

When did the concept of “celestial sphere” fall?

I'm just done reading The Great Ptolemaic Smackdown, and it provided a good timeline of establishing heliocentrism, broad acceptation of Kepler's system, and the initial (failed) Galileo's experiment ...
5
votes
0answers
100 views

Which astronomer set his beard on fire because he left the cap off his telescopes finder?

There is a famous story of an experienced astronomer setting his beard on fire because he left the cap off his telescopes finder. I know it's said to be true of Galileo, but I thing it's relatively ...
25
votes
9answers
11k views

Simple experimental evidence that Earth revolves around Sun

What are the simplest experiments or calculations that give evidence that the earth revolves around the sun? Can you please explain them and reference the history? Many simple explanations such as ...
29
votes
2answers
3k views

We know what a nova is, but how?

I work with astrophysicists and require some basic knowledge of many astronomical sources, however research priorities often demand that most of human knowledge on a subject be taken for granted. I ...
5
votes
2answers
1k views

How did the authors of Surya Siddhanta find the diameters of other planets in the solar system?

The Surya Siddhanta, "a Sanskrit treatise in Indian astronomy from the late 4th-century or early 5th-century CE" is truly a great work. But how was it possible for the writers to find the exact ...
2
votes
1answer
70 views

Mercury mapping attempts before Mariner 10?

Mercury's surface was not mapped up-close until Mariner 10 passed by in 1974. This was followed by MESSENGER in 2008. I have seen several attempts of mapping Mars that came before space exploration, ...
0
votes
1answer
700 views

How was the time of equinox measured in ancient times?

In the book "The Crime of Claudius Ptolemy" by Robert Newton, on page 81, it reads as follows: When we measure the time of a solstice, we measure the time when the meridian elevation angle of the ...
28
votes
1answer
3k views

How did Ole Christensen Romer measure the speed of light?

How did Ole Christensen Rømer, who in 1676, shortly after Galileo's death, was said to have measured the speed of light as 220,000 km/s by timing the orbits of Io around Jupiter? My only guess is ...
71
votes
2answers
12k views

Could the dinosaurs have seen the asteroid that killed them?

Wikipedia says the Chicxulub impactor is thought to have been a 10-15 km diameter object. Would it have been visible to a (human*) naked eye before impact? And if so, would it have appeared like a ...
1
vote
1answer
57 views

Is the American Astronomical Society 230 years old?

The BBC News item Light shed on mystery space radio pulses is interesting enough in its own right. But I noticed that it is reporting on news from the 231st meeting of the American Astronomical ...
2
votes
0answers
165 views

How does Ptolemy prove in the following excerpt that the Earth could not be outside of the axis spanning between the poles of the celestial sphere

I have trouble interpreting the following excerpt: “Against the first of these three positions militate the following arguments. If we imagined [the earth] removed towards the zenith or the nadir ...
3
votes
1answer
169 views

How did Ptolemy prove in the following excerpt that the Earth is not cylindrical?

I have trouble interpreting the following excerpt: “Nor could it [the Earth] be cylindrical, with the curved surface in the east-west direction, and the flat sides towards the poles of the ...
4
votes
0answers
88 views

What is a “limited array”?

I'm reading about the history and making of ESO's Very Large Telescope and I've found this article that says the scientific community had a choice between three suggestions: a one-piece 16m-telescope, ...
3
votes
1answer
556 views

When did astronomy first discover that the stars are bigger than the moon?

We take it for granted these days that the stars are unimaginably bigger than the planets and the moons. But when you look at the sky, it does not appear this way. The moon looks bigger and brighter ...