Mrthfx

Where and when has Thucydides been studied?

Pointing to problems without suggesting solutions

What does 丫 mean? 丫是什么意思？

Table formatting with tabularx?

Fit odd number of triplets in a measure?

Why can't fire hurt Daenerys but it did to Jon Snow in season 1?

2018 MacBook Pro won't let me install macOS High Sierra 10.13 from USB installer

How to make triangles with rounded sides and corners? (squircle with 3 sides)

Order between one to one functions and their inverses

Trying to understand entropy as a novice in thermodynamics

The Nth Gryphon Number

Short story about astronauts fertilizing soil with their own bodies

Find general formula for the terms

latest version of QGIS fails to edit attribute table of GeoJSON file

Twin's vs. Twins'

NIntegrate on a solution of a matrix ODE

When to apply negative sign when number is squared

.bashrc alias for a command with fixed second parameter

Relating to the President and obstruction, were Mueller's conclusions preordained?

What did Turing mean when saying that "machines cannot give rise to surprises" is due to a fallacy?

Found this skink in my tomato plant bucket. Is he trapped? Or could he leave if he wanted?

In musical terms, what properties are varied by the human voice to produce different words / syllables?

Releasing Patch File for BSD3 Licensed Project

Did pre-Columbian Americans know the spherical shape of the Earth?

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

1

$begingroup$

I read the following in C. S. Lewis, Miracles (page 77-8)

The immensity of the universe is not a recent discovery. More than seventeen hundred years ago Ptolemy taught that in relation to the distance of the fixed stars the whole Earth must be regarded as a point with no magnitude.

There was no reference given, but I assume this would be in the Almagest. However, I don't know where in that work (or elsewhere) Ptolemy discussed this. I want to read his explanation for that view.

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

astronomy

share|improve this question

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

$endgroup$

add a comment | 

1

$begingroup$

I read the following in C. S. Lewis, Miracles (page 77-8)

The immensity of the universe is not a recent discovery. More than seventeen hundred years ago Ptolemy taught that in relation to the distance of the fixed stars the whole Earth must be regarded as a point with no magnitude.

There was no reference given, but I assume this would be in the Almagest. However, I don't know where in that work (or elsewhere) Ptolemy discussed this. I want to read his explanation for that view.

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

astronomy

share|improve this question

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

$endgroup$

add a comment | 

$begingroup$

I read the following in C. S. Lewis, Miracles (page 77-8)

The immensity of the universe is not a recent discovery. More than seventeen hundred years ago Ptolemy taught that in relation to the distance of the fixed stars the whole Earth must be regarded as a point with no magnitude.

There was no reference given, but I assume this would be in the Almagest. However, I don't know where in that work (or elsewhere) Ptolemy discussed this. I want to read his explanation for that view.

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

astronomy

share|improve this question

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

$endgroup$

share|improve this question

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

New contributor

Frank Hubeny is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 5 hours ago

Frank HubenyFrank Hubeny

10615

2 Answers
2

active

oldest

votes

2

$begingroup$

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 relative positions of the stars in the sky would change during one night. But this is not observed.

By the way, a similar argument will imply that if the Earth is rotating about the Sun
(or moves in some other way), the distance to the stars must be much larger than the size of this motion. In particular the diameter of the orbit of the Earth around the Sun is negligible in comparison to the distance to the stars.

This was the most serious argument against the Heliocentric system, and it is also
due to Ptolemy. Until the acceptance of Copernicus theory, people just could not believe that the distance to the stars can be so large.

share|improve this answer

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

$endgroup$

add a comment | 

1

$begingroup$

Almagest, Book 1, chap. 5 ................

share|improve this answer

answered 3 hours ago

sand1sand1

88457

$endgroup$

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "587"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

Frank Hubeny is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fhsm.stackexchange.com%2fquestions%2f8509%2fwhere-did-ptolemy-compare-the-earth-to-the-distance-of-fixed-stars%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

2

$begingroup$

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 relative positions of the stars in the sky would change during one night. But this is not observed.

By the way, a similar argument will imply that if the Earth is rotating about the Sun
(or moves in some other way), the distance to the stars must be much larger than the size of this motion. In particular the diameter of the orbit of the Earth around the Sun is negligible in comparison to the distance to the stars.

This was the most serious argument against the Heliocentric system, and it is also
due to Ptolemy. Until the acceptance of Copernicus theory, people just could not believe that the distance to the stars can be so large.

share|improve this answer

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

$endgroup$

add a comment | 

2

$begingroup$

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 relative positions of the stars in the sky would change during one night. But this is not observed.

By the way, a similar argument will imply that if the Earth is rotating about the Sun
(or moves in some other way), the distance to the stars must be much larger than the size of this motion. In particular the diameter of the orbit of the Earth around the Sun is negligible in comparison to the distance to the stars.

This was the most serious argument against the Heliocentric system, and it is also
due to Ptolemy. Until the acceptance of Copernicus theory, people just could not believe that the distance to the stars can be so large.

share|improve this answer

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

$endgroup$

add a comment | 

$begingroup$

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 relative positions of the stars in the sky would change during one night. But this is not observed.

By the way, a similar argument will imply that if the Earth is rotating about the Sun
(or moves in some other way), the distance to the stars must be much larger than the size of this motion. In particular the diameter of the orbit of the Earth around the Sun is negligible in comparison to the distance to the stars.

This was the most serious argument against the Heliocentric system, and it is also
due to Ptolemy. Until the acceptance of Copernicus theory, people just could not believe that the distance to the stars can be so large.

share|improve this answer

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

$endgroup$

share|improve this answer

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

answered 1 hour ago

Alexandre EremenkoAlexandre Eremenko

25.6k13694

1

$begingroup$

Almagest, Book 1, chap. 5 ................

share|improve this answer

answered 3 hours ago

sand1sand1

88457

$endgroup$

add a comment | 

1

$begingroup$

Almagest, Book 1, chap. 5 ................

share|improve this answer

answered 3 hours ago

sand1sand1

88457

$endgroup$

add a comment | 

$begingroup$

Almagest, Book 1, chap. 5 ................

share|improve this answer

answered 3 hours ago

sand1sand1

88457

$endgroup$

share|improve this answer

answered 3 hours ago

sand1sand1

88457

answered 3 hours ago

sand1sand1

88457

answered 3 hours ago

sand1sand1

88457