Ancients and Unobservable Lunar Eclipses

I have recently been wondering if ancient (pre-telescop)
astronomers/astrologers would have been able to predict upcoming lunar
eclipses which they would not have been able to see because the eclipse
would have happened while it was daytime for them.

I am leaning towards thinking that it would have been possible (as in
allowable) for the more sophisticated a/a's. It would have required only
four things.

1. Motive. They would have had the impetous to keep track of it because of
it's great importance in their belief systems.

2. The concept of a lunar eclipse being the moon passing through the
earth's sun-shadow. Would they have been aware of this phenomon, even if
they assumed an earth-centric system? I am thinking, yes.

3. The ability to track the invisible earth's shadow on the ecliptic. This
ought not be too difficult.

4. The practice of tracking the moon from evening to morning and projecting
it through the sky on a short-term basis.

Are there more items in the list that I have not included?

Am I being too gracious in supposing what their capabilities could have
been. Recall that I am asking about any society at any time before the
invention and spread of the telescope.

Any comments about the plausibility or weakness of my suppostion are
invited.

Thanks.

- Paul

"Paul" wrote in message
m...
I have recently been wondering if ancient (pre-telescop)
astronomers/astrologers would have been able to predict upcoming lunar
eclipses which they would not have been able to see because the eclipse
would have happened while it was daytime for them.

I am leaning towards thinking that it would have been possible (as in
allowable) for the more sophisticated a/a's. It would have required only
four things.


I am sure the ancient Greek astronomers (and certainly Hipparchus, for
example) would have been able to do this. And the telescope was invented in
1609 (or first used by Galileo, actually invented shortly before) but
astronomers in the middle ages and Renaissance could predict eclipses. Look
up the story of Columbus and the eclipse prediction he used to persuade
local natives in the West Indies to help him. This was about 100-110 years
before the telescope. The calculations were done using Ptolemaic astronomy
but worked perfectly well for this purpose.

1. Motive. They would have had the impetous to keep track of it because
of
it's great importance in their belief systems.

2. The concept of a lunar eclipse being the moon passing through the
earth's sun-shadow. Would they have been aware of this phenomon, even if
they assumed an earth-centric system? I am thinking, yes.

I recall that the correct cause of lunar eclipses was realised by the
Greeks. Look up Aristarchus.


3. The ability to track the invisible earth's shadow on the ecliptic.
This
ought not be too difficult.


Much harder, though, you need to keep track of the position of the lunar
node (crossing point) because an eclipse can only take place in the vicinity
of a node. But they could do this in ancient times, after a lot of careful
observations.


4. The practice of tracking the moon from evening to morning and
projecting
it through the sky on a short-term basis.

Are there more items in the list that I have not included?

Am I being too gracious in supposing what their capabilities could have
been. Recall that I am asking about any society at any time before the
invention and spread of the telescope.

Any comments about the plausibility or weakness of my suppostion are
invited.

For more detail you need to look up some history of astronomy in a library.
But certainly, astronomers have been able to predict lunar eclipses (and
solar eclipses) since at least 500BCE. Try a google search on the word
"saros".

--
Mike Dworetsky

(Remove "pants" spamblock to send e-mail)

On 5 Sep 2003 21:21:06 -0700, (Oriel36)
wrote:


1. Motive. They would have had the impetous to keep track of it because of
it's great importance in their belief systems.
My only comment to this is the "ancients" didnt have TV, or mass
media, so about the only thing they had to do with their spare time
apart from staying alive was to watch the stars.

And as they didnt have Light pollution then, we can only guess at the
sky that they saw.

The Neanderthals even had a basic understanding of seasons, this they
got from observation of the skies
--
---
The two most abundant elements in the universe are Hydrogen and stupidity.
Why is the ratio of Hydrogen to Stupidity less in usenet than anywhere else in the universe?

wrote in message
...
The Neanderthals even had a basic understanding of seasons, this they
got from observation of the skies

How do we know this?

- Paul

Paul wrote:

The Neanderthals even had a basic understanding of seasons, this they
got from observation of the skies

How do we know this?

From their old usenet posts, of course.

Paul (the other one)

"Paul F. Dietz" wrote in message
...
Paul wrote:

The Neanderthals even had a basic understanding of seasons, this they
got from observation of the skies

How do we know this?

From their old usenet posts, of course.


Yes, I recall meeting some of them now.

- Paul
Schrum