[WalterBright]

I sometimes watch those TV shows about ancient civilizations. They often talk about "astonishing" astronomy they used.

In reality, all they did was track the sun. This can be done simply by putting a vertical stick in the ground, and marking the path the tip of the stick traces in the ground. This way, the calendar and solstices can be accurately determined.

The shows will also talk about the "amazing" technology that enabled, say, a hole in a wall to shine on a statue for one special day a year. Again, rather simple to do using the same idea as the stick in the ground.

The third thing that annoyed me was their "incredible" astronomical knowledge in predicting eclipses. All that is is collecting observations over decades and then recognizing the pattern. There is no astronomical knowledge involved. They still had no idea what the sun, moon, and planets were, nor even the layout of the solar system.

[swatcoder]

> They still had no idea what the sun, moon, and planets were,

The composition of celestial bodies is useless trivia until you have some very modern material and energy sciences that might start turning to them for inspiration. There will almost certainly be a collapse of the modern world, and losing that information will be the very very least of our problems.

> nor even the layout of the solar system.

Depending on which civilizations you're talking about and how ancient you mean, the paths of visible roving bodies (planets) were actually pretty well known in many places for thousands of years. The models used to anticipate positions were often more convoluted than ours, but projected space and heliocentrism are ultimately just an optimization that wasn't obvious, necessary, or meaningful given what little practical use there was to the paths of those planets until very recently.

What those pop history shows mostly achieve is just reminding people that astronomical and scientific knowledge didn't start in the European Enlightenment, which is the takeaway that many people (in the US, especially) carry after high school. They're not really meant for someone like yourself. There's much more you might actually be impressed by in academic history/archaeology/anthropology and even in certain written pop history sources.

[antognini]

Also worth noting that pretty much every ancient civilization ended up figuring out the order of the planets, at least relative to earth. (It turns out not to be so difficult since this is directly related to their sidereal periods.)

[WalterBright]

If you stand at the center of a circle, and have a man walk a circle at radius r from you, and another man walk a circle at radius 2r, it will take the second man twice as long to complete the circle.

It's not a great leap to apply that to the planets.

But it's not proof that the planets were ordered that way.

Science happens when one invents an explanation for observed phenomena, and then the explanation (theory) makes a prediction, then an experiment is devised, and the theory is validated if the prediction matches the theory, or tossed aside if it doesn't. In other words, the scientific method. That appeared fairly recently, and the consequences were an explosion of knowledge.

[jrussino]

> There will almost certainly be a collapse of the modern world

I hope your certainty is misplaced; this is just about the most horrifying prediction I can imagine.

As far as I can tell, we're at a particularly precarious transition point with regard to how much energy we consume. If society "collapses" before hitting some technological checkpoint we don't get to try again - at least, not for a looong time - because we've nearly used up all of the low-hanging fruit in the planet's energy resources (fossil fuels).

[WalterBright]

Sure they watched the paths. That doesn't tell them what they were, how far away they were, helicentric vs geocentric, etc. Anybody can watch paths and notice they repeat.

> heliocentrism are ultimately just an optimization that wasn't obvious, necessary, or meaningful given what little practical use there was to the paths of those planets until very recently

True, but that wasn't my observation. My observation is it was not advanced, sophisticated, etc.

[felipeerias]

It was actually extremely complex and sophisticated. Getting accurate measurements was seriously tricky and making sense of them involved doing complex calculations (particularly spherical trigonometry) by hand. Some phenomena, like the precession of the equinoxes, required aggregating observations which had been taken over several centuries.

A good book to get a sense of this complexity is “The Light Ages” by Seb Falk.

[WalterBright]

Unfortunately, a calculation that matches a pattern does not confer any understanding of the nature of the solar system.

[HelloMcFly]

I think you're underselling the accomplishment of determining some of these things, particularly predicting eclipses. And I think there's quite a bit to be said about novel applications that emerge out of tracking the sun, like announcing seasons for citizens to help know when to plant, reap, store, etc. to manage agriculture across empire. Often they amazing thing was taking a small thing and spinning into a massive, society-impacting solution.

[antognini]

One of the most impressive aspects of Babylonian and Chinese eclipse predictions was simply the social organization that was required to collect the necessary data. These records were collected almost continuously over centuries. The Babylonian astronomical records which span around seven centuries and are arguably the longest continuous scientific program any civilization has produced.

[shagie]

It then helped establish the study of the precession. Hipparchus used the Babylonian astronomical information to look into changes over hundreds of years.

https://en.wikipedia.org/wiki/Babylonian_astronomy#Influence...

> In 1900, Franz Xaver Kugler demonstrated that Ptolemy had stated in his Almagest IV.2 that Hipparchus improved the values for the Moon's periods known to him from "even more ancient astronomers" by comparing eclipse observations made earlier by "the Chaldeans", and by himself. However Kugler found that the periods that Ptolemy attributes to Hipparchus had already been used in Babylonian ephemerides, specifically the collection of texts nowadays called "System B" ....

https://en.wikipedia.org/wiki/Axial_precession and https://en.wikipedia.org/wiki/Hipparchus

> Earlier Greek astronomers and mathematicians were influenced by Babylonian astronomy to some extent, for instance the period relations of the Metonic cycle and Saros cycle may have come from Babylonian sources (see "Babylonian astronomical diaries"). Hipparchus seems to have been the first to exploit Babylonian astronomical knowledge and techniques systematically.

> ...

> Hipparchus probably compiled a list of Babylonian astronomical observations; Gerald J. Toomer, a historian of astronomy, has suggested that Ptolemy's knowledge of eclipse records and other Babylonian observations in the Almagest came from a list made by Hipparchus. Hipparchus's use of Babylonian sources has always been known in a general way, because of Ptolemy's statements, but the only text by Hipparchus that survives does not provide sufficient information to decide whether Hipparchus's knowledge (such as his usage of the units cubit and finger, degrees and minutes, or the concept of hour stars) was based on Babylonian practice

[WalterBright]

> you're underselling the accomplishment of determining some of these things, particularly predicting eclipses

If you keep records over the decades, you can predict it. It's just a pattern, not an understanding. It wasn't until the last century, however, that the application of math to the precise orbits was able to predict the track of an eclipse very accurately.

[HelloMcFly]

> If you keep records over the decades, you can predict it.

Of course we know that now, but that level of understanding is hardly trivial to societies at those levels of development. To use our current understanding to be so underwhelmed - and to not be at all impressed by the scale at which they applied it for transforming and modernizing aspects of their growing societies - I don't know man, it honestly kind of shocks me and bums me out in equal measure.

[WalterBright]

When I was a boy, I had a newspaper route. It required me to deliver the newspapers at around 5AM, when it was still dark. While biking around the neighborhood throwing newspapers at houses, I would also watch the night sky.

It wasn't long before I started noticing patterns.

Ancient people also lived largely outside. They'd see the patterns, too. This isn't amazing or sophisticated or incredible.

[antognini]

Those kinds of shows can be sensationalized and shallow, but if you're interested in learning more in depth about ancient astronomy (shameless plug) I have been doing a podcast on the subject. So far I've covered the astronomy of the Babylon, Greece, Rome, India, prehistoric Europe, Subsaharan Africa, and am currently five episodes into the astronomy of premodern China.

https://songofurania.com

[n1b0m]

Thanks for sharing. Just started listening