A 26,000-Year Astronomical Monument Hidden in Plain Sight

7 years ago (blog.longnow.org)

Great article but I found this one easier to understand including quotes from the artist about how it works, https://www.quora.com/At-the-Hoover-Dam-what-is-the-meaning-...

For some reason the author doesn't even mention https://en.wikipedia.org/wiki/Alcyone_(star) which is written into the map.

What better place to preserve a star map than an indestructible cement dam in the desert.

  • > What better place to preserve a star map than an indestructible cement dam in the desert.

    I'd suggest away from the base of a substantial cliff face might improve your preservation odds.

I always find articles interesting that are about how the sky would have looked at different points in time. For example, how the current constellations looked 10,000 years ago, or will look in the future. https://www.wired.com/2015/03/gifs-show-constellations-trans...

  • Check out the history of the 'pole star' https://en.wikipedia.org/wiki/Pole_star#History

    In classical antiquity, Beta Ursae Minoris (Kochab) was closer to the celestial north pole than Alpha Ursae Minoris. While there was no naked-eye star close to the pole, the midpoint between Alpha and Beta Ursae Minoris was reasonably close to the pole, and it appears that the entire constellation of Ursa Minor, in antiquity known as Cynosura (Greek Κυνοσούρα "dog's tail") was used as indicating the northern direction for the purposes of navigation by the Phoenicians.[1] The ancient name of Ursa Minor, anglicized as cynosure, has since itself become a term for "guiding principle" after the constellation's use in navigation.

    Alpha Ursae Minoris (Polaris) was described as ἀειφανής "always visible" by Stobaeus in the 5th century, when it was still removed from the celestial pole by about 8°. It was known as scip-steorra ("ship-star") in 10th-century Anglo-Saxon England, reflecting its use in navigation. In the Hindu Puranas, it is personified under the name Dhruva ("immovable, fixed").

    In the medieval period, Polaris was also known as stella maris "star of the sea" (from its use for navigation at sea),

  • John North's book Stonehenge: Neolithic man and the cosmos explored the consequences of the precession for early structures in the UK that he interpreted as having astronomical significance (opinions vary on that one).

  • Interesting indeed! I suppose this is a sound argument against astrology -- a few thousand years ago you'd be looking at a different sky, how can you have a well-defined set of astrological symbols when their respective skies are changing, albeit slowly.

    • Astrology does take the Earth's precession into account; as the vernal equinox precesses from one zodiac constellation to another every 2150 years, it becomes a different age. You might know the 60's song "Age of Aquarius"; that's what the song is referencing. (I'm not saying there's any validity to astrology, just pointing out an interesting connection.)

    • They could believe that the meaning of the different signs changes as the corresponding constellations change.

      For an entertaining science fiction look at that possibility, see season 2 episode 5 of "The Orville". Briefly, they encounter a civilization that believes strongly in astrology, to the point of using it as the basis of a very rigid caste system that pretty much determines at birth what jobs are open to you and what your place will be in society.

      I don't want to give any spoilers, but I will say that the question of what happens when a constellation changes is an important one in this episode.

    • this is a sound argument against astrology

      TLDR: I'm guessing you don't actually know a heck of a lot about astrology. Your assertion looks baseless to me.

      Long form:

      Not really. Astrology is basically observed associations from the point of view of the Earth. For example, it will mark planets as "retrograde," which means they appear to be moving backwards from our view here on Earth, though no planet ever actually turns around and moves backwards.

      I've studied astrology some. I think there are some serious issues with traditional western astrology, such as the fact that most meanings, rulerships, etc, were assigned at a time when humans observed the night sky with the naked eye. We have only relatively recently discovered additional planets (thanks to telescopes) and kind of shoe-horned those in (to traditional astrology), mostly without research, from what I gather.

      One somewhat famous astrologer once proposed in one of her books that we should include the Earth in all astrological charts "because if we ever colonize Mars, we will need to include the Earth in those charts." Mathematically speaking, the Earth is already included, implicitly, in the House System, though it could stand to be assigned rulership etc and included more explicitly in other ways.

      Yeah, no one here has any clue what the hell I'm going on about. I'll shut up now.

I appreciate that this monument is in the northern hemisphere and so the discussion of Polaris is entirely appropriate. But still some universal statements are made which are simply false when we remember there is one half of the world that looks to the other celestial centre in the night sky. One example:

> The reason we have historically paid so much attention to this celestial center, or North Star, is because it is the star that stays put all through the course of the night. Having this one fixed point in the sky is the foundation of all celestial navigation.

The Polynesian navigators, who achieved amazing feats of open water navigation, managed to sail deep into the southern hemisphere (as far south as New Zealand) where Polaris is simply not ever visible. But they still practiced celestial navigation without this 'foundation'. [1] The European explorers, who sailed around the Cape of Good Hope and through the Strait of Magellan and across the Southern Atlantic, Pacific and Indian Oceans, also likewise had to do without this 'foundation'.

When you come from the southern hemisphere you notice this casual, unthinking "northern hemispherism" all the time.

[1] https://en.wikipedia.org/wiki/Polynesian_navigation#Navigati...

In the very first sentence, I appreciate what I think is an intentional use of five digit year formatting.

The Long Now Foundation isn’t getting caught with its pants down in an amateur Y10K bug!

“YYYYY” FTW

Author mentions "axial precession" repeatedly without explaining it. 2/3 of the way down comes this gem:

> it is worth explaining what exactly axial precession is.

This kind of writing just irritates me.

  • i'm bothered a bit by the fact that in the cartoon animation the earth appears to rotate only two or three times during an entire 25,000+ year axial precession cycle.

    • I didn't know about axial precession and that visualization was what made it clear for me. Literally a picture that is worth hundreds, if not thousands, of words.

    • It’s a bit like a camera capturing the wheel of a fast moving car such that it appears to be rotating very slowly.

  • Those of us who have known about axial precession for decades don't need to see it redefined in every article. ELI5 gets old after a while.

Interesting. I like it.

The monument isn't 26000 years old, but the themes are incredibly old. The astronomical alignments, mysterious guardian sphinxes. This does seem like a 1930s contribution to artsy ideas going back through bronze age Egypt, Mesopotamia and lots of other places.

Wow. I love the Art Deco style. My absolute favorite aesthetic right now, maybe ever. I haven't found anything I like more to be honest except Classical.

  • I was at the Hoover Dam recently, and I was struck by how Socialist Realist (read: Soviet) much of the original art looks:

    https://photos.app.goo.gl/GTQxcVtVKhgTURsG9

    My favorite structure is probably the improbably Star Wars/Tatooine flavored parking garage though!

    • That's how a lot of stuff from that era looked in the US. The roaring 20s and the bummer-30s had lots of stuff like that. Maybe you just have an incorrect mental 1:1 mapping between stuff popular 100 years ago everywhere and the Soviets?

      2 replies →

Great article - a bit wordy - but great sleuthing. I've been the Hoover dam and it is pretty amazing to behold. Always nice to see that certain people will dig a little deeper and question their surroundings a bit more.

I assumed this was some really old, maybe Egyptian or African, site that was finally understood to be an astronomical map or something. I'm stunned that this is some kind of secret American history.

Makes we wish I could see Hoover Dam someday, a thing I have never had any desire to do before. But this is cool.

This is wonderful. It's a brilliant way to mark the date, beautifully executed.

> The view that you really want to have of the plaza is directly from above. You would need a crane to get this view of the real thing,

This is what drones were invented for. I'd love to see a picture of the whole clock.

It wasn't well described, but do people really not get the idea that it's about astronomy somehow?

I'm was dissapointed that the statues seem to play no role at all, no nifty alignment of shadows seems like a wasted oportunity if you are making an astronomy monument.

Title fix: delete “old”. (The monument depicts a 26k-year cycle; it isn’t 26k years old.)

  • The article's title had 'old' in it at the time I posted, and I didn't notice. Looks like it's been edited since.

    Mods: can you edit the title, as I no-longer can.

Funny - or sad, actually - how even The Long Now can't be bothered to run a website which will function without third party calls. Bootstrap, Fontawesome, Cloudfront, and Google are not necessarily expected to stay in business for the next 10.000 years.