Astrolabe: Shipwreck find 'earliest navigation tool'
bbc.com
bbc.com
If you are interested in how similar devices might have been made 100s and 1000s of years ago you should check out the latest videos on the Clickspring Youtube Channel [1]. Chris is building a copy of the Antikythera mechanism (mostly) without using modern tools and he is doing a stellar job.
The quality of his videos and his attention to detail is _amazing_! If you are into this kind of stuff you will most likely end up binge watching his whole channel over the weekend.
[1] https://www.youtube.com/channel/UCworsKCR-Sx6R6-BnIjS2MA
I think he just uses the Mill and the CNC to speed things up, but some parts (like the gears) he does completeley by hand with a file even though he could do it way faster and more precise on a mill.
https://en.wikipedia.org/wiki/History_of_the_compass#Early_n...
> The compass was used in Song Dynasty China by the military for navigational orienteering by 1040–44,[15][28][29] and was used for maritime navigation by 1111 to 1117
At the very least, summarize your post and link to the extrapolation. "This is specifically a marine astrolabe for determining latitude from the elevation of a specific star, not a generic astrolabe with many other functions. It's also not the earliest navigational tool. These names and distinctions are important, and getting them wrong is indicative of damaging, incorrect click-bait journalism. I go into more detail on my blog: [link]"
I wonder where else we can apply this observation?
In the use of ECC memory, maybe? Or when analyzing web analytics, perhaps: if your site traffic only shows a small percentage of mobile users, you might choose not to optimize for mobile browsers. But instead there could be a problem with the source of your observation: Just like the archaeologists who discovered this marine astrolabe aren't observing both successful and unsuccessful sailors at that time in history, you're looking at the subset which has shown up on and used your site, and who have analytics enabled. It could be that mobile users aren't showing up in your "shipwrecks" because they're quickly bouncing from your difficult-to-use site or because their search engine can see that your site isn't optimized and it doesn't recommend you to them.
Alternatively, only a few boats would have had one, and the ones that did were using them to strike out further afield than their less well-equipped contemporaries. Since they could be more confident about their location, they could venture further from land and might get caught by storms more easily.
The sea is a cruel mistress. Ships regularly get wiped out despite state-of-the-art navigation. I would suspect that the vast majority of shipwrecks throughout mankind's history has little do with navigation and everything to do with the inherent danger of the open ocean.
al-Risalah al-Asturlabiyah – A Treatise on the astrolabe.
Zij-i Ilkhani (Ilkhanic Tables) – A major astronomical treatise, completed in 1272.
Conceptually, it's interesting that longitude is mostly useful only if you know your latitude (that's because 1degre of change in longitude does not translate to the same distance traveled whether you're at the equator or at the pole.)