Ancient navigational experiment - HELP NEEDED

[Swoop]

Long story short: Mate of mine is a real, actual, bonafide Druid and has been working on a theory about ancient navigational techniques for years now. There's a big experiment when the lunar eclipse is on and he's looking for people all over the world to....well basically, look up when the moon turns red and mark what they see on a star chart using very, very low tech techniques like ancient man may have.

Details here: http://www.stonehenge-druids.org/science.html

[cantab]

I shan't say it absolutely wasn't done, but this method seems to me to be both not needed and flawed.

Not needed because determining longitude without a chronometer was only a problem at sea. On land East-West distances can easily be measured. On a boat with the shoreline in sight they can still be fairly easily measured, and in some civilizations sailors would prefer to stay in sight of the coast to help them navigate. The problem then isn't in mapping the coast of Europe, Iceland, or North America in detail, but in accurately working out the distance between those places across the empty Atlantic.

Flawed because a lunar eclipse is a gradual event. There's no obvious sharp "now" cue to observe. So each single observer won't get a very precise figure for their location. If you had lots of observations you could apply statistics to get more precise locations, but it seems unlikely at best that Neolithic Britons had developed that kind of mathematics.

[LordFerret]

Not needed ...

Flawed ...

I think you've missed the point of the exercise... "... working on a theory ...", "... (an) experiment ...", "... using very, very low tech techniques like ancient man may have."

[legoclone09]

Interesting, this is rather cool. Also reminded me about the eclipse, I would've forgotten about it!

[LordFerret]

I've a friend of mine who left this past Sunday to travel to Israel for the 'Blood Moon'. She'll return with pictures (I hope). If the skies here are clear, I'll be trying to get some pictures. Those living in the eastern tip of Brazil, like Recife, should get an awesome view.

Image Credit: https://in-the-sky.org/news.php?id=20150928_10_100