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The ancient navigators

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posted on Jun, 24 2022 @ 06:53 PM
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originally posted by: anonentity
a reply to: Hanslune

When all is said and done, do you really need longitude except for placing a landmass on a map? Lattitude is easy enough to work out, then all you have to do is decide if it's left or right. In the old sailing ships from Britain, it was sail south till the butter melts and then turn right. You always ended up in the Caribean as long as you didn't sink.



The Brits and French both thought it was important enough to fund projects to find a way to get clocks to work at sea. So, yeah it was important when you are headed in a direction other than directly north south. Like when at sea where do you turn to east or west to round Cape Horn of the Cape of Good Hope. How do you find Bermuda? You can't coast to it. You need to find it in the middle of an ocean you can go N-S but it is inefficient and dangerous you can come up to it at night. Thousands of sailing ships went aground because they didn't have the ability to judge Longitude. Lloyds of London could tell you all about it.

I picked at year at random: 1844
en.wikipedia.org... Note how many went ashore. Commercial ships often didn't carry expensive clocks, before that no such clocks existed.



posted on Jun, 24 2022 @ 07:00 PM
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a reply to: Hanslune


Yes point taken, dead reckoning has its limitations. But you can still clear Cape horn by latitude, just by making sure you are well off.



posted on Jun, 24 2022 @ 07:43 PM
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originally posted by: anonentity
a reply to: Hanslune


Yes point taken, dead reckoning has its limitations. But you can still clear Cape horn by latitude, just by making sure you are well off.



Yes you can guess because other than knowing the NS direction you have no idea about EW. That is why Prince Henry's Portuguese went by the coastal route around Africa. It was only later that some more daring folks swung further west and found better winds but still had to use dead reckoning. As to when to make the turn. One reason islands were found then lost again in the South Atlantic and Pacific was due to restraints caused by lack of clocks or accurate measurements from a moving ship.



posted on Jun, 24 2022 @ 07:58 PM
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originally posted by: Harte

originally posted by: bloodymarvelous

originally posted by: Harte

originally posted by: bloodymarvelous
If we want to go back on topic: do you think the Torquetum was invented by Aristothenes? Or do you think he found it in one of the many books the library kept?

No. That instrument dates no earlier that the 12th Century AD.


originally posted by: bloodymarvelousCould an extremely ancient civilization have had the technology to determine longitude, long prior to the invention of reliable clocks?

No. And you can't use the torquetum to establish longitude.




You're right. I confused the words "Tanawa" and "Torquetum".

Apparently the purpose of the "Tanawa" was to allow you to accurately measure the Moon's position in the sky, and then knowing what day it is, you could calculate what hour it was by looking at the stars behind the Moon.

Knowing the correct time is what allows navigators to determine their longitude (unless they have GPS, in which case they would use that today.)

In order to find longitude on a trip, you have to know what time it is at a different, known, longitude - such as the longitude of the spot your trip began from - at the moment of your observation.


That's what is so cool about the Tanawa theory. You CAN know what time it is somewhere else by using the Moon. Or at least you can know where you are relative to the Moon's absolute location in the sky. (Either of which is enough to determine Longitude.)

If you know the Moon's location relative to you at ...say... 10pm local time (as determined by the stars), and you know from a chart what it's location would be if you were standing near the Library of Alexandria at 10pm on this day of the year, then you can figure out how many degrees (or what fraction of pi/a circle) you are away from that longitude.




You also have to have a system of latitude and longitude, which the ancients certainly didn't have.

Harte


I think you are really trying to smear them if you think they were too stupid to understand "North, South vs "East, West"

If they didn't have "degrees", they could use "radians", or any concept of a "fraction of a circle"




originally posted by: anonentity
a reply to: fromunclexcommunicate

Harte says you can't get longitude without a clock. But the rising of the stars and the position of the moon and the sun are the hands of a celestial clock. Better than a mechanical clock as it's the real thing, not a proxy. All the angles are peculiar to your position on the globe at that particular time of the year.
So the question would be how much did the ancient navigators know, did they just calculate in degrees or minutes and seconds. Because if they calculated in Minutes of arc, they must have had some way to do the timing, as they would have known that a degree is sixty nautical miles on the earth's surface measured from its center anywhere on the surface. Which makes a minute as a sixtieth of that which is, of course, one nautical mile.


The main problem for ancient navigators to get longitude, is that every point on the same line of Latitude sees an identical set of stars at some time in the day. So if you don't know what time it is, you don't know which point of latitude you are at.

However: The Moon is an exception to this. Different points on Earth will see the Moon at a different point in the sky, at any given time in the day. The reason is because the Moon moves about 30 degrees every day.

So if you look at the stars and realize they are now located where they would be at 10pm in your home port (meaning it is 10pm local time, but could be any time at your home port, maybe 4 am or 12 noon for all you know.)

Once you've determined local time, and you know what day it is, if you know where the Moon should be at that time in your home port, and you can then measure the Moon's location to within 1/2 a degree, you now know your latitude to within 30 degrees. (If you can measure it more precisely then you know your latitude more precisely.)

If the OP's link is accurate, then this is exactly the method the ancient navigators in that story used.




edit on 24-6-2022 by bloodymarvelous because: (no reason given)



posted on Jun, 24 2022 @ 08:18 PM
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a reply to: bloodymarvelous

If you could get that down to half a degree, which is thirty miles, that would be getting close to what a quick fix would be with a sextant anyway. So the Hapgood maps don't look so stupid in that light.



posted on Jun, 25 2022 @ 06:36 AM
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originally posted by: Hanslune

originally posted by: Harte

originally posted by: anonentity
a reply to: fromunclexcommunicate

Harte says you can't get longitude without a clock. But the rising of the stars and the position of the moon and the sun are the hands of a celestial clock. Better than a mechanical clock as it's the real thing, not a proxy. All the angles are peculiar to your position on the globe at that particular time of the year.

Harte points out that, although you can tell time at sea, you can't get your longitude from what time it is.

Harte thinks you need to learn about how longitude is calculated.

Harte


There is a way to measure longitude without a clock but it requires that you can observe the full moon when you are near the equator (don't recall the 'safe area'). Not to sure how useful that would be in the real world and it would be difficult to do in a bobbing boat but is possible if on land and have a stable base and accurate enough equipment and have a previously obtain information on the angles of the moon and a star that can be observed.

academic.oup.com...

Requires a previously existing system of longitude.
You can't locate your longitude on the Earth's surface unless you know the longitude of the place you started from.

Harte

Harte



posted on Jun, 25 2022 @ 06:45 AM
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originally posted by: anonentity
a reply to: Hanslune

When all is said and done, do you really need longitude except for placing a landmass on a map? Lattitude is easy enough to work out, then all you have to do is decide if it's left or right. In the old sailing ships from Britain, it was sail south till the butter melts and then turn right. You always ended up in the Caribean as long as you didn't sink.

A version of this is exactly what was used by the Polynesians. It was only truly useful for getting them home from exploratory journeys.
Once colonization was established, they used the Sun, Moon and stars along with currents and other observable things to track where they were in relation to where they were going, and once a place could be sighted, they were home free.
And if it ended up being the wrong place, so much the better - new territory.

Getting home to tell the tale was the most important thing. You sailed back West until you sighted land. Once you're there, you know where you are - even if it isn't the island you were aiming for.

What I'm saying is - the MOST important instrument that was absolutely required for sea travel at the time was a large set of testicles.

Harte
edit on 6/25/2022 by Harte because: of the wonderful things he does!



posted on Jun, 25 2022 @ 08:39 AM
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originally posted by: Harte

originally posted by: Hanslune

originally posted by: Harte

originally posted by: anonentity
a reply to: fromunclexcommunicate

Harte says you can't get longitude without a clock. But the rising of the stars and the position of the moon and the sun are the hands of a celestial clock. Better than a mechanical clock as it's the real thing, not a proxy. All the angles are peculiar to your position on the globe at that particular time of the year.

Harte points out that, although you can tell time at sea, you can't get your longitude from what time it is.

Harte thinks you need to learn about how longitude is calculated.

Harte


There is a way to measure longitude without a clock but it requires that you can observe the full moon when you are near the equator (don't recall the 'safe area'). Not to sure how useful that would be in the real world and it would be difficult to do in a bobbing boat but is possible if on land and have a stable base and accurate enough equipment and have a previously obtain information on the angles of the moon and a star that can be observed.

academic.oup.com...

Requires a previously existing system of longitude.
You can't locate your longitude on the Earth's surface unless you know the longitude of the place you started from.

Harte

Harte


Alexandria would probably have been their "Greenwich". Some scholar there would have compiled exhaustively detailed notes on the Moon's position throughout the course of a year.


The conventions of calling it "longitude" and "latitude" aren't necessary. They're just helpful if you want to teach a whole generation of navigators how to do it (which didn't happen, apparently. Since it didn't become widespread.)

You just need to know Earth is a spinning spheroid. (Which it appears Aristothenese did know). The poles and equator are natural places to measure your angles from.



posted on Jun, 25 2022 @ 12:08 PM
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originally posted by: Harte

originally posted by: Hanslune

originally posted by: Harte

originally posted by: anonentity
a reply to: fromunclexcommunicate

Harte says you can't get longitude without a clock. But the rising of the stars and the position of the moon and the sun are the hands of a celestial clock. Better than a mechanical clock as it's the real thing, not a proxy. All the angles are peculiar to your position on the globe at that particular time of the year.

Harte points out that, although you can tell time at sea, you can't get your longitude from what time it is.

Harte thinks you need to learn about how longitude is calculated.

Harte


There is a way to measure longitude without a clock but it requires that you can observe the full moon when you are near the equator (don't recall the 'safe area'). Not to sure how useful that would be in the real world and it would be difficult to do in a bobbing boat but is possible if on land and have a stable base and accurate enough equipment and have a previously obtain information on the angles of the moon and a star that can be observed.

academic.oup.com...

Requires a previously existing system of longitude.
You can't locate your longitude on the Earth's surface unless you know the longitude of the place you started from.

Harte

Harte


Exactly and you also need precise measurements requiring instruments to compare to already existing data. So, probably not terribly useful for folks in ancient times sailing around the world in wooden ships suffering from scurvy, having their wooden boats eaten up by teredo worms and running out of fresh water and lacking methods of preserving food for long voyages.

However the Polynesians over came a lot of this and did so but it took them thousands of years to develop this methods and it probably had a high loss rate. Navigators had to memorize where they have sailed from in order to know where they are. They also stayed in an area they understood and didn't (AFAWK) tried sailing around the world or to Europe- they made it to Africa and they may have gotten to SA.



posted on Jun, 25 2022 @ 07:53 PM
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a reply to: Harte

Also bearing in mind that a voyaging canoe was made out of wood, if they were in an inferno of bad weather it just filled up with water and you hung on till it passed. If the hulls filled up you were stable. Then you bailed it out and if you still had a mast sailed on, if you didn't you rowed. They were also fast so time at sea and the risk of bad weather problems were lessened. Cook saw an outrigger doing about eighteen knots in Hawai, and was dumbstruck. Also, the arctic tern leaves Alaska in winter and heads for New Zealand, if you followed their migration pattern you were going to end up where they rested.
We think in terms of metals and plastics, but a good carpenter will tell you there is a wood for most practicable applications. Even things like sextants. Bearings etc. They had lathes back then as you can see the centering marks on those Dendera Bowles, so who really knows.



posted on Jun, 25 2022 @ 11:52 PM
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originally posted by: anonentity
a reply to: Harte

Also bearing in mind that a voyaging canoe was made out of wood, if they were in an inferno of bad weather it just filled up with water and you hung on till it passed. If the hulls filled up you were stable. Then you bailed it out and if you still had a mast sailed on, if you didn't you rowed. They were also fast so time at sea and the risk of bad weather problems were lessened. Cook saw an outrigger doing about eighteen knots in Hawai, and was dumbstruck. Also, the arctic tern leaves Alaska in winter and heads for New Zealand, if you followed their migration pattern you were going to end up where they rested.
We think in terms of metals and plastics, but a good carpenter will tell you there is a wood for most practicable applications. Even things like sextants. Bearings etc. They had lathes back then as you can see the centering marks on those Dendera Bowles, so who really knows.


I don't recall the use of the term 18 knots. The British ship was a cargo ship built to carry coal and not particularly fast.



Cook observed that the Tahitian pahi could sail faster than the Endeavour: “...their Large canoes sails much faster than this Ship, all this I believe to be true & therefore they may with Ease sail 40 Leagues a day or more


40 leagues per day = 4.33 knots, so to get 18 knots they would need to travel 276 leagues. Modern racing canoes can go 45 knots



posted on Jun, 26 2022 @ 02:28 AM
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a reply to: Hanslune

Down wind with the following sea they have been clocked at thirty knots.



posted on Jun, 26 2022 @ 05:29 AM
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a reply to: anonentity

The ancient Egyptian sailing vessels (that Maui would have used) were not planing hull canoes.
Nile boats that plied the Mediterranean sea were typically less than 50 feet in length.
The longer journeys from Africa west were on ships large enough to carry a barrel of dried Egyptian limes(to prevent scurvy).
Maui probably sailed East towards India in similar sized ships.



posted on Jun, 26 2022 @ 08:47 AM
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a reply to: fromunclexcommunicate

Now I can not recall the name of the TV series and this was well before I had the internet, probably before you were born BUT.

I recall a TV Series of documentary's that explored some of the mysteries of the people's and cultures of the Pacific, one of objects the looked at were a set of similar stone structures on some very distantly separated Polynesian islands and in particular a sun burst type symbol that appeared several times during there exploration, they also found this sun burst symbol in of all places the Yemen and it was believed to have had pre-Islamic origin, a similar symbol was also found in India, this along with several other suggestive similarity's had the show suggesting that at least one migration into the pacific had it's origin's in India or Arabia.

There may have been several such migrations over the years.

As for planing that is an interesting point, you know a lot of ancient cultures built vessels that while there hull's were technically displacement hull's also had planing features, the Vikings for example used a technique which was hardly unique to there culture to overlay the above plant's over the lower plant's creating rill's along which air became trapped as the hull moved through the water, though these hull's were technically displacement hulls there shallow draft along with the air running along these rill's turned them into affective planing hull's at higher speeds such as when they rowed fast or had a good wind.

But like I say this technique was probably once very wide spread.

The galley's of Rome and Carthage and the Greek World were almost all displacement hull's and they are not known to have used planing features in there ship's and in fact once the battering ram is added if anything at high speed it would force the prow to dig down into the waves BUT some of them were definitely large enough to, if they had the dried foods, sailed the pacific if they had ever ventured that far.

The Egyptians also remember were not simply locked to the Nile though it was and remains the lifeblood of Egypt, no they also had access to and sailed the seas, the Mediterranean, the Red Sea and both north and south along the coasts and perhaps also into the deep ocean and did so since ancient times trading with both known and unknown civilizations and reaching even ancient China though records that otherwise may tell all about that were sadly burned when Qin established his dominance over the seven kingdoms.

Later before Columbus about a hundred years prior a Chinese Admiral had sailed all over the Pacific and almost definitely reached the America's, the reason we don't hear about that and the reason that there are not MORE (there was a rumoured ruin of a Buddhist monastery in the Andes though that may be just a claim as I have never seen an image of it) Chinese ruins in the US and South America is that while he was away HIS Emperor whom had wanted to expand China's influence at the time when it was still great had Died and was replaced by a more conservative emperor his son whom was inspired by Confucianism ideals and believed that China should look inward and lock out the world, a protectionist that caused Imperial China to go into a state of decline and stagnation, he ordered the grand fleet burned to the water line, there maps destroyed and there records burned.

History may have been VERY different.

While they also do not demonstrate planing features one odd thing about the Chinese ship's is that long before the Titanic's transverse bulkheads the same feature was used in Chinese ships for hundred and perhaps even thousands of years and some think that it may have been inspired by the structure of a cane.

Basic rule of thumb for anyone that does not understand what we are talking about.

Planing hull's minimise there drag through the water by either riding up over the water when at speed OR trapping air under the hull that reduced friction from the water.

Displacement hull's do not have this feature so they have to use more force to push through the water but today as in the past most merchant vessels are displacement hulls.

These Polynesian canoe were technically NOT planing hulls and it was there long, narrow sleek shape that allowed them to move faster though they were still displacement hulled and those outriggers simply provided stability they otherwise would not have had due to there narrow shape and without that they would have rolled.

I will bet a Viking long boat would have beaten them for speed as though a combination of both planing and displacement the Viking vessels ship lap construction and shallow draft allowed them to almost fly over the water with a good wind or when the men were rowing at there fastest.

Though we don't know how long the technique of Ship Lap planking hull construction lasted we do know that there are some extremely ancient rock glyph's in Norway and other Scandinavian country's that suggest boats very similar to the Viking ship's may have been used by them for thousands of years.

edit on 26-6-2022 by LABTECH767 because: (no reason given)



posted on Jun, 26 2022 @ 03:28 PM
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a reply to: Harte

Polynesia UK, US; is a subregion of Oceania, made up of more than 1,000 islands scattered over the central and southern Pacific Ocean.

My memory isn't very good and I can only vaguely remember my prison escape 50 years ago in a rowing Dory.
Strangely enough I can still remember the half naked girls running around the island we camped on with little cutouts in their bikini tops though.

Rigging a tarp as a sail is more like the desperate measure of escaping from Alcatraz using raincoats.
If you are sailing in an area with a dense assembly of islands and you only vaguely know where your destination is supposed to be, you might detour to the windward side of an island to avoid losing your breeze.
If you are sailing something as primitive as an Egyptian boat you aren't going to be able to point up into the wind very far later if your destination turned out to be further to the windward.

A tarp rigged dory has similar problems, you can't just steer away from a broad reach without moving the trailing edge of your tarp 20 or 30 degrees back from the front. And you will need to put an oar blade down on the leeward side of the boat to act as a leeboard to keep you from being blown sideways onto the rocky shore of Hardwood island.

50 years ago it was less than a ten nautical mile sail, but of course there is the return journey to consider and that would be a long row.. Of course the Polynesians probably already knew the technical limits of their boats.



posted on Jun, 26 2022 @ 03:49 PM
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a reply to: fromunclexcommunicate

If you are young and fit you can do incredible distances fast in a twelve-foot dingy. They cant really sink and if they turn over you just get them upright and jump back in. So in all probability, most of the world would have been sailed first by these small boats. Size doesn't seem to be the problem. The problem comes with the bigger boats , and there bigger problems.



posted on Jun, 26 2022 @ 05:11 PM
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a reply to: fromunclexcommunicate

I apologize you are not so young as I assumed and have certainly lived to tell the tale far more than most on this site.

That sounds like something you should write a biography about even if you do it as a novel and change the identity's if that is your wish but that escape from whomever was holding you captive is certainly something that catches the imagination.

It must have been a terrible place to risk the wide pacific not knowing if you were even going to make it.

I am not much older than 50 so I am definitely your junior and you certainly have my respect after reading that.



posted on Jun, 26 2022 @ 05:29 PM
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a reply to: LABTECH767




It must have been a terrible place to risk the wide pacific not knowing if you were even going to make it.


The larger Egyptian ships would have had provisions that would last several weeks and maybe a young crew that had never seen a typhoon. Mauri probably sailed past Thursday island through the Salomon sea and picked up water and provisions in French Polynesia. The native islanders there knew the Pacific pretty well. According to this video OP posted part of the Mauri mission was to establish the antimeridian? But of course this was a couple centuries BC and the Prime Meridian(gold) had not been chained through Paris yet(LOL).



posted on Jun, 26 2022 @ 05:41 PM
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a reply to: fromunclexcommunicate

Wouldnt have they been Phonecian in the pay of the Pharaoh, it seems they were the main maritime presence, during the Bronze age at least. They seemed to be regulars getting the tin from Cornwall. Since trade was not colonization, they would be engaged in a mutually beneficial enterprise. Which would could have lasted indefinitely. until the Roman empire started to threaten Carthage.



posted on Jun, 26 2022 @ 07:27 PM
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a reply to: anonentity

Common coast hugging phoenician ships that were used to ply the Mediterranean sea were called trireme derived from Latin: trirēmis "with three banks of oars"; 'triērēs, literally "three-rower"). Sounds like a lot of mouths to feed for voyages that were expected to last more than two weeks. But maybe specially modified versions for the ocean crossing expeditions?
Maui would have needed a vessel that would sail closer to the wind if he was going to make it to the Antimeridian. Most of the Phoenician ships were designed for only downhill runs..



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