Since this is all rather complicated and dependent on latitude [and if you're on a ship, changes in longitude, too] you need something more regular. The clock is as regular as star time, with the added benefit that you can use it regardless of dailight or atmospheric conditions. "It's the statue, man, The Statue."
You can still find antique timetables which aren't corrected for GMT. The guard would have either have to keep adjusting his watch, or add and subtract a certain time offset in his head.
Central standardised time - and it might as well be mean time, to make life simpler - becomes inevitable once people start travelling faster than a horse does.
I was sure I'd read that it wasn't so complicated for ancient mariners. After all, they were crossing the seas thousands of years before the clock.
Have you heard of this?
Avoiding Chrichton Miller's theories about whatever he theorises about, do these technological explanations sound feasible? Don't fight forces, use them R. Buckminster Fuller.
True. Before they had accurate clocks on board, they'd just sail on a parallel (a set latitude) and just wait until they'd arrive at destination. They'd just check the maximum height of the sun to remain at the set latitude. They didn't know their longitude E or W.
I have a question (Mig or DoDo ?) : is it possible to calculate some value of time just by sun / moon / stars observations ?
How much time do you have to make the observations? "It's the statue, man, The Statue."
Galileo also proposed used the positions of Jupiter's moons as a very distant clock.
For obvious reasons, neither of these ideas was as useful as having an accurate timekeeper.
There's a good overview here.
http://www.crichtonmiller.com/longitude.htm
I don't have the tech. knowledge to know whether this guy is making things up or telling the truth, but I've been linking to his info. He is claiming that there was, indeed, a simple way of measuring both latitude and longitude using a device based on the celtic cross.
Is he crazy? Is it nonsense? Certainly he is claiming that this was used thousands of years into the past. I'm very interested in reading a tech person's view(s) of this guys tech. theories.
What I mean by that is: he has a lot of other theories too, but...does his device work? Don't fight forces, use them R. Buckminster Fuller.
Here is what I understand, tell me where I go wrong.
[edit]
How to mark a standard time reference before Greenwich and clocks? What could be the same for all, yet different at different longitudes?
Well...nothing. There has to be a reference point. So, how about where you live?
Ceebs! My mind is blown again!
Look at draco (but you know all this! Humour me!) There it lies, at the centre of the ecliptic pole. The true centre...is dark. No star.
Well...
Maybe not....
The ecliptic pole. I needed that. Our celestial pole is at the bottom of Ursa Minor, the last star. Polaris. In the time of the Egyptians (have I understood this correctly?) our north pole pointed more or less directly at the third star in Draco's tail.
http://www.pakhomov.com/duat.html
The galactic equator...
Another wheel!
It's like taking mushrooms, but it isn't. How about learning all this, and then taking mushrooms?
Whoooosh!
Celestial north, south, east, west
(indulge me!_
Ecliptic north, south, east, west.
Galactic north, south, east, west.
The moon.
The planets.
Add psilocybin, a hill, a clear sky, no unwanted earth-light, warmth, soft grass, like back...
VOOOOM!
And the report back?
Hyperbolic trajectories!
http://ourworld.compuserve.com/homepages/dp5/dust2.htm
Ach...I ramble.
...so...recapping. Longitude is time from somewhere. You look up. There is Draco. It marks out the spot above the sun. There is the moon. It measures time against the sun (in degrees--and therefore in minutes and seconds?) There are the stars. We don't point to the ecliptic pole. We point to the celestial pole. Polaris. This difference is enough, if measured accurately, to work out where we are on the planet...because...
we know where the moon should be, relative to the stars. And at two different points on the globe, the difference: moon, pole star, draco = movement?
The only way to navigate by the moon is to work out the angular differential from a star over time and motion with the help of an almanac reference This requires tracking the moon along the ecliptic and using certain stars in known constellations that the Egyptians called a decan of which there were 36 in one complete Zodiac to make up 360 degrees. But that knowledge is insufficient on its own, there is a crucial requirement, an instrument of sufficient accuracy The moon tracks over the earth at 720 nautical miles per hour and moves against the zodiac (a great circle) 30 arc minutes in 60 minutes of time during which the position of the observer has spun through 900 nautical miles on a great circle. To find a longitude position by measuring the angular difference requires an accuracy of observation of at least 1 arc minute to achieve a longitude accuracy of 15 nautical miles at the equator reducing in proportion by latitude.
So the questions are:
1) Could humans many years ago have worked this out?
My answer: yes. They had the sky. They had time. They had brains like ours. Earth--axis. Sun--axis. Moon--relationship.
???
Did humans long long ago--thousands of years, counting 2,3,4, and beyond...beyond even the disappearance of..the ice...
http://en.wikipedia.org/wiki/Ice_age#Recent_glacial_and_interglacial_phases
...did they know this more than 10,000 years ago? I can't see why not. (It's taken me about a week to start getting my head around it.)
2) Did they have the mechanical means to use this information for longitudinal navigation? Did they have a sense of lateral time? -- I am here now, and you are there now, but where you are, it is a different time...of day and, if you are in New Zealand, year. But it is still Now.
So...now where am I?
Did they have measuring devices for that? Which would have been useful to understand where on earth they were, relative to their home. And I'm assuming everyone knew the earth was a globe. (Well, I'm assuming those who had worked out the relationship of the celestial pole to the ecliptic pole knew the earth was a globe.)
The galactic equator! The galactic north pole!
As I understand it, the argument comes down to: did they use snakeskin as an exponential device in order to calculate longitudinal movement? Why would they need it? Because they sailed across seas, I assume. A nagivator's riddle. Where am I? Where am I going? How far am I from where I started?
http://www.crichtonmiller.com/sophia.htm
Crazy theories!
But I learned about longitude, and the celestial equator, and...yes! The ecliptic north pole!
Ah, the power of the internet...I ramble to this screen and get to see...the universe in pictures.
Cough cough! Don't fight forces, use them R. Buckminster Fuller.
I'm assuming everyone knew the earth was a globe.
There is no evidence for anyone at the time of Columbus thinking the world was flat. in fact the flat earth story was the invention of Washington Irvine,
The ancient Greek and Egyptians new that the world was round and calculated its size correct to within 1% and 5% respectively, and considering that they used people who paced out the distance between Thebes and Cairo as a basline for the calculations that wasn't bad.
The timepeice is still the difficult step in calculating longitude, without complicated calculations. although if you wish to take on these calculations there is evidence of a variety of observatories in India, china and (I think)Iran. to work out the difference, you would have needed to combine the observations at these several sites to work out what was happening.
could they have done it thousands of years ago? that's hard to say, If you ask an Archaeologist, youll just get the answer of it being "Ritual" which is their get out line when they don't want to say "We don't know". Any idiot can face a crisis - it's day to day living that wears you out.
So...
...the snakeskin is needed for the accuracy somehow...maybe to pinpoint and then to read off? Because snakeskin was a finer measure (the tip of the scale--yet still visible to the human eye--than any manmade mark--at the reading end, not just for the tangential?
(I think he's in wild speculation with the snakeskin...but I enjoy wild speculation!) Don't fight forces, use them R. Buckminster Fuller.
to even know that one can determine longitude through the apparent position of the moon against the fixed stars, one would have to have compiled accurate almanacs at two widely separated locations, and then compared them. "It's the statue, man, The Statue."
4)5) Regarding how accurate, much more accurate than 61 arc seconds. That's about twice the Moon's apparent diameter, and the distance the Moon travels in the sky in 111 minutes! If we go from time to latitude, it is not nice at all.
Migeru wrote about measurement precision, e.g. you want to measure the position of the center of the moon, but you have a luminous object just below 30 arc seconds in diameter.
To emphasize what gave me for thinking about the snakeskin, it wasn't simply its use, but this:
The skin of a snake is exponential
I'm not sure what's exponential about it BTW, I tipped that the scales get bigger away from the head or something. *Lunatic*, n. One whose delusions are out of fashion.
DoDo, I don't follow myself either!
Backing way up: all I (mis?)understand is:
It's possible (using specific events such as eclipses) to bring exactitude to our study of the earth-sun-moon-stars relationships. We can measure different combinations, so I'm assuming that ancient peoples could in theory have known how to calculate movement west-east/east-west.
(And as Migeru said: why would they think there'd be any difference, unless they had travelled east-west/west-east, taking their almanacs, far enough to discover the differences--or else they met people from somewhere else who had almanacs...which didn't match? I like this idea because either
a) two different groups came to the same conclusions re: rotation, position, etc...
or
b) the various groups were, in fact, connected--just maybe not at the speeds we imagine; maybe they communicated once a year or even less? I have no idea. I just like the concept.)
I can imagine that people who knew of other locations could work out their longitude relative to those other locations (did I read somewhere that the pyramids were an ancient equivalent of Greenwich? Zero = the north south line between a pair of pyramids or somesuch.)
Then I can imagine someone attempting to do this on a boat--no success. Maybe they would try different techniques, different devices. This guy's device...has he tested it at sea? Certainly it seems that holding something out at arms length while one gently or not so gently bobs up and down does not sound right. So then my question about minimum useful measurements. You're saying that the minimum feasible is the width of two moons, which is a useless measurement?
When it comes to degrees I get lost.
(I thought latitude wasn't a problem--you measure a star's height against the horizon or somesuch...I could well be wrong...I really am out of my depth at this point.)
With the snakeskin, I think he wanted his theory to match up to...all the signs. I suppose it's possible to e-mail him and ask what he meant.
And...bowing humbly...
I thank you again! Don't fight forces, use them R. Buckminster Fuller.
Certainly God doesn't like the idea that people once upon a time were sharing knowledge:
11:6 Yahweh said, "Behold, they are one people, and they have all one language; and this is what they begin to do. Now nothing will be withheld from them, which they intend to do.
11:7 Come, let's go down, and there confuse their language, that they may not understand one another's speech."
11:8 So Yahweh scattered them abroad from there on the surface of all the earth. They stopped building the city.
11:9 Therefore the name of it was called Babel, because Yahweh confused the language of all the earth, there. From there, Yahweh scattered them abroad on the surface of all the earth.
http://www.awitness.org/biblehtm/ge/ge11.htm
These are old pre-flood/post-flood myths, seen through the eyes of the Torah; I prefer myths that involve some happy humans somewhere communicating and getting along. The stars...seem a useful, because obvious, point , which might be the same myth seen a different way (except for the God confusing everyone part.) Certainly we have myths of before/after and the only cataclysmic before/after we have is the ending of the last ice age, which would confound all old social relationships...unless one were free from the effects--isolated. Yet it seems that all communities have flood myths; which would make sense if there were a global connection network pre-melt...
...contact between disparate groups. You mentioned that to understand the concept of longitude (or maybe I misunderstood!), one would have to have an almanac and then travel with it.
I don't know how far you'd have to travel west-east/east-west before the naked eye and memory pointed out that things had changed. Maybe never? See how little I know! In my imagination I see a person far from home, staring up at the sky as the moon goes past and thinking, "Hold on. That shouldn't be there, it should be over there." His friend from the other faf-flung tribe pats his knee. "Happened to me first time I came to where you live. Here, have one of these. It'll help," he adds, handing him a large mushroom...
*:R Don't fight forces, use them R. Buckminster Fuller.
I now get what you mean with the eclypses, e.g. that the ancients could have been aware of the Moon's parallax and put that in almanachs. This is the case at least with the Greeks -- Hipparchos is credited with the measurement of the Moon's parallax using a soler eclypse (probably 129 BC).
But for a navigator to get the parallax at an unknown location, that's another thing. So if, say, we want to get the error under just 3' for the Moon anywhere in the sky, the guessed location must be precise by 320 kilometres, while the error of the final result will be around half of that or more -- not very efficient. *Lunatic*, n. One whose delusions are out of fashion.
it's the difference between landing at Standstead--miles from London! Where to stay?
and landing in a country where they know of you and welcome you; and if you arrived a hundred miles (or whatever measurement you choose)...away from where you were heading...there wasn't a problem.
So I think the problem must have been aiming at small islands. They are the things you can miss.
If it was a problem; and if they didn't have alternative navigational methods as adjuncts to--or even alternatives to--the sky.
If you ask the following question:
"That's north, that's south, that's east, that's west" pointing, "Are we moving? And if we are, which way are we moving?"
If they look confused, you say, "The sun rises in the east and," drawing an arc, "it sets in the west. Which way are we moving?"
I asked a colleague today.
"Clockwise," she said. "I suppose we're moving clockwise."
But, for an hour or so she was as fascinated as me by the basic movements of planet (spin), sun (axis), moon (moooovement), and stars (tick tock)....
What was the measure of efficiency before those huge ice-sheets melted? Because humans have been around for long before they melted. I'm beginning to think...hmmm...who wouldn't have been inundated? Who would'nt have had their life revolutionised. Maybe some people in India, in China, the himalayas must have changed; but maybe they changed, and the inhabitants could change with the himlayas, which are still growing...
Bhutan has an "Annual Happiness Index"...or somesuch. Was it Laurent who pointed out the ridiculousness of GDP? It's ridiculous. An overthrow, and overhang, of Empire. "It's over there, grab it!"
The sun is our source of life. If we harness the sun's powers...we still live on an unstable ball of energy, with fruity effects--us!
So risk is ever present. But now people have no sense of solar risk, or lunar risk, or stella risk. All the risks are human-created. War. Famine. Destitution.
DoDo!
You got me rambling!
Thanks for all your input. Very much appreciated! Don't fight forces, use them R. Buckminster Fuller.
And you got me thinking! Thinking about a hypothesis I would normally have dismissed out of hand (due to its bad wording). Soon I'll post a second summary as top-level comment. *Lunatic*, n. One whose delusions are out of fashion.
If you're at the same latitude on the same night, there should be no parallax. "It's the statue, man, The Statue."
15 degrees of latitude is one hour of difference in local time, during which the moon will move by 33 arc minutes (about one Moon apparent diameter). So that's the kind of accuracy we're talking about. "It's the statue, man, The Statue."
An instrument capable of sidereal measurement to 1 arc minute would result in an accuracy of 7.5 nautical miles at 45ºN
It is one thing to determine the distance between two (pointlike) starts to 1 arc minute by naked eye (with the aid of his instrument) but quite another to locate the moon to that accuracy. "It's the statue, man, The Statue."
First unit of time: the day. Division: day and night.
(For the astronomer with lots of time: place a stone on top of a wall where the sun comes up. Repeat for 230 days. The sun will then, (sort of), go back down the stones, then back up, then back down)
Second unit of time: the year. Division: into four. (the central stone in the row of stones divides them into two and the sun passes up and down the row, so four divisions)
Add the moon.
Start watching when the moon is just visible after the sun has gone down. (Crescent moon.) Note that each day the moon arrives later. It is lagging behind the sun. It lags more and more until the moon is only just getting up when the sun is going down. Then the moon is only visible at night, then it is only visible late at night, then it is lit by the almost-rising sun, then it is hidden by the sun and then you don't see it for a bit, and then it reappears, in the evening, just after the sun has gone down (crescent moon.)
Third unit of time: one mo(o)nth.
Now become a keen mathematician. Realise that you can divide the sky up into "moon chunks". The moon moves a certain distance away from the sun each day and finally comes back to where it was: a circle. Divide the circle into moon chunks. How long does it take the moon to go all the way round and back to where it started? 29.5 days, more or less. let's say 30 and you can divide your cicle into thirty chunks.
Plant some sticks in the ground in a circle. Each stick stands straight up but is in the direction of one of those moon chunks.
Now: you have four fingers on each hand. Splay out your fingers and measure off roughly equal measurements between each stick.
Next time the sun comes up it creates shadows on the sticks. As the shadows interact, work out a pattern.
Fourth unit of time: I have no idea whatsoever what I have just created!
Here's how ancient civilisations have divided up the day:
http://en.wikipedia.org/wiki/Hour
Circles can be divided into two, then four, then eight, then sixteen, then thirty two, then sixty four, then one hundred and twenty eight, then two hundred and fifty four, then five hundred and eight...
You could use those numbers to measure time.
Now...which values of time would you like to use ;)
We have sixty seconds and sixty minutes (minute as in tiny as in the smallest discernable measurement on a sundial--well, that's what the article says), twenty four hours...
Now...you have some timeframes. Day night. Month. They'll do for now. We don't have to work, we live in a land of plenty and make love when we can.
So...we are bored with making love one evening. We sit outside and stare at...the stars. We watch the moon going past them. ????? The moon is moving relative to the stars. We become mathematicians again, divide up the sky. Well, there are all those stars...why not make up some patterns and then, given that we know the sun comes up and goes down and the moon goes slower than the sun and given that we know we're drawing a circle...we could use our sticks! We could build large screens at the stick points and watch the stars we can see from our now-blinkered site. Note some of the brighter ones, draw some imaginary shapes to remind us of them...
...and then we'd notice that each month there's a difference...
...between the type of moon and the stars behind it. The moon is moving relative to the stars over its monthly course! It gets back to the same stars after 27 days, but it isn't the same kind of moon (full, crescent) until 29.5 days!
Enough! Build an atomic clock! Hold on. The sun...is atomic...
...I think it all depends what you wish to measure. If you wish to have an abstract measure...but how? Time must tick relative to something... How about
;)
(All errors my own; all corrections appreciated. The sun and the moon relationship--I've been watching it develop for the past six days...) Don't fight forces, use them R. Buckminster Fuller.
Arithmetical: 12 has a larger number of divisors (1,2,3,4,6,12) than any other number smaller than 18.
Geometrical: it is trivial to divide a circle into 12 equal sections, as you don't even need a variable-girth compass. "It's the statue, man, The Statue."
For the non-mathematical among us (or the non geometrical)--who would be me--I had to look it up.
Here's what I got.
To draw a circle you need a compass of some kind. The point is the centre and the line you draw is the circumference. Take the same compass, put it's point somewhere on the circumference and then draw another circle, which will bisect the orginal circle in two places. Move the compass to one of these bisection points and repeat. You will now have...three marks on your circle, because...because your new circle will bisect the circumference at a new point and also at the old point...keep going until you have...six divisions.
Now look at the circles you have drawn. They meet. Draw lines from where they meet to the centre of the original circle...voila! The circle is divided into twelve!
Did I get that right?
(And I'm presuming it is slightly out because the circumference is the diameter times pi, or the radius times pi times two...?
And lo....maths!
(Thing is, as I understand it the greeks weren't inventors of this knowledge; they learnt it over in Alexandria, and so I am assuming it is ancient knowledge, far pre-dating the greeks, but we call them the discoverers because...well, a reason I can think of: the destruction of the library in Alexandria.)
And as this all started, for me, with Gaianne's comment about knowledge being destroyed, how about this gem?
We found a large number of books in these characters and, as they contained nothing in which were not to be seen as superstition and lies of the devil, we burned them all, which they (the Maya) regretted to an amazing degree, and which caused them much affliction.
Only three Pre-Columbian "books" of Maya hieroglyphics (also known as a codices) and fragments of a fourth are known to have survived. Collectively, these works are known as the Maya codices.
http://en.wikipedia.org/wiki/Diego_de_Landa
The famous Library of Alexandria was created by Ptolemy I Soter and its first librarian was Zenodotus of Ephesus.
BTW, the second librarian was Eratosthenes of Cyrene, who was the first to measure the Earth's cicumference... "Dieu se rit des hommes qui se plaignent des conséquences alors qu'ils en chérissent les causes" Jacques-Bénigne Bossuet
My mind acheth.
So...I have read up on the library and have some questions.
1) Why were the greeks running a library in Alexandria?
My initial assumption: because the Pharaoh stumped up the cash.
After Ptolemy I Soter, on of Alexander's successful generals, secured the kingship for himself of conquered Egypt, Theophrastus turned down the Pharoah's invitation in 297 B.C.E to tutor Ptolemy's heir, and instead recommended Demetrius, who had recently been driven out from Athens as a result of political fallout from the conflicts of Alexander's successors
http://www.perseus.tufts.edu/GreekScience/Students/Ellen/Museum.html#RTFToC3
Oh, intrigue! Greek generals bashing about, establishing a centre of learning in Egypt. Why Egypt?
Well...was it a historic centre of learning? Or was it...opportune?
So. It was founded by a greek dictator exile, another greek declared himself king of Egypt, and soon enough the dictator was translating, starting with the Old Testament.
Sounds to me as though the greeks had the cultural and economic clout to set up a "world library" and had greeks as librarians, and the works of greeks such as Aristotle and Plato; but the idea was to collect the world's knowledge which, for me, pre-supposes a world of knowledge they wanted to capture, for many reasons but I assume at least some were scientific.
But Ikernov nussink! I'm just following a thread...in my head...
...What about the vedic traditions?
I can't see that knowledge was unshared. My guess: the various knowledge bases were seeking to coalesce under the shadow of power-battles among the rich and powerful.
So I'd expect some greek bias in the library, but I'm only interested in...what? In the capacities of human thought and invention I suppose. And also (look around us!) at the power of...human power...to break knowledge, to destroy information deleterious to the human power...that would seek to break it.
I must thank you, Melanchthon, and you too, DoDo! Don't fight forces, use them R. Buckminster Fuller.
You can make that crop circle with a single piece of string, a stick and a plank. "It's the statue, man, The Statue."
....Not plants that were entirely indigenous to Africa.
Or alternatively the presence of large stone carved sculptures on the North East coast of South America, that have undeniably negroid features. You can't be me, I'm taken
Actually, it's quite feasible to cross the Atlantic by dead reckoning (speed * time passed = distance, and direction by a corrected compass) alone, with reasonable accuracy. In the 70s and 80s, before everyone had GPS, quite a few sailors didn't want to bother with a sextant, and just crossed that way.
The error upon arrival depended a lot actually on the speed of the boat : the faster the boat, the less chances of small errors on boat/current speed/course building up to result in large errors upon arrival.
Regarding the mummies with nicotine and cocaine traces, that's still a matter of dispute -- contamination, chemical products during mummification, and African plants now gone are among the other possibilities. For the latter speaks that there is wild tobacco discovered somewhere in the South of Africa, and that the formation of the Sahara definitely must have caused some extinctions.
If there was regular trade with America, there is also the question of a trace in the historical record. There is one candidate, Punt, unfortunately the description doesn't fit America. It does fit India though, and the route there does involve one crossing of high seas (the Arabian Sea).
As far as I know, the "undeniably negroid features" of Olmec heads is something peddled by Mormons and some US Black nationalists, no more science. *Lunatic*, n. One whose delusions are out of fashion.
http://www.crystalinks.com/olmec.html You can't be me, I'm taken
I suppose it comes down to asking whether plants that might exist but have never been found and have left no trace are more likely than voyages that might exist and have never been found.
Olmec vs Egyptian tie-ins are a bizarre suggestion archaeologically. There's one big similarity - pyramid building - but not much else.
If the two cultures were closely related, you'd have expected some overlaps in imagery, writing (hieroglyphics, especially) and so on. But there's really next to nothing.
If you allow for some trade, it's possible Olmec visitors to Egypt might have seen the pyramids and though 'Good idea! Let's do that too!' But I think it's unlikely there was ever more of a connection than that.
So it remains a mystery. (And probably always will.)
