Ancient Navigators Could Have Measured Longitude -- in Egypt in 232 B.C. !

21st Century: Science and Technology Magazine ^ | Fall 2001 | Rick Sanders

[restornu]

Figure 1 PROBABLE ROUTE OF THE EGYPTIAN VOYAGE IN 232 B.C. Deciphered rock and cave inscriptions from the Pacific islands, western New Guinea, and Santiago, Chile, tell of an Egyptian flotilla that set sail around 232 B.C., during the reign of Ptolemy III, on a mission to circumnavigate the globe. The six ships sailed under the direction of Captain Rata and Navigator Maui, a friend of the astronomer Eratosthenes (ca. 275-194 B.C.), who headed the famous library at Alexandria. Maui's inscriptions, as deciphered in the 1970s by epigrapher Barry Fell, indicated that this was a proof-of-principle voyage, to demonstrate Eratosthenes' theorem that the world was round, and approximately 24,500 miles in circumference.

[Arkady]

I'm a FReeper and I know something about history.
I know that islam carried on a lot of Greek/Hellenistic science without improving on it.
Until the Iranian muslim Al-Ghazzali (1058-1111) told his people to turn their back on science and philosophy. He instructed them to concentrate only on their religion.
Following his advice, the khalifah burnt the library of Baghdad in 1150.
At the same time, Saint Thomas (1225-74) told the West that science and Christianity were not in conflict.
He even argued that Aristotle was a kind of pre-Christian saint.
Science does shake belief in God and make people question religion. But not all religions choose to quake at the sight of it and turn their back on progress.
The greatest example of fine machinery up until modern times was the mechanical clock, which was invented by monks in monasteries.
The West has been shaped by Christian values and has led the world in technological achievements. It would be great if some other religions would quit holding their cultures hostage in a self-imposed Dark Age and quit blaming their troubles on the West.
Just for the record, the nose of the Sphinx was not destroyed by Napoleon's troops but by a muslim (or sufi if you prefer) around 1300 A.D. who thought it was idolaritous.
While all cultures have engaged in artistic vandalism, a religion that hates representational images of any kind, is likely to do more than their share.
Long live Charles Martel!

[aruanan]

Who was involved in the civil war?

Not Christians. That came later, after Constantine.

The museum and library survived for many centuries but were destroyed in the civil war that occurred under the Roman emperor Aurelian in the late 3rd century AD....

In the East, [Aurelian] defeated Zenobia's troops easily and occupied Palmyra in 272. Shortly afterward, an uprising broke out in Egypt under the instigation of a rich merchant, who, like a great part of the population, was a partisan of the Palmyrene queen.In response, Aurelian undertook a second campaign, plundering Palmyra and subjugating Alexandria. These troubles, however, along with the devastation of the great caravan city, were to set back Roman trade seriously in the East. Later, rounding back on the Gallic empire of Postumus' successors, he easily defeated Tetricus , a peaceful man not very willing to fight, near Cabillonum. The unity of the empire was restored, and Aurelian celebrated a splendid triumph in Rome. He also reestablished discipline in the state, sternly quelled a riot of artisans in the mints of Rome, organized the provisioning of the city by militarizing several corporations (the bakers, the pork merchants), and tried to stop the inflation by minting an antoninianus of sounder value. His religious policy was original: in order to strengthen the moral unity of the empire and his own power, he declared himself to be the protégé of the Sol Invictus (the Invincible Sun) and built a magnificent temple for this god with the Palmyrene spoils. Aurelian was also sometimes officially called dominus et deus: the principate had definitely been succeeded by the “dominate.” In 275 Aurelian was murdered by certain officers who mistakenly believed that their lives were in danger.
--Encyclopedia Britannica

[RnMomof7]

But you believe they were Jews (that spoke a unknown dialect of Egyptian..that could not be the language decipered here as no one but joseph Smith could read it ) not Egyptians..you can't have it both ways rest this does not help you much:>)

[thulldud]

All you gloaters are the same in every age: ignorant fools, taking credit for things not of your own doing, living off the seed corn that was laid in store by your more energetic and foresighted ancestors.

If I have seen further than other men, it was because I was standing on their glasses....

(No, I didn't make that up. Don't remember the proper attribution.)

[Fiddlstix]

Bump

[altayann]

What, the sky?

Sorry, couldn't resist. :)

[Sacajaweau]

Longitude IS a great book and I give them as gifts as I bought several first editions.

My son gave me the book "ZERO" The Biography of a Dangerous Idea, by Charles Seife.

Try it, you'll like it!!

[Spirited]

"I have this strange feeling that those pyramids are pointing to something really, really important."

The unusual location of the Great Pyramid suggests that it was the monument spoken of in Scripture by Isaiah the prophet.
Isaiah 19:19-20
"In that day shall thee be an altar to the Lord in the midst of the land of Egypt, and a pillar Hebrew "Matstsebah" correctly translated means monument) at the border thereof to the Lord. And it shall be for a sign, and for a witness unto the Lord of HOsts in the land of Egypt."

Since the full official name of the Pyramind, the Great Pyramid of Giza, means, in English, the Great Pyramid of the Border, the answer to the apparently contradictory definition of Isaiah is found in the Great Pyramid. The only spot on the face of the earth that completely answers this description, both geometrically and geographically, is the precise place where the Great Pyramid actually stands."

Page 13, "The Great Pyramid Decoded", E. Raymond Capt

[T. P. Pole]

Long live Charles Martel!

Wow, that's a reference you don't hear that often. I've long considered Tours to be the most significant turning event in western culture. Most folks don't even know what it is. Just imagine what the world would be like without the hammer.

[Orion78]

Bump for later reading

[ex-Texan]

Charles Martel had a little bit to do with the defeat of the Moslems, eh?: Clickity Click Click !

[John Locke]

Oh, good grief! No one "destroyed" Egypt and/or its skills and knowledge. It didn't ended like a brick through a plate glass window; ...

No, it ended when the last Librarian of Alexandria was dragged from her chariot by a screaming mob of fanatics, had the flesh scraped from her bones by oyster shells, was then dismembered and, so it is said, her remains were partially eaten, and the rest burned.

Hypatia of Alexandria, 415 AD.

[Mr_Magoo]

BTTT for a later read

[John Locke]

The greatest example of fine machinery up until modern times was the mechanical clock, which was invented by monks in monasteries.

Nope: by Ctesibios of Alexandria in about 618 AUC (135 BC). Pagan Greek, of course.

The "pendulum clock" as we know it today was invented by Christiaan Huygens in 1656. The clocks used by monks were typical Dark Age technology, which is to say inferior to their predecessors in Antiquity and their sucessors in modern times. The only significant improvement in a thousand years was the verge escapement, developed in the late fourteenth century, and almost certainly not by monks, since of the three English clock makers whose names have survived from that period, all were lay people.

[Consort]

Equatorial-torquetum

[John Locke]

Since the full official name of the Pyramind, the Great Pyramid of Giza, means, in English, the Great Pyramid of the Border

I'd appreciate a reference to that. My sources say the Pyramid of Cheops was called akhet khufu, which means, unsurprisingly, "pyramid of cheops". The Egyptian word for pyramid is derived from their word for "horizon", not "border". It's a religious metaphor but the explanation is a bit long.

[John Locke]

Time, I guess, for a post that addresses the main topic. Could the Ancients determine longitude, and if so, how?

Please note that I regard the "expedition" as fantasy, it is the engineering that interests me.

First, it is almost certain that the Hellenistic Age did know how to measure longitude, because we have maps that prove it. Or, at least, copies of those maps. The most famous - or infamous - is probably the Piri Reis map discussed in Charles Hapgood's fascinating book Maps of the Ancient Sea Kings, but there are better examples.

The Dulcert Portolano of 1339 is in my opinion the best, because it contains fewer copying errors than most, mesured by islands, rivers, estuaries etc. It could not have been produced in the Middle Ages - their idea of a map is the Mappa mundi in Hereford Cathedral, 1289 or so.

So an earlier civilization drew the original portolano, which is further indicated by some features of the map, for example the Guadalquivir is shown with an estuary, as it was in Greek times, rather than a delta. I don't buy Hapgood's thesis that the map makers came from Atlantis, so that leaves the Ancients.

Now, the average error in longitude on the Dulcert Portolano is about 45 minutes arc, three quarters of a degree, or at that latitude about 40 nautical miles. Good enough for point-to-point navigation.

So yes, they did it. But how?

Not with a marine chronometer, that's also pretty certain. No such device is described in the texts, and all we know of ancient clocks says they could not have kept accurate time on a moving vessel. That had to wait until Harrison's time.

That leaves a natural clock, and the obvious first choice is the moon. Would it work?

The math is simple. The moon revolves once around the Earth in 30 days, which is 12 degrees a day or 30 minutes arc an hour. The Earth rotates once in 24 hours, which is 15 degrees an hour or one degree in 4 minutes.

Therefore, to measure longitude accurate to one degree, you need to measure time accurate to 4 minutes. If you are measuring time by tracking the moon against the fixed stars, well, in 4 minutes it moves just 2 minutes arc, one-thirtieth of a degree, or, if you prefer, just one-fifteenth of its own diameter.

Could you do that with naked-eye observation? Absolutely not. Working with the largest and best astronomical instruments ever built, at Uraniborg on the island of Hveen, the great Tycho de Brahe could achieve only half that accuracy.

So you need a faster-running clock, or a telescope, or both. From Heron of Alexandria's Catoptrica, we know the Ancients understood enough of the science of optics to build telescopes, and from Herodotus we have mention of an instrument that sounds very like a telescope, but alas there is no direct proof or "smoking tube".

And if you have a telescope, you will find in the sky as fine a clock as you would ever need: the Galilean satellites of Jupiter. That's my best guess as to how they did it.

[newguy357]

Long live Charles Martel!

Yes!

Good post

[newguy357]

Yes, it is a reference that needs to made more often. One of the most important battles (if not the most important battle) in the last two thousand years. It is also more proof that islam has been violent since its invention.