This time it's Atlantis: Secret Star Mappers of a Lost World, which I watched on Hulu.com. In the interests of full disclosure, I knew from the title that it would probably be crap, but there was the slightest minuscule chance that they would surround the discussion of a fictional utopia with some actual science. There is a little bit. but then they had to spoil it for me.
I'm not going to debunk the whole show. I'll limit myself to one item. Since they gave you a bucket of garbage, perhaps we can at least pull something real out of it. At right about 31 minutes into the program there's a discussion of ancient maps, and ... oh, well, I'll just give you the quote:
"These seeking maps show accurate east-west distances, and that requires a knowledge - and accurate knowledge - of time. you have to measure time to get that. Now, they didn't have clocks back then. They didn't have timepieces at 2000, 3000 B.C. So they had to have another mechanism by which they could measure time. And that mechanism is the slow wobble of the Earth's axis, which would cycle once in 25,920 years. And with this rate of the wobble of the Earth's axis, the constellations of the zodiac appear to move along the horizon. They knew this rate, therefore they could measure time, and therefore measure east-west distances."Now, there is absolutely no way to say this politely, so I'm not going to try. This is a tremendous load of complete bullshit. The author of this astonishingly ignorant statement is James I. Nienhuis, who is the author of "Ice Age Civilizations". I mention the book because it's prominently featured as a credential under his name, and which (oddly) I found in its entirety as a PDF file on GenesisVeracityFoundation.com. I'd link you to it, but you've got Google, same as me.
Nienhuis is a young Earth creationist, but more important to the current discussion, he has not the slightest clue on how navigation and cartography are done. I'm going to focus purely on two things here, one from the frontspiece of his book and one from the quote above, because the one informs the other, and I don't want you to think I'm taking his ignorance out of context. Let's start with the book:
"The precise measurements and religious observances of the apparent movements of the sun and constellations of stars, in their orderly and predictable course in the sky, was a great passion for the ancients, and such is reflected in their legends, megalithic buildings, and navigation maps, which reveal the ancients' awareness of the solar equinoxes and solstices, and also, which reveal that they actually measured the precession of the earth's axis, the slow gyroscope-like wobble of the earth's axis in space, that would cycle once in 25,920 years. Those ancients could measure the earth with this knowledge because it allowed them to accurately calculate the radius and, so then, the circumference of the earth, and thereby, they were prepared to execute measurements for the accurate mapping and navigation of much of the globe within a few centuries during the Ice Age."One does not need any knowledge of the Earth's precession, much less its period, to make an impressively accurate estimate of the circumference of the Earth. Eratosthenes of Cyrene did it in the 3rd century B.C.E.. Here's how:
Pretty simple and obvious, right? Nienhuis would have you go 25,920 years out of your way to get the answer to that dead simple geometry problem. He would have you believe that ancient, esoteric superscience was necessary to solve a problem that could be solved with a stick.
I repeat: with a stick.
Hogwash. Nienhuis doesn't display an understanding the rudiments of navigation. When we're done in a moment, you will, though. So settle in and we'll go through the basics
Even knowing the circumference of the Earth, it's difficult to measure distances between landmasses because you can't just pace off the distance. But you know that the Earth is round; and regardless of whether you believe it rotates or the Sun moves around it, the Sun appears to move from east to west, with local noon occurring at whatever spot happens to be directly under it. Now, if you have a clock, then you set it to the correct time for your home port. Then, as you travel, you note the position of stars... it matters little which. You then note the difference in where you perceive them to be where you are and where you'd expect them to be back home. This tells you were you are.
Now, to do this you're going need to know the circumference of the Earth at your latitude. Look at a globe and you'll see that the lines of latitude actually form circles, and the circles get smaller as you near the poles.
You remember from plane geometry that circumference = pi * diameter. Because the Earth is a spheroid, we can calculate how big each circle is. It size varies with the distance from the Equator, so any line of latitude's circumference is pi * diameter * cos(latitude). If you're using a calculator, remember that we express latitude in degrees. We can then calculate how far along that line we've traveled by determining how much local time differs from the time back home.
Here's an example:
For my simple example, I'm going to use the easiest star, which also happens to be the one closest to us. It's the Sun.
When at my home port of Charleston, I set my clock to 12:00 exactly at solar noon. Then I travel to Casablanca. At solar noon in Casablanca I look at my watch, which says 7 am. So I have observed that "noon" in Casablanca occurs 5 hours earlier than noon in Charleston. I also know my latitude, which I got from looking at the pole star Polaris the night before and noting how high off the horizon it appeared to be. Since Casablanca's at 33.5N, and Charleston's at 32.7N, I'm going to average them out and say they're both on the 33rd parallel for our purposes. Thanks to the method I learned from Eratosthenes, I know that the Earth is about 24,900 miles around, which makes its diameter 7,926 miles.
Armed with all of this, I calculate that the circumference of the 33rd parallel is
equatorial diameter * pi * cos(latitude)
7926 * 3.14159 * cos(33)
about 20,883 miles
I also know there are 24 hours in the day, and I'm five hours away from my home port. So the distance I've traveled is 20,883 / 24 * 5, or about 4,350 miles, which is pretty close to what we'd sail if we stayed on the 33rd parallel and didn't take the Great Circle route (which would save us a couple of hundred miles).
There is no circumstance in which knowing about a 25,000 year-long cycle will help you with this calculation.
Now, in practice, the sun's not going to stick around waiting for you, and at night you'd use star charts. These will tell you what latitude and longitude a particular star is expected to be at a particular time and day of the year, and knowing where it is versus where you expected it to be you can calculate your position the very same way we did it using the Sun. After all, the Sun in simply the closest star. But again, these charts are only useful if they tell you where to expect the stars now. Your charts should be accurate and recent.
Now, Atlantis... beats it into you that the modern method of map making is based on the relationship of time to distance. It's stated over and over and over again, along with the assertion that this is somehow, in a completely undefined way, associated with the knowledge of the Earth's precession. In fact, as you can see for yourself above, where the stars were thousands of years ago is of precisely useless in cartography or navigation. It's useless when calculating your longitude; it's useless when calculating your latitude, and it's useless when determining the time. They are conflating two completely different forms of time measurement, trusting that you won't notice that the one thing they have in common is the word time.
While I'm at it... "modern" cartography depends a lot on the GPS satellites, and is no longer done by reading the stars with a sextant.If you want to calculate your longitude, what you need is a chronometer, not a calendar. What the ancients had to do was figure out a way to tell the time of day. Could they?
Well, Nienhuis makes a big deal out of the lack of "clocks". But without qualification, when you hear "clock" you're thinking in terms of a modern timepiece, no more primitive than a clockwork mechanism with gears and springs. That's not the only way to tell time. Here are a few others, known and used by the ancients:
- Water clocks tell the time in several ways... the simplest is the steady drip of water through a small hole in the container, the remaining water level indicating the time. Some used wheels to measure a steady flow, or had various levels of complexity, but you get the point. These are the oldest confirmed clocks, known to exist in Babylon in the 16th century B.C.E.
- Candle clocks tell the time via the slow and steady burn of a candle marked along its length with graduations that indicate the amount of time it's been burning, or the amount of oil left in a lamp.
- Hourglasses tell the time by the slow release of sand. They're not terribly accurate.
In mentioning these ancient clocks, I'm not saying this is how it was done, or that these are the only ways to do it. But keep in mind that ancient thinkers were not idiots. They were so used to working within the limitations of their technology that things that seem like insurmountable problems to us were commonplace challenges to them.
While accurate timepieces are needed for accurate measurements on long voyages, that doesn't mean that less accurate timepieces are useless... they're just useful for a shorter period of time. These ancient clocks were not terribly accurate, but then again they didn't really have to be. They just had to be accurate enough to get you to your next landfall. At that point you can re-calibrate using local observations. Although you may navigate at night, when you're mapping, it's daylight. And yes, the errors are cumulative, but look at an ancient map. They're not nearly so precise as the gushing of these presenters would have you believe.
I'm going to leave it at that for now. There's so much wrong here that I got tired watching it.
Postscript: One more thing before I put this issue aside. This bit of debunking has nothing whatsoever to do with having an open or closed mind It has nothing to do with whether or not you believe that the description of an allegorical anti-utopia in the writings of one ancient scholar represent historical fact. It doesn't matter whether you think the Earth was born yesterday. It has to do with math.
A closed mind won't change the math, and it's not possible to just brush it aside. And when Nienhuis is so completely wrong about such a fundamentally simple concept that is so easy to verify that you can do it right there in your armchair, you absolutely owe it to yourself to take other statements he makes with a skeptical attitude.
This isn't a passing mistake. It's a fundamental error. It leads the introduction of his book. He expounds on it in this movie. Ask yourself whether deliberately misleading you, does not check his facts, or is simply abysmally bad at fact-checking. Then ask which of these would make it OK to take his word at face value.
Post-Postscript: Why did I not calculate the Great Circle route? Partly because it's a pain in the ass and I'm giving you an introduction, not a course in spherical trigonometry. But if you're interested, here's how [link]. The linked site will not only give you the formulae; it will give you code you can use to do the spherical trig on your computer.
But the main reason is the same as why the Mercator projection was preferred by sailors... it gives true compass bearings. An ancient sailor is not only going to eschew the complicated math, he's going to be more concerned with knowing where he is than optimizing his route. So the distance I gave is that which you'd travel if you sailed due East for the entire trip.