Columbus and the Eclipse: truth or UL?

[Fretful Porpentine]

From an article on eclipses in this morning's Raleigh News & Observer:In late 1503, Spanish explorer Christopher Columbus became stranded with his crew on what is now Jamaica. Columbus quickly wore out his welcome with the island's natives, and they refused to supply him with fresh food and water. He told the inhabitants that a powerful god would turn the moon dark red if they did not help him. Columbus knew from his calendar that a lunar eclipse would appear in February 1504. When the eclipse occurred, the natives quickly provided the supplies
My knee-jerk reaction: It seems unlikely, to say the least, that the Jamaicans had never seen an eclipse before ... and the whole story sounds a lot like the sort of tall tale an explorer would tell about the ignorant natives, immediately prior to enslaving them. (Also, I'm really hoping it's false so I can use it as an example of a questionable factoid when I teach freshman comp in the fall.) Does anybody know for sure?

[ignatiusjreilly]

There's another thread here with a similar topic:

http://www.straightdope.com/ubb/Forum3/HTML/005049.html

I don't know how Columbus could have predicted one so quickly when he really didn't know where he was, exactly, in relation to Europe where any earlier equations (however rough) might have been derived. Then again, I don't know enough about the math involved - maybe one's location is unnecessary, but at least that's my theory.

Or even if other scientists in Europe had predicted an eclipse in Europe, and he knew that date, I don't think an eclipse in Europe is always visible in Jamaica, too. If it really happened, maybe he just got lucky

So in roundabout way, I would say it's unlikely to have happened. Of course, this story has been going around for a very very very long time, so maybe it is true to some degree.

[Ursa Major]

I'd guess that this story was inspired by Mark Twain's "A Connetecut Yankee in King Arthur's Court".

[John Corrado]

Ursa- I'll double-check my references, but I had always heard that this story inspired Mark Twain, not vice-versa.

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JMCJ

Curmudgeon Of The Day Winner, 1/19/00
As Selected by RTFirefly

[rowrrbazzle]

from Fretful Porpentine:
My knee-jerk reaction: It seems unlikely, to say the least, that the Jamaicans had never seen an eclipse before ... and the whole story sounds a lot like the sort of tall tale an explorer would tell about the ignorant natives, immediately prior to enslaving them. [b]

I don't know if this story is true. If it is, you are almost certainly correct that they had seen lunar eclipses before. The reason is that these are seen by anyone who can see the moon at the right time, up to half of the earth. However, that doesn't mean they thought of it as a purely natural event as we do today. They could still attribute it to the gods being angry. This would allow CC to take the credit for it, being influential with the gods or even one of them.

Originally posted by johnnyharvard:
[B]I don't know how Columbus could have predicted one so quickly when he really didn't know where he was, exactly, in relation to Europe where any earlier equations (however rough) might have been derived. Then again, I don't know enough about the math involved - maybe one's location is unnecessary, but at least that's my theory.

Or even if other scientists in Europe had predicted an eclipse in Europe, and he knew that date, I don't think an eclipse in Europe is always visible in Jamaica, too. If it really happened, maybe he just got lucky.

See above. If he knew there was going to be a lunar eclipse on that night, it was worth a shot to try to use it to control the natives because these are seen over very wide areas.

[b]Solar[b] eclipses are different. Partial ones are seen over smaller areas, and of course total solar eclipses are visible only in the path of totality which is 60 or so miles wide max.

This is why most people have seen multiple lunar eclipses, but very few have seen a total solar eclipse. I'm 48 and I've seen six or more lunar eclipses. I've also seen about four partial solar eclipses, but I've never seen a total solar eclipse. I traveled to Canada in '72 to see that total solar eclipse, but it became cloudy that day.

[Jinx]

Jinx concurs: It is possible for a lunar eclipse to be visible in both Europe and Jamaica. I add that, contrary to public opinion, lunar eclipses are LESS COMMON than solar eclipses. The math shows you cannot have two subsequent lunar eclipses while you can have two subsequent solar events. Lunar eclipses simply cover a wider area (like your hand's shadow when brought up close to a flashlight).

As for the natives, even if they had seen dozens of lunar eclipses before, it doesn't mean they weren't any less afraid! Even now, superstitions of all kinds are hard to break.

I have heard of this Columbus story, but I cannot confirm nor deny its validity. (Maybe this is where Twain got the plot device he used in "CT Yankee in King Arthur's Court"?

[frolix8]

CNN just ran this story on their website in an article about tonight's eclipse. No references of course, so it could still be UL as far as I'm concerned. As for Columbus, supposedly he thought he was in India, half way around the world from Europe, how could the same eclipse, which lasts around 80 minutes, be visible in both places? Or did CC just take a chance out of desperation?

I'll be viewing tonight's from my hot tub, it's at 10:00 or so CST.

[Arnold Winkelried]

Originally posted by frolix8:
As for Columbus, supposedly he thought he was in India, half way around the world from Europe, how could the same eclipse, which lasts around 80 minutes, be visible in both places

How about the reverse hypothesis: Columbus, who was not an astronomical expert, assumed that an eclipse would automatically be visible over the whole world?

[Jinx]

In brief, the time you quote is for the local event. This does not exclude the fact that there is a vast range of vantage points from which the proper perspective is achieved to witness the alignment.

[ignatiusjreilly]

Well, I think someone's already posted somewhere that Columbus actually did think he was in India and apparently he thought the actual size of the globe to be much smaller. So assuming he gets both of those wrong, then he might have accidentally backed into the correct hypothesis that the eclipse was going to be visible at that particular time and place.

I'm too lazy to look it up... Does anyone know Columbus' thoughts on the rotation of the earth and day/night? Could he have thought that he was on the opposite side of the world from Europe, yet that it was still going to be daytime and nighttime simultaneously in the two locations? What did he know of celestial mechanics? Just that the world was round, or did he know more?

[AWB]

According to this catalog of lunar eclipses, (http://sunearth.gsfc.nasa.gov/eclipse/LEcat/LE1501-1600.html) there was an eclipse on 3/1/1504. The technical info doesn't say, but this date is probably Gregorian instead of Julian, so the date would've been 2/20/1504 Julian.

Let me slog through the math to see if that one was visible in Jamaica.

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Judges 14:9 - So [Samson] scraped the honey into his hands and went on, eating as he went. When he came to his father and mother, he gave some to them and they ate it; but he did not tell them that he had scraped the honey out of the body of the lion.

[ignatiusjreilly]

Actually Torq, that's what I was trying to ask? Not did Columbus really know the size of the difference in time between Jamaica and Europe, rather, did he know there was any difference at all? I would assume he had some inkling, but since people traveled so slowly in those days, and instantaneous communication was unavailable, I would not expect for Columbus to have said "I traveled 2000 miles, therefore I am 4 hours ahead of Spain and the eclipse will occur at the point in the sky" (or whatever the actual facts may be)

[Triskadecamus]

          Prediction of lunar eclipses is taken for granted now days. The mathematics is fairly abstruse, given the time period. With the inability to even fix longitude, and the absence, of either pendulum clocks, (Christiaan Hyugens wouldn't even be born until 1629) or the compilation of long term data on positional astronomy (Tycho Brahe waiting until 1546 for his first observations of any sort, and those not astronomical) Christo seems to be fairly far out on a limb with his prediction. While it may be true that very skilled practitioners of astrology would have a good idea of the day on which a lunar eclipse would occur, (I doubt it, but it is possible) the proposition that a navigator would study such information is fairly farfetched.

          I have a pretty fair interest in astronomy, and a pretty good memory. I haven't a clue when the next lunar eclipse is going to happen. (Other than the one tonight, I mean.) I saw one, when I was a kid and another when my youngest son was just a kid. Couldn't tell you the dates for a dollar. Not even for David B's infamous $10,000! While there were probably at least a few erudite scholars interested in such things at that time, sharing of knowledge was not the rule of science in the Sixteenth Century. Such arcana were guarded, and revealed only to the trusted acolytes of the masters.

          Navigation was an art, not a science, in the days of Christopher Columbus. Currents, wind, weather, and performance of ships were the stuff of navigation, in the days of the Great Explorers. Yes, you needed to know the exact direction of North. The constellations visible from the various latitudes, in the various seasons, and the latitudes of the important features of the "Known World." Given that Chris didn't even update his charts from the time of Ptolemy leaves one to wonder if he kept up his subscription to Astrology Today.

<P ALIGN="CENTER">Tris</P>
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The road to truth is long, and lined the entire way with annoying bastards.
-- Alexander Jablokov, The Place of No Shadows

[jab1]

Columbus did, indeed, believe the Earth to be smaller than it really is, which is what convinced Queen Isabella to finance his voyage. He thought it to be only 12,000 miles around, less than half of what it really is. There were many scholars who knew better, but through reputation, power of speech, and, perhaps, personal charm, he got his three ships and crews.

AFAIK, he never changed his belief about the size of the Earth, even after finishing his last voyage.

TRIVIA NOTE: Greek mathematician Eratosthenes calculated the size of the Earth nearly 300 years before the birth of Christ. He wasn't precise, but it was closer than anyone else had managed at the time.

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&gt;&lt; DARWIN &gt;
____L___L__

[Fretful Porpentine]

Thanks, everybody. JoeyBlades, I'll keep an eye out for the story you mentioned, although I doubt it will turn up again now that the solstice is over. Oh well, something tells me it won't be hard to mind more nuggets of misinformation in the media :rolleyes:.

[Irishman]

Joey Blades, Fretful Porpentine, I found these two links about the topic.
http://www.badastronomy.com/bitesize/fullmoon_perigee.html
http://www.snopes.com/spoons/fracture/fullmoon.htm

Neither one really addresses the topic in detail, though the snopes page dismisses it.

[Jinx]

Johnnyharvard has shown that Columbus did, perhaps, prove that two wrongs may indeed make a right!

[AWB]

According to my calcs, the lunar eclipse would've taken place from 5:33 PM to 9:47 PM Jamaica time. Sunset that day wasn't until 6:15 or so, so the Moon was already starting to eclipse when it rose that evening. At Time of Greatest Eclipse (7:40 PM), the Moon would've had an altitude of 13.2o.


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Judges 14:9 - So [Samson] scraped the honey into his hands and went on, eating as he went. When he came to his father and mother, he gave some to them and they ate it; but he did not tell them that he had scraped the honey out of the body of the lion.

[ignatiusjreilly]

Thank you! Thank you!

And for my next trick, I'm gonna make this beer disappear...

[AWB]

Even if ol' Chris didn't know he wasn't near India, he did know how far west of Europe he was. This info is important in figuring the altitude angle and time of the eclipse.

If there were accurate charts of eclipses in the 16th century, he at least could've known about it. Whether he used this to his advantage, who knows.

This was also a plot of a "McHale's Navy" episode, only it was a solar eclipse triggered by ENS Parker flicking his cigarette lighter. :)

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Judges 14:9 - So [Samson] scraped the honey into his hands and went on, eating as he went. When he came to his father and mother, he gave some to them and they ate it; but he did not tell them that he had scraped the honey out of the body of the lion.

[Jinx]

Oh, sure! Oldest Navy trick in the book. It's in the "Sailor's Guide to Survival Handbook". :D

[JoeyBlades]

Fretful Porpentine,

Nearly completely ignoring your original question and focusing on your next to last statement:


(Also, I'm really hoping it's false so I can use it as an example of a questionable factoid when I teach freshman comp in the fall.) Does anybody know for sure?


Recently, just prior to the celebrated Winter Solstice, I received a number of emails and even saw a story printed in a local tabloid. I'm looking, but I can't find the message. The crux of it was that the Lakota Sioux, led by Chief Crazy Horse, attacked Fort Laramie, Wyoming on December 21st, 1866 (the date of the previous Winter Solstice). The article went on to make claims about the wisdom of the Chief in planning the attack during the unusually bright moon light and how the frontier settlers were surprised.

There was only a few of problems with this whole story. I doubted that the astronomy knowledge of the Lakota Sioux was sufficient to predict an event that occurs only once every 100 years or so. Plus, the folks at the fort were not likely to be too surprised since this was the second attack that week. An earlier attack had failed due to a miscommunication between Crazy Horse and one of his leaders. Finally, the clincher. The time of the attack and the victory was during the daylight. The battle was over before the moon ever had a chance to illuminate the activities.

Now if you can just track down the original factoid, maybe this would help. Sorry I can't be more help than this - I will continue to get my hands on the original messages (I'm sure I tossed the newspaper).

[torq]

Columbus didn't really need to know where he was. He knew (presumably) where the moon had been, and when, last night. That would tell him where it would be, and when, on "eclipse night". If the moon is visible during the eclipse, the eclipse is visible.

The only trick would be knowing when the eclipse would occur local time; it wouldn't be as impressive a prediction if it didn't occur on command or was mostly over before the moon actually rose. Without accurate chronometers... which I didn't think they had in the late 15th century, at least not ones that would be accurate during a protracted ocean voyage... it might have been tricky for him to know what time it was back in Europe when it was noon in Jamaica.

[scr4]

You know, if Columbus did observe an eclipse on his trip, he would have written down what time it happened in local time. Then when he got back to europe he could have asked the astronomers what time it happened in europe, and from the difference, figure out the longitude of his destination to within 10 degrees at least. It seems to me that either he didn't see the eclipse, or he knew he didn't go to India, or he didn't put any effort into finding out where he did go.

[JoeyBlades]

Thanks Irishman!

[Jinx]

Some food for thought: Astrolabes were used early on to model what was observed in the sky. There were similar devices, as well, which could predict some events within a reasonable margin of error. These inventions were built under the geocentric premise, but these contraptions modelled observations - empirical data from which a pattern was seen. They didn't really need to understand the formal mathematical algorithms we know now.

I cannot say for certain if lunar eclipses were predicted with these, but it is not out of the question. Also, Stonehenge itself has been reported to predict solar eclipses, so you don't always need to understand all the math to build a working model!

[jab1]

The eclipse was visible here in L.A., even in the middle of Downtown. To see that orange moon rise over a brightly-lit skscraper was :cool:

CNN reported the eclipse was visible over nearly all of North and South America. Question: Was it visible south of the Antarctic Circle, where, I presume, it's daylight nearly all the time this month? A red Moon in a blue sky would've been REALLY :cool:

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&gt;&lt; DARWIN &gt;
____L___L__

[jab1]

Well, in checking out this website http://sunearth.gsfc.nasa.gov/eclipse/LEplot/LE2000Jan21T.gif it looks like the eclipse wasn't visible in Antarctica, which, on the map, is clearly in the shaded "No Eclipse Visible" Zone. Oh, well.

But I found something REALLY interesting: There will be a partial solar eclipse visible in North America this coming Christmas. (http://sunearth.gsfc.nasa.gov/eclipse/SEplot/SE2000Dec25P.gif)

I predict there will be more end-of-the-world, Christ-is-returning, millennial madness as that day approaches.

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&gt;&lt; DARWIN &gt;
____L___L__

[Jinx]

Did anyone seem to notice the right limb being slightly brighter than the rest of the moon's face during totality? Why should it?

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You'd be red in the face, too, if you just mooned all those people!

[Irishman]

Jinx, because the right limb of the regular moon is brighter than the rest. Look at the surface - see all that black? See the glowing right? Now scale down the light, and you see how the right stays lighter?

[RM Mentock]

CNN reported the eclipse was visible over nearly all of North and South America. Question: Was it visible south of the Antarctic Circle, where, I presume, it's daylight nearly all the time this month? A red Moon in a blue sky would've been REALLY cool

Lunar eclipses only occur during full moons, because the moon must be directly opposite the sun, in relation to the earth, so that it can fall into the earth's shadow. Also, the full moon rises when the sun sets--so the lunar eclipse can't be seen high in the sky during daylight.

.

[rowrrbazzle]

Jinx:

Did anyone seem to notice the right limb being slightly brighter than the rest of the moon's face during totality? Why should it?

Irishman:

Jinx, because the right limb of the regular moon is brighter than the rest. Look at the surface - see all that black? See the glowing right? Now scale down the light, and you see how the right stays lighter?

That is incorrect. The reason that part of the moon was brighter is that the moon didn't pass through the exact center of the earth's shadow. That part of the moon was nearer to the edge of the umbra.

If you live on the West Coast, you can see a total lunar eclipse on July 16. For this eclipse, the moon will be almost exactly centered in the umbra, and the moon should be illuminated much more evenly.

[rowrrbazzle]

Originally posted by zgystardst:
If you live on the West Coast, you can see a total lunar eclipse on July 16. For this eclipse, the moon will be almost exactly centered in the umbra, and the moon should be illuminated much more evenly.

Oops, [b]that's[b] not completely correct. According to NASA's eclipse pages, for the West Coast, the moon will set before totality, so the moon won't appear evenly illuminated there.

[frolix8]

Just to clear something up, lunar eclipses are not local phenomena like solar eclipses. We all are looking at the same moon at the same time, if a shadow falls across it we all see it. The times are different only because of the time zones, the event happens simultaneously everywhere. Last night's event was great, we had one of the darkest nights in a long time and the moon at one point looked like a peach hanging in the sky. Eerie.

[Jinx]

Irishman, I've looked at the moon over and over for many years. In all that time, I have failed to observe any portion of the surface appearing significantly more luminous than another (excluding the craters).

Zgystardst, I'm confused by your answer. The right limb always stayed close the edge of the umbra? If it was consistently brighter, then maybe Irishman's suggestion has merit?

The wind chill was too wicked for me despite several layers of clothing, so I didn't stay out to observe the entire "totality" portion of the show.

Still :confused:

[Irishman]

The craters are what I'm talking about. They are unevenly distributed to the left side. They have a lower albedo than the right side.

However, I won't argue with the statements about the offcenter penumbra. I didn't stay up completely through totality, so I didn't see if the brightness changed sides, or stayed higher vs. lower. From what I saw, the right side stayed consistently brighter than the left. The path of the shadow went from lower left to upper right. I would expect if the path were the answer that the upper left would have been brighter, or the shading would have changed through the course of the eclipse, but I did not stay up to see.

[Irishman]

Here is a picture.
http://antwrp.gsfc.nasa.gov/apod/ap000113.html

[Major Feelgud]

I've seen the same plot device in:

1) H Riger Haggard's King Solomon's Mine
2) One of the Tintin books by Herge
3) One of Enid Blyton's children's books

The story is unlikely because I would assume that the natives would have seen one previously. However, having said that, having lived over 35 years in many parts of the world, I've still never seen one! I have to ask my parents whether they've seen one or not.

[rowrrbazzle]

Originally posted by Jinx:
Irishman, I've looked at the moon over and over for many years. In all that time, I have failed to observe any portion of the surface appearing significantly more luminous than another (excluding the craters).

Zgystardst, I'm confused by your answer. The right limb always stayed close the edge of the umbra? If it was consistently brighter, then maybe Irishman's suggestion has merit?

After re-checking the diagram of the eclipse (at one of the links on the page Irishman gave the url for), here's my conclusion:

Looks like I'm wrong. According to the eclipse diagram and my previous theory, the brightest part of the moon should have been on its lower edge, shifting from the right at the beginning of totality and the left at the end. This is not what anybody saw, including me. I saw the brightness as you described.

But I can't say I've ever noticed the effect Irishman states. So I'm confused, too.

At this point I'm just gonna shut up and wait for someone who knows more about this than I do.

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"But where were the Spiders?"