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.
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:.
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.
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!
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.
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
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
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?
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.
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.
Oops, that’s 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.
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.
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.
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.
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.
