Time to learn something new!

Did you know that Vikings used sundials on their ships? I'd imagine that it would be difficult to line them up precisely. As it turns out, it was, especially when it was cloudy. That's why the Vikings used crystals to determine the sun's position and help with navigation, even when it was cloudy.

Really (Supporting information)

It turns out that these crystals are feldspar that contain haematite in microscopic layers, so they reflect polarized light. Since the crystal is invariant, the orientation of the crystal to get the reflections is directly proportional to the location of the sun. Since clouds do not change the polarization of light (except in rare circumstances), the technique works even when it's cloudy.

I love learning things like this.

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A Note:

Spam quarantine systems should not use the words "Delete" and "Deliver" on two buttons that are adjacent.

*sigh*

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These are the shots from the Omaha Zoo's Kingdom of the Night display. As an experiment, I did most of this sans-flash. It was good for me to experiment with low light, but I did violate my plan twice, both instances where the animal just wouldn't cooperate. If I had a better camera, I might be able to avoid that, but that's not in the cards yet.

The flickr set is here.

( Highlights - 10 images )

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So, the Henry Doorly Zoo has a jungle that you can go in. By the time I got there, it was getting late, and dusk was falling, so some of the pictures didn't turn out as well as I'd like. Also, I had skipped lunch (I was distracted by fuzzy animals, fancy that), so I got tired. Interestingly, I can tell the difference in photo quality when I didn't eat right. I'll have to do better about that.

Here is the set.

( Highlights - 10 images )

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Last set from the Henry Doorly Zoo. I rushed through the aquarium at the end of the day, as they were closing. These are the only shots I liked from there. It's hard to take photos in aquaria.

( Highlights - 3 images )