Perhaps these will help. It's a slightly different section of the same subject, shot about 45 seconds later. This first image is cropped to 66% x 78% of the whole frame.
Here is a tight crop of the above, focusing on relevant detail. In the tight crop, the dimensions work out to be about 1.3 microns per pixel on the subject. That makes the fine filaments be around 5 microns diameter.
I will also share that the whole structure was hanging vertically at the time I first saw it, stretching from my backyard lawn to roughly 20 feet up in the branches of a tree. Despite that the air appeared to be dead calm, there was actually too much breeze for me to frame and focus accurately. Here is what the thing looked like in the best picture I got that way:
The total time between all pictures now shown in this topic was 4 minutes and 18 seconds.
It's a tough one. Had me faked out several times, even when I was looking at the real thing. Parts of the story I didn't figure out until I was sorting through the pictures afterward!
And the winner is: everybody! I think we'll declare this to be an N-way tie of good answers, though nobody quite hit the bullseye.
Of course the fact is that I don't know the whole story, either.
What I do know is that this thing first attracted my attention because it was long, thin, and hanging from a tree in my backyard.
My first thought was that some kid had lost their kite, and I was looking at the string. When I got closer I could see that it wasn't any sort of woven kite string, but rather it looked like thin nylon filament. I remember thinking at the time that perhaps a bird had delivered me a long piece of fishing leader. As I reached out to pull it down from the tree, I could see that it was covered with tiny frost crystals. No surprise there, since everything else was too.
The surprise came when I did pull it down from the tree. It was far too stretchy and weak to be fishing leader.
Aha! This is silk! Time for the camera!
So I hung the strand then hanging from my hand back onto a low branch and ran to the house to quickly assemble camera, lens, and flash. Then back outside, in a rush to get photos taken before rising temperatures spoiled the thing.
It was a close race.
As you can see from the images, my shot of the hanging structure shows quite a rough structure. I'm thinking it was probably still all ice at that time. But it was moving around too much to get a clear shot.
So I relocated the strand to stretch between a couple of fixed boards, and tried again. That got me the first image I posted in this thread. It shows a slighted melted frost structure, refracting autumn leaves on the ground below.
Trying to get more informative shots, I realized that one broken end was placed where I could get a good shot, so I did that and had the hugely good fortune to accidentally capture the naked silken core as it draped over the surface of the unbroken section. That was the second image I posted here. As you can see, only 4 minutes exposure to the slightly higher temperatures of rising sun, placement closer to the ground, and/or a few flash exposures was enough to substantially melt the frost and produce the appearance of built-up ice.
I had to go do some other things after grabbing those shots, but I came back several hours later to photograph whatever was left. That was the last image, showing some naked silk.
Putting all this together, I'm thinking that the affair started with two strands of silk forming a thin thread, collecting enough frost overnight to increase the overall diameter from less than 10 microns to more than 400 microns -- big enough to see from 50 feet away against a dark background.
We still don't know what produced the silk. Personally I think that most likely it's a spider's dragline. In large part that's because the tree is a non-native locust that doesn't host any caterpillars I'm aware of. But I don't know the whole fauna and in any case there's always the oddball caterpillar that goes wandering and then changes its mind. So maybe it was a caterpillar. Or maybe something else I haven't thought of yet.
In any case, I found this whole subject quite interesting. Hope you did too!
rjlittlefield wrote:
We still don't know what produced the silk. Personally I think that most likely it's a spider's dragline. In large part that's because the tree is a non-native locust that doesn't host any caterpillars I'm aware of. But I don't know the whole fauna and in any case there's always the oddball caterpillar that goes wandering and then changes its mind. So maybe it was a caterpillar. Or maybe something else I haven't thought of yet.
Not proof, but e.g. silk moth larvae spin twin threads of silk (for cocoons). So an abseil line is one possibility.
Harold
My images are a medium for sharing some of my experiences: they are not me.
