Thursday, October 15, 2009

Reality and Simulation

Live or Memorex?

March 18, 2009

I woke up in a grouchy mood, still sulking about the credibility issues. I got out well before sunrise, didn't wait for Scott to get out of his tent, and drove right past Melinda's encampment to the end of the road. I grabbed my boat along with the rest of my gear and started the long portage across the sill, down the ATV trail, to the put-in on Willow Flat. All the way I was pondering whether my services were still actually needed on this project. I didn't feel like more uncorroborated detections from me alone would accomplish anything at this point; encounters by others would be much more valuable. I might have come to the end of my usefulness unless I got something on tape or anyone else got something at all.

Once I got out on the water, my mood improved. It was an absolutely perfect morning, with clear skies, calm winds, sunrise glows in the east, and birds calling everywhere. I paddled a short ways north from the put in, and then floated stationary for a bit while I got the video camera out. I had never actually paddled on Willow Flat before, and I was quite impressed with it. It was beautiful, and seemed to provide the perfect vantage points for listening to the woods to the west. I decided to shoot a video panorama from my location, just because it was such a nice morning.

Towards the end of this panorama, I heard and recorded a gorgeous, perfect series of double knocks coming from the woods to my west, at a distance I would have guessed at roughly a half a kilometer. They were, to my ears, absolutely identical to the series I had heard in February, three weeks earlier. They also seemed to be originating from the same patch of woods, just a few hundred meters farther north than the February series. As I described in the earlier post, I decided with some disappointment over the next two minutes that I had actually only heard Scott's 7:00 simulated double knock series, not the real thing. Damned simulators. Here's the entire video segment, edited only to add titles marking the time and pointing out the double knocks. The final (third) one is the easiest to hear. There's a fairly long stretch after the double knocks where you are just looking at a closeup of my trousers while I dig around for my GPS, in order to get an accurate time stamp on the video:

Even if these were just Scott's simulations, they were essentially identical to the "real" double knocks we have heard at the site over the last two years and will give a sense of what we have been chasing around.

After deciding I had only heard the simulations, I continued paddling slowly north along the slough and made no effort to pursue the double knocker. I had enough video of Scott in the woods already. I had only covered a few hundred meters more by 7:30, when the next set of simulations was due. I turned on the video camera and prepared to record these as well, just for comparison. I was assuming that Scott was working in a different area than he had originally planned; the turnaround had been at least 1500m from my 7:00 location, and there was no way that what I heard had been that far away. I figured he must have decided to work instead closer to the lake, probably starting at the camping and parking area at the northwest end of the lake and heading in to the woods from there.

When the 7:30 simulations began, I was quite surprised. They were barely audible, seeming to be extremely far away. They also were well off to the west; if Scott had been where I was guessing, he should have been more towards the southwest. This time it sounded like he really was a mile away near the turnaround. The winds remained dead calm; the conditions had hardly changed in the previous half hour. Yet these sounds were nothing like what I heard at 7:00. In addition to being much fainter, they were much "wimpier" in quality. They didn't have the booming resonance or crispness of the earlier double knocks; they just sounded like a stick whacking a tree. They also were much less even in timing. Some of them were quite slow, a "whack, whack" rather than a "BAMbam;" others were so close in timing they seemed to just be one single "smack." When I later went through the video, I could not definitely pick out any of these double knocks.

I found this quite curious. Had Scott done the 7:00 set from near the lake and then gone back west to the turnaround for the 7:30 set? If he had stuck with the original plan, could sound propagation really have been that different between the two events? In that circumstance, neither of us would have moved very much in the intervening 30 minutes, and if anything we should have been closer at 7:30 than at 7:00. There was also the difference in quality. Had Scott done a virtuoso performance on the perfect tree at 7:00 and then gone in to a slump with a bad tree at 7:30? I had never used the double knocker myself, but I had been told it required a bit of practice and was somewhat sensitive to the tree on which it was secured. Scott had not used it much before; yesterday he and Ryan had commented about the unevenness of his results. This was consistent with what I heard at 7:30; it was not consistent with what I heard at 7:00. All rather peculiar...

At 8:00 I settled in to listen again. The winds remained quite light, but the day was advancing and the nocturnal decoupled atmospheric boundary layer (also known as the morning calm) was likely beginning to break. I heard nothing; it turns out Scott had skipped this set. At 8:30 I did hear the simulations; they sounded just like what I had heard at 7:30 and again not at all like what I heard at 7:00. This started to get me wondering. At 9:00 I heard another wimpy uneven and very faint set. After this a breeze picked up and I heard nothing more.

Other than getting confused by the double knocks, I was enjoying discovering this new part of the WMA. At its far northwestern end, Willow Flat grades into a fairly extensive boneyard of dead and dying trees. This also got me thinking in another direction, about the opening up of these lakes in areas that the USGS had mapped as closed forest, and the causes of this apparent tree decline. Of course, this made me wonder it there was any relation between the localized tree decline and the MIMDKWTFII.

As often seems to happen, my return paddle was now upwind. Midday rendezvous was planned at the barn, which was a long windy paddle, long muddy portage, and short drive away. I got there a bit before noon, and waited for Scott. My earlier concerns about not reporting anything I might see or hear had presumed events that I had not managed to document. This time I had documentation on the video camera, so I tossed all the credibility worries aside, The first question for Scott was "Where were you at 7:00?"

He had in fact stuck to the original plan. He had parked at the turnaround, walked a short distance in to the woods, and done his double knock simulations right on schedule at 7:00. This put him over 1800m away from me. It was of course possible to hear the simulator from that distance; I had done just that at 7:30 that morning. But to hear it loud and crisp and sounding like it was only a few hundred meters away? That was harder to understand. Scott and I checked his watch against my GPS, finding that he was only 2 seconds behind me. Melinda arrived at the lunch rendezvous a bit later. At 7:00 she had been sitting on alert listening from the southeast shore of Rhodes Lake, near the end of the road, and had heard nothing. She was closer to Scott than I was, with a good portion of the distance between them skirting the open water of the lake. The entire path from Scott to me had been through the woods. I pointed out (repeatedly and probably annoyingly) that strange things can happen with sound propagation; still the circumstances were not quite adding up. Had I really just heard Scott's simulations, or had I in fact heard a response to Scotts simulations?

Perhaps the videotape would help sort this out. If the sounds had registered on it, we could see how closely they lined up with the times that Scott's simulations should have occurred. He was fairly certain that he had begun within a few seconds of the nominal start time at 7:00:00 CDT, and was completely certain that he had done 5 simulations at 10 second intervals. Fortunately, I had timestamped the video by putting my GPS in the frame at the end. When I returned home, I'd get the video off the camera and see what shook out.

On the drive home later that day, when I got back in to cell phone range I discovered a voicemail from "Jacob." Steve Sheridan had confessed to faking his "mystery woodpecker" photo.

Oy, what a day...

Other posts in this series:



At 11:06 AM, Blogger cyberthrush said...

I'm not quite clear, but I take it neither Scott nor anyone else heard the 7:00 DKs you heard; and if that's so is that because they were that much farther away from the potential source than you were, or they were upwind and you were downwind or something else??? (I assume after doing the simulations Scott would be closely listening for a response).

At 11:57 AM, Blogger Bill Pulliam said...

That's correct, neither heard anything. There was no discernible wind; as you can see in the video the water is nearly mirror flat, with just the ripples from my own boat. Next Tuesday's post will include a map and more discussion. Melinda's not hearing anything is especially interesting as she was closer to Scott than I was, and had been within earshot of him and his simulator for most of the previous day so she knew well what his simulated DKs sound like. It does suggest that I was closer to the sounds that I recorded than she was, as it seems unlikely she would have failed to notice them if they were as loud at her location as they were at mine. This would place them between me and the head of Rhodes Lake, in the woods, several hundred meters from me, somewhat farther from Melinda, and a kilometer or more from Scott.

At 4:50 PM, Blogger cyberthrush said...

Again, just to be clear: listening to the video it almost sounds like the "series" of DKs are emanating from different directions (may just be an artifact of the way the boat is turning), but you felt confident at the time that they were all coming from the same point-source (or just the same general direction?) -- or is there any degree of uncertainty about that (as you yourself say, the 3rd DK almost sounds different/closer than the first two)?

At 5:08 PM, Blogger Bill Pulliam said...

Well the video doesn't really give any direct indication of the direction of a sound. The first one I did not consciously register. The second one did, and was coming from the direction in which I immediately swung the camera to face. The third one came from that direction as well, but this time with the camera pointed right at it. Relative to the direction of the camera, the first and second ones came from behind, the third came from directly in front. This is a function of the direction of the camera not the direction of the sound.

So the camera picked up the first two in spite of being pointed away from them, another thing that seems unlikely if they were simulations 1800m away.


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