the best i can do, while scratching my head, is to say "huh?" but very entertaining . . .
the best i can do, while scratching my head, is to say "huh?" but very entertaining . . .
Great stuff, Professor. Have to admit that I saw the 21 minute run time and decided that I had to wait till the right time and cup of coffee to absorb the knowledge, but indeed, it was worth it. The statistical probability of being able to use either suspension was enlightening. I have had a couple of occasions where I ended up by-passing the continuous loop and larksheading the whoopie sling directly to the hammock body, but I was still able to hang with whoopies. I agree with MedicineMan on this on--no real advantage to the SRS, IMHO. But if the question comes up, I can now say with authority that Professor Hammock's thorough analysis supports that position.
I (a newbie, admittedly) seem to reside in that part of the country where the real-world tree copse density usually ranges from 100 to 750 trees - cause many times I've had to shorten or eliminate my whoopies. Or, maybe, i'm still not very good at site selection.
This situation has left me looping whoopies back on themself, using continuous loops or dogbones several times in less than a year - non-adjustable.
So, I'm seeing a silver-lining here with the SRS.
- By carrying only an additional 2-rings (or perhaps something lighter as noted in the original SRS thread).
- Then, lengthening my whoopies and using the "tail" to build the SRS system (no extra cordage to carry).
Can I increase my odds of finding a suitable hang spot by way - more (a technical term) than 5%
Either way it's still good to know that the SRS method can give an advantage at times.
Copse pS pW
100 .41 .37
250 .73 .68
500 .74 .63
750 .55 .41
So, does this mean that the probability of finding a hang spot using a SRS can be
- 7.4% greater in a 250-tree copse,
- upto 17.5% greater in a 500-tree copse?
- and about 34% greater in a copse of 750 trees?
I'm no math guy and I'm only on my first coffee for the day, so let me know if this is correct?
- Loki my videos
"Climb the mountains and get their good tidings.
Nature's peace will flow into you as sunshine flows into trees.
The winds will blow their own freshness into you, and the storms their energy,
while cares will drop away from you like the leaves of Autumn." — John Muir
Thanks for the interest FIMB. Good question, we'll have to take that up in the graduate course on hammock engineering.
Thanks Shewie. As soon as the kid wrapped the tape around his hand twice I knew were we in for a Siberian hitch. Tried that with Amsteel once, and it was really really hard to undo.
hey Sailor. For this model trunk size doesn't play a role (as it would if the length of tree straps were under study). For a S. Sempervirens patch I'd bring a machete. Forget "leave no trace". This is "leave no goldenrod"...
thanks for watching...
Stairguy! Awesome peapod you've got, showcased in shug's video. I'm a fan of peapod use in winter too. My mother has a picture of me at age 5 lecturing a few neighborhood kids...they're sitting in small chairs on a patio and I'm standing up talking away. Her prescient comment on the photo, "Age 5, the Absent-minded Professor".
I expect new degree programs in CHS to be springing up all over the nation, with particular concentrations in universities near major hiking trails.
My interpretation of the model predictions are that, once the tree density is sufficiently high, your change of finding a hanging spot _somewhere_ in a large enough region is very good. Where the probabilities get low is where you get particular about where you hang. And even here, the "probability" is that a given small area has a hang with the characteristics you want. If that probability is 1 in 4, that means (on average) you end up checking out (only) four small area sites before you find what you're looking for. But yes I agree, going prepared to hang from a variety of tree separations is the way to go.
I've looked at Octave, and run Matlab infrequently (so infrequently I always have to relearn how to use it). For these simulations the path of least resistance for me was to write the simulation in Python,
and have the scripts pump out gnuplot data and plotting files. Given a bunch of plots (the generation of which is all scripted of course) I put them together in a program call ImageJ (free Java program, comes out of NIH) into an animated display. ImageJ will put out an animated .gif from all this, but I prefer a screen capture program SnapProX that produces .mov which is easy to introduce into the video editor.
Thanks SGT, I know what you mean about initial reaction to long videos. Whose got the time??? Thanks for watching anyway.
Thanks for watching Craig. My preferred method has rings of some kind at the very ends of the hammock. I use 8' of cord that has a 3 inch fixed eye at one end. The fixed eye goes over the marlin spike hitch. The working end of the cord comes down to the ring where I tie it off using a slippery buntline line hitch, or more often a variation on sort of doubled slippery half hitches.
Thanks gmcttr. In my experience models tend to confirm what experience and common sense suggest. That certainly was the case for me here. My experience---I have to hunt around a bit, but not a lot, to find a pair of trees that work. The model explains why that is.
Hi Jay! My first thought going over the side was "Dang! Have to open up the hammock a bit more before dropping into it". My second thought was "Have to work this into the video somehow!"
Hiya WV. Point noted. That said, I could go on and on and on and on and on about the philosophy of the level of detail in simulation models. I'm working on a paper this month written with a colleague entitled "The Dark Side of Detail – What Your Mother Never Told You About Abstraction". We can take up the question sometime at a hang...
Great, glad for that Callahan. One of the things I try to do is anticipate the kinds of questions that might be asked that can be answered with close up visuals. I'm a visual learner myself....
Shug! Thanks for stopping by. Yes, one does not want to mess with "The Mexican Madman"
hope you had popcorn!
Vectran will squash for sure. Spyderline will resist, but there's a possibility of the core breaking, at least for the smaller diameters, if one fully load bearing strand goes on top of another. I've seen that happen to 3mm Spyderline inside of a garda hitch made with two rings. Large force concentrated on small area---not so good. I did some some experiments with a Hennessey Safari and its stock suspension. That cord is BIG and I wouldn't worry much about it.
Thanks Fronkey, Galen is a natural ham.
Ha! I was at the back of the class drawing free body diagrams of hammock suspensions.
"Save time"? You could put together 3 or 4 SRS suspensions in the time it takes to slog through 21 minutes of Professor Hammock! I appreciate the viewing though.
Glad someone gets my jokes! Teaching as I often do to large classrooms of none-native-English-speakers, my under the radar sense of humor tends not to be understood.
Thanks MM. Hey, I was hoping to see that secret hammock you referred to in your New Years Eve hike video... Could it be the elusive, ah, well, I better not say it in public. Leave the moment of revelation to you.
Thanks for watching, but more importantly, happy retirement! Saw your FB posting about New Years Eve being your last day on the force. What a night to stand down, I'm sure.
Take thy ease, sire.
Grizz
(alias ProfessorHammock on youtube)
Awesome video Professor, and that Lucho star, man he must have cost a pretty penny to get in.............
I think you summed it up rather well, SRS not a better solution. WOW did that Dutch biner get destroyed wish there was a camera on that sucker when you plopped in the hammock, seeing that in slo-mo would have been fantastic, HA grizz200.
"yesterday is history, tomorrow is a mystery, but today is a gift---thats why its called a present" - Master Oogway
It's always best if your an early riser!
yeah, we all have to be prepared to adapt to local conditions. I'm always packing an SMC ring and a couple of Amsteel extender cords . Costs me half an ounce of not-rigorously-necessary weight, but opens up many options.
A qualified yes, the qualification being the probabilities being noted here are those of finding you can hang in one given pre-selected spot. You can turn that around and estimate the average number of spots you'd (randomly!) check before finding one to your liking, and you'd find that the SRS is better from the point of view of that metric.
My more negative conclusion is based on a less tightly quantified measure, and that is of human experience, and human perception of chance. Did you know that casinos use psychologists to figure out where to place slot machines with varying degrees of success probabilities and payoffs, with the objective of pulling players deeper into the casino and play with larger stakes with the hope of larger payoffs? Frequent wins with low payoffs are placed by the door, while deeper in the wins are bigger but less frequent. Even if the long run expected gain (expected loss, actually) is less beneficial for the player on the bigger payoff machines, that's where players are drawn. Even if the expected benefit is the same on both types of machines, one has to be able and willing to play on the lower-rate-higher-payoff machines longer to hit the wins that even up the average outcomes. Players' gut feelings about the probabilities is based on what they see happening with other players.
If I gave you a coin that was weighted to turn up heads one out of three times on average, and another that was weighted to turn up heads one out of four times, how reliable would your guess be of which was which based on four throws of each? Yet one will turn up heads 25% more of the time than the other. You could tell the difference statistically by taking many tosses, but not with just a handful. My argument that SRS is not perceptibly better than the whoopie sling puts the emphasis on "perceptibly", because in our experience we don't have to look so hard (or gather so many "random" trials) when we're looking for a place to hang.
And, as one perceptive reader PM'd me this morning, site selection involves a number of factors not included in this model. All models are wrong. But some of them are useful nevertheless.
yes, I'd have liked to have dual cameras going, but just have one camera stand...
thanks for watching!
Last edited by GrizzlyAdams; 01-03-2013 at 17:38.
Grizz
(alias ProfessorHammock on youtube)
I also noticed the flattening compression of the Amsteel and was a little concerned about it reducing the rating of the line. It would be nice if Dutch or somebody with the right equipment could do a stress test and find out if and how much the breaking strength is reduced. Seems like a while back somebody tested cordage and posted results. Don't know why I think it was Dutch.
I'm still trying to figure out why there are so many cops in the woods. Shouldn't they be Rangers?
Even substantially derated, I wouldn't expect a problem in the short term as the flattened area of the adjustable loop is only subjected to 1/2 the weight.
Once the SRS has been used many times is when I would feel concerned. At that time, a given area of the rope may have been flattened several times and due to varying hang distances could end up between the hammock and ring where it would be subjected to the full force being applied.
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