dmaker Posted November 4, 2015 Share Posted November 4, 2015 Here is another response from someone at the University of British Columbia after I explained that bigfoot enthusiasts think bigfoot is responsible for some of these types of tree breaks: I hadn't realized this was a thing. Well, there are plenty of trees that twist due to a number of reasons, and the twist isn't revealed until the bark is removed (or the branch broken). An example of these that are readily spotted in British Columbia's interior are ponderosa pine trees. Here's a study on the biomechanics of grain spiral in ponderosa pines: http://www.math.utah.edu/~cherk/publ/spiralf.pdf (Why grain in tree trunk's spiral: a mechanical perspective). From that study, they found that if the grain angle was greater than 37°, the failure prediction (of breaking) increases dramatically for that species. That angle could be higher or lower for other species. It just seems like there are easier explanations to me for the phenomenon. Research and Biodiversity Informatics Manager University of British Columbia Botanical Garden and Centre for Plant Research 2 Link to comment Share on other sites More sharing options...
WSA Posted November 4, 2015 Author Share Posted November 4, 2015 Hold on. Bhodis question is exactly on topic. The topic is tree breaks, what is the evidence? What could better support the assertion that bigfoot might have twisted the limb than to collect something like unknown primate DNA from hair or skin cells found on the limb near the break? How is that not on topic? I was responding to a post that has since been deleted. His question about DNA is pertinent, I agree. Link to comment Share on other sites More sharing options...
dmaker Posted November 4, 2015 Share Posted November 4, 2015 ^^ My apologies. Link to comment Share on other sites More sharing options...
Branco Posted November 4, 2015 Share Posted November 4, 2015 I think that if you had shared the fact that the limb under question was from a Sassafras tree in Western TN, he would not have suggested that you view the ponderous Ponderosa Pine report as reference. Besides, you misled the man by "explaining that Bigfoot enthusiasts 'think' bigfoot is responsible for some of these types of tree breaks". Link to comment Share on other sites More sharing options...
WSA Posted November 4, 2015 Author Share Posted November 4, 2015 It is always good to get subject matter expertise. To be clear though, from my personal point of view, the weakness of the limb in question isn't exactly what I need explained, and I guess probably the nature of this break isn't exactly the most compelling. It is within the range of human strength, I'm guessing. A soft wood and a weak point of failure doesn't leave you with a whole lot...just the context of the occurrence, according to the witness, which some find compelling, and some do not. The B.C. expert might need a better case to work on, or maybe the possibility opened up a conversation with colleagues we might hear about later. Thanks Dmaker for the information. I want to read that paper in depth when I get the chance. I've seen ponderosas like that....longleaf and loblolly too. They are the very devil to split lengthwise as there is no grain to "run out." lateral strength is probably something else all together. Link to comment Share on other sites More sharing options...
dmaker Posted November 4, 2015 Share Posted November 4, 2015 (edited) I think that if you had shared the fact that the limb under question was from a Sassafras tree in Western TN, he would not have suggested that you view the ponderous Ponderosa Pine report as reference. Besides, you misled the man by "explaining that Bigfoot enthusiasts 'think' bigfoot is responsible for some of these types of tree breaks". How is that misleading? Join the thread yourself if you think I am misrepresenting anything. http://forums.botanicalgarden.ubc.ca/threads/twisted-tree-breaks-possible-causes.87521/#post-343950 Edited November 4, 2015 by dmaker Link to comment Share on other sites More sharing options...
Guest Posted November 4, 2015 Share Posted November 4, 2015 If there is torque, the vector potentially will follow the direction of the spiral. Otherwise the vector of a snow mass on a branch will be in the same direction of the gravitational pull. *snipped* If a person hangs onto a tree limb to break it, is the applied force be more likely to be in a vertical direction (read: up and down) or in a twisting motion? Are tree branches perfectly straight or no? If so than the answer would be, up and down. Where I come from branches have many shapes (YJFhf, to name a few), and hanging on crooked branches creates leverage and twists. The shape of the branches don't effect gravitational pull and the directional vectors of that pull towards the earth. Unless the trees in your neighborhood defy the law of gravity and the laws of motion, which I doubt. The branches do exert an equal and opposing force against whatever it is exerting a force against it. The shape of the branch may aid in providing an opposing force. But a hanging mass follows the law of gravity and will pull in the direction of gravity, unless the mass changes direction as I wrote in my last post. BTW, I'm enjoying this discussion and the theories behind tree manipulation because I weave baskets for fun (and profit) and use a variety of materials for my baskets (reed, rattan, grape vines, honeysuckle vines, willow, wire, etc.) So I have practical experiences with manipulating plant material into shapes I want them to be. I thought this was pretty straight forward but ok, try this experiment: lift your right arm until it's shoulder height and bend your elbow to a 90 degree angle, horizontal to the ground. Now push down on your right hand with your left. What kind of force do you feel on your right shoulder? Link to comment Share on other sites More sharing options...
Rockape Posted November 4, 2015 Share Posted November 4, 2015 Here is another response from someone at the University of British Columbia after I explained that bigfoot enthusiasts think bigfoot is responsible for some of these types of tree breaks: I hadn't realized this was a thing. Well, there are plenty of trees that twist due to a number of reasons, and the twist isn't revealed until the bark is removed (or the branch broken). An example of these that are readily spotted in British Columbia's interior are ponderosa pine trees. Here's a study on the biomechanics of grain spiral in ponderosa pines: http://www.math.utah.edu/~cherk/publ/spiralf.pdf (Why grain in tree trunk's spiral: a mechanical perspective). From that study, they found that if the grain angle was greater than 37°, the failure prediction (of breaking) increases dramatically for that species. That angle could be higher or lower for other species. It just seems like there are easier explanations to me for the phenomenon. Research and Biodiversity Informatics ManagerUniversity of British Columbia Botanical Garden and Centre for Plant Research You had to go ask a Botanical forum to know that? Really? Link to comment Share on other sites More sharing options...
dmaker Posted November 4, 2015 Share Posted November 4, 2015 (edited) To know what, Rock? I joined to get experienced input as to common natural causes for breaks like this. Me simply saying that there are many natural causes that should be top of the list first was met with resistance here. So I sought out an expert forum for opinions. Since my opinion counts for squat around here because I am unwilling to bigfoot at the top, or even on, the suspect list. Edited November 4, 2015 by dmaker Link to comment Share on other sites More sharing options...
Rockape Posted November 4, 2015 Share Posted November 4, 2015 (edited) <To know what, Rock?> To know there are multiple natural explanations for that limb break that have nothing to do with bigfoot. Otherwise it's Edited November 4, 2015 by Rockape Link to comment Share on other sites More sharing options...
dmaker Posted November 4, 2015 Share Posted November 4, 2015 I'm trying to participate in the thread in a meaningful way It seems that simply stating the obvious is not good enough if the obvious does not include propelling bigfoot to the top of the list of suspects. Having the benefit of expert opinion behind you can sometimes help. What? Someone was wrong on the internet somewhere else? Ugh! I had plans tonight.... Link to comment Share on other sites More sharing options...
Rockape Posted November 4, 2015 Share Posted November 4, 2015 <Having the benefit of expert opinion behind you can sometimes help.> And you think that's going to make any difference here? If so, good luck with that. 1 Link to comment Share on other sites More sharing options...
WSA Posted November 4, 2015 Author Share Posted November 4, 2015 (edited) <Having the benefit of expert opinion behind you can sometimes help.> And you think that's going to make any difference here? If so, good luck with that. I heard that. What I had hoped this thread could do is analyze and provide discussion of something a little more concrete than anecdotal accounts, which some find to be a polarizing form of evidence. I'm no expert in footprints, primate morphology or photography...but I do have some experience and knowledge on this subject. I realize that taking anecdotal descriptions from anecdotal accounts may not be much of a distinction for some...but maybe there is just enough of a chance to apply some objectivity to these things to allow for some kind of middle ground explanation of them. At least that is my goal. We'll see. Edited November 4, 2015 by WSA Link to comment Share on other sites More sharing options...
zman1967 Posted November 4, 2015 Share Posted November 4, 2015 Maybe someone could send some pictures of possible BF tree breaksto the botanist forum for their opinions on actual samples. Seems just asking what could cause twisting breaks is rather broad. The cut limb with the beetle larva in it shows no scale so how do we not know it is just a 1/4 branch? Link to comment Share on other sites More sharing options...
dmaker Posted November 4, 2015 Share Posted November 4, 2015 ^^ I did that. With one picture, at any rate. One from a BFRO report. Link to comment Share on other sites More sharing options...
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