Bigfoot snapped a 24" diameter Oak Trunk

No, he said the tree fell, they heard another noise which they assumed was the ape hitting the ground.
 
So they never even saw the Bigfoot at all, only heard a noise nestled inside the noise of the tree falling.
 
former JREF member Bipto said:
For those keeping score, we've now documented around eight tree breaks in the area immediately surrounding where we stay, including one from today. When I say "tree break" I don't mean a branch or a sapling. I mean whole, fully mature trees. We discuss one of these events for which I was present on the last BFS (episode 60). There was another that night we heard not too far off, though it sounded old and rotted. There was one during the week before. There have three this week and a couple sprinkled around the other teams. Not all the journals are edited yet so eight is an estimate but's it's not far off (if it's off).



Today's was interesting because, unlike those I was present to experience, the tree involved was heathy and green. It stood about 60 yards away from the cabin and was about 50-60' tall with a diameter of 20-24". It was broken off about two feet above the ground. The wood was fresh and yellow and wet and showed no signs of disease or damage. It's breaking sounded like a gunshot as it snapped and fell. After the tree started to fall, the member present heard another thudding secondary impact we suspect was an ape falling out of the tree. This is exactly what I experienced a few weeks ago.



Why all these trees are being brought down can only be speculated upon. Is it a new escalation of aggression? Is it a new favorite tactic to rile us up so we put on a show for them? Is this the sign of a new ape in the area or a newly ascended juvenile looking to make a name for himself? Impossible to say. We have documented the occasional tree break and fall in the past, but they were far less numerous and far apart from one another. All I know for sure is trees are being brought down purposefully and systematically by animals of incredible weight and/or impressive strength on a fairly regular basis. If anything, the events are accelerating.
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For perspective.
 
Cotter said:
SO, a 700 lb object, traveling at 20 mph creates 6256 lbs of force.
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What the heck physics are you using? First, to find a force you need to know something with units of time. A 700 lb object traveling at 20 mph can exert a small force (if it decelerates gradually) or a huge force (if it decelerates slowly).

(Actually, it looks like what you did was to multiply 700lbs by 8.9 meters per second to get 6256 "pound" meters per second, taking pounds as though it were a mass unit. Anyway, that's a momentum, not a force, and in perhaps the worst momentum units ever invented. If you can't see the problems with that you should not be attempting this calculation.)

Second, to break an elastic object it does not suffice to exert a force on it for a short time. (Same for torque.)

For example, you can exert a spectacular amount of force---very briefly---when striking something with a hammer. Go find a piece of 1x2 lumber, clamp it down by one end, and try to snap it in half by hitting the free end with a hammer. You can't do it, even though the force is large enough to drive a large nail into the wood---your best hammer swing will make the board "spring" a bit and bounce back unbroken.

Then take the same piece of lumber and try to snap it by adding a large static load. (You can even do this by pushing it with your shoulder.) The force is comparatively small---far from sufficient to push a nail through the wood---but because it's sustained it can actually put a lot of energy into bending and bending and bending the article all the way to failure.

(As if that was the main problem with this story ... )
 
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MikeG said:
Even if it were to produce the force needed to snap the tree, the tree wouldn't break 40 feet below the point of impact, in just about the strongest part of the tree. That's just ridiculous.
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Hi Mike! Been a while, I hope this response finds you in good health and spirits.

It depends really, the closer to the load you are, the less torque you experience.

The way I think of it. (perhaps I'm wrong), but imagine you have a 1/4" dowel sunk into a piece of wood. Then hang some sort of weight on it. My guess is it will break where it is attached to the wood.

The dowel would bend the length until it gets to the fixed point, where the forces would concentrate.
 
Resume, bipto is a current member here not former (he hasn't been banned).

So no visual at all with the tree only sound. Do I have this sound sequence correct?...

1. Snap (like gunshot) the trunk breaks.
2. Thud the Bigfoot hits the ground.
3. Crash the whole tree hits the ground.

It happened in that order?
 
GT/CS said:
Uh, no.

The bigfoot was running along a branch, which is attached to the trunk, meaning there was no force applied to the trunk because it was negated by the force applied to the branch, which was attached to the trunk.

For every action there is an equal and opposite reaction.

It's the same as trying to sail a boat with a fan in the boat. The boat won't move because the fan is on the boat, pushing the other way.
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Agreed. However, I don't want to get into a "BF running on a branch" discussion as I only wanted to show that a 700 lb force, when at a velocity and applied at a location can produce the torque at the base needed to topple it.

However, the 'equal and opposite' reaction as pertaining to acceleration on the branch: The force the branch experiences is a sum of partial forces due to the acceleration of the force. If you accelerate the 700 lbs over say, 10 ft, but stop it in 1 foot, more force is transferred on the deceleration than on the acceleration.

This can be seen by the tree vs. car pics. The car used more time to accelerate to the speed than it did to stop from it.

Additionally, (and here we're REALLY getting out there) if the tree came toward the force due to acceleration of the force, then reached the apex of the pendulum and began swinging back before the 700 lb force reached the trunk, additional forces would be applied due to the momentum/interia of the trunk swing.
 
No, he did say he saw a flash of Grey, and an ape in the tree, I can't pin down which Tree fall this occurred concurrently to, however.
 
LTC8K6 said:
700 pounds at 20mph gets me about 9,500 foot pounds, with online calculators.
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At 45 feet from a cantilevered point?

I'd like to see this as I don't think it is correct.

Can you show the work or provide the link?
 
ben m said:
What the heck physics are you using? First, to find a force you need to know something with units of time. A 700 lb object traveling at 20 mph can exert a small force (if it decelerates gradually) or a huge force (if it decelerates slowly).

(Actually, it looks like what you did was to multiply 700lbs by 8.9 meters per second to get 6256 "pound" meters per second, taking pounds as though it were a mass unit. Anyway, that's a momentum, not a force, and in perhaps the worst momentum units ever invented. If you can't see the problems with that you should not be attempting this calculation.)

Second, to break an elastic object it does not suffice to exert a force on it for a short time. (Same for torque.)

For example, you can exert a spectacular amount of force---very briefly---when striking something with a hammer. Go find a piece of 1x2 lumber, clamp it down by one end, and try to snap it in half by hitting the free end with a hammer. You can't do it, even though the force is large enough to drive a large nail into the wood---your best hammer swing will make the board "spring" a bit and bounce back unbroken.

Then take the same piece of lumber and try to snap it by adding a large static load. (You can even do this by pushing it with your shoulder.) The force is comparatively small---far from sufficient to push a nail through the wood---but because it's sustained it can actually put a lot of energy into bending and bending and bending the article all the way to failure.

(As if that was the main problem with this story ... )
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Hi Ben, thanks, if I've buggered up the units, I apologize, I'll look back into it, wouldn't be the first time a conversion has burned someone.

More to come.
 
Drewbot said:
No, he did say he saw a flash of Grey, and an ape in the tree, I can't pin down which Tree fall this occurred concurrently to, however.
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It appears the NAWACers have experienced several incidents in which wood apes have snapped trees.
current JREF member bibpto said:
In the case of the tree I saw fall down, I also saw something large and dark fall through the foliage, wait about three seconds, then run off at high speed. It fell into heavy brush so I heard and felt the impact and then saw a quick flash of grayish colored critter fly off like the wind.

Secondary impacts could be from the tree that's fallen or other parts of trees it's taken out on the way down or it could be the animal responsible for the break. In the case of the one I saw, it was undoubtedly the animal.
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Not only does it happen, it seems to be a regular occurrence. Those rascally wood-apes!

Oh, and this too:
You know said:
We've seen them in trees. As I said, we previously thought it was only smaller, younger ones as the thing I saw jump from one tree to another couldn't have weighed more than 100 pounds or so and that's typically what we've seen, but we have multiple accounts now from our operations in X of apes in trees. We're not speculating, we've caught them in the act. The major change this year is it appears as though larger animals might also be up in trees and literally leveraging their mass to bring them down
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Meanwhile, through the beauty of the Intertubes, I found a "Body-slam a tree" online calculator. They figured far more parameters than my measly calcs, including -

Padding - stuff like muscles and fat. I'm stick-thin and would have fared badly in my 'break the tree' swing.

Bone structure - I'm pretty old and sedentary and more likely than a young, vigorous skinny person to suffer fractures.

Bottom line - the calculator suggested I limit my "body-slam a tree" efforts to a bamboo cane. The final ignominy - "One of the thin ones, mind, like you use for beanpoles"
 
So Bigfoot intentionally brings down a big tree and then runs away fast as the wind? It has no interest in the tree after it brings it down?
 
Hi Ben,

Thanks for the clarification.

Doing a bit of massaging, I can still arrive at a number very close by making an assumption that all forces are transferred within .2 seconds.

Regarding the elasticity, aren't ALL objects elastic to a degree?

I get your point on the impact vs constant load (something I've been pondering) and the moment calculation I used (though from incorrect inputs originally) assumed a constant, not an impact force.

However, one portion of this 700 lb force breaking a tree discussion that hasn't been mentioned is apparently the tree was swinging back and forth. How would a pendulous tree swing with an intermittent, but timed 700 lb force at say 5, 10, 15, or 20 mph affect the force?

Also, taking into the 'swing' of the tree, would you agree or disagree that the most torque experienced during the swing would be at the base of the tree, where it is fixed to the ground and doesn't allow for bending?

There's lots of variables, and I appreciate the feedback.
 
Cotter, this 700 pound swinging you are referring to, the one that gets replicated in wind storms on a fairly regular basis, would be far outweighed by the force of a windstorm hitting the canopy.
 
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