If it doesn't agree with experiment, it's wrong. Part II

[Redwood]

Quick point, for the benefit of everyone, except FF, who couldn't possibly understand:

In kinematics, we have velocity, defined as change of position over time = dx/dt.

Then we have acceleration, change of velocity over time, or in differential calculus, the time derivative = dv/dt = dx/dt². For an object at constant velocity, dv/dt = 0.

(I hope that none of this is going over anyone's head. )

But we can also have a change in acceleration (which may have a name somewhere, but I don't know what it is) = da/dt = dv/dt² = dx/dt³. An object falling in a vacuum has constant acceleration, so da/dt = 0.

But it's perfectly possible to have a changing rate of acceleration, as when one varies the thrust in a rocket; in which case da/dt =/= 0, and may be >0 or<0.

When you drop a brick, da/dt=0, but when it breaks through a piece of tissue paper, da/dt goes from zero to negative. This does not mean that the brick decelerates (dv/dt=negative). It merely experiences an interval where its acceleration was less than g.

 

[FalseFlag]

Well, that's the problem. He doesn't.

Why does he need numbers? What would they prove?

Wouldn't they be if you're doing an honest investigation?

Numbers that describe, for starters:

1- material strengths of the towers and how they are represented in the model..... TO SCALE

2- acceleration of the tower's falling mass due to gravity between floors - which depends on the distance/time fallen and how his close placed floors are TO SCALE and allow the falling weight to gain momentum


The list is vast, but you get the point......


Who am I kidding? Trolls already know the point, and argue against them and logic in an effort to elicit responses.

Right?

None of what you have just said has anything to do with what Cole was trying to replicate.

 

[FalseFlag]

Obviously cuz there's no evidence of explosives.

None.

Which proves beyond a shadow of a doubt that his experiment is invalid.

Every sane person sees and admits this.

Your statements prove you don't understand what Cole was demonstrating. They also prove you have failed to examine and accept all available evidence that exists.

 

[FalseFlag]

Exactly.


Now, a competent person could form an experiment around this predicting how many sheets of paper, or how thick that paper must be in order to stop the brick. Or how many sheets of paper, suspended 5 ft apart will slow the brick significantly enough so that the brick falls at an average of say, 1/4 g acceleration.

This is of course similar to making a prediction about the falling tower. How strong should the structure below/floors and their connections be in order to stop/slow to 1/4 g.

Guess what?

It takes math to make those predictions.

Cole doesn't do that now, does he?

Is Cole demonstrating how many pieces of paper it takes to stop a brick?

 

[FalseFlag]

No they are not.

Cole explained what his experiments were about. Your refusal to accept this does not change his experiments.

 

[FalseFlag]

But it will not necessarily decelerate to zero, right?

Imagine Cole used something other than wood to represent the floors (and this is where scale comes in).

Suppose he used graham crackers.

Or tissue paper.

And then he dropped the weight.

What would happen?

(a) The weight would stop sooner.
(b) The weight would stop at exactly the same floor.
(c) The weight would descend further.

Choose one.

What do Newton's laws say about that?

What happens if we modify the experiment slightly?

Hank

You have questions, make up your own answers.

 

[FalseFlag]

That highlighted part still seems to imply that they are the "equal and opposite" forces addressed in Newton's 3rd Law, which is FF's incorrect belief. The Earth pulls down on the building and the building pulls up on the Earth with equal force, so the 3rd Law is satisfied. Where they come in contact, the building pushes down on the Earth and the Earth pushes up on the building, equally, and again in perfect accordance with the 3rd Law. But these aren't just two different forces -- they're two different types of forces -- and if they don't happen to exactly balance each other, the building comes down. FalseFlag, the simple proof that the two are not necessarily "equal and opposite" is what happens when the maximum contact force that the ground can sustain is just slightly less than the gravitational force: The foundation slowly sinks because the slight difference between the two forces allows a slow downward acceleration.

The distinction becomes even more important in the case of a falling section of building impacting the intact section, because then the contact forces in collisions are due to both gravity and inertia, and they are limited by how much contact force the structure below can actually sustain. By missing the distinction between the forces, FalseFlag misses that the maximum upward force acting to slow the falling mass is just equal to whatever contact force the structure below can sustain -- by Newton's 3rd Law. If that sustainable contact force is greater than the combined force of gravity and inertia, the collapse halts. Otherwise, the collapse continues. Either of these two possible outcomes will be in perfect accordance with Newton's 1st and 2nd Laws, but if FF wants to predict which one will occur, he will need some actual values and, as tfk has repeatedly pointed out, he needs a lot more information then Newton's Laws provide, e.g. how to estimate the sustainable contact force.

Seriously, you don't get any more of my time. Continue your delusions on your own.

 

[sts60]

...But we can also have a change in acceleration (which may have a name somewhere, but I don't know what it is) = da/dt = dv/dt2 = dx/dt3...

It's called the "jerk". I am not kidding.

 

[Andy_Ross]

Part II?????


You've got to be kidding me? How?

Easy, the aim of all CT proponents is just to keep the conversation going.
If they can do that then it is a victory.
I would think this could run to a part 3 or even 4 by the summer.
FF will not have modified his position and will still be ******** 'Newtons Laws' all over the thread as an answer to every post.

 

[Myriad]

Gravity pulls you down, and the electromagnetic forces between atoms where you contact the earth keep you from falling through the ground. Gravity is a force. Electromagnetism is a force. They are different forces whose magnitudes are equal, and the vectors of the forces are in the opposite directions.

They are equal in magnitude and in opposite direction, but they are not action-reaction pairs so Newton's third law doesn't apply to them. They do not have to remain equal. For instance, if there is a strong magnet in your pocket and a metal plate under the ground you're standing on, there are now three forces acting on you: gravity pulling you down, the magnet pulling you down, and the ground holding you up. None of those three forces are equal, although the sum of two of them is equal to the third.

To understand the role of Newton's third law, you need to consider all the relevant forces. (There are six, in the above magnet-in-your-pocket case.) Avoiding "complication" by omitting them will lead to wrong answers, such as your claim that an object accelerating downward from the force of gravity must decelerate if it strikes and crushes a stationary object on the way down, which is wrong.

Now you want to bring up action-reaction pairs to further complicate the issue. Complicate it all you want. I have given you and the other members of this forum 100 percent correct explanations to the previous questions you have asked.

Physics is as complicated as it is. Leaving things out or pretending laws say something different than what they actually do, in a futile attempt to avoid "overcomplicating," will lead to wrong answers, as it has done for you for just about everything you've claimed. For example, due to failing to consider all the relevant forces acting on objects, you have repeatedly come to the erroneous conclusion that an object accelerating downward from the force of gravity must decelerate if it strikes and crushes a stationary object on the way down, which is wrong.

All you and the other members do is say I'm wrong, without making any attempt to cite a credible source that proves I'm wrong. I will not continue to do this.

I'll stop pointing out that you're wrong, and explaining exactly what mistake you are making that causes you to be wrong, when you stop being wrong.

 

[FalseFlag]

Quick point, for the benefit of everyone, except FF, who couldn't possibly understand:

In kinematics, we have velocity, defined as change of position over time = dx/dt.

Then we have acceleration, change of velocity over time, or in differential calculus, the time derivative = dv/dt = dx/dt². For an object at constant velocity, dv/dt = 0.

(I hope that none of this is going over anyone's head. )

But we can also have a change in acceleration (which may have a name somewhere, but I don't know what it is) = da/dt = dv/dt² = dx/dt³. An object falling in a vacuum has constant acceleration, so da/dt = 0.

But it's perfectly possible to have a changing rate of acceleration, as when one varies the thrust in a rocket; in which case da/dt =/= 0, and may be >0 or<0.

When you drop a brick, da/dt=0, but when it breaks through a piece of tissue paper, da/dt goes from zero to negative. This does not mean that the brick decelerates (dv/dt=negative). It merely experiences an interval where its acceleration was less than g.

You are playing the semantics game, and you have written a whole lot of meaningless stuff to try to make a simple issue more complicated.

At the instant of impact the acceleration changes. Acceleration changes because there is a force exerted that is in the opposite direction of the original acceleration. When an accelerating object experiences an acceleration in the opposite direction we say it decelerates.

Again, you are trying to complicate something that does not need to be.

 

[FalseFlag]

FF will not have modified his position and will still be ******** 'Newtons Laws' all over the thread as an answer to every post.

You're right. I will never modify my position, because I know I am right. I have provided links to credible sources that show I am right.

Where you're wrong is that you assume I will keep playing the games that are going on here. That is not going to happen.

 

[FalseFlag]

Deleted

 

[cantonear1968]

Easy, the aim of all CT proponents is just to keep the conversation going.
If they can do that then it is a victory.
I would think this could run to a part 3 or even 4 by the summer.
FF will not have modified his position and will still be ******** 'Newtons Laws' all over the thread as an answer to every post.

Then by all means I suspend my incredulity and will simply enjoy the show!

 

[Andy_Ross]

I want to revise my last statenent. I think part 3 before the end of April, there are enough Rubes to keep feeding him.

I even have a go myself every now and again.

 

[cantonear1968]

You're right. I will never modify my position, because I know I am right. I have provided links to credible sources that show I am right.
Where you're wrong is that you assume I will keep playing the games that are going on here. That is not going to happen.

The number purple smells like sunshine!

All those words are in my credible source: the dictionary.

I guess that makes me right.

 

[pgimeno]

It's called the "jerk". I am not kidding.

Yep, and I used that to make a bad joke at JayDeeHess' expense (sorry about that JDH)

 

[cantonear1968]

I want to revise my last statenent. I think part 3 before the end of April, there are enough Rubes to keep feeding him.

I even have a go myself every now and again.

I wouldn't say rubes. After all, under certain circumstances, I myself have paid $5 at the carnival to play whack-a-mole.

 

[pgimeno]

I would think this could run to a part 3 or even 4 by the summer.
FF will not have modified his position and will still be ******** 'Newtons Laws' all over the thread as an answer to every post.

I predict suicide by mod before there's a part 4.

 

[HSienzant]

You have questions, make up your own answers.

Is that what you do?

Why would you suggest that, instead of answering those simple questions?

Here they are again.

But it will not necessarily decelerate to zero, right?

Imagine Cole used something other than wood to represent the floors (and this is where scale comes in).

Suppose he used graham crackers.

Or tissue paper.

And then he dropped the weight.

What would happen?

(a) The weight would stop sooner.
(b) The weight would stop at exactly the same floor.
(c) The weight would descend further.

Choose one.

What do Newton's laws say about that?

What happens if we modify the experiment slightly?

Hank

Punt and we'll know why.