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Conservation of Momentum

Posted: Mon Jul 15, 2013 6:22 pm
by Walter
Merlin - yes, it's much friendlier to ignore what other people are saying. There a number of posts that show quite clearly that the loop propagates even when the rod led is not connected to the rod tip. You can argue that you are unable to view the videos but there a number of statements that describe clearly what is happening in those videos. It seems to take a "schoolboy" approach before you will even pay attention to them.

You still haven't answered my question - are you agreeing with Gordy that does not exist in the real world?

Conservation of Momentum

Posted: Mon Jul 15, 2013 7:48 pm
by Paul Arden
Grey area for me Walter, excerpts with full creditation is fine I believe. Running a full article certainly contravenes UK copyright laws. US is a little bit different I believe. Anyway it's not the sons thing to simply republish someone else's work in its entirety without their permission. I don't know if the gents are still alive although I certainly hope so of course! Lasse is making some requests. The article is in an archived The Loop publication, the Fall 1980, you might have it already Walter. There may be faults in it, I don't know - but it would be nice to get it on the Board.

I'll resend you a copy tonight Aitor. From man memory I thought you actually commented on it.

Cheers Paul

Conservation of Momentum

Posted: Mon Jul 15, 2013 8:45 pm
by James9118
With regard to the videos where the rod leg is 'cut' (line shot with no attachment etc.) - does anyone think there may still be tension present? You're still moving the fly line through the air with it's incumbent drag (magnified if using something like MPR cord). Also look at the 'angle of attack of the released rod leg - is that presenting more area in the direction of travel as it drops with gravity?

Conservation of Momentum

Posted: Mon Jul 15, 2013 9:24 pm
by Walter
James9118 wrote:With regard to the videos where the rod leg is 'cut' (line shot with no attachment etc.) - does anyone think there may still be tension present? You're still moving the fly line through the air with it's incumbent drag (magnified if using something like MPR cord). Also look at the 'angle of attack of the released rod leg - is that presenting more area in the direction of travel as it drops with gravity?
That must be it. You've hit on the answer. We know it can't be conservation of momentum keeping the loop propagating because Gordy and Merlin say there is no such thing so that's impossible. It's a medieval fallacy that only hacks and alchemists believe in. We only study CoM in physics classes because universities are secretly run by the Illuminati :ninja: and they don't want us to know the truth.

Here's a thought:

Let's imagine that the fly line consists of three parts. A fly leg, a rod leg, and a loop that joins them. Replace the fly and rod legs with balls. Now pick up the fly leg ball and throw it. Does the rod leg ball start moving at exactly the same time and velocity as the fly leg ball because the two are joined by a section of fly line? Or does the rod leg ball stay where it is until the line joining both balls goes tight? Does the rod leg ball then only start moving if I hold it back or if it is offset from the fly leg ball or will it start moving even if it is resting an a frictionless surface or floating in space? Now that both balls are moving can you give me an idea of how fast the two balls are moving? Would you, for instance, use a non-existant principle like conservation of momentum to get the answer to that question or would you ask if the thrower had long arms or short arms? Or would you make a demo where you throw both balls at the same time and velocity and then say that there is no way that the string can go tight?

Conservation of Momentum

Posted: Mon Jul 15, 2013 10:15 pm
by James9118
Wow, by your sarcasm I assume you already know where I sit with regard to this, perhaps you let me know?

Conservation of Momentum

Posted: Mon Jul 15, 2013 11:11 pm
by Walter
You call that sarcasm? I haven't begun to sarcast. We obviously need some toilet paper and leaf blowers to really dig into this.

Conservation of Momentum

Posted: Tue Jul 16, 2013 6:17 am
by Merlin
I suggest you read post 229 again Walter. I am not a moderator for this thread, anyway I have no obligation of any kind to read carefully all posts nor to answer all questions. Thanks to those who heavily contribute to document the forum and who share their ideas, but I have a limited time available for SL.

As long as there is air drag there is no Com, but you can skip it as we skip gravity most of the time when speaking about fly lines.

I have the same worry than James about tension in the case of free flight, but there must be some at the loop level. I wonder if modeling can be done easily, there is one missing equation at start since one cannot say that the rod leg is in a standstill anymore.

Merlin

Conservation of Momentum

Posted: Tue Jul 16, 2013 9:31 am
by Walter
[quote="Merlin"]
As long as there is air drag there is no Com, but you can skip it as we skip gravity most of the time when speaking about fly lines.
[/quote]

Still not very clear. There are always outside forces. Given that are you saying com never happens? That it is a fallacy? That it is taught in physics classes as some sort of joke? That it can never give meaningful results?

Interesting. You also seem to have a problem with N3. Are there any other generally accepted physics concepts you want to refute? Maybe we would be better off discussing basic principles rather than trying to discuss complex problems.

Conservation of Momentum

Posted: Tue Jul 16, 2013 9:53 am
by Merlin
I am going to follow your kind advice and become a silent throw stoner each time something does not please me. I will do my little studies on my own and with academics. Usually they are polite people.
I rely on you Walter to take over, that should be an easy task. All the best.
Merlin

Conservation of Momentum

Posted: Tue Jul 16, 2013 1:26 pm
by Walter
Merlin,

This is a repeating theme with you. You make inferences about things such as CoM is an invalid concept and when questioned you get upset and want to shut down the board. Have fun with your friendly academics but before you get too far with them I would explain to them that you don't believe in concepts like N3 or CoM and then see how friendly they are when you consistently ignore any attempt to discuss it farther. :oh: