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## Analysing loop propagation

Moderator: Torsten

Graeme H
Posts: 1951
Joined: Fri Jan 25, 2013 2:54 pm
Location: Perth, Western Australia

### Re: Analysing loop propagation

So you are unable to see that a loop is a transverse wave with a loose end in the medium? Okay, I thought that was pretty clear.

Oh well. I guess we won't analyse loops again.

Cheers,
Graeme
FFi CCI

Paul Arden
Posts: 14068
Joined: Thu Jan 03, 2013 11:20 am
Location: Belum Rainforest
Contact:

### Re: Analysing loop propagation

It’s complicated and I just think it takes us down a rabbit hole. I don’t see the propagation of the loop wave as being vertical but if it is then wavelength is the height of the loop and amplitude is the unrolled loop. How is this going to help me?! For me that is totally meaningless.

So as a process of elimination it’s not a wave. And since James says it’s not a wave then I feel that I’m in the clear it’s been useful!

I’m not being ironic. I’m actually serious. There is nothing to be gained. So to answer your question - I have absolutely no idea

Cheers, Paul
It's an exploration; bring a flyrod.

Flycasting Definitions

Mangrove Cuckoo
Posts: 385
Joined: Tue Jan 29, 2013 7:51 am

### Re: Analysing loop propagation

Graeme,

From a spectator in the grandstands I have to admit your last photos make a pretty strong impression!

And, as a student of science, I know that reality as we perceive it is definitely not an either / or thing... as: is light a wavelength or a particle?

For the non scientific folks... that question has been going on forever... and it turns out it is probably both... or neither. We can use models and equations that work from both points of view. But there are discrepancies that neither can explain. So, it is likely it is us that are the problem.

Graeme's wave is not as far out as my idea that is based on flying Frisbees and gyroscopes!
"Technique is the proof of your seriousness"

Wallace Stevens

Merlin
Posts: 1477
Joined: Wed Jan 09, 2013 8:12 pm
Location: France

### Re: Analysing loop propagation

We spend too much energy on useless topics. The loop is not a wave then, so what? What would it change if it was? I can understand that the strict wave equations do not apply completely to a loop and what does it brings to knowledge?

Merlin
Fly rods are like women, they won't play if they're maltreated
Charles Ritz, A Flyfisher's Life

Graeme H
Posts: 1951
Joined: Fri Jan 25, 2013 2:54 pm
Location: Perth, Western Australia

### Re: Analysing loop propagation

I'm not implying anyone here is a flat earther, but I'm going to paraphrase this to show how a deeper understanding of underlying concepts can help in ways we do not begin to appreciate until the basics are established:
We spend too much energy on useless topics. The earth is not a sphere then, so what? What would it change if it was? I can understand that the seasons do not apply completely to a flat earth and what does it brings to knowledge?
300 years ago, flat earthers could go about their daily life with no consequences for their beliefs. It simply did not matter to them what shape the earth is because they did not need to consider the implications of a spherical earth. Air travel or weather predictions were not on their radars (and neither were radars ... ) If we never want to discuss loops and how they might be controlled, it makes no difference to us whether we have a wave or not.

There are questions asked here on SexyLoops to which some people answer "We are a LONG way from reaching an understanding of this topic". For those who dismiss the loop as a wave, that will always be the case in the same way that flat earthers will never be able to explain the Coriolis Effect or gravity - these things simply don't fit within their framework of understanding. I say "speak only for yourself" when you you make such statements.

I teach casting to students and I aim to take my own casting as far as I can. I've used my understanding of this to improve all sort of things I do and teach. For example, these things are easier to do or explain when the loop is treated as a wave:
• Morphing loops
• Excessive overhang
• Landing an aerial mend in the correct location
• How snap casts work
• Increasing line carry
• Check hauling (forced turnover)
• Roll casting
• The 180° Rule
• Explaining how pull back works
• Controlling underpowered curve casts
If all we ever do is mathturbate here on a forum, it makes no difference if the loop is a wave or not. However, it has real world consequences for me when I cast and teach, so exploring the concept is not a frivolous pursuit. I use it every time I cast.

Cheers,
Graeme
FFi CCI

Graeme H
Posts: 1951
Joined: Fri Jan 25, 2013 2:54 pm
Location: Perth, Western Australia

### Re: Analysing loop propagation

Paul Arden wrote:
Wed Sep 23, 2020 3:11 pm
It’s complicated and I just think it takes us down a rabbit hole.
Can we just give the Flycasting Physics Sub-Forum this name please?
FFi CCI

Lasse Karlsson
Posts: 4186
Joined: Wed Jan 09, 2013 9:40 pm
Location: There, and back again
Contact:

### Re: Analysing loop propagation

Graeme H wrote:
Wed Sep 23, 2020 10:31 pm

I teach casting to students and I aim to take my own casting as far as I can. I've used my understanding of this to improve all sort of things I do and teach. For example, these things are easier to do or explain when the loop is treated as a wave:
• Morphing loops
• Excessive overhang
• Landing an aerial mend in the correct location
• How snap casts work
• Increasing line carry
• Check hauling (forced turnover)
• Roll casting
• The 180° Rule
• Explaining how pull back works
• Controlling underpowered curve casts

Cheers,
Graeme
Hi Graeme

Interesting list, I would love to hear how treating the loop as a wave makes it easier to explain those things, as opposed how they are explained now

Cheers
Lasse
Your friendly neighbourhood flyslinger

http://www.karlssonflyfishing.com

***Bring Mark back!!!!!! ***

Bianchetti Ivan
Posts: 169
Joined: Wed Sep 30, 2015 8:25 am

### Re: Analysing loop propagation

If you explained the waves using the launch, I'm afraid it wouldn't work, so ....

Graeme H
Posts: 1951
Joined: Fri Jan 25, 2013 2:54 pm
Location: Perth, Western Australia

### Re: Analysing loop propagation

Lasse Karlsson wrote:
Thu Sep 24, 2020 6:03 am
Hi Graeme

Interesting list, I would love to hear how treating the loop as a wave makes it easier to explain those things, as opposed how they are explained now

Cheers
Lasse
Perhaps at another time in another sub forum. This section is mainly about physics (but I always like to relate that back to practical applications, so I mentioned that list here because someone above asked "who cares and to what end?".)

Cheers,
Graeme
FFi CCI

Dirk le Roux
Posts: 477
Joined: Thu Sep 19, 2013 5:09 pm
Location: Pretoria, South Africa

### Re: Analysing loop propagation

gordonjudd wrote:
Mon Sep 14, 2020 3:08 pm
A jerk is readable in Gordy's pull-back cast rod leg velocity and at the same time an opposite direction jerk is readable in the fly leg velocity - centripetal force explains it for me.
Dirk,
Not only is it readable, the jerk derived from the measured velocity profiles in that pull back cast can be calculated as shown below.

Since the calculated correlation coefficient between those two jerk curves was only 12%, I don't think you can cherry pick a time range that fits with your centrifugal force theory while ignoring the 88% of the time when there is no correlation between the two jerk curves.

Invoking jerk as an explanation for the delay in the fly legs velocity increase relative to the start of the pull back is a derivative too far for me.

Gordy
Hi Gordy

I have replied to this post at the original thread.

Cheers,
Dirk