Ways of explaining the physics of fly casting

Walter & Group....

To help our new Group members, I have attached Walter Simbirski's notes on fly casting physics.

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[GH] I expect that from time to time as we try to explain physical things in layman's terms, we will have some unavoidable collisions ....... as "plain speak" collides with "physics speak".

Scientists understand one another. Laymen may well understand one another. Sometimes, however, scientists and laymen have problems communicating.

The physicist will likely be more scientifically accurate. His scientifically correct information may actually be useless in a teaching situation, yet yield an informed instructor who can digest and "translate" this information to a student using simple language.

The layman may have an explanation which while not necessarily correct from a physics standpoint may well serve to get into students' brains and yield good casting results.

Here is an example :

Server Sadik has made some comments in Craig Buckbee's message from several days ago. Server's comments are in red.

I'm somewhere in-between.

Gordy

"[GH] Craig Buckbee offers an admittedly non-scientific teaching message which might well be considered the antithesis of Server's paper. It is, nonetheless, in plain language which makes good sense to me.

[SS} see remarks below

and would probably be well understood by his students :-

gordy,

as to the line following the tip, the "aerial pencil"...

to beginners i teach that the line follows the tip. works great, no problems.

BUT

if i have an advanced caster, a caster that wants more, i explain that the line following the tip is a lil' white teaching lie, that in fact the line goes where the momentum of the cast sends it.

[SS] What could this mean?? The fly line at the rod tip (unquestionably to the least technical of any readers if no hauling is involved) is the crucial connection of rod and fly line. Visualize a fly line knotted to the tip top. All forces on the fly line and therefore any momentum changes come at the rod tip not at some imaginary point below the tip. This assertion - "lil' white teaching lie" - has no technical merit. If it helps you personally by all means retain it but be aware that it is not correct.

Al Buhr taught me this. it was one of those "ah ha" moments. it made sense to me, it hit home. now, especially when casting distance i do not only think of the tip, now i include putting my mind's eye (thanks to JimV for that term) below the tip where i feel the momentum is born.

[SS] Momentum change is born from forces, the only force on our "knotted fly line" comes from the tip top of the rod.

depending on the rod and distance desired it may be about 2 -3 feet below the tip, maybe deeper.

[SS] See my last statement.

i am NOT a scientist .... so, explaining it to myself, where the momentum is, is "where the peak bend of the rod is when i release the it"

(... where the bend is when i stop.... where the bend is when i release my grip on the cork)

crazy? make sense at all?

craig "

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[GH] Server is technically correct, as I see it.

Craig, however, has made statements which while not fully correct from a scientific point of view, may well serve to help casting students.

In the fly casting physics papers (attachments), Walter Simbirski has distilled detailed physics down to understandable levels.

All three of them make sense to me.

Gordy