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A Little Learning

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plissaman

A Little Learning

Yes, correspondents are correct. My remarks were pretty stupid, as they usually are. Apologies. No one needs to be told what they don’t know.

I was trying to make the point that in bathtub vortex flow there is huge body of theoretical and experimental research and probably no unk-unks, in the sense that there are no unknowns. We just can’t put ‘em all together.

To be constructive, the issue can be idealized to a container with an exit orifice dispensing fluid in air. Jes holdin’ up a funnel in the breeze, M’am!

If the losses are small the exit flow speed at the edge of the emitted jet is approximated by V*2 =2gh, independent of the fluid density, as was hypothesized by Leonardo (c. 1500), and well known to Galileo (c.1600), Newton (c.1700) and Bernoulli (1750). If swirl vanes are introduced, then the rate of outflow is reduced, since the vortical exit flow is inclined to the vertical. If you have a narrow, long, constricted nozzle, or filters, then, a’course, again outflow is reduced, and can be calculated if these impedances are defined

If it swirls of its own accord, then, unless tests show this to be equally distributed clockwise and anti, one must assume that one’s water or funnel is twisted or God is a casuistic Jester – both quite likely. Or that the earth is spinning, a modern hypothesis, denied by the Bible, but supported by my astronaut friends who claim to have actually observed same.

As Nick notes, gedanken experimenten are a wonderful source of insight and “paradoxies”, and simple kitchen experiments for this case very productive. A’course, with real experiments, a lotta control issues go without saying, so I won’t.

Peter Lissaman, Da Vinci Ventures

Expertise is not knowing everything, but knowing what to look for.

1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA
tel:(505)983-7728

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
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David Eric Smith

Re: A Little Learning

Hi Everybody,

Thank you for each of these.

Total apologies for the thing about mantras, which I did not intend as an insult to anybody, because I am keenly aware that several of you have done a lot more to actually solve and understand the system under discussion than I have. Also, I value the track of this discussion a lot, and its attempt to be critical of things that I think deserve that criticism.

It was a scientist friend who meditated every day (and whose mental poise was much better than mine) who first told me that the physiology of the mantra was suppressed pre-frontal cortical activity, and that the mantra does it better than mere quiet, because it is very hard to actually quiet a mind, whereas filling it with some kind of redundant activity is easier. I too always found that fascinating, all the more because it seems to have some good effects.

I probably shouldn't have expressed a frustration that really originates from the disconnect between Schroedinger and Kolmogorov, which it took me a needless 7 years to realize was largely understood by others, since I am also sympathetic to the difficult balance between using words habitually to get things done, and being cautious with the boundaries between intuition and the scope of definitions.

Anyway, apologies for saying something snotty in an email that was intended for people I respect.

Eric

On Jun 30, 2011, at 12:50 PM, [hidden email] wrote:

Yes, correspondents are correct.  My remarks were pretty stupid, as they usually are.  Apologies.  No one needs to be told what they don’t know.

I was trying to make the point that in bathtub vortex flow there is huge body of theoretical and experimental research and probably no unk-unks, in the sense that there are no unknowns.  We just can’t put ‘em all together.

To be constructive, the issue can be idealized to a container with an exit orifice dispensing fluid in air.  Jes holdin’ up a funnel in the breeze, M’am!

If the losses are small the exit flow speed at the edge of the emitted jet is approximated by V*2 =2gh, independent of the fluid density, as was hypothesized by Leonardo (c. 1500), and well known to Galileo (c.1600), Newton (c.1700) and Bernoulli (1750).  If swirl vanes are introduced, then the rate of outflow is reduced, since the vortical exit flow is inclined to the vertical.  If you have a narrow, long, constricted nozzle, or filters, then, a’course, again outflow is reduced, and can be calculated if these impedances are defined
.
If it swirls of its own accord, then, unless tests show this to be equally distributed clockwise and anti, one must assume that one’s water or funnel is twisted or God is a casuistic Jester –  both quite likely.  Or that the earth is spinning, a modern hypothesis, denied by the Bible, but supported by my astronaut friends who claim to have actually observed same.

As Nick notes, gedanken experimenten are a wonderful source of insight and “paradoxies”, and simple kitchen experiments for this case very productive.  A’course, with real experiments, a lotta control issues go without saying, so I won’t.

Peter Lissaman, Da Vinci Ventures

Expertise is not knowing everything, but knowing what to look for.

1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA
tel:(505)983-7728

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

lrudolph

"thought experiments"

In reply to this post by plissaman

Nick having expressed some outrage at what he perceives
as (nefarious?) "thread hijacking" (what I prefer to
think of as "thread drift", but, hey), I'm starting a
new thread.

It seems to me that "thought experiment" (and its
German original) is a misleading phrase; further,
it seems to me that Nick, of all people, ought to
agree with me when I say that the phrase is misleading
because it suggests that a "thought experiment" is
a particular sort of "experiment", and that the
particular sort that it is, is one performed upon
reified "thoughts" on the stage of the Cartesian
Theatre.

What one is actually *doing* (I claim), when conducting
a "thought experiment", is much more analogous to
calculating than it is to experimentation. (I realize
that in a group so loaded with simulators, them's likely
to be fighting words; sorry, guys.) It is, in other
(maybe better) words, a more-or-less systematic and
more-or-less rigorous contemplation of the axioms one
has adopted (more or less explicitly), and/or of the
formal model one has designed, that is performed with
the particular end-in-view of discovering necessary
consequences of the axioms/formalities that were not
obvious, and that may be surprising or "paradoxical".
This description seems to me to fit Einstein's
elevator Gedankenexperiment (which I take to be
the archetype of thought experiments) perfectly.

It fits what Nick called his own "thought experiment",
about vortices, less well perhaps--how well it fits
depends on how much (if at all) Nick sees in his
account of that "thought experiment" what *I* saw
jumping out of it, namely, that among his (implicit)
axioms are some bits of intuition about physical
systems (not too explicitly acknowledged as such)
that, coupled with his (more or less) formal model,
seem to lead ineluctibly to counter-factual predictions
about some actual physical systems.

Of course when I put things like that, I can see why
someone who has the "key experiment" (is that the phrase?
something like it) paradigm always clearly in mind (which
I don't), in which the essence of an "experiment" is that
it can torpedo a purported theory, might want to say
"Yes, a 'thought experiment' is *precisely* a 'type
of experiment', you bozo!" Yet I still feel that
"thought experiments" are closer to "just-so stories"
(except without the negative connotation) than they
are to "real experiments" (which *my* intuition says
should involve smells, and if possible explosions
and huge voltages).

Thoughts?

Experiments?

Lee Rudolph

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

glen ep ropella

Re: "thought experiments"

[hidden email] wrote at 06/30/2011 01:03 PM:
> What one is actually *doing* (I claim), when conducting
> a "thought experiment", is much more analogous to
> calculating than it is to experimentation.

Odd synchronicity that this would come across Twitter only an hour and a
half after you said that! ;-)

Cosmic Pluralism: How Christianity briefly conquered the solar system

http://io9.com/5817219/

--
glen e. p. ropella, 971-222-9095, http://tempusdictum.com

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

Eric Charles

Re: "thought experiments"

In reply to this post by lrudolph

Lee,
Not an answer, but more grist to the mill:

Interestingly, if we believe in the cartesian theatre, then your points hold better - In a world in which I have perfect knowledge of my own mind, it should be impossible to perform a thought experiment, because I could never get a result that was not what I expected to get. While we could try to design a series of thoughts to lead someone else to a desired point, there would be nothing experimental about its effects on our own mind.

On the other hand, if we deny the cartesian theatre, then a thought experiment should be possible. If we do not have clear access to our own minds, then it should be possible to "test run" a series of thoughts and to find something other than what we expected.

Eric

P.S. After writing this, I realize that I consider one of the key features of an honest experiment that it is possible for it to result other than as we expect (which is related to my disdain of funding agencies that only fund things with sufficient 'pilot data' to virtually guarantee the promised result).

On Thu, Jun 30, 2011 04:03 PM, [hidden email] wrote:

Nick having expressed some outrage at what he perceives
as (nefarious?) "thread hijacking" (what I prefer to 
think of as "thread drift", but, hey), I'm starting a
new thread.

It seems to me that "thought experiment" (and its
German original) is a misleading phrase; further,
it seems to me that Nick, of all people, ought to
agree with me when I say that the phrase is misleading
because it suggests that a "thought experiment" is
a particular sort of "experiment", and that the 
particular sort that it is, is one performed upon
reified "thoughts" on the stage of the Cartesian
Theatre.  

What one is actually *doing* (I claim), when conducting
a "thought experiment", is much more analogous to 
calculating than it is to experimentation.  (I realize
that in a group so loaded with simulators, them's likely
to be fighting words; sorry, guys.)  It is, in other
(maybe better) words, a more-or-less systematic and
more-or-less rigorous contemplation of the axioms one
has adopted (more or less explicitly), and/or of the  
formal model one has designed, that is performed with 
the particular end-in-view of discovering necessary 
consequences of the axioms/formalities that were not 
obvious, and that may be surprising or "paradoxical".
This description seems to me to fit Einstein's 
elevator Gedankenexperiment (which I take to be 
the archetype of thought experiments) perfectly.

It fits what Nick called his own "thought experiment",
about vortices, less well perhaps--how well it fits
depends on how much (if at all) Nick sees in his 
account of that "thought experiment" what *I* saw
jumping out of it, namely, that among his (implicit)
axioms are some bits of intuition about physical
systems (not too explicitly acknowledged as such)
that, coupled with his (more or less) formal model,
seem to lead ineluctibly to counter-factual predictions
about some actual physical systems.  

Of course when I put things like that, I can see why
someone who has the "key experiment" (is that the phrase?
something like it) paradigm always clearly in mind (which
I don't), in which the essence of an "experiment" is that
it can torpedo a purported theory, might want to say 
"Yes, a 'thought experiment' is *precisely* a 'type 
of experiment', you bozo!"  Yet I still feel that 
"thought experiments" are closer to "just-so stories"
(except without the negative connotation) than they
are to "real experiments" (which *my* intuition says
should involve smells, and if possible explosions
and huge voltages).

Thoughts?

Experiments?

Lee Rudolph

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

Eric Charles

Professional Student and
Assistant Professor of Psychology
Penn State University
Altoona, PA 16601

Nick Thompson

Re: "thought experiments"

Eric, Lee,

I have never been a thread-fascist before, but I am glad that this is a new thread because, on the other one, I actually reported an real-life experiment and got results that disconfirmed the theory. Those gallons of water I spilled down the sink were NOT in my mind.

If I have perfect knowledge of the contents of my own mind, do I also have perfect knowledge of the implications of that knowledge? So, if I know set theory, I know number theory? Etc. Somehow, I don’t think even the most enthusiastic Cartesian would buy that.

By the way, I have always thought of mathematics as the field in which people do formalized thought experiments.

Nick

From: [hidden email] [mailto:[hidden email]] On Behalf Of ERIC P. CHARLES
Sent: Thursday, June 30, 2011 6:01 PM
To: [hidden email]
Cc: [hidden email]
Subject: Re: [FRIAM] "thought experiments"

Lee,
Not an answer, but more grist to the mill:

Interestingly, if we believe in the cartesian theatre, then your points hold better - In a world in which I have perfect knowledge of my own mind, it should be impossible to perform a thought experiment, because I could never get a result that was not what I expected to get. While we could try to design a series of thoughts to lead someone else to a desired point, there would be nothing experimental about its effects on our own mind.

On the other hand, if we deny the cartesian theatre, then a thought experiment should be possible. If we do not have clear access to our own minds, then it should be possible to "test run" a series of thoughts and to find something other than what we expected.

Eric

P.S. After writing this, I realize that I consider one of the key features of an honest experiment that it is possible for it to result other than as we expect (which is related to my disdain of funding agencies that only fund things with sufficient 'pilot data' to virtually guarantee the promised result).

On Thu, Jun 30, 2011 04:03 PM, [hidden email] wrote:

Nick having expressed some outrage at what he perceives

as (nefarious?) "thread hijacking" (what I prefer to

think of as "thread drift", but, hey), I'm starting a

new thread.

It seems to me that "thought experiment" (and its

German original) is a misleading phrase; further,

it seems to me that Nick, of all people, ought to

agree with me when I say that the phrase is misleading

because it suggests that a "thought experiment" is

a particular sort of "experiment", and that the

particular sort that it is, is one performed upon

reified "thoughts" on the stage of the Cartesian

Theatre.

What one is actually *doing* (I claim), when conducting

a "thought experiment", is much more analogous to

calculating than it is to experimentation.  (I realize

that in a group so loaded with simulators, them's likely

to be fighting words; sorry, guys.)  It is, in other

(maybe better) words, a more-or-less systematic and

more-or-less rigorous contemplation of the axioms one

has adopted (more or less explicitly), and/or of the

formal model one has designed, that is performed with

the particular end-in-view of discovering necessary

consequences of the axioms/formalities that were not

obvious, and that may be surprising or "paradoxical".

This description seems to me to fit Einstein's

elevator Gedankenexperiment (which I take to be

the archetype of thought experiments) perfectly.

It fits what Nick called his own "thought experiment",

about vortices, less well perhaps--how well it fits

depends on how much (if at all) Nick sees in his

account of that "thought experiment" what *I* saw

jumping out of it, namely, that among his (implicit)

axioms are some bits of intuition about physical

systems (not too explicitly acknowledged as such)

that, coupled with his (more or less) formal model,

seem to lead ineluctibly to counter-factual predictions

about some actual physical systems.

Of course when I put things like that, I can see why

someone who has the "key experiment" (is that the phrase?

something like it) paradigm always clearly in mind (which

I don't), in which the essence of an "experiment" is that

it can torpedo a purported theory, might want to say

"Yes, a 'thought experiment' is *precisely* a 'type

of experiment', you bozo!"  Yet I still feel that

"thought experiments" are closer to "just-so stories"

(except without the negative connotation) than they

are to "real experiments" (which *my* intuition says

should involve smells, and if possible explosions

and huge voltages).

Thoughts?

Experiments?

Lee Rudolph

============================================================

FRIAM Applied Complexity Group listserv

Meets Fridays 9a-11:30 at cafe at St. John's College

lectures, archives, unsubscribe, maps at http://www.friam.org

Eric Charles

Professional Student and
Assistant Professor of Psychology
Penn State University
Altoona, PA 16601

glen ep ropella

Re: "thought experiments"

Nicholas Thompson wrote at 06/30/2011 05:51 PM:
> By the way, I have always thought of mathematics as the field in which
> people do formalized thought experiments.

That depends on what you mean by "formalized".

--
glen e. p. ropella, 971-222-9095, http://tempusdictum.com

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org