Re: Droping a Slinky (Q&A)

Posted by Eric Charles on
URL: http://friam.383.s1.nabble.com/Droping-a-Slinky-Q-A-tp6851732p6852723.html

Sorry for any confusion.

It was the videos that I thought people might like... and then any discussion it generated might be bonus. Maybe I shouldn't have said anything, and just forwarded the videos.

The demonstrator in the video has been teaching physics at the University of Sydney for quite a long time. He uses information-speak in a few places. One example is when he explains that the bottom does not move:

"until the bottom end gets the information that the tension has changed. It takes time for that information to propagate down through the slinky to reach the bottom end. It is propagating down as a compressional wave."

The host/narrator in the video then throws in the term 'know' a couple of times, and the demonstrator goes along with it smoothly.

In contrast, Bruce gave a perfectly good explanation without any of that additional baggage. So why do so many people (including professional physicists) find the 'information' and 'know' language so appealing?

Eric

P.S. I thanked Bruce off list for the very cool and insightful explanations regarding the speed of light, but I'll mention my thanks again here.



On Sun, Oct 2, 2011 12:58 AM, "Nicholas Thompson" <[hidden email]> wrote:

Hi, Eric,

 

I agree that using the term signal to describe “anything that happens” or term “information” to describe “anything related to anything that happens” is bad form. 

 

But who did that?  Certainly not Bruce. 

 

When you (eric)  wrote

Why would you want to take that perfectly good explanation and insert things like "The bottom part of the slinky doesn't know to move until it gets information indicating that the top part is falling." The idea that you enhance the physical description of the slinky by anthropomorphizing it in that way is weird

 

Who were you quoting?  I know people who talk like that.  But the “you” was a “one-you” not a “you-you”, right?

 

And what about hero Gibson’s use of the term?  Doesn’t he refer to “information pickup” as if the physical relation between two thing constitutes knowledge about the one provided by the other? 

 

I haven’t looked at the videos yet.

 

Nick

 

From: [hidden email] [mailto:[hidden email]] On Behalf Of ERIC P. CHARLES
Sent: Saturday, October 01, 2011 9:44 PM
To: Bruce Sherwood
Cc: The Friday Morning Applied Complexity Coffee Group
Subject: Re: [FRIAM] Droping a Slinky (Q&A)

 

Bruce says:
Until the ("sound" or "mechanical") wave in the slinky propagates down to lower parts of the hanging slinky, there is no reason/cause for the lower parts of the slinky to change position, and they don't. And as long as the lower parts of the slinky are stretched, they will continue to support the load below them just as they had been doing before the top of the slinky was released. Hence the bottom of the slinky will not move until the wave has propagated down far enough that the slinky just above the bottom is no longer stretched.

I says:
Yes, exactly!
Why would you want to take that perfectly good explanation and insert things like "The bottom part of the slinky doesn't know to move until it gets information indicating that the top part is falling." The idea that you enhance the physical description of the slinky by anthropomorphizing it in that way is weird. (Note, this clearly isn't a Shannon 'information' thing either... at least not as far as I can tell. I cannot see anything analogous to a decision being made after a clarification of uncertainty. There is no analog to signal and noise.)

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

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