[time-nuts] "Q for dummies"

[Tom Van Baak]

Ole,

For a two-sentence summary, I think the wine glass example of Q works 
fine. The audience typically knows about bells ringing and wine glasses 
singing, so this factoid resonates with them. But the issue is then: 
what's the point; why is a long bright ring better than a short dull 
plink. That's where it gets hard.

For a deeper look, I keep a list of articles about Q here:

http://leapsecond.com/pages/Q/

Of those, I would recommend reading at least this one all-time classic 
note from Bell Labs:

http://leapsecond.com/pages/Q/1955-The-Story-of-Q-Green.pdf

It's relevant to from quartz and atomic clocks, from wine to earth rotation.

/tvb


On 1/26/2021 4:28 AM, Ole Petter Ronningen wrote:
> Hi, All
>
> I am going to give a presentation to non-nuts, and in one of the slides I
> touch on Q - not wanting to spend more than a sentence or two on the
> subject, I wonder if the following analogy works:
>
> "A quality long-stemmed, thin-walled wine glass will ring for a long time
> after we give it a little tap - this is high Q. A thick-walled, stubby milk
> glass will barely ring at all, just a dull "plink" - this is low Q. The
> energy we put in dies out very quickly."
>
> As I am sure is embarrassingly evident, I have a rather tentative grip on
> the subject myself..
>
> Ole