[e2e] evolution of bandwidth as a term

Cannara cannara at attglobal.net
Fri Oct 3 11:07:09 PDT 2003


David, a reply to correct your first part here was already made by someone, so
I'll just take the "axle" one.  Rotation dynamics is a spectral quantity. It
has all the attributes of a signal, albeit a very narrow-bandwidth (correct
meaning) one.  Every variable, in whatever units, legitimately has a
derivative associated with it, thus a spectrum.  If you've ever owned an
oldish Jaguar sedan, you'd understand about the spectra of axle & driveshaft
signals, as sensed by the seat of your pants.  :]  Perhaps my signature line
for the other prolific mailgroup I enjoy will serve to authenticate my
axle-signalling knowledge...
--
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

"David P. Reed" wrote:
> 
> In a side conversation about a more subtle ambiguity, a list reader
> reminded me that there are two interpretations of the word "bit" that we
> tend to use.   One kind of bit is a symbol which has two states
> (conventionally called 0 and 1).   Another is a unit of information (or
> negentropy) that can measure the information content of a system
> state.   So, in fact, "bits per second" can be used to measure quite
> different things.   For example, CNN delivers multiple megabits/second in
> the first interpretation, and <10 bits/second in the second interpretation
> (if you watch it all day every day, how many bits of new information will
> have been delivered to your brain in each second?)
> 
> So knowing the unit does not tell you what is being measured.   Both
> interpretations are denominated in bits/second, just as axle rotation rates
> and bandwidth are denominated in Hz.
>




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