[e2e] Why do we need TCP flow control (rwnd)?
David P. Reed
dpreed at reed.com
Fri Jul 11 23:59:58 PDT 2008
Not to be picky, but a pound lump of U-238 by itself is probably not a
Poisson emitter, either. Neutrons, etc. do interact with the other
elements of the generating process, perhaps triggering additional
events. And an atom of U-238 generates a single event. Probably also
not a Poisson process.
Perhaps U-238 in a very, very low-density empty region of space?
I prefer to think of Poisson processes as entirely in the domain of
mathematics - a calculation tool - given the difficulty of proving
anything is a Poisson process. How do we know that the apparent
indeterminacy (randomness) of physics is essential in reality or merely
a determinacy inaccessible to us, below the planck limit? My philosophy
of science suggests that it does not matter, but yours may differ.
Ted Faber wrote:
> On Fri, Jul 11, 2008 at 02:59:13PM -0700, Lachlan Andrew wrote:
>
>> Greetings Ted,
>>
>> 2008/7/11 Ted Faber <faber at isi.edu>:
>>
>>> True Poisson processes are rare; the only one I can think of off the top
>>> of my head is radioactive decay.
>>>
>> Just to be picky, that isn't Poisson either, although it is well
>> approximated as Poisson on "short" time-scales (relative to the
>> half-life).
>>
>
> No observations on my students' Normality? :-)
>
> You're correct, of course. I do believe that the radioactive decay of a
> pound of U-238 over a month is a Poisson process, but on timescales
> close to the half-life it is not. Smaller samples or isotopes with
> shorter half-lives would not be. That's what I get for
> underspecification. :-)
>
>
More information about the end2end-interest
mailing list