|
|
Re: Simple random number generator?
Posted:
Dec 20, 2012 8:06 PM
|
|
On 12/20/2012 03:15 AM, Michael Press wrote:
> In article<87licvisn2.fsf@bazspaz.fatphil.org>,
> Phil Carmody<thefatphil_demunged@yahoo.co.uk> wrote:
>
>> Michael Press<rubrum@pacbell.net> writes:
>>> In article
>>> <0.ef56b5652decd19bb478.20121128013501GMT.87k3t6v7ay.fsf@bsb.me.uk>,
>>> Ben Bacarisse<ben.usenet@bsb.me.uk> wrote:
>>>
>>>> Good quality, hardware-generated random number sequences (if our current
>>>> understanding of quantum effects is correct) are random in a different
>>>> way to the digits of pi. It helps if the terminology is be able to
>>>> distinguish between them.
>>>
>>> I do not see how quantum effects can be used to generate
>>> random sequences. Coherent systems are stable and highly,
>>> if not perfectly, predictable.
>>>
>>> Hardware generated random sequences usually read Schottky
>>> noise off some device (a sound card in a computer) and use
>>> that. This can be modeled using entirely classical physics.
>>
>> Are you sure? Shottky noise is white noise, and thus is
>> indistinguishable from thermal (Johnson-Nyquist) noise.
>> So you can statistically model it the same way, but that
>> doesn't mean it's actually caused by classical mechanics.
>> I can't find any references to Shottky noise that don't
>> mention some quantum effect.
>
> _What_ quantum effect? So far I am the only one who
> does not gloss over this question. That `quantum
> effects' are involved does not imply that they
> beget stochastic effects.
>
> Experiment and analysis of time series show that
> radioactive decay has an unexplained component. Further
> this unexplained component is no more complicated or
> less simple than diffusion across a membrane. Bluntly,
> equivalent to deflation of a bicycle tire.
>
> By `quantum' I read `wave theory of matter'. The
> original Bohr theory is as good as we have for what
> might actually be happening.
>
> (Personally I do not adhere to any interpretation used
> to psychologically make the experiments more palatable;
> preferring to confront as best my faculties allow the
> raw facts.)
>
We tend to take "measurement" as an objective practice.
But I think there's a subtle interplay between theory
and practice or experimental physics.
Measuring is a phenomenon involving physicists, their
apparatus and what they're observing. (maybe? )
In practice, a sophisticated measurement relies on a long
chain of observations, calculations and assumptions on
what's negligible. These days, it will likely invoke
electro-magnetic theory, since digital measurements
are so common .
The statistics of quantum mechanics has to do with
"observed things", the result of measurement in the
wider sense (approximately).
What is "measuring" in physics, in a once-and-for-all
definition?
dave
|
|
