Re: Toaster to Generate Random Numbers

From: Bill Unruh (unruh@string.physics.ubc.ca)
Date: 01/11/03 

From: unruh@string.physics.ubc.ca (Bill Unruh)
Date: 11 Jan 2003 22:02:38 GMT

Guy Macon <. http://www.guymacon.com/resume.html .> writes:

]Bill Unruh wrote:
]>
]>Guy Macon <. http://www.guymacon.com/resume.html .> writes:
]>
]>]Bill Unruh wrote:
]>
]>]> The noise structure of "thermal noise"-- eg the noise
]>]> coming from a resistor with a constant current source across it, has
]>]> correlations, especially at long times (1/f noise).
]>
]>]There is a problem with the theory that resistors have 1/f noise.
]>]What is the amplitude of the signal at DC? At very, very close
]>]to DC? Are the real-world answers really infinty and very, very
]>]large?
]>
]>]Of course it would take forever to answer the first question with
]>]an experiment and a very, very long time to answer the second.
]>
]>1/f noise is very very poorly understood. The experimental fact is that
]>almost all systems which have been measured for a "very very " long
]>time, show 1/f noise, and there is no indication that it disappears at
]>"very very very" long times.

]I am well aware of this. The problem is that the amplitude of the
]current approaches infinity as the frequency aproaches DC. This
]implies that I could take a resistor with a constant 1mA current
]source across it, wait long enough, and measure millions of amps
]going through it. Could this possibly be true?

No, with a constant current source, the current will remain constant.
However you could measure a million volts across it ( which you would if
the resistor developed an open circuit ) Or with a contant voltage
source, teh current would go th 1million amps, which it would if the
resistor developed a shor-- again a not impossible event. (of course at
that point your voltage source might crap out as well.)

]A further problem I have is that intensity of the light coming from
]quasars has 1/f noise fluctuations. That's a fairly long period for
]the experiment, but then again, Quasars are very bright. Does their
]brightness really increaese without limit as you wait longer and
]longer?

I guess so.

Note that it does not "increse without limit" it fulctuates, and the
fluctuation is sometimes very large.
]

]--
]Email Guy Macon guymacon+YOUR NAME GOES HERE@spamcop.net <html><head></head>
]<body>Electrical engineer
] for hire: Los Angeles / Orange County CA USA 714-670-1687 See my resume at
] http://www.guymacon.com/resume.html .</body><html><!-- www.guymacon.com -->

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