Quote:
" As the number of electrons N decreases, the statistical fluctualtions in the number becomes an increasing fraction of the total, limiting circuit performance and making circuit design more difficult.
".
this doesn't prevent me from further reading, just wonder what statistical fluctualtions actually mean, in simple language.
thanks
Think of the current as a measure of how many electrons pass through a wire every second.
But, this number is just an average. If you were to count the actual number of electrons every second, it would usually be different than the average number. These fluctuations from the average are what the person you are quoting is talking about.
Mark
A basic example would be to measure the height of 100 people. You will get
100 different values (assuming your method of measurement has enough resolution).A second example would be to measure the output voltage of 100 photo sensors that were illuminated with a constant source. Again, 100 different values are expected.
A third example would be to collect data on the time before failure of 100 light bulbs.
Statistics are used to deal with data that are known to be subject to random fluctuations. Almost all data are, by the way.
The bigger your sample is, the closer your estimate of [something] is to the estimate that you would make with subsequent large samples.
You're probably most accustomed to [something] being the average of some measurement of the sample, so consider an average weight. If you take the average weight of samples of, say, five people at a time then the results depend a lot on which five people you choose this time as opposed to next time, and your sample to sample variation will be large.
If, on the other hand, you weight people in groups of 500 then you would intuitively expect that the average weights of successive groups would be closer to each other than the average weights of the groups with just five people each. (For this statistic, it turns out that the expected value of the spread of the average will scale by the square root of the number of samples but that's not really germane here.)
So, turning it around, starting with mean weights determined by samples from large groups, the fluctuation in the results will be greater when the number of samples include in each group is reduced.
-- Rich Webb Norfolk, VA
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