Geiger counter readings from a radioactive source consisting of many nuclei. Note that the random variations are very small, relative to the general pattern of decay.
The time units on the horizontal axis are arbitrary, so this could represent pretty much any type of nucleus. The numbers could be seconds, minutes, years, or centuries (though obviously it's not practical to run Geiger counters for that long!).
<a rel="nofollow" class="external text" href="https://www.youtube.com/user/GalileosPendulum">Matthew Francis</a>
CC BY 3.0
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