Monday, April 19, 2010

Autumn maths

Plotting the number of post-it notes on the wall with respect to time gives an approximate exponential relationship... The same as that followed by the radioactive decay of atoms. (Most natural systems have exponential relationships. When asked in a physics lecture how something changes, it was often safe to say "exponentially?" if you didn't know).
The model finds a decay constant of -0.05 +/- 0.025 per hour (Figure 1). If the natural log of the data and model are taken (Figure 2), we can see the deviation of the data from a pure exponential (represented by the linear data trend-line, and the model data), to something more complex. This could be due to the small sample size (25), and inhomogeneity in the stuck-ness of the post-it notes.

statistics and modeling.xls

statistics and modeling.xls

Sunday, April 18, 2010