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murphy's law special issue

Issue 7 - February 2001

Murphy's law of tumbling toast test ressults

tumbling toast test logo The three experiments were conducted by a total of 1,005 pupils in the UK (694 in primary schools, 311 in secondary schools)

Experiment 1: Does buttered toast tend to land butter-down ?

Total number of drops:
Total number of butter-down landings:
Rate of butter-down landings:
9821
6101
62.1% = 12% higher than chance

To find out if this 12 per cent difference is statistically significant, we can calculate its "p-value" - that is, the chances of getting at least as big a difference as that observed just by fluke. This probability turns out to be extremely low (p ~ 10-127) Thus the 62 per cent rate is both substantially, and statistically significantly, different from the rate expected by chance alone.

Experiment 2: Is butter the cause ?

Results

Total number of drops:
Total number of "B"-down landings:
Rate of "B"-down landings:
9748
5663
58.1% = 8 % higher than chance and 4% lower than buttered toast

Again, statistical significance tests against the null hypothesis of a 50:50 split gives an extremely low p-value (~ 10-57). Toast with just a "B" on it thus still lands face-down at a rate substantially, and statistically significantly, different from value expected by chance alone.

Experiment 3: Is height the cause ?

Results

Total number of drops:
Total number of "B"-down landings:
Rate of "B"-down landings:
2038
953
46.8% = 3 % lower than chance and 15% lower than buttered toast

Statistical analysis

Both these differences are statistically significant (p = 0.003 and 10-37 respectively).

So increasing drop height to 2.5 metres gives a substantially and statistically significantly higher probability of producing a butter-up landing.

Conclusions

  1. Toast really does have a tendency to land butter-side down.
  2. The presence of butter is not the major cause of butter-side down landings.
  3. The principal cause is height: toast falling from waist-height does not have enough time to come butter-side up again.

MORE >


current issue header

sum pages icon
Murphy's Law Of Toast

Murphy's Law At work !

Primary Worksheet

Secondary Worksheet

Test Results

Law of Toast is true

the Cosmic Connection

The Winners


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