The Nicene Creed as a Rationality Test

PZ Myers at his most pugnacious:

The Nicene Creed is not a profession of the basic orthodoxy of the Christian faith.  It's a rationality test.

If you believe one line of it, you've failed.

Ouff!

Mushroom

Now autumn is here the fungi are starting to come out.  I came across this mushroom yesterday in Reading University grounds.  I think it is of the genus Russula but, as there seem to be hundreds of species in that genus, I don't think I will go any further in my attempts to classify it. 

Snail Shell Graters

I watched the first episode of the rerun of Ray Mears' Wild Food last night.  In it Ray and Gordon Hillman visit Arnhemland to find out how Australian Aborigines went about searching for and preparing their food.  Towards the end of the program their hostess is preparing a type of yam that needs soaking overnight to make it edible.  She takes an empty snail shell, with a stick pokes a hole in its side, and then proceeds to use it to grate the yam into thin strips.  Mears and and Hillman are quite impressed by the simplicity and effectiveness of this tool and they speculate that if such a shell turned up in an archaeological dig, it would be unlikely to be recognised as a tool.

Snail Telegraphy

 

The Proceedings of the Athanasius Kircher Society is a wonderful repository of the strange and bizarre.  Browsing its pages is  an ideal way to while away an spare hour or two.  Today I came across there this 19th century proposal to use telepathy between snails as a means for communicating over long distances.

Everyday Graphs, No 2: Losing Weight

Like many women, my wife Liz often worries about her weight.  A few months ago she decided to make a determined effort to avoid high calorie foods and to get more exercise.  She started weighing herself frequently and recording the results in her diary.  However, it never seemed to occur to her to plot a graph of the results.  Instead she seemed to judge her progress on whether  the current measure was up or down on the previous one.  She would come home and say "I've put on 2 pounds!" and be sad, or "I've lost 2 pounds!" and be happy. 

I tried to explain to her about measurement error and that 2 pounds was probably not a significant difference, but she just wouldn't listen.  On one occasion she became quite distressed because, apparently, she had suddenly "put on 10 pounds", only to find, to her great relief, that "it all came off again" the following day.  I repeatedly told her that she should not be concentrating on the difference between the last two measurements but, instead,  should be looking at the overall trend, and for that you need to plot a graph. 

Eventually, I got her to sit down at the kitchen table with her diary and together we plotted the  measurements out.  The the result was the above graph (except that I have subtracted an arbitrary constant from all the values to disguise the true weights - we are only interested in the differences here).  There are three things to notice about this graph:

• The points show a clear and unambiguous downward trend.  Liz is successfully losing weight: over 4 months she had lost about 7 pounds.  I was surprised by this; from the way she had been going on I had assumed that she must be actually putting weight on.
  
• All but 2 of the points scatter within a few pounds of the downward trend line.  I was correct in saying that a difference of 2 pounds between two consecutive measurements was not worth worrying about.
• However, there are 2 points that stand well above the trend line and these require some explanation.  But they are almost certainly not the result of Liz suddenly putting on a lot of weight and then losing it all the following day.  Somehow those measurements must have been faulty.  There are various ways this could happen but I like to think that Liz forgot to put her handbag down before she stepped onto the scales.

Without plotting the graph, Liz would probably never have realised that her weight was slowly and steadily going down.  Instead, she would have continued to be distracted by insignificant changes and the occasional faulty measurement.  With the graph these can be clearly seen for what they are: irrelevant.  Indeed, I would go as far as to say that any method of weight loss should include graph plotting if it is to be effective.  Anyone attempting to lose weight must get a feel for how their weight changes over time and a graph is the best thing for giving that feel. 

(Postscipt: The latest measurement, on September 15th, comes in at just under 0.5 stone on the above scale, so the downward trend is continuing.  It looks as if Liz is on target for having lost 1.0 stone by November.)