Strange coincidence

white and blue floral table lamp

 

My mother’s birthday was the 15th of October. My good friend, the late Michael Jacobs, a fine author, was also born on that day, but many years later. Michael’s mother, the late Maria-Grazia, was born on the 8th of May. I was born on the same day, but many years later.

The chance of two people sharing the same birthday is quite small. It is 1 in 365 or 0.0028. Things get more interesting when one considers a group of people. In a room of 23 people, the chances that two people share a birthday is 0.5 or 50%, and when there are 75 people the probability increases to 0.99 or 99% (see: https://betterexplained.com/articles/understanding-the-birthday-paradox/ and https://en.wikipedia.org/wiki/Birthday_problem).  

I have no idea how to calculate the probability that my mother and my good friend share the same birthday AS WELL AS his mother and me sharing the same birthday. It is too long since I studied statistics and probability at school!Even then, I doubt I could have worked it out.

 

 

Photo by fotografierende on Pexels.com

Whether it will rain or not

 

Whether the weather be fine
Or whether the weather be not,
Whether the weather be cold
Or whether the weather be hot,
We’ll weather the weather
Whatever the weather,
Whether we like it or not. 

[anonymous]

 

One of the best ways to engage a stranger in conversation in the UK is to begin talking about the weather. Because of its unpredictability in the British Isles, there is always much to discuss.

There is at least one explanation of why it is so difficult to forecast British weather reliably. I read about it in a book about chaos theory some years ago, so please forgive me if my explanation is not totally clear. As I understand it, weather forecasting is done using mathematical models involving a complex set of  interlinked equations. The forecaster feeds multiple parameters into the equations, and a result is obtained that allows the weather to be predicted reasonably accurately. This model is quite reliable in many parts of the world, but not here in the UK. The problem is that when the parameters for the region containing the British Isles, whose weather system is affected by far more complex and many more influences than in other places (I do not know why), are fed into this set of equations, instead of one solution, several appear because the parameters introduce a large degree of instability into the forecasting model. Hence, the uncertainty in British forecasting that occurs. 

Nowadays, I use a popular weather forecasting app on my mobile ‘phone. It provides several predictions of what the weather will be like during different times of the day and several days following it. Potentially useful are the rainfall predictions which are expressed as a percentage, 0% being ‘rain completely unlikely’ and 100% being ‘rain inevitable’. So far, so good.

If the app predicts rainfall of less than about 5%, I do not bother to take an umbrella or rain coat, otherwise I do. Things can go wrong. Suddenly, out of the blue, rain falls heavily. I look at my app. Suddenly, what had been a prediction of, say, 3% becomes a prediction of, say, 78%. The app appears to be responding to the weather (or recording it), rather than predicting it.

Moral of the story: take an umbrella.

 

Poem from: https://www.poemhunter.com/poems/weather/page-1/22212436/#content

Adding up

CALCULATOR

When I was at high school in the second half of the 1960s, I studied, amongst other things, maths, physics, and chemistry. All of these subjects require calculation, sometimes quite complicated. There were no pocket calculators and few computers accessible to schoolkids in those days. 

For complicated calculations, we had to rely on working out the arithmetic with pen and paper, or with tables of logarithms, or using slide rules. Today, you would find it difficult to buy either a table of logarithms or a slide rule. By the way, calculating with the latter required one to make an estimate of the answer to ascertain which power of ten the anser should be. For example, should it be in the hindres, thousands or hundreds of thousands? Also, when making divisions using slide rules, there were almost always two possible answers, only one of which was correct. A rough estimation done on paper or in one’s head, would determine which of these two was the right one. 

If you are getting lost already, stop worrying because this will not get more complicated.

In the late ’60s or early ’70s, pocket electronic calculators entered the market place. At first, they required enormous pockets and pockets filled with money because they were quite expensive. Well, they were certainly beyond my means.

In late 1973, I began working in a laboratory with a view to collecting experimental data to be submited eventually in a PhD thesis. One of the other PhD students in our laboratory came from Kuwait. He would travel there occasionally to visit his family. When he returned from one of his trips home, he brought me a wonderful gift. It was a Casio pocket calculator. Reading this today, you will probably think that was a lousy thing to give, as you can go into shops all over the place and buy a pocket calculator for a very modest price, maybe no more than the cost of a packet of cigarettes. However, when I received my Casio, it was a very precious gift both financially and in terms of labour saving.

And, now one does not even need to buy a calculator because there will be one installed in your mobile telephone. I suppose this is progress. However, progress is a word I do not like to use because in medicine a ‘progressive’ disease is one that continues to get worse, often leading to death.

 

Picture taken at Russell Market in Bangalore, India