This isn’t a true story. I wrote it to show that we should view predictions based on scientific observations with extreme caution. A biologist decided to study the rabbit population on a small farm. So he decided on a reasonably reliable way to assess the number of wild rabbits living on the farm at the… Continue reading 16.8 Predictions: be careful what you believe

Why should we bother to think about writing numbers? You’ve probably been writing numbers, without any problems, since you were about 5 years old. There are two reasons. The first is that writing very large numbers like 1 000 000 000 000 is a pain – there must be a better way of doing it.… Continue reading 16.7 Writing numbers: it’s not as simple as it seems

Before you read this post, I suggest that you read post 16.5. At the centre of every atom there is a dense core called its nucleus. However, some nuclei are unstable and spontaneously disintegrate to form a more stable nucleus, giving rise to a different kind of atom. This process is called radioactive decay. We… Continue reading 16.6 Exponential decay: radioactivity

How often have you heard or read the phrase “Exponential growth”? What does it mean? Do the people who use it always know – I doubt it! Let’s think of a colony of bacteria growing happily (if bacteria can ever be truly happy). In an interval of time, t, the colony doubles in size. Suppose… Continue reading 16.5 Exponential growth: bacteria

It can be the same as standing still!   I suggest you read post 16.2 before reading this. What is the difference between movement at a constant velocity and standing still? If you think carefully about it you may decide that the answer is – nothing! If you’re bothered by my use of the word… Continue reading 16.4 Movement

Black swans vs white coats Before you read this post, I suggest you read post 16.1 and post 16.2 How often have you read or heard the phrase “Scientifically proven”? If you’ve read my first two posts, you may suspect that scientists can’t prove that anything is true. And you would be right. Science can… Continue reading 16.3 Scientific proof

Many people believe that scientific laws can’t be broken. This is based on a misunderstanding of the phrase “scientific law”. In the year 1687 Isaac Newton published a book called Philosophiae Naturalis Principia Mathematica in which he stated three important ideas which he believed govern how things move. We now call them Newton’s laws of… Continue reading 16.2 Scientific laws can be broken

Drug companies should prove their products are completely safe before they sell them I suspect that most people agree with this statement. I also suspect that journalists would be very critical of any politician who disagreed with it! But how can we prove that a medicine will always be safe for everyone? Let’s forget ethical… Continue reading 16.1 Drug safety testing