Appointments of scientists and engineers in industry are often very dependent on the procedures of Human Resources departments. They often place a lot of reliance on results from “assessment centres” that provide general information about a person but not about his or her specialist abilities. This general information may be very useful – but it… Continue reading 16.11 Giving a scientist a job

Of course it won’t! The reason we don’t believe that it will is because we can’t see any reason why it should. We don’t believe things unless we have a good reason. But I would expect people who owned expensive cars to be, on average, healthier than people who own old, inexpensive cars or no… Continue reading 16.10 Will driving an expensive car make you healthier?

I suggest that you read post 16.4 before this. You have probably been taught that the sun doesn’t move around the earth. But you can see that it does! What’s happening? Let’s start with what you can see. This is always a good place to start. It’s much better than blindly accepting what somebody else… Continue reading 16.9 Does the sun move around the earth?

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