14 JANUARY 2015

# How Does the Concept of Chance Relate to Knowledge and Knowing?

When did something happen to you unexpectedly or by chance? A good number of things in everyday life might seem like a coincidence, or a lucky chance, also known as serendipity. Chance underpins our everyday thinking. How much safer is it to travel by car than by bike? Should I take a risk?

We might claim we know something if it is very likely or highly probable. In your study of science you might typically ask, what’s the most likely explanation? You might be justified in thinking critically about events that seem improbable. Carl Sagan observed that, “Extraordinary claims require extraordinary evidence.”

There are many examples of chance discoveries in a number of subject areas. In history we might evaluate the impact of accidental events and so-called chance happenings. In World War II the D-Day landings were postponed by a day due to the forecast of bad weather.

There have been many accidental discoveries in natural science. In the nineteenth century, Michael Faraday made metallic gold colloids by accident. In 1928, Alexander Fleming’s chance discovery of Penicillin led to a cure for various bacterial infections.

You might investigate how the accidental discovery of cosmic microwave background radiation in the 1960’s by radio-astrononers, Arno Penzias and Robert Wilson led to the Big Bang Theory. Their chance discovery led to their award of the Nobel Prize in 1978. You could investigate other potential candidates for accidental discoveries in science including velcro, teflon or the microwave oven.

The concept of chance goes hand in hand with Maths. In this clip Professor David Spiegelhalter, the Professor of the Public Understanding of Risk explores the statistics behind the everyday choices we make, for example the relative risks of travelling by bike or car. In this video clip he explores the science of chance and our shared knowledge of life expectancy. You can explore these concepts further at his website.

If you want to explore a mathematical perspective further, you might investigate Bayes' Theorem which relates current probability to prior probability and was developed by Thomas Bayes in the eighteenth century.

A number of things that happen are improbable. If we consider the chance or likelihood of the universe existing, or the probability of human evolution, it's not very likely according to Dr Alice Roberts who in her recent book, sets out the biological narrative that tells the story of our development from a single cell to an organism with around 100 trillion cells. The chance of you existing as an individual is vanishingly small if you consider the contingent factors. Alice Roberts describes the development of a single cell into a person as a biological ‘natural miracle’, given its unlikeliness, even if it requires no belief in divine intervention.

In conclusion, does something have to be highly likely for us to claim to know it? Might we be justified in knowing things that are improbable and if so on what grounds? If you want to investigate the concept of chance further you could address some of the following questions, or generate your own knowledge questions.

General questions and Knowledge questions

-  What are examples of chance happenings or chance discoveries in different areas of knowledge including natural science, human science, and history?
-  We might discover something by chance, but can we invent something by chance? Why? Why not?
-  We might claim to know things that are improbable. To what extent are we justified?
-  What do we know about the science of chance?
-  Is the concept of chance the same as the concept of risk, surprise, luck, accident, likelihood or probability?What arguments might be put forward?
-  Is there such a thing as a ‘chance event’ or ‘chance happening’? Is a chance event the same as an unpredictable event or an unlikely event?
-  How important is the concept of chance in our shared knowledge of history and science?