Why are Simpler Explanations Usually Better?

According to Wiliam of Ockham (c. 1288 - c. 1347), if there are competing explanations for a phenomenon, the simpler explanation is to be preferred. The simpler explanation is often the correct one. It can be summarized as "With all other [...]

An episode of the TOKTalk.net podcast, hosted by ok, titled "Why are Simpler Explanations Usually Better?" was published on December 24, 2007.

December 24, 2007 · TOKTalk.net

Summary

http://www.toktalk.net/wordpress/wp-content/uploads/MP3/006-toktalk-simplicity.mp3 The purpose of science is to make things simpler and not more complicated. Scientists strive to discover theories and explanations that simplify the view of our world and not complicate them. According to Wiliam of Ockham (c. 1288 – c. 1347), if there are competing explanations for a phenomenon, the simpler explanation is to be preferred. The simpler explanation is often the correct one. It can be summarized as “With all other things being equal the simpler solution is the better one.” Simpler explanations rely on fewer assumptions which can not be proven or disproven. In this edition of TOK-Talk I would like to explore the difference between a good and a bad explanation. Why are simpler explanations usually the better ones? Listen to find out! Sometimes I am asked the question, why science is so complicated. I remember that during my studies at university, I also asked my professor the very same question. At that time I was very intrigued by the complexity of the biochemical events that occur in living cells. He laughed, but in a well meaning way, I’d have to add, and responded that everything is complicated only if you hear it for the first time. If you hear something over and over again, then you start to become used to it. Naturally, I have to admit that many aspects of the sciences are indeed difficult to understand for the “non-initiated”. There are several reasons to it. Many scientific concepts are difficult to imagine and often we are missing suitable analogies to our real-life world. We have a difficulty in drawing parallels. If I tell you, for example, that the DNA, the genetic information in each one of our body cells is over 2m long, then this is difficult to imagine how you can fit so much DNA into one single cell. We simply do not have any real-life comparison. The DNA is just unimaginable thin. Or another example: the total surface area of our lung is about 100m². That’s the area of my apartment. And the total length of all blood vessels in the human body is nearly 100000km. This is 2 and a half times around the earth, or 1/3 of the way to the moon. This is of course difficult to imagine, because we are missing a link to our everyday experience. And let’s not talk about the dimensions in the universe or time scales of billions of years. I claim that not even scientists can imagine these dimensions, but they have learned to at least work with these numbers. These were now rather subjective perception of complexity in the sciences. But are there are also other criteria. William of Ockham lived in the 13th and 14th century. He was a scholar and an early proponent for the KISS principle: Keep it Short & Simple. The purpose of science is to make things simpler and not more complicated. Scientists strive to discover theories and explanations that simplify the view of our world and not complicate them. According to Ockham, if there are competing explanations for a phenomenon, the simpler explanation is to be preferred. The simpler explanation is often the correct one. It can be summarized as “With all other things being equal the simpler solution is the better one.” Please don’t laugh right now, but as you know, I sometimes like to give extreme examples to make my point clear. – I have got a little thermometer here. When I place the thermometer into the sun then the mercury rises. When I put it into the shadow, the mercury drops. Do you know why this happens? There is a little invisible demon inside the glass column. In the sun the demon wakes up and makes the mercury go up. When it’s dark the little critter goes to sleep and the mercury column drops. During a bright winter day the demon is asleep. It is hibernating and will only wake up in spring. Sometimes the little demon wakes up even during winter and makes the mercury go up a bit… You see, the little demon is very convenient. We are [...]

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