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Tuesday, December 23, 2008

Hypothesis God & Ockham’s razor

This column was written for the World Federation of Science Journalists (WFSJ)

In 2009 it will be 150 years ago that Charles Darwin published his evolution theory. It will also be 400 years ago that Galileo Galilei was the first to discover the heavens by looking through a telescope. So, we are soon to celebrate both the International Darwin Year and the International Year of Astronomy.

Apart from celebrating these events and explaining to the public the powerful insights that evolution theory and astronomy have given us, science journalists will have an extra job to do. We can be sure that creationists, intelligent-design-dreamers and religious believers will do their utmost to cast doubt on the theory of evolution. And it will be our job to counteract.

The strategy of creationists and other believers will be the same as the one the tobacco industry has used in the debate about the health effects of smoking: casting doubt. The trick is easy: creationists point at those questions that science hasn’t answered yet – obviously always the most difficult nuts to crack – and conclude either that science doesn’t know anything about the origin of life, or that science and religion are two equally valuable ways to understand the world.

Both conclusions are of course invalid. If scientists don’t know all about a phenomenon, it doesn’t mean they know nothing. And whereas science produces knowledge, religion produces only beliefs. Scientists test their theories with experiments – the scientific method. Religion doesn’t have a validated method of investigation.

Interestingly enough, it is the freedom to doubt that has made science so successful, and it is the lack of doubt that has made religion often so problematic.

Personally I get bored to death by discussing with creationists about evolution theory. Their arguments are always the same and they have no facts to support their beliefs. Science, on the contrary, shows a still growing body of facts that support evolution theory. For example: the scientific Breakthrough of the Year 2005 – as chosen by the magazine Science – was the fact that we can now see evolution in action on the genetic level. A splendid discovery that deepens Darwin’s insights. No religious book has given us that insight.

Unfortunately, it doesn’t matter for creationists how large the body of scientific knowledge has grown. For them the discussion always comes down to questions that science has not yet answered, and of course to the question what happened at the first moment. Hypothesis God can be used to ‘explain’ that the universe was ‘created’. But those that are happy with this hypothesis should be equally happy with the hypothesis that Cookie Monster created everything, or Tweedledum and Tweedledee, or that a bunch of drunken Gods and Goddesses were enjoying an orgy that created the world. And so on. No way to check any of these assumptions.

To save a lot of time and energy in discussing with creationists, let me give my shortest version to end the discussion with creationists.

It’s based on what philosophers call Ockham’s razor, named after the 14th century English philosopher William of Ockham. A modernized version Ockham’s razor reads: ‘don’t make more assumptions to explain a phenomenon than logically necessary’. Ockham’s razor cuts away superfluous assumptions. For example: the attraction between the earth and the moon can be explained by the theory of gravity. Adding the hypothesis that God created the earth, the moon and gravity, doesn’t explain more of the attraction between the earth and the moon. Therefore Hypothesis God is superfluous.

Everybody has the freedom to believe, but once you are interested in knowledge, then Hypothesis God is a superfluous assumption. We can explain a great deal of the visible universe by describing it in terms of matter, energy, space, time and gravity. We can make observations, do experiments and test our theories. But nowhere in our reasoning does Hypothesis God explain anything better than science does. On the contrary: Hypothesis God hasn’t given any insight in the universe that has been able to withstand experimental tests. Science has given plenty of insights that have been able to withstand experiments.

Only if we start thinking about the moment of creation – assuming that there was such a moment – does Hypothesis God do equally well or bad as the scientific hypothesis of a Big Bang. (But all the 13.7 billion years after the beginning, astronomy does infinitely much better than Hypothesis God…). As we have no way to tests any theory about the first moment, we can assume any beginning, but it’s not science anymore.

Ockham’s razor is the shortest version I know to end the discussion with creationists. So, let’s sharpen Ockham’s razor. We’ll need it soon in the discussions with creationists, in whatever disguise.

Let’s start the New Year with launching a two-step rocket. The first step celebrates the International Year of Astronomy. The second step, automatically launched once the first step is already high up in the air, celebrates the International Darwin Year. This two-step rocket shows the power of science as a unified body of knowledge to understand the world: because it is the evolution of the universe that has led by chance to the evolution of life.

A happy New Year! Cheers!