A further interlude: a bit on truth

Having promised myself not to get involved in any instant coffee student philosophy discussions, I'm going to have to tread quite carefully around this. But Robin poked me on the subject and it does merit some thought. This still officially counts as an interlude ... I am loathe to attempt to formally define or question the concept of 'truth'. And I have previously stated that for current purposes, I'm assuming science is not a list of absolute facts (or truths).

The earth is flat.

What do we mean when we say something is true or false? I mentioned the flat earth model earlier so let us start with that. The statement "The earth is flat" is definitely false. (False is much easier to spot than true.) Here is a collection of photos of the earth taken from space. Conspiracy theorists may wish to dispute their veracity ... but not with me. Thanks all the same.

A flat earth model is very useful if you are building a house, but architects using the flat earth model know that the earth isn't actually flat. I hope.

What about the statement "The earth is round"? If you were pedantic to the point of being antisocial, you might argue that strictly speaking the earth is an oblate spheroid and not perfectly round at all. Is the statement still true? It's fairly accurate. It's probably the best single syllable description of the shape of the earth. It's not as if 'round' is a strictly-defined geometric term in any case. Biscuits are round. People's heads are round. Round-ish.

So in common usage 'true' and 'false' are not absolute black and white concepts.

The earth is 7000 years old.

Some biblical literalists use the creation stories in the Old Testament to assert that the earth is only six or seven thousand years old. Some will even couch this assertion in scientific terms and claim it can be supported by a legitimate use of the scientific method. A quick google will bring up a number of such papers.

This assertion is false. Uncontroversially and incontrovertibly false. This model of the earth's history is contradicted by a truly massive weight of evidence. It is as easily falsifiable as the suggestion that the earth is flat.

Note that this does not instantly disqualify it from being a scientific model. As I said earlier:

"Scientific models and theories are not 'true' or 'false'. They are 'useful' or 'not useful' in particular contexts."

and

"Science is a set of well-defined models that can be tested against observation."

If you can find a context where the assumption that the earth is 7000 years old has an application, and you can express it in terms that allow it to be tested against observation in that context, then it will become a useful scientific model.

I will buy an iPod for the first person who can give me an example of a context where this assertion is useful and a method for testing it. Any size and colour you like. The answers "to prove the literal truth of Genesis" and "by reading the word of God" will receive a mystery booby prize.

So ... being demonstrably false does not stop something from being science; failing to satisfy the simple criteria of a scientific model and not applying the scientific method stops something from being science.

I have no idea if this satisfies Robin's qualms about "true" versus "useful". I'm sure he'll tell me.