Tuesday, February 23, 2010

"Scientists say"

Ben Goldacre of bad science has constantly pointed out this rather major failing in science reporting. The news seems to think a story has been told if an argument from authority has been made. i.e. "a scientist said this was extremely unlikely".

This is bad, bad science. If a scientist is making a scientific announcement, then they have reasoning behind what they are saying, reasoning that anyone should be able to verify, given enough time. If they do not, then they should no more be listened to than Prince Charles does. By using "scientist says" you are underlining this idea of scientists as untouchable people in lab coats who conduct hidden magic rituals. They don't, usually. They publish, they produce results and arguments, which can be looked at and assessed.

I understand one can't explain the whole science, but usually there is a basic argument that can be made.

Take a report on the news on homeopathy.

"One part of a hundred is taken out, and mixed with water, and this process is repeated many times. Scientists say that this means its just water".

Well... they don't say it. Its just a bloody fact. If you distill something multiple times, you will begin to run out of particles of that substance. There exists homeopathic remedies which have been distilled 24 times. Or more than Avagadro's constant, the number of particles in a mole. In other words, once you've distilled 24 times, then theres only a 60% chance of there being a single original molecule left in the water. This page provides a table given the relative substances- at only 8 distillations we have the acceptable amount of arsenic in drinking water.

This is a factual argument. Its just the case that if you dilute something enough, all that remains is water. It may be magical water, but there is absolutely no mechanism that would transfer the properties we know of. If it were true that this happened, we'd all be in an extreme amount of trouble, as water is being diluted all the time with hundreds of substances...

The point of this is not entirely to rant about homeopathy, but to underline that its not hard to make these arguments. There is no controversy here, this is not some obscure scientific discovery, this is basic fact, that I could demonstrate with numerous experiments. If you dilute a substance enough you'll no longer have that substance anymore. Theres no need to say "scientists say" as if theres some kind of confusion here. There just isn't.



Post a Comment

<< Home