OK, I’ll give it away. Every time you flip the coin, statistically speaking you’ll eliminate half the audience. After two flips, you’ll only have half of that, or 1/4 the original. After the next flip, it’s 1/8, then 1/16, etc.

After you flip 7 times, you’ll be down to 1/128. So statistically, if you start with 128 people, after six flips you should have only 2 left. In real life that may be different (if everyone chooses heads, you can eliminate everyone with one flip!), but when we did it in Australia it worked out perfectly!

However, if the presentation is suitably planned, it anticipates all of the critical questions (e.g. “how come that result shows x or y or z to be the case?”, or “but what about this interpretation that implies q or r to be true, or at least possible, instead?”).

If enough detail and logical reasoning are presented, no-one needs to ask any further questions.

The question of “why” is often a very different (and difficult) question to answer. Having established that something happens, it is usually not too hard to establish how it happens (although many things do require ingenious experiments and/or measurements to establish which of two or three possible explanations is the case), but it is then a very large step to establish why it happens. How does the sun shine? It is down to nuclear physics (the fusion of hydrogen isotopes into helium). Why does the sun shine? That is a far deeper and more philosophical question.

The question “Do I think it happens?” is perhaps not so relevant, unless you mean “Do I agree with the interpretation that has been placed on these data?” or “Do I agree that the data are sufficiently accurate and reliable to infer such things from them?”. If you cannot genuinely fault the way in which data were gathered (or the way in which an experiment was performed), and if you cannot fault the logic behind the interpretation of the data, then you must accept the conclusion (unless there is an alternative possibility that the author has not even thought of, but would produce exactly the same results in the situation under discussion; in this case, you would need to come up with a prediction in which your interpretation and the other person’s interpretation would yield different results, then do the experiment or make the observation to prove which is wrong).

For example, in another reply to one of the BA’s blog pages, I mentioned that some people choose not to believe in evolution. This is a very uncritical way to think: whether evolution happens (or not) does not depend on whether (or not) certain people choose to believe in it. If anyone genuinely wished to refute the concept of evolution, they would need to assess all of the data (200 years of fossil record, potassium-argon and uranium dating of rocks, the beautifully simple mechanism provided by the biochemistry of DNA as a carrier of genetic information, and so on), assess, on a case-by-case basis, the way it has all been interpreted and then come up with an alternative, coherent explanation that describes how each piece of evidence should be interpreted and how it fits into the new framework. This is a tall order, and it has not, to my knowledge, even been attempted. Thus, the concept of evolution remains the best explanation available for the data we have.

Apologies to anyone who got bored reading this, I kind of got carried away.

Incidentally, X, there are two ways you can make your online presence more credible: first, use a name that is a bit less anonymous; and, secondly, check your typing before clicking the “submit” button. Everyone makes typing errors, but in your comment above, they are so frequent it almost obscures the meaning of your text.