So perhaps a little comment on how they arise might be worth spending some time on.
I start with a rather simple example.
The singer James Brown died in 2006 and the Michael Jackson three years later in 2009.
We have a widely published "last picture" of Michael Jackson in an open coffin. We also have such a picture for James Brown.
Here are the two side by side:
Looking at them, it is clear that something is not right... Both not only have the exact same coffin, but also the light is throwing reflections on both of them in exactly the same way in both pictures, and both coffins have the same small imperfections in the folds of the fabric surrounding them, The flower arrangements are the same down to the last leaf, and Michael Jackson wears the same clothing as James Brown.
So we can be pretty certain the Jackson photo is photo-shopped. In fact, his head is from a standard autograph photo, and anyone who has ever seen a dead body after rigor mortis knows that usually facial muscled relax completely, making the face look somewhat different. This head clearly has facial muscle tone, and is a much younger Michael Jackson than the one who died.
So what are we to make from that? The average person would conclude an over-eager journalist, perhaps, or a macabre joke.
But this photo-shopped picture is used widely on the internet as "proof" that Michael Jackson faked his own death.
This is giving us a clue how conspiracy theories emerge:
First, we need an important or widely reported event. Then someone discovers something unexpected within the general reporting, something odd, such as this photo.
Then comes the crucial step: this oddment is "explained" by a much wider theory for which there is no actual evidence.
The photo, fake as it is, does not provide any kind of evidence about Jackson in fact not having died at all. The two things are not connected, as there are a whole range of other explanations for such a photo, and as a rule, the simplest is the most likely.
Whatever human people report tends to have the occasional lie or inconsistency in among the broad truth. A conspiracy theory often correctly identifies such an inconsistency only to make that part into a centre piece of a complete newly created reality.
