People areconstantly seeingthings in the sky they dont understand.
But for some sightings, theres no known explanation.
The problem is that people jump to the conclusion unknown = aliens.
And when you think about it, this is fairly odd.
Anyway, I like to do maths instead.
It tells us how we should update our beliefs based on new evidence.
There are two factors in the equation.
One (second bracket) is how likely we think aliens are.
Some might say 50:50, making this factor one, while othersmay make it very low, like 10-23.
This needs to be multiplied by another factor (first bracket), often called the Bayes factor.
It denotes how specific the evidence we see is for aliens v no aliens.
In other words, specificity is hugely important.
That the world is strange is not evidence for aliens.
Sure, there is lots of weird footage.
Theres not even a photo of an alien.
I start with assuming that aliens visiting is pretty unlikely I place it somewhere around one in a billion.
Indeed, that we havent been paved over already is animportant piece of evidence.
If it was a real alien, the probability of the footage would be 1.
This would not be enough to think it must be real.
But it would be alarming enough to see if my friends are seeing the same thing.
Surely they cant all go mad at the same time that would be even less likely.
If they agree I would boost my estimate by a few more orders of magnitude, to maybe 1/10.
I would also check for evidence that it isnt a super-prank.
As for the current evidence, what would convince me otherwise?
More specific evidence, not just blurry lights moving apparently fast.
I suspect actual evidence for visits from extraterrestrial intelligence will be hard to miss.
The search will no doubt go on, but we should look for specific things, not blurry ones.
