[jerf]

This is another example of the "probability noise floor" I mentioned yesterday: https://news.ycombinator.com/item?id=39112610

You can't be one-in-a-trillion confident about any particular DNA result, even if that's what the nominal probability from the DNA analysis itself seems to say, because it is objectively observable that there are plenty of other sources of errors of all sorts. You can only get down to that "noise floor" of probabilities. This can still be a very useful result, but it's important to not let it be any more important that it deserves.

Even if you have a magic machine that you can point at someone and it goes "boop" if they are guilty, you still must consider the probability that someone faked the "boop", or has swapped in a different shell that looks the same but makes the same "boop" when someone remotely triggers it or that the speaker was broken so even though the magic machine tried to "boop" nobody could hear it. All of these are quite realistic and of a much higher probability than the magic machine existing in the first place.

(This is also arguably the root problem with the still-popular "The computer said it so it must be true". Even if you assume the computer really is 100% accurate, which itself is a transparently false proposition when examined in daylight, there's still plenty of other reasons why one should not give the computer too much confidence.)

[BobaFloutist]

It's almost a corollary to how a lot of magic tricks work. Sure, you probably could sneak a card from one place to another, but why not just have a second card?

You could predict someone's behavior, but why not simply hedge against every possibility?

Magic does involve a good amount of sleight of hand, but it mostly relies on getting people to accept flawed premises. The most essential part of any given trick is the bit where you tell them what's going to happen: even as they reject it and try to bring skepticism to bear, they're often working off of (carefully placed) incorrect assumptions.

[looofooo0]

One saterical German book about about a communist cangoroo introduced the idea of a dirty bomb. Basically you collect as many hair, skin cells and other human remains of as many humans as you can find. And at the end of your crime you let it explode.