Argument from Ignorance
The Fallacy
Saying something is true just because nobody has proven it's false yet.
Why it's wrong
Just because we don't know the answer, doesn't mean you can make up any silly answer and call it true.
Example
Nobody has ever proven that the moon ISN'T made of cheese, so it must be made of cheese!
What the Fallacy?! (ELI5 Edition)