I don’t think wizards can detect magic that easily. Patronus is definitely easy to detect, it radiates both in visible light and in… emotional waves, whatever that is ;)
But think about how it’s hard to detect someone who is polyjuiced, or someone who is imperiused. Or how Dumbledore had to cast spells to detect what transfigured objects did Harry has on him when he looked for Hermione body.
It seems perfectly plausible that wizards can’t detect (without actively casting some detection spells) a transfiguration that happens on the microscopic scale and can’t see.
I am assuming that Voldemort, about to attempt the subversion of a prophecy to destroy the world, is not standing around in a graveyard with Harry Potter, a recently reanimated Hermione with unicorn powers and a bunch of Death Eaters of at least slightly questionable loyalty without any detection spells raised at all.
I don’t think wizards can detect magic that easily. Patronus is definitely easy to detect, it radiates both in visible light and in… emotional waves, whatever that is ;)
But think about how it’s hard to detect someone who is polyjuiced, or someone who is imperiused. Or how Dumbledore had to cast spells to detect what transfigured objects did Harry has on him when he looked for Hermione body.
It seems perfectly plausible that wizards can’t detect (without actively casting some detection spells) a transfiguration that happens on the microscopic scale and can’t see.
I am assuming that Voldemort, about to attempt the subversion of a prophecy to destroy the world, is not standing around in a graveyard with Harry Potter, a recently reanimated Hermione with unicorn powers and a bunch of Death Eaters of at least slightly questionable loyalty without any detection spells raised at all.