"How does the mirror know it's there?"

It's unfortunately a question that's been asked far too much on the internet recently, but for every confused mirror-owner, there are a dozen more people roasting them for their theories.

Ever looked in a mirror? Yep? Then you'll probably be familiar with the fact that the image in it isn't always the same.

But despite the fact most of us have lived with this knowledge every day for most of our lives, questions about reflections have gone viral on TikTok, with people using various objects placed behind a piece of paper to suggest that mirrors might have a lot more going on than we know about.

TikTok/@notdanephew

One person used a crystal to demonstrate the 'phenomenon', one used a plug - one even used an egg, but they were all asking the same question: 'How does the mirror know the object is there, when there's a piece of paper blocking it?'

The confused parties placed their cameras next to the mirrors to prove that they still managed to reflect the 'hidden' object, prompting one to pitch the existence of a 'mirror world'.

"What if mirrors aren't what we think," they added in the post, which has since been shared and entirely torn apart on Reddit.

"Clearly very little thinking is happening here," one person wrote after watching the clip, while another commented: "If this is not trolling then we as humanity are doomed."

TikTok/@sarawebbscience

Another baffled viewer wrote: "No way they're that old and legit called it the "mirror world" unironically."

The thing is, the explanation as to why the object is still visible isn't really that tough to get your head around.

It's all to do with perspective, and the reflection of light. The mirror has no idea what it's reflecting, because it doesn't have a brain. (I can't believe I even had to type that).

Instead, it just reflects incoming light, with the scene changing depending on the perspective you're looking at.

Light doesn't hit the mirror in a single beam - it's coming from all around, at all angles, and some of the light bouncing off the 'hidden' object still manages to reach the mirror from the edge of the paper.

As TikToker and Astrophysicist Dr Sara explains, the more light blocking the object, the less visible the object will be.

So, there you have it - I can assure you there is no mirror world, but it's fun to imagine there might be. Or maybe terrifying is a better word?